星空女人频道: 2013-09-15

2013年9月21日星期六

Climate change: Polar bears change to diet with higher contaminant loads

Researchers expect the climate to become warmer in the future and predict that climate change will have a significant impact on the Arctic. How will a warming Arctic affect the polar bears?

The East Greenlandic population of polar bears resides in an area, where the Arctic sea ice is expected to disappear very late. However, the decline in the ice sheet here occurs at a rate of almost 1% per year, one of the highest rates measured in the entire Arctic region.

How does this affect the prey of the polar bears -- and, in turn, the polar bears' intake of contaminants? An international team of researchers set out to explore this question. The team counted researchers from the Greenland Institute of Natural Resources, Aarhus University (Denmark) and a number of Canadian institutions including: Dalhousie University, Great Lakes Institute for Environmental Research, University of Windsor, Carleton University and the National Water Research Institute.

The researchers studied the fatty acid profiles in the adipose tissue from a unique material of 310 polar bears hunted by East Greenland Inuits from the Scoresbysund area in the years from 1984 to 2011. The composition of fatty acids in the fat tissue of the polar bears namely reflects the profile of fatty acids in their diet.

The results show that the polar bears primarily feed on three species of seals: the high Arctic ringed seal and the two sub-Arctic species harp seal and hooded seal. Moreover, the results showed that the diet of the polar bears had changed over the almost 30 years during which the samples were collected. In this period, the average relative decline in the ringed seal's significance for the polar bears diet was 42%. Similarly, the intake of the sub-Arctic seals increased during the same period. Also, the researchers found that polar bears are generally in better condition now, so at a first glance the polar bears should be happy with this development.

Climate change undermines improvements

There are, however, a couple of problems that might mar the happiness, explains Professor Rune Dietz, Aarhus University:

"The problem is that the sub-Arctic seals that the polar bear has switched to, have a higher content of contaminants because they live closer to the industrialised world and are higher up in the food chain. Therefore, climate change undermines the improvements that you would otherwise have obtained owing to international regulations in the use of environmental use of persistent organic pollutants (POPs). We can see that the content of the POPs after year 2000 decreases slower in the polar bear than in, the ringed seal."

In the long term, the polar bear may very well lose access to the sub-Arctic seals as these depend on packed ice where they give birth to their cubs and are exposed to sunlight allowing them to form vital vitamin D.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.

SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc

we are focus on the following fields,and hope we can help you.

TOSHIBA Transistors YAGEO Resistors ON Transistors chip Filter saws IDT IC Thin Film Resistors MAXIM IC INTERSIL IC Thick Film Resistors Chip Inductors LED Other Parts Vishay resistors Kingbrigt LED Voltage Regulators Transistors Current Sensors Resistors Resistor Networks IC(Integrated Circuits) ON Diodes Ligitek LED TOSHIBA Diodes NEC Diodes MURATA IC NEC Transistors SANYO IC BB IC IR Diodes ST Transistors Transistors Switches Electronic News ROHM Resistors AD IC TI IC TDK IC Chip Fuses Digital Transistors Diodes Inc ALTERA IC NXP Transistors
http://www.suvsystem.com/a/6063.aspx

Antibacterial products fuel resistant bacteria in streams and rivers

Sep. 19, 2013 — Triclosan -- a synthetic antibacterial widely used in personal care products -- is fueling the development of resistant bacteria in streams and rivers. So reports a new paper in the journal Environmental Science and Technology, which is the first to document triclosan resistance in a natural environment.

Share This:

Invented for surgeons in the 1960s, triclosan slows or stops the growth of bacteria, fungi, and mildew. Currently, around half of liquid soaps contain the chemical, as well as toothpastes, deodorants, cosmetics, liquid cleansers, and detergents. Triclosan enters streams and rivers through domestic wastewater, leaky sewer infrastructure, and sewer overflows, with residues now common throughout the United States.

Emma Rosi-Marshall, one of the paper's authors and an aquatic ecologist at the Cary Institute of Ecosystem Studies in Millbrook, New York explains: "The bacterial resistance caused by triclosan has real environmental consequences. Not only does it disrupt aquatic life by changing native bacterial communities, but it's linked to the rise of resistant bacteria that could diminish the usefulness of important antibiotics."

With colleagues from Loyola University and the Illinois Sustainable Technology Center, Rosi-Marshall explored how bacteria living in stream and river sediments responded to triclosan in both natural and controlled settings. Field studies were conducted at three sites in the Chicago metropolitan region: urban North Shore Channel, suburban West Branch Dupage River, and rural Nippersink Creek.

Urbanization was correlated with a rise in both triclosan concentrations in sediments and the proportion of bottom-dwelling bacteria resistant to triclosan. A woodland creek had the lowest levels of triclosan-resistant bacteria, while a site on the North Shore Channel downstream of 25 combined sewer overflows had the highest levels.

Combined sewers deliver domestic sewage, industrial wastewater, and storm water to a regional treatment plant using a single pipe. Overflows occur when a pipe's capacity is exceeded, typically due to excessive runoff from high rainfall or snowmelt events. The result: untreated sewage flows directly into rivers and streams.

The research team found that combined sewer overflows that release untreated sewage are a major source of triclosan pollution in Chicago's North Shore Channel. In addition, their findings support past work that indicates sewage treatment plants can effectively remove triclosan from wastewater.

John Kelly of Loyola University Chicago, the paper's senior author, comments, "We detected much lower levels of triclosan at a site downstream of a sewage treatment facility as compared to a site downstream of combined sewer overflows. And we demonstrated a strong link between the presence of triclosan in the environment and the development of triclosan resistant bacteria."

Nearly 800 cities in the United States rely on combined sewer overflows, with the Environmental Protection Agency citing them as a major water pollution concern.

Artificial stream experiments, conducted at Loyola University, confirmed field findings that triclosan exposure triggers an increase in triclosan-resistant bacteria. In addition to the creation of these resistant bacteria, researchers also found a decrease in the diversity of benthic bacteria and a shift in the composition of bacterial communities. Most notable were a 6-fold increase in cyanobacteria and a dramatic die-off of algae.

Rosi-Marshall explains how these shifts could affect aquatic life, "Cyanobacteria are less nutritious than algae and can produce toxins. In triclosan-polluted streams and rivers, changes in microbial communities could negatively affect ecological function and animal communities."

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

NXP Diodes IR Diodes DIODES Transistors Ligitek LED ST Diodes Metal Can Packages Transistors Military IC Civil IC Resistors PANASONIC Resistors components Fleld Effect Transistors HARRIS IC TOSHIBA Transistors Renesas parts IC Freescale Semiconductor YAGEO Resistors Infineon Technologies Transistors Xilinx IC Zener Diodes Connectors Electronic News IR transistor INTERSIL IC Industrial IC Diodes Inc ON Transistors LITTELFUSE Diodes Thin Film Resistors MURATA IC TOSHIBA Diodes Low Ohmic Resistors NEC Diodes About US Discrete Semiconductor Transistors MOTOROLA IC IDT IC Dialight LED ALTERA IC Vishay resistors
http://www.suvsystem.com/a/6065.aspx

Power Renesas reveals power peripherals on 32bit MCU family

2013/09/20

02oct13Renesas 1052 Renesas has unveiled two power control peripherals on high pin-count versions of its RX63T 100MHz 32bit microcontrollers: a high-speed PWM generator and a adaptive hardware control loop.

“The functions are implemented in hardware, so the processing capabilities of the 32bit RX core can be applied to the main processing routine, motor or inverter control for example, while dc-dc power management control takes place simultaneously.” said the firm.

Higher resolution pulse generation comes through a 32x phase-locked loop which boosts PWM sub-system clocking to 3.2GHz, increasing resolution to 312.5ps when the core is clocked at 100MHz. This compares to 10ns resolution available previously. PWM counting is 16 bit.

The control loop block implements a hardware proportional-integral control loop algorithm that also automatically maintains PSU performance in the face of production variations in components including the main inductor and capacitor.

“Components variation of up to -35/+50% could be accepted,” said the firm.

To help designers to generate starting values for the various algorithm parameters, the company is developing an Excel-based simulation tool.

The two new blocks are only available in 100, 112, 120 and 144pin versions of RX63T microcontrollers.

Electronics Weekly has been told that the two blocks have been in the silicon for a while, but only now are they qualified and tested.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Resistor Arrays Multi-units Transistors Civil IC Thin Film Resistors LED Military IC Switching Diodes NXP Transistors chip Filter saws Voltage Regulators Transistors YAGEO Resistors ON Transistors Cypress IC PANASONIC Resistors FAIRCHILD diodes Dialight LED Transistors Freescale AD IC Electronic News TDK IC Digital Transistors NXP Diodes About US TOSHIBA Transistors DIODES Transistors Texas Instruments(TI) IC NEC Transistors Discrete Semiconductor Transistors Transistors Chip Ferrite Beads Schottky Diodes Diodes Inc ST Diodes Chip Fuses ON Diodes INTERSIL IC Capacitor Atmel IC Metal Can Packages Transistors INFLNEON Diodes
http://www.suvsystem.com/a/6057.aspx

Building bridges between nanowires

Quantum effects

Mocking also managed to craft new 1D structures with two different metals, iridium and cobalt -- obtaining entirely different results. For instance, he was able to prove that quantum effects occur to iridium when heated to room temperature, leading to the wires always being 4.8 nanometres, or a multiple thereof, in length. This astonishing result was published in Nature Communications earlier this year. When cobalt, the third of the metals, was heated, no wires were formed. Instead, little 'islands' and 'nanocrystals' appeared.

Bottom-up nanoelectronics

Mocking used the semiconductor germanium as substrate for each of the three metals, as it is easy to work with at relatively low temperatures and possesses a suitable crystal structure. Scanning Tunneling Microscopy (STM) is ideally suited to investigate these structures. His research is of fundamental importance, as surprising physical effects are noticeable when deconstructing to the lower dimensions, up to 1D. It also allows for the 'bottom-up' crafting of electronic switches: start with the smallest, self-organising structures, add molecules, and proceed from there. The process is still in its infancy, but may become an alternative to the current 'top-down' approach, which entails removing ever more parts from a larger structure. The gold and iridium-inducted wires may form starting blocks for the process. The cobalt islands, though less suitable to this new type of electronics science, do provide fundamental new insights.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Densest array of carbon nanotubes grown to date

Sep. 20, 2013 — Carbon nanotubes' outstanding mechanical, electrical and thermal properties make them an alluring material to electronics manufacturers. However, until recently scientists believed that growing the high density of tiny graphene cylinders needed for many microelectronics applications would be difficult.

Share This:

Now a team from Cambridge University in England has devised a simple technique to increase the density of nanotube forests grown on conductive supports about five times over previous methods. The high density nanotubes might one day replace some metal electronic components, leading to faster devices. The researchers report their finding in the journal Applied Physics Letters, which is produced by AIP Publishing.

"The high density aspect is often overlooked in many carbon nanotube growth processes, and is an unusual feature of our approach," says John Robertson, a professor in the electronic devices and materials group in the department of engineering at Cambridge. High-density forests are necessary for certain applications of carbon nanotubes, like electronic interconnects and thermal interface materials, he says.

Robertson and his colleagues grew carbon nanotubes on a conductive copper surface that was coated with co-catalysts cobalt and molybdenum. In a novel approach, the researchers grew at lower temperature than is typical which is applicable in the semiconductor industry. When the interaction of metals was analyzed by X-ray photoelectron spectroscopy, it revealed the creation of a more supportive substrate for the forests to root in. The subsequent nanotube growth exhibited the highest mass density reported so far.

"In microelectronics, this approach to growing high-density carbon nanotube forests on conductors can potentially replace and outperform the current copper-based interconnects in a future generation of devices," says Cambridge researcher Hisashi Sugime. In the future, more robust carbon nanotube forests may also help improve thermal interface materials, battery electrodes, and supercapacitors.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

2013年9月20日星期五

Business Semi equipment orders slip

2013/09/20

The SEMI book-to-bill went negative in August at 0.98.

The book-to-bill has been positive all year. In July it was 1.0, and in June 1.1.

August bookings were $1.06 billion – 11.9% lower than July’s $1.21 billion, and is 2.7% lower than the August 2012 level of $1.09 billion.

August billings iwere $1.08 billion – 10.1% lower than July’s $1.20 billion, and is 18.7% lower than the August 2012 level of $1.33 billion.

“While some investment activity may be slowing, we see spending by foundries and flash memory suppliers to be key drivers for investments for the remainder of the year and into 2014, ” says SEMI CEO Denny McGuirk.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

PANASONIC Kingbrigt LED NEC Diodes NS IC Texas Instruments(TI) IC Microchip IC Resistor Networks Electronic News LINEAR IC Discrete Semiconductor Transistors VISHAY IC IDT IC ROHM Resistors FAIRCHILD diodes TOSHIBA Transistors Diodes NEC Transistors Chip Ferrite Beads Xilinx IC AD IC Atmel IC IR Diodes MURATA IC ST Transistors NXP Transistors Diodes Inc Other Parts Zener Diodes High Precision Resistors LITTELFUSE Diodes Voltage Regulators Transistors Resistors Fairchild Semiconductor Transistors components Thin Film Resistors MOTOROLA IC Chip Inductors BB IC Fast Recovery Diodes Freescale Semiconductor
http://www.suvsystem.com/a/6050.aspx

Business Agilent spins off electronic measurement business

2013/09/20

Agilent has split in two. One company, called Agilent, is focussed on life sciences, diagnostics and applied markets and the other company, not yet named, is focussed on electronic measurement.

The companies will be separately listed on the New York stock exchange.

The motive behind the split is to maximise the share price of the Agilent life sciences and diagnostics part of the business by not having the drag of the lesser performing electronic measurement unit.

The NYSE liked the move with Agilent shares going up sharply.

The Agilent life sciences and diagnostics company has sales of about $4 billion. The electronic measurement company has sales of about $3 billion.

The new Agilent life sciences and diagnostics company will consist of two groups: the chemical analysis group and the life sciences and diagnostics group.

Agilent was spun off from HP in 1999.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Business SanDisk sampling iNAND Extreme

2013/09/20

SanDisk is sampling iNAND Extreme – fast NAND – to tablet manufacturers. It delivers sequential write/read speeds up to 45/150 MB/s, and random write /read speeds up to 800/4K IOPS.

SanDisk’s iNAND comes in EFDs and MCP (Multi-Chip Package) forms with densities from 4GB to 128GB.

“We have clearly just scratched the surface of the potential for tablets to transform the user experience,” sats SanDisk’s Drew Henry.

and our iNAND Extreme enables developers to introduce the next wave of highly responsive tablets that offer richer entertainment, awe-inspiring graphics, and more productive business applications.”

Tablets are growing 55% this year, says Strategy Analytics, to over 180 million units.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Civil IC chip Filter saws NXP Diodes MAXIM IC Ligitek LED Kingbrigt LED Cypress IC Resistors Thin Film Resistors Vishay resistors VISHAY IC Infineon Technologies Transistors ROHM Resistors ALTERA IC INFLNEON Diodes Chip Inductors TDK IC IR Diodes YAGEO Resistors Metal Can Packages Transistors PANASONIC MURATA IC Texas Instruments(TI) IC Diodes Zener Diodes NEC Transistors SANYO IC LED part Connectors BB IC Diodes Inc components IDT IC Renesas parts IC Industrial IC ON Transistors Xilinx IC Chip Ferrite Beads Low Ohmic Resistors Transistors
http://www.suvsystem.com/a/6048.aspx

Analogue and Discretes Yorkshire firm wins touch control place in drill

2013/09/20

25sep13Peratech 400 Australian tool firm Globalpower has licenced Peratech’s quantum tunnelling touch control elastomer for use in a rechargeable drill.

Branded QTC, the elastomer changes resistance when squeezed, and North Yorkshire-based Peratech can tune its properties to suit various applications – for example, it has been formulated support the edge of LCDs, allowing force on the display can be measured to add a third dimension to touch control.

“The drill is designed to be used in tough conditions with a five year warrantee, so we needed to have a switch that was reliable. QTC sensors have no moving parts so they have a long operational life and are proof against dust, dirt and liquids,” said Peter Hosking, head of Globalpower. “The look and feel was a critical part of the design. Touch technology enabled us to create an intuitive control interface that is responsive with the slightest changes in pressure on the sensor, instantly changing the speed of the drill.”

As well as being force rather than movement activated, Global has also gone out on a limb in a conservative market and moved away from the traditional arrangement of a finger-operated activation push button to control speed from zero upwards, plus a separate forward-reverse switch. Instead it has an index-finger force button for forward speeds, and a middle finger force button for reverse speeds.

Power comes from a 12V 4Ah Li-ion battery.

Peratech has been working with the UK Centre for Process Innovation, which is based in the North East, to create QTC inks that can be printed using standard techniques.

“This makes them easy to mass produce, plus they can be printed at the same time as other printed electronic components onto plastics, textiles, etc,” said Peratech.

Through Government R&D grants, it has three PhD students working on its material science and connections with two University laboratories.

“This helps Peratech develop the science much faster than we could do on our own,” said CTO David Lussey, “Thanks to this funding, we have doubled the number of patents that we are filing every year.”

There is a video of the 12V touch drill.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Thick Film Resistors Voltage Regulators Transistors Microchip IC ALTERA IC LITTELFUSE Diodes INFLNEON Diodes SANYO IC Switching Diodes Resistors Schottky Diodes About US Connectors IR transistor VISHAY IC BB IC INTERSIL IC Fairchild Semiconductor Transistors Metal Can Packages Transistors Vishay resistors PANASONIC Industrial IC Dialight LED HARRIS IC TOSHIBA Transistors TI IC Civil IC Cypress IC Chip Fuses PANASONIC Resistors Renesas parts IC Zener Diodes LINEAR IC Diodes Inc High Precision Resistors Switches Infineon Technologies Transistors Digital Transistors Diodes NEC Diodes Thin Film Resistors
http://www.suvsystem.com/a/6046.aspx

Clues to growth of colossus in Coma cluster of galaxies

Sep. 19, 2013 — A team of astronomers has discovered enormous arms of hot gas in the Coma cluster of galaxies by using NASA's Chandra X-ray Observatory and ESA's XMM-Newton. These features, which span at least half a million light years, provide insight into how the Coma cluster has grown through mergers of smaller groups and clusters of galaxies to become one of the largest structures in the Universe held together by gravity.

Share This:

A new composite image, with Chandra data in pink and optical data from the Sloan Digital Sky Survey appearing in white and blue, features these spectacular arms. In this image, the Chandra data have been processed so extra detail can be seen.

The X-ray emission is from multimillion-degree gas and the optical data shows galaxies in the Coma Cluster, which contain only about one-sixth the mass in hot gas. Only the brightest X-ray emission is shown here, to emphasize the arms, but the hot gas is present over the entire field of view.

Researchers think that these arms were most likely formed when smaller galaxy clusters had their gas stripped away by the head wind created by the motion of the cluster through the hot gas, in much the same way that the headwind created by a roller coaster blows the hats off riders.

Coma is an unusual galaxy cluster because it contains not one, but two giant elliptical galaxies near its center. These two giant elliptical galaxies are probably the vestiges from each of the two largest clusters that merged with Coma in the past. The researchers also uncovered other signs of past collisions and mergers in the data.

From their length, and the speed of sound in the hot gas (about 4 million km/hr), the newly discovered X-ray arms are estimated to be about 300 million years old, and they appear to have a rather smooth shape. This gives researchers some clues about the conditions of the hot gas in Coma. Most theoretical models expect that mergers between clusters like those in Coma will produce strong turbulence, like ocean water that has been churned by many passing ships. Instead, the smooth shape of these lengthy arms points to a rather calm setting for the hot gas in the Coma cluster, even after many mergers.

Large-scale magnetic fields are likely responsible for the small amount of turbulence that is present in Coma. Estimating the amount of turbulence in a galaxy cluster has been a challenging problem for astrophysicists. Researchers have found a range of answers, some of them conflicting, and so observations of other clusters are needed.

Two of the arms appear to be connected to a group of galaxies located about two million light years from the center of Coma. One or both of these arms connects to a larger structure seen in the XMM-Newton data, and spans a distance or at least 1.5 million light years. A very thin tail also appears behind one of the galaxies in Coma. This is probably evidence of gas being stripped from a single galaxy, in addition to the groups or clusters that have merged there.

These new results on the Coma cluster, which incorporate over six days worth of Chandra observing time, will appear in the September 20, 2013, issue of the journal Science. The first author of the paper is Jeremy Sanders from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany. The co-authors are Andy Fabian from Cambridge University in the UK; Eugene Churazov from the Max Planck Institute for Astrophysics in Garching, Germany; Alexander Schekochihin from University of Oxford in the UK; Aurora Simionescu from Stanford University in Stanford, CA; Stephen Walker from Cambridge University in the UK and Norbert Werner from Stanford University in Stanford, CA.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Electronic News LITTELFUSE Diodes Chip Ferrite Beads Metal Can Packages Transistors VISHAY IC TI IC PANASONIC Xilinx IC MOTOROLA IC Microchip IC Voltage Regulators Transistors Infineon Technologies Transistors ALTERA IC Cypress IC Texas Instruments(TI) IC Rectifier Diodes NEC Diodes Current Sensors Resistors Low Ohmic Resistors SANYO IC chip Filter saws NS IC Digital Transistors Diodes Connectors About US High Precision Resistors PANASONIC Resistors ON Diodes Thick Film Resistors FAIRCHILD diodes DIODES Transistors NEC Transistors Resistor Networks Capacitor Switching Diodes Switches Renesas parts IC Discrete Semiconductor Transistors Dialight LED
http://www.suvsystem.com/a/6042.aspx

Seismologists puzzle over largest deep earthquake ever recorded

"It's a mystery how these earthquakes happen. How can rock slide against rock so fast while squeezed by the pressure from 610 kilometers of overlying rock?" said Thorne Lay, professor of Earth and planetary sciences at the University of California, Santa Cruz.

Lay is coauthor of a paper, published in the September 20 issue of Science, analyzing the seismic waves from the Sea of Okhotsk earthquake. First author Lingling Ye, a graduate student working with Lay at UC Santa Cruz, led the seismic analysis, which revealed that this was the largest deep earthquake ever recorded, with a seismic moment 30 percent larger than that of the next largest, a 1994 earthquake 637 kilometers beneath Bolivia.

Deep earthquakes occur in the transition zone between the upper mantle and lower mantle, from 400 to 700 kilometers below the surface. They result from stress in a deep subducted slab where one plate of Earth's crust dives beneath another plate. Such deep earthquakes usually don't cause enough shaking on the surface to be hazardous, but scientifically they are of great interest.

The energy released by the Sea of Okhotsk earthquake produced vibrations recorded by several thousand seismic stations around the world. Ye, Lay, and their coauthors determined that it released three times as much energy as the 1994 Bolivia earthquake, comparable to a 35 megaton TNT explosion. The rupture area and rupture velocity were also much larger. The rupture extended about 180 kilometers, by far the longest rupture for any deep earthquake recorded, Lay said. It involved shear faulting with a fast rupture velocity of about 4 kilometers per second (about 9,000 miles per hour), more like a conventional earthquake near the surface than other deep earthquakes. The fault slipped as much as 10 meters, with average slip of about 2 meters.

"It looks very similar to a shallow event, whereas the Bolivia earthquake ruptured very slowly and appears to have involved a different type of faulting, with deformation rather than rapid breaking and slippage of the rock," Lay said.

The researchers attributed the dramatic differences between these two deep earthquakes to differences in the age and temperature of the subducted slab. The subducted Pacific plate beneath the Sea of Okhotsk (located between the Kamchatka Peninsula and the Russian mainland) is a lot colder than the subducted slab where the 1994 Bolivia earthquake occurred.

"In the Bolivia event, the warmer slab resulted in a more ductile process with more deformation of the rock," Lay said.

The Sea of Okhotsk earthquake may have involved re-rupture of a fault in the plate produced when the oceanic plate bent down into the Kuril-Kamchatka subduction zone as it began to sink. But the precise mechanism for initiating shear fracture under huge confining pressure remains unclear. The presence of fluid can lubricate the fault, but all of the fluids should have been squeezed out of the slab before it reached that depth.

"If the fault slips just a little, the friction could melt the rock and that could provide the fluid, so you would get a runaway thermal effect. But you still have to get it to start sliding," Lay said. "Some transformation of mineral forms might give the initial kick, but we can't directly detect that. We can only say that it looks a lot like a shallow event."

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

订阅：博文 (Atom)