Synthesis, crystal structure and in vitro antitumor activity of di-n-butyltin 4′-(7-oxabicyclo [2,2,1]-5-heptane-2,3-dicarboximide) benzoates

Dibutyltin(IV) oxide reacts with the cantharidin analogue, 4′-(7-oxabicyclo [2,2,1]-5-heptane-2,3-dicarboximide) benzoic acid, A, to give the complexes [(p-C₈H₈NO₃-C₆H₄-COOBu₂Sn)₂O]₂ (1) and (p-C₈H₈NO₃-C₆H₄-COO)₂SnBu₂ (2) which had been characterized by IR and ¹H, ¹³C, ¹¹⁹Sn NMR. Single X-ray crystal structure analysis has been determined for compound (1), which was analogue to most other [(RCOOBu₂Sn)₂O]₂. The dimer features central of Bu₄Sn₂O₂ unit with the two Bu₂Sn groups being linked via bridging oxygen atom. Each tin atom adopts distorted trigonal bipyramidal structures via two carbons from a dibutyl moiety and three oxygen atoms from cantharidin derivative and bridging oxygen atom. In vitro tests show compounds 1 and 2 exhibit high cytotoxicity against P388 and HL-60.     

基于双M-Z干涉仪的光纤周界防护系统

基于光纤双Mach-Zehnder干涉仪(MZI)结构对周界防护系统进行了设计研究。通过对两路经过不同延时的相同信号进行互相关运算,实现了对振动入侵点的定位。提出了一种分段数据处理方法,有效地提高了定位稳定性及准确性。测试结果表明,该双Mach-Zehnder干涉仪周界防护系统可以实时对振动点进行定位,在传感光纤长度为2km、采样率为2MHz时定位精度优于200m,能够长时间连续稳定工作。     

两端对称负折射率缺陷复合光子晶体:多通道滤波和光开关

采用传输矩阵法对两端对称负折射率缺陷复合光子晶体结构[D(AB)mD]N的透射特性进行了研究.结果表明:当N=2时,该结构透射谱的禁带出现两个完全共振透射峰,当N增加时,每个共振透射峰又分裂为N-1条；当复合光子晶体的层数m逐渐增加时,透射峰的品质因子逐渐提高,且分裂的共振透射峰距离逐渐减少；既为该结构实现高品质的多通...     

Normal Mode Splitting in a Cavity Optomechanical System with a Cubic Anharmonic Oscillator

The strong coupling between a macroscopic mechanical oscillator and a cavity field is essential for many quantum phenomena in a cavity optomechanical system. In this work, we discuss the normal mode splitting in a cavity optomechanical system with a cubic nonlinear movable mirror. We study how the mechanical nonlinearity affects the normal-mode splitting behavior of the movable mirror and the output field. We find that the mechanical nonlinearity can increase the peak separation in the spectra of the movable mirror and the output field. We also find that the heights and linewidths of the two peaks are very sensitive to the mechanical nonlinearity.

     

Synthesis and antifungal activity of chalcone derivatives

In the present study, using chalcone as a lead compound, a series of its derivatives (compounds 1–30) were designed and synthesised. Their activity of anti-pathogenic fungi of plants has been evaluated. It is found that these compounds have good antifungal activity against Sclerotinia sclerotiorum, Helminthosprium maydis, Botrytis cinerea, Rhizoctonia solani and Gibberella zeae. Among them, the inhibition of growth for compound 30 against S. sclerotiorum showed 89.9%, with the median effective concentrations (EC₅₀) of 15.4 μg mL^? 1. The inhibition of growth for compounds 28, 29 and 30 at a concentration of 100 μg mL^? 1 against H. maydis is 90.3%, 90.7% and 91.1%, with EC₅₀ of 15.1, 18.3 and 18.1μg mL^? 1, respectively.     

Detection of scattered light pulses at femto-Joule level by using a picosecond BBO optical parametric amplifier

We report a technique for detecting weak scattered light pulses based on a 532 nm pumped picosecond β-barium-borate collinear optical parametric amplifier. The measured maximum slope gain factor of the amplifier was found to be around 10⁷, and the energy detection limit was of the order of fJ/pulse for the signal of 730 nm and the idler of 1.5 μm at a pumping intensity of 2.83 GW/cm². The linearity of the gain for this amplifier was found to be excellent for a seeding level of lower than 420 fJ per pulse. The maximum gains and the energy detection limits for the scattered light pulses from various scattering targets were found to be poorer than that from the reflective mirror, owing to the degraded beam quality and the depolarization of the scattered light. A reduction of the maximum gain for the scattered light with the increase of the angle of incidence, which causes pulse broadening and reduces the photon flux of the signal, was investigated. The feasibility of detecting weak scattered light in the infrared by using idler-to-signal frequency up-conversion was also demonstrated, in which the infrared seeder located in the idler branch of the amplifier was injected as the seeding beam and was then parametrically up-converted into the visible signal branch, with an even higher gain.     

ITER装置CTB盒冷屏绝热结构初步设计与分析

根据装置系统对CTB盒的绝热性能要求,文章对CTB盒的真空绝热层的选型、搭接处理和真空度保证措施进行了分析和设计,并分别对辐射传热、固体导热、气体导热的表观传热系数,和绝热结构总的热损失进行了数值计算。经初步检验,该绝热结构的设计是可信的,并且其总的热损失能够满足ITER设计文集的要求,为CTB盒内部冷屏的设计和制造提供了可靠的技术参数。     

基于微腔效应增强单层二硫化钨光吸收

提出基于金属薄膜-分布式布拉格反射器微腔效应增强单层二硫化钨光吸收的多层薄膜结构.运用光学传输矩阵理论研究了其输运特性,发现由于金属薄膜-分布式布拉格反射器的微腔效应,在间隔层和覆盖层之间形成电场强度极大值,有效促进入射光与单层二硫化钨的相互作用.综合优化金属层、间隔层和覆盖层厚度,单层二硫化钨在612 nm处的光吸收提高了38倍,达到78.42;.进一步探讨了光入射角、分布式布拉格反射器周期、间隔层折射率与单层二硫化钨光吸收的关系.研究结果表明,上述结构参数的变化可有效调控单层二硫化钨的吸收峰值.研究结果为制备高性能单层二硫化钨光电探测器等新型光电子器件提供了新思路.     

The Stationary Optomechanical Entanglement Between an Optical Cavity Field and a Cubic Anharmonic Oscillator

International Journal of Theoretical Physics - Currently, the creation of the quantum entanglement is still one of the most challenging goals. Here, we theoretically investigate the stationary...     

Diode-pumped self-Q-switched Cr,Nd:YAG laser with 7-W average output power

We report a diode-pumped self-Q-switched 1064-nm Cr,Nd：YAG of 16-18 ns. The maximum average output power up to 7 W, 3370, is obtained in a simple and compact linear cavity by using transmittance of 1570. The laser operates at TEM00 mode with a laser with pulse duration in the range corresponding to a slope efficiency of a plane-concave output coupler with a pump power of 14.2 W.