Sunday, September 26, 2010

20 new things for today

  1. I had lunch with Tony (he serves as the instructor for the junior students).
    1. During the lunch I realized that I should have paid more attention to the brand names of the tools, for he asked several times about the names which I cannot tell.
    2. He also mentioned that it is important to initiate, when I said there are relatively less casual talks on science compared with that abroad. He also encouraged me to initiate a party inviting all the Northeastern people of China in this institute, if I want to get to know people from other areas.
    3. He said he works 13 hrs a day.
    4. He pushed himself to read by listing the books, when he was in college. He doesn't need the list now, for he already got used to reading every day.
  2. We use different lenses, and we differentiate them by their focal length (by saying focal length we simplify the lens set as one piece of lens). Larger focal length--like in our lab we have 105mm, 85mm, and 50mm lenses—means lower optical power, which is associated with larger magnification of distant objects, and a narrower angle of view. Conversely, shorter focal length or higher optical power is associated with a wider angle of view. In our lab we make two lenses connected front to front, and this makes the rears of the lenses facing cortex and CCD, separately. Fine adjustments should be made to make sure the cortex captured sharply on the CCD, which includes adapter applied between lenses or between lens and CCD, finely tuned distance between lenses and cortex, and etc.

Saturday, September 25, 2010

20 new things for today

  1. Agar cools quicker than I anticipated. Drop 3-4 drips of it and screw the ring quickly.
  2. Japan releases Chinese trawler captain, but refuses to apologize. It is said that China's banning on raw material (Rare earth) exportation to Japan, which is crucial for the high-tech industry in Japan, is the real stirring response for the Japan's release.
  3. One of the usages of rare earth elements is to produce phosphor. Got its name from element of phosphorus, but phosphor has a completely different mechanism on lightening—the former is because of chemiluminescence (some oxidization-reduction reaction), whereas the latter is because of phosphorescence (slow decay, >1ms) or fluorescence (quick decay, tens of nanoseconds).
  4. But why materials made of rare earth element emit light? Simply put, it's because of the electronic band structure in the crystals. An incoming particle (such as a UV photon) excites an electron from the valence band (trapped and cannot move under usual state) to either exciton band or conduction band. The excitons are loosely bound electron-hole pairs which wander through the crystal lattice until they are captured as a whole by impurity centers. The latter then rapidly de-excite by emitting scintillation light (fast component). As for the elections excited to the conduction band, the holes associated with them in the conduction band are independent (compared to the loosely bound pairs in exciton band). Those holes and electrons are captured successively by impurity centers exciting certain metastable states not accessible to the excitons. The delayed de-excitation of those metastable impurity states, slowed down by reliance on the low-probability forbidden mechanism, again results in light emission (slow component).
  5. Usage? Lighting, mainly on fluorescent lamps, and on some occasions used on metal halide lamps. Glow-in-the-dark toys. Electroluminescence (used commonly in LCD backlights). White LED (turning the blue light from LED into white). Cathode ray tube (television).

Tuesday, August 24, 2010

Matlab demo we should really make good use of!

I found Matlab demo really impressive.
The voice of the narrator is friendly, and the techs introduced are useful and also enlightening.

You can find the link to the demos easily in help-matlab-demos. Enjoy!

Sunday, June 27, 2010

Mu-ming Poo's Letter to his students in 2002

Mu-ming Poo is head of the Division of Neurobiology, Department of Molecular and Cell Biology at University of California, Berkeley, California, USA. He is also director of the Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.

To all lab members:

Over the past several months, it has become clear to me that if there is no drastic change in the lab, Poo lab will soon cease to be a productive, first-rate lab that you chose to join in the first place. Lab progress reports over the past six months have clearly shown the lack of progress in most projects. One year ago, when we first moved to Berkeley, I expressed clearly to everyone my expectation from each one in the lab. The most important thing is what I consider to be sufficient amount of time and effort in the lab work. I mentioned that about 60 hr working time per week is what I consider the minimal time an average successful young scientist in these days has to put into the lab work. There may be a few rare lucky fellows like Florian, who had two Nature papers in his sleeve already, can enjoy life for a while and still get a job offer from Harvard. No one else in the lab has Florian's luxury to play around.

Thus I am imposing strict rules in the lab from now on:

1. Every one works at least 50 hr a week in the lab (e.g., 8+ hr a day, six days a week). This is by far lower than what I am doing every day and throughout most of my career. You may be smarter or do not want to be as successful, but I am not asking you to match my time in the lab.

2. By working, I mean real bench work. This does not include surfing on the computer and sending and receiving e-mails for non-scientific matters unrelated to your work (you can do this after work in the lab or at home), and excessive chatting on nonscientific matters. No long lunch break except special occasions. I suggest that everyone puts in at least 6 hr concentrated bench work and 2+ hr reading and other research-related activity each day. Reading papers and books should be done mostly after work. More time can be spent on reading, literature search and writing during working hours when you are ready for writing a paper.

3. I must be informed in person by e-mail (even in my absence from the lab) when you are absent from the lab for a whole day or more. Inform me early your vacation plan. Taking more than 20 working days out of one year is the maximum to me. In fact, none of you are reporting any vacation and sick leave on your time sheet (against the university rule, although I have been signing the sheets), but you know roughly how many days you were not here.

On the whole, I understand and accept the fact that you may not fulfill the above requirements all the time, due to health reasons, occasional personal business. But if you do not like to follow the rules because it is simply a matter of choice of life style, I respect your choice but suggest you start making plans immediately and leave the lab by the end of January 31. I will do my best to help you to locate a lab to transfer or to find a job.

If you do accept the conditions I describe above, I am happy to continue to provide my best support to your work, hopefully more than I have done in the past. I will review the progress of everyone in the lab by the end of June of 2002. I expect everyone to have made sufficient progress in the research so that a good paper is in sight (at least to the level of J. Neuroscience). If you cannot meet this goal at that time, I will have to ask you to prepare to leave my lab by the end of August.