Identification and characterization of insect-specific proteins by genome data analysis

Background: Insects constitute the vast majority of known species with their importance including biodiversity, agricultural, and human health concerns. It is likely that the successful adaptation of the Insecta clade depends on specific components in its

Determinations of residual furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in fish feeds by HPLC-UV and LC-MS/MS, respectively

The antibacterial drug furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.

Scattering of linear water waves by a fixed and infinitely long rectangular structure parallel to a vertical wall in oblique seas

The scattering of linear water waves by an infinitely long rectangular structure parallel to a vertical wall in oblique seas is investigated. Analytical expressions for the diffracted potentials are derived using the method of separation of variables. The unknown coefficients in the expressions are determined through the application of the eigenfunction expansion matching method. The expressions for wave forces on the structure are given. The calculated results are compared with those obtained by the boundary element method. In addition, the influences of the wall, the angle of wave incidence, the width of the structure, and the distance between the structure and the wall on wave forces are discussed. The method presented here can be easily extended to the study of the diffraction of obliquely incident waves by multiple rectangular structures.

Response amplitude and hydrodynamic force for a buoy over a convex

A buoy as an offshore structure is often placed over a convex such as a caisson or a submerged island. The hydrodynamic fluid/solid interaction becomes more complex due to the convex compared with that on the flat. Both the buoy and the convex are idealized as vertical cylinders. Linear potential theory is used to investigate the response amplitude and the hydrodynamic force for a buoy over a convex due to diffraction and radiation in water of finite depth. These are derived from the total velocity potential. A set of theoretical added mass, damping coefficient, and exciting force expressions have been proposed. Analytical results of the response amplitude and hydrodynamic force are given. Finally, the numerical results show that the effect of the convex on the response amplitude and hydrodynamic force for the buoy is ignored if the size of the convex is relatively smaller.

Efficient Mode-locked and Q-switched Nd∶YVO_4 Laser with Semiconductor Saturable Absorber Mirror

We reported an efficient diode pumped Nd ! YVO, 1 064 nm laser passively mode-locked and Q-switched by a semiconductor saturable absorber mirror(SESAM). At the incident pump power of 7. 5 W, 2. 81 W average output power was obtained during stable CW mode locking with a repetition rate of 111 MHz. The optical conversion efficiency was 37. 5% , and the slope efficiency was 39%. So far as we know, this is the highest optical-optical conversion efficiency with a SESAM at home.

Comparative studies of semiconductor saturable absorber mirror mode-locking dynamics in pulsed diode-end-pumped picosecond Nd:GdVO4 and Nd:YAG lasers

Ultrashort pulses were generated in passively mode-locked Nd:YAG and Nd:GdVO4 lasers pumped by a pulsed laser diode with 10-Hz repetition rate. Stable mode-locked pulse trains were produced with the pulse width of 10 ps. The evolution of the mode-locked pulse was observed in the experiment and was discussed in detail. Comparing the pulse evolutions of Nd:YAG and Nd:GdVO4 lasers, we found that the buildup time of the steady-state mode-locking with semiconductor saturable absorber mirrors (SESAMs) was relevant to the upper-state lifetime and the emission cross-section of the gain medium.

Resonant Raman Scattering and Photoluminescence Emissions from Above Bandgap Levels in Dilute GaAsN Alloy

The transitions of E0 ,E0 ＋A0, and E＋ in dilute GaAs（1-x） Nx alloys with x = 0.10% ,0.22% ,0.36% ,and 0.62% are observed by micro-photoluminescence. Resonant Raman scattering results further confirm that they are from the intrinsic emissions in the studied dilute GaAsN alloys rather than some localized exciton emissions in the GaAsN alloys. The results show that the nitrogen-induced E E＋ and E0 ＋ A0 transitions in GaAsN alloys intersect at a nitrogen content of about 0.16%. It is demonstrated that a small amount of isoelectronic doping combined with micro-photoluminescence allows direct observation of above band gap transitions that are not usually accessible in photoluminescence.

800nm Semiconductor Absorber with Low Temperature Method and Surface State Method Combined Absorber for Kerr Lens Modelocking of Ti∶Al2O3 Laser

A novel 800nm Bragg mirror type of semiconductor saturable absorption mirror with low temperature method and surface state method combined absorber is presented.With which passive Kerr lens mode locking of Ti∶Al2O3 laser pumped by argon ion laser is realized,which produces pulses as short as 40fs.The spectrum bandwidth is 56nm,which means that it can support the modelocking of 20fs.The pulse frequency is 97.5MHz;average output power is 300mW at the pump power of 4.45W.

双面二维硅微条探测器的沾污失效分析及修复；Contamination failure analysis and repairing for double side two dimensional silicon microstrip detectors

硅微条探测器通过微电子工艺制作,易因沾污导致性能下降甚至失效;裸露的键合引线,也易因机械力形成隐性或显性失效。对上述现象的研究可用于修复、维护探测器并在设计和工艺流程中改进其性能。本文通过光学、电气手段分析其结构和制作工艺流程,根据沾污性质在不同条件下清洗探测器,中测后根据芯片图形、封装方式和电气要求修复探测器,最后采用同位素α能谱测试修复效果。对一块沾污后失效(无法加载偏压)的硅微条清洗后在大气环境,N面接地,P面加载负偏压条件下进行了测试,结果显示:170 V全耗尽,平均漏电流2.94μA,5.486 MeV的α峰能量分辨率约1.28%。失效键合所在条的另一面各条能谱观测到假峰,键合修复后消除。因沾污失效的硅微条探测器经过合适的清洗、修复,部分可以恢复性能,但清洗对表面和结构有损伤,须谨慎。另外,键合失效后,因信号不能引出导致的电荷积累会通过电容效应影响其它灵敏区。文章提示,探测器应存放于洁净,恒温,低湿度,避光,避强电磁干扰的环境,以提高能量和位置分辨率,并增加工作稳定性,延长使用寿命。