掺溴聚-4-甲基-1-戊烯的合成研究

 液溴与聚-4-甲基-1-戊烯（PMP）的四氯化碳溶液反应，在光照条件下得到溴代PMP，通过红外与元素分析确证了其结构。并通过热重分析对其性能进行了初步的研究。研究发现，在光照条件下溴原子很容易与PMP中叔丁基上的氢原子发生取代反应，得到化学掺杂溴原子的聚合物。该聚合物在150℃以下比较稳定，在150℃以上就会失去HBr。采用此种方法，可得到掺杂均匀的低密度材料。     

退火温度对KDP晶体光学均匀性的影响研究

 研究了磷酸二氢钾（KDP）晶体热退火前后光学均匀性的变化，发现适当温度下退火可以降低KDP晶体的内应力，提高晶体的消光比，从而提高晶体的光学均匀性。实验证明，50℃下退火即可消除部分内应力，110℃下退火可以消除生长鬼影和鬼线。但是,退火温度太高（如170℃）,也可能使晶体的均匀性降低。     

神光-Ⅱ装置三倍频实验中靶场单元技术的改进

 主要介绍为了满足神光-Ⅱ高功率激光装置三倍频光（351nm，3ω）的物理实验要求，靶场三倍频模拟光源和瞄准监视系统两个主要单元技术的改进，即三倍频模拟光源由基频光（1 053nm，3ω）通过腔外的KTP+BBO晶体倍频获得，再经八路分光系统和主激光耦合；瞄准监视系统由透射式光学系统改进为反射式光学系统，避免原系统存在较大的色差，提高瞄准精度。     

Notable shift of ultraviolet intensity on Sn-doped ZnO nanostructure fabricated by sol–gel method

Sn-doped ZnO (SZO) thin films are deposited by sol–gel dip-coating method with Sn content at 0 at.% and 1–15 at.% with an increment of 2 at.%. The structure and luminescence of the films are investigated. X-ray diffraction results indicate that all the SZO samples show preferential orientation along the (002) direction, and the scanning electron microscope exhibits that the surface morphology of the films change from nanoparticles to nanorods with increasing Sn concentration. X-ray photoelectron spectroscopy reveals that Sn exists as valence of +4 in the matrix. The photoluminescence peaks at 381 and 398 nm are observed in all the samples. The ratio of intensity of peak at 381 nm to that of peak at 398 nm differed markedly. The intensity of peak at 398 nm might be due to the response for the Sn atoms, while the intensity of peak at 381 nm is probably related to the quantum size effect.     

The Discrete Subgroups and Jфrgensen’s Inequality for SL(m,Cp)

In this paper, we give discreteness criteria of subgroups of the special linear group on Qp or Cp in two and higher dimensions. J rgensen's inequality gives a necessary condition for a nonelementary group of Mbius transformations to be discrete. We give a version of Jфrgensen's inequality for SL(m, Cp).     

SET‐LRP of acrylonitrile in ionic liquids without any ligand

Use of ionic liquids as reaction media was investigated in the design of an environmentally friendly single electron transfer‐living radical polymerization (SET‐LRP) for acrylonitrile (AN) without any ligand by using Fe(0) wire as catalyst and 2‐bromopropionitrile as initiator. 1‐Methylimidazolium acetate ([mim][AT]), 1‐methylimidazolium propionate ([mim][PT]), and 1‐methylimidazolium valerate ([mim][VT]) were applied in this study. First‐order kinetics of polymerization with respect to the monomer concentration, linear increase of the molecular weight, and narrow polydispersity with monomer conversion showed the controlled/living radical polymerization characters. The sequence of the apparent polymerization rate constant of SET‐LRP of AN was k_app ([mim][AT]) > k_app ([mim][PT]) > k_app ([mim][VT]). The living feature of the polymerization was also confirmed by chain extensions of polyacrylonitrile with methyl methacrylate. All three ionic liquids were recycled and reused and had no obvious effect on the controlled/living nature of SET‐LRP of AN. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Structure and dynamics of self-organized neuronal network with an improved STDP rule

Nonlinear Dynamics - The chemical synapses in a neural network are known to be modulated by the neuronal firing activities through the spike-timing-dependent plasticity (STDP) rule. In this paper,...     

Simultaneous determination of calycosin‐7‐O‐β‐d‐glucoside,calycosin, formononetin,astragaloside IV and schisandrin in rat plasma by LC‐MS/MS: application to a pharmacokinetic study after oral administration of Shenqi Wuwei chewable tablets

A rapid, sensitive and reliable high‐performance liquid chromatography–mass spectrometry (LC‐MS/MS) method was developed and validated for simultaneous quantification of the five main bioactive components, calycosin, calycosin‐7‐O‐β‐d ‐glucoside, formononetin, astragaloside IV and schisandrin in rat plasma after oral administration of Shenqi Wuwei chewable tablets. Plasma samples were extracted using solid‐phase extraction separated on a CEC₁₈ column and detected by MS with an electrospray ionization interface in multiple‐reaction monitoring mode. Calibration curves offered linear ranges of two orders of magnitude with r > 0.995. The method had a lower limit of quantitation of 0.1, 0.02, 0.1, 1 and 0.1 ng/mL for calycosin, calycosin‐7‐O‐β‐d ‐glucoside, formononetin, astragaloside IV and schisandrin, respectively. Intra‐ and inter‐day precisions (relative standard deviation) for all analytes ranged from 0.97 to 7.63% and from 3.45 to 10.89%, respectively. This method was successfully applied to the pharmacokinetic study of the five compounds in rats after oral administration of Shenqi Wuwei chewable tablets. Copyright © 2014 John Wiley & Sons, Ltd.     

Single-axis ultrasound levitation system with annular clamping forces

Based on the principle of acoustic levitation,a single-axis ultrasonic levitation system(SAULS) with convex sides was designed.A normal SAULS only provides a levitation force(LF) against the gravity of the sample.While,such systems also provide an annular clamping force(ACF) surrounding the levitated samples,and improve levitation stability of samples in the standing wave field.Using the finite-difference time-domain method,we investigated the force distributions in different resonance cavities and the factors that influence the magnitude of the levitation force in optimizing the SAULS and the ACF.The theoretical analyses and experimental results indicate that the stability of levitation in this special SAULS is improved with the ACF from its designed convex-side feature.It can be developed into a simple device in levitating and moving samples steadily in related experiments and applications.     

Progresses and advances in Arctic underwater acoustics study

As a part of underwater acoustics, the study and development of Arctic Acoustics is later than underwater acoustics about several hundred years. After World War II, the study of Arctic Acoustics attracts many interests by some developed countries, especially U.S. and pre-Soviet Union. The research works obviously have some kinds of cold war brand. After the Cold War, with the gradual warming trend of Arctic area, the ocean acoustic environment in Arctic and its adjacent area have been considerably concerned. The 8 countries of Arctic rim organized exclusive "Arctic Council" in 1996. The white paper of "China Arctic Policy"was published in January 26, 2018, the Chinese government declared that China is a close Arctic country, and is the responsible stakeholder of Arctic interests. The new advances in Arctic research works axe introduced in this paper, including the results of scientific survey and studies about Arctic underwater acoustics of Chinese researchers. It is showed that the Arctic underwater acoustical research area is not only parallely copy the topics what traditional underwater acoustics covered, e.g. environment noise,reverberation,and propagation, but also the topics which is specifically based on the Arctic environment. Some of these research fields cannot be included in the traditional shallow water, deep water acoustics, e.g. the ice-water interface feature, ice covered semi-acoustic channel effect, the communication and navigation of UUV in the condition of under ice, and the adaptation of sonar technique, equipment in the ice-covered environment, etc.