2013-02-19
Sina Corp posted better-than-expected fourth-quarter revenue and profit amid concerns about the slowing growth of Chinese online advertising.
Bill Gates said he was not satisfied with the company's pace of innovation over the last few years, and that it had mishandled its early mobile strategy
- View PhotoReuters/Reuters - Microsoft founder and philanthropist Bill Gates listens alongside Mexican businessman Carlos Slim (not pictured) during a news conference after taking part in the inauguration of a new research …more
2013-02-18
GaN --- Gallium nitride
Gallium nitride (GaN) is a binary III/V direct bandgap semiconductor commonly used in bright light-emitting diodes since the 1990s. The compound is a very hard material that has aWurtzite crystal structure. Its wide band gap of 3.4 eV affords it special properties for applications in optoelectronic,[4][5] high-power and high-frequency devices. For example, GaN is the substrate which makes violet (405 nm) laser diodes possible, without use of nonlinear optical frequency-doubling.
Its sensitivity to ionizing radiation is low (like other group III nitrides), making it a suitable material for solar cell arrays for satellites. Military and space applications could also benefit as devices have shown stability in radiation environments.[6] Because GaN transistors can operate at much hotter temperatures and work at much higher voltages than gallium arsenide (GaAs) transistors, they make ideal power amplifiers at microwave frequencies.
Laytec Upgrades In-Situ GaN LED Monitoring System
Feb 18, 2013Today, according to the Solid State Lighting road map, the wavelength variation across a wafer should be less than 1 nm. This means a less than 1 K (10C) variation of the GaN surface temperature during InGaN MQW growth.
LayTec’s Pyro 400 is widely used for enabling fab-wide GaN surface temperature uniformity in many LED manufacturers production lines.
Meanwhile, more complex LED structures and tighter cost reduction targets need even more advanced in-situ metrology. Figure 1, below, shows such an example; ternary InGaN and AlGaN layers cause emissivity changes that lead to 0.7 K error of the UV pyrometry reading.
Figure 1: Effect of changing emissivity to UV pyrometer temperature reading: up to 0.7 K errors show up without emissivity correction during growth of a GaN/AlGaN-GaN-SL/InGaNMQW/ GaN structure
LayTec‘s answer to this challenge is the Pyro 400 Gen 2. Along with in-situ UV pyrometry the new generation tool includes real-time UV emissivity correction for enhanced accuracy of GaN surface temperature during growth of more complex LED structures.
A further challenge to reliable GaN temperature control in HB-LED production is the view-port coating.
Figure 2 shows its effect just before maintenance; the UV transmission of the view-port is significantly reduced and an uncorrected UV pyrometer would give a -10 K temperature artefact. Pyro 400 Gen 2 solves this problem,too. Laytec claims the tool automatically senses and corrects these coatings and enables a long-lasting 24/7 accuracy in HB-LED emission wavelength.
Figure 2: GaN MOCVD view-port before (red) and after maintenance (blue): the transmission at the 400nm detection wavelength of a UV pyrometer is suffering from the window coating (red). The resulting -10K artifact is avoided by Pyro 400 Gen2
Last, but not least, an assisting infrared pyrometer has been integrated into Pyro 400 Gen 2 for simultaneous monitoring of wafer pocket temperature throughout the full LED growth run.
Chinese telecommunications company Huawei said on Monday it had not worked with an institute in Singapore on any projects in the specialist field of an American engineer who died mysteriously last year shortly after leaving the institute.
2013-02-17
meteor in russian injured 1000
CHELYABINSK, Russia (Reuters) - Thousands of Russian emergency workers went out on Saturday to clear up the damage from a meteor that exploded over the Ural mountains, damaging buildings, shattering windows and showering people with broken glass.
Divers searched a lake near the city of Chelyabinsk, where a hole several feet wide had opened in the ice, but had so far failed to find any large fragments, officials said.
The scarcity of evidence on the ground fuelled scores of conspiracy theories over what caused the fireball and its huge shockwave on Friday in the area which plays host to many defense industry plants.
Nationalist leader Vladimir Zhirinovsky told reporters in Moscow it could have been "war-mongers" in the United States. "It's not meteors falling. It's a new weapon being tested by the Americans," he said.
A priest from near the explosion site called it an act of God. Social media sites were flooded with speculation about what might have caused the explosion, if not a meteorite.
"Honestly, I would be more inclined to believe that this was some military thing," said Oksana Trufanova, a local human rights activist.
Asked about the speculation, an official at the local branch of Russia's Emergencies Ministry simply replied: "Rubbish".
Residents of Chelyabinsk, an industrial city 1,500 km (950 miles) east of Moscow, heard an explosion, saw a bright light and then felt a shockwave that blew out windows and damaged the wall and roof of a zinc plant.
A fireball traveling at a speed of 30 km (19 miles) per second according to Russian space agency Roscosmos, blazed across the horizon, leaving a long white trail visible as far as 200 km (125 miles) away.
NASA estimated the meteor was 55 feet across before entering Earth's atmosphere and weighed about 10,000 tons.
It exploded miles above Earth, releasing nearly 500 kilotons of energy -about 30 times the size of the nuclear bomb dropped on the Japanese city of Hiroshima in World War Two, NASA added.
"We would expect an event of this magnitude to occur once every 100 years on average," said Paul Chodas of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California.
"When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones."
DIVERS SEARCH LAKE
Search teams said they had found small objects up to about 1 cm (half-an-inch) wide that might be fragments of a meteorite, but no larger pieces.
The Chelyabinsk regional governor said the strike caused about 1 billion roubles ($33 million) worth of damage.
Life in the city had largely returned to normal by Saturday although 50 people were still in hospital. Officials said more than 1,200 people were injured, mostly by flying glass.
Repair work had to be done quickly because of the freezing temperatures, which sank close to -20 degrees Celsius (-4 Fahrenheit) at night.
Emergencies Minister Vladimir Puchkov inspected the damage after President Vladimir Putin sent him to the region.
His ministry is under pressure to clean up fast following criticism over the failure to issue warnings in time before fatal flooding in southern Russia last summer and over its handling of forest fires in 2010.
Putin will also want to avoid a repeat of the criticism that he faced over his slow reaction to incidents early in his first term as president, such as the sinking of the Kursk submarine in 2000 which killed all 118 people on board.
($1 = 30.1365 Russian rouble
2013-02-16
Top 10 stories from the week of Feb. 11:
Top 10 stories from the week of Feb. 11:
1.) Salesforce CEO Benioff Invites Laid Off Yammer Employees to Work for Him
2.) Microsoft Could Make Billions From Office for iPad
3.) Apple Working on Fix for iOS 6.1 Passcode Hack
4.) American Express Cardholders Can Now Tweet to Buy
5.) HBO to Finally Let Subscribers Stream HBO Go to TV Over AirPlay
6.) A Big Year for Apple’s iPhone in India
7.) Bill Gates on Philanthropy, Steve Jobs and the Microsoft Product That Never Was
8.) Yes, Intel Is Building a Web TV Service (A Box, Too)
9.) The Cloud’s Dirty Little Secret
10.) Apple MacBook Pros With Retina Display Get Faster, Cheaper
For more of the week in review, you should follow us on Facebook and Twi
2013-02-13
Join Google + with President Obama
State of the Union: Fireside Hangout with President Obama
Tomorrow, February 14, 4:50 PM On Thursday, February 14th, President Obama will join the latest in a series of "Fireside Hangouts" – a 21st century take on FDR’s famous radio addresses – to talk about his State of the Union Address.
During the +Google+ hangout, the President will answer questions from Americans across the country about the issues and policies laid out in the speech.
How you can join: Right now, you can submit a question for the President and vote on your favorites on the White House +YouTube Channel: http://at.wh.gov/hC22N
On Tuesday, February 12th at 9:00 p.m. ET, watch President Obama's State of the Union Address on the +The White House Google+ page and at http://youtube.com/whitehouse
Then, be sure to watch the hangout live on Thursday, February 14th at 4:50 p.m. ET on the +The White House Google+ page and at http://youtube.com/whitehouse
Learn more about the State of the Union Address and how you can get involved at http://wh.gov/SOTU
#firesidehangout #sotu