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。     

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).     

Location privacy preservation approach towards to content sharing on mobile online social network

A privacy access control model for content sharing was presented to fine-grained control users' location infor-mation associated with sharing content in mobile social network. A k-anonymity privacy algorithm for privacy settings was given to protect against inference attack on a content sharing service provider server. To balance the privacy and quality of service, a location shifting method was presented. Finally experimental results demonstrate the validity and practicality of the proposed approach.     

SQL注入攻击及防御技术的研究

近年来,SQL注入攻击成为黑客攻击网站获取信息的主要技术手段,网站管理员要有效防御攻击就要了解SQL注入攻击的方法并采取相应的措施进行防御。就SQL注入攻击技术、SQL注入攻击的防御及基于ISAPI过滤器的防御系统进行了详细的研究,为有效防御SQL注入提供了方法及手段。     

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.     

碳自掺杂g-C3N4光催化性能的原位光微量热-荧光光谱研究

通过在尿素前驱体中添加单宁酸, 原位缩聚形成碳自掺杂石墨相氮化碳(g-C₃N₄). 利用X射线光电子能谱(XPS)、 场发射扫描电子显微镜(FESEM)、 X射线衍射(XRD)仪和同步热分析(TG-DSC)等方法对碳自掺杂 g-C₃N₄的形貌、 物相结构和能带价态组分进行表征分析, 结合紫外-可见吸收光谱(UV-Vis)和原位光微量热-荧光光谱联用仪获得碳自掺杂g-C₃N₄降解罗丹明B的原位热/动力学信息和三维荧光光谱信息, 探讨了光催化降解罗丹明B的微观机制. 结果表明, 单宁酸浓度≤10 mg/mL时, 碳会取代七嗪单元结构的氮原子形成g-C₃N₄骨架碳自掺杂; 单宁酸浓度≥ 20 mg/mL时, 碳以无定形形式沉积负载在g-C₃N₄表面上形成无定形碳自掺杂. 骨架碳自掺杂g-C₃N₄形成的π电子有效缩短了禁带宽度, 减小了光生电子-空穴复合几率, 比无定形C掺杂g-C₃N₄显示出更优异的光催化性能, 催化主要活性物种为h⁺和·O{}_{\mathrm{2}}^{-}. 碳自掺杂g-C₃N₄光催化降解过程可分为光响应吸热、 降解污染物放热平衡过程和稳定放热3个过程. 其中骨架碳自掺杂g-C₃N₄(C/N摩尔比为0.844)在光照1000 s内, 三维荧光光谱检测的RhB降解率锐减, 光照1000 s后, 其RhB降解率为87.6%, 分别是原始g-C₃N₄和无定形碳自掺杂g-C₃N₄的3.13倍和1.95倍. 光照1000 s后, 光微量热计显示以矿化和降解非荧光发色中间产物为主, 并保持以热变速率为(0.9799±0.5356) μJ/s稳定放热, 为拟零级反应过程, 是光催化反应的决速步骤.