LIA组元的脉冲功率调制系统研制

本文介绍一种以加速组元为终端负载的纳秒脉冲功率系统。获得的加速间隙电压为350kV，90ns(半高宽)，波形上升时间为30ns；Blumlein主开关工作电压大于280kV，抖动小予1.5ns(均方根值)。对同轴场畸变开关性能的进一步改善作了必要的讨论，提出了用等场强原则偏置触发极，比通常采用自然中位面方法，可使开关工作电压提高8．7％。     

制导光缆中光纤寿命预期

介绍了光纤寿命预期的疲劳实验方法和筛选实验方法。采用这两种方法，利用电子万能材料试验机和光纤筛选复绕机对室温下光纤进行了疲劳性能实验。实验得出，在张力小于850g的情况下，制导光纤的寿命可以达到10年以上；光纤的韦伯参数md和疲劳参数nd的大小影响光纤寿命。实验表明，当光纤的使用状态受力较大时，或使用贮存状态相差较大时，宜选用动态方法进行寿命预期；当贮存和使用状态受力变化不大时，宜选用筛选复绕方法预期光纤寿命。制导光纤寿命模型宜选用动态疲劳模型，通信光纤可选用筛选实验模型。实验还表明，提高光纤的抗疲劳因子nd和减小光缆中光纤的应变，可以更好地保持光缆中光纤的使用寿命和可靠性。     

Characterization of inner layer thickness change of a composite circular tube using nonlinear circumferential guided wave:A feasibility study

The feasibility of using the nonlinear effect of primary circumferential guided wave (CGW) propagation for characterizing the change of inner layer thickness of a composite circular tube (CCT) has been investigated. An appropriate mode pair of the fundamental and double-frequency CGWs (DFCGWs) has been selected to enable the second harmonics of primary wave mode in the given CCT to accumulate along the circumferential direction. When changes in the inner layer thickness (described as the equivalent inner layer thickness) take place, the corresponding nonlinear CGW measurements are conducted. It is found that there is a direct correlation between change of equivalent inner layer thickness of the CCT and the relative acoustic nonlinearity parameter (Δβ) measured with CGWs propagating through one full circumference, and that the effect of second-harmonic generation (SHG) is very sensitive to change in the inner layer thickness. The experimental result obtained demonstrates the feasibility for quantitatively assessing the change of equivalent inner layer thickness in CCTs using the effect of SHG by primary CGW propagation.     

How Does van der Waals Confinement Enhance Phonon Transport?

We study the mechanism of van der Waals(vdW)interactions on phonon transport in atomic scale,which would boost developments in heat management and energy conversion.Commonly,the vdW interactions are regarded as a hindrance in phonon transport.Here we propose that the vdW confinement can enhance phonon transport.Through molecular dynamics simulations,it is realized that the vdW confinement is able to make more than two-fold enhancement on thermal conductivity of both polyethylene single chain and graphene nanoribbon.The quantitative analyses of morphology,local vdW potential energy and dynamical properties are carried out to reveal the underlying physical mechanism.It is found that the confined vdW potential barriers reduce the atomic thermal displacement magnitudes,leading to less phonon scattering and facilitating thermal transport.Our study offers a new strategy to modulate the phonon transport.     

氧化钙改性高岭土对垃圾渗滤液中氨氮的去除研究

采用氧化钙对高岭土进行改性,并用XRD、SEM和FT-IR对改性高岭土进行了表征。将改性高岭土应用于垃圾渗滤液的处理,考察了改性高岭土投加量、渗滤液初始pH、时间等因素对氨氮去除效果的影响,并对其吸附机理进行了研究。结果表明,氧化钙改性高岭土的产物主要是胶凝材料水化物(硅铝酸钙和含Al的C-S-H凝胶),形貌为蜂窝状;向氨氮含量为3520mg/L、pH为7.53~7.80的垃圾渗滤液中投加160g/L吸附剂,吸附60min,氨氮的去除率达82.66%,吸附量为18.19mg/g。氧化钙改性高岭土对氨氮的吸附符合Langmuir等温模型,动力学上符合准二级动力学方程,其相关系数分别为0.9678,0.9989。同时,该吸附过程包含了膜扩散和颗粒内扩散。     

预烧温度对CaO-Li_2O-Sm_2O_3-TiO_2微波介质陶瓷介电性能的影响

用固相反应法制备了CaO-Li2O-Sm2O3-TiO2(CLST)微波介质陶瓷。通过改变预烧温度(1 000~1 200℃)研究其对CLST微波介质陶瓷介电性能的影响。研究过程中,对预烧粉体与烧结陶瓷进行XRD与SEM分析,对陶瓷的介电性能εr、Q、τf进行了测试。结果表明,预烧温度对CLST微波介质陶瓷介电性能有较大影响,在预烧温度1 150℃,烧结温度1 340℃时可获得较好的介电性能:εr=112,Q=845,τf=52×10-6/℃。     

CCD组件靶面脏斑成因分析及解决方法

通过三项试验,找到了CCD摄像机组件靶面脏斑形成的原因。潮湿的自然环境、温度变化和运输振动三个因素促成CCD组件机壳内的水汽吸附灰尘,凝聚到芯片靶面上形成脏斑。提出了解决脏斑问题的具体方法。通过在CCD组件的装配、包装过程中采取针对性措施来保证密封性能,这样就能在存储和运输过程中避开空气中的灰尘、水汽等脏斑源,靶面上就不会因受潮而产生脏斑。采取这些措施后,在后续产品中脏斑问题得到了彻底解决。     

LTE协议解决方案及系统实现

介绍了LTE特点及现状.协议测试及重要性根现状给出了LTE协议测试解决方案并通过安立公司的MD8430A基站仿真器和MD8435A终端仿真器外加两台控制PC搭建测试平台,在平台上成功实现了LTE终端从搜索注册网络建立连接信令流程及数据传输物理层仿真.仿真速率上行达到50Mbit/s下行100Mbit/s的高速率传输,给出了各流程源程序,对于LTE移动终端的研发具有重要的作用.     

RICB：基于缓冲区溢出的整数溢出漏洞动态分析

Integer overflow vulnerability will cause buffer overflow. The research on the relationship between them will help us to detect integer overflow vulnerability. We present a dynamic analysis methods RICB (Run-time Integer Checking via Buffer overflow). Our approach includes decompile execute file to assembly language; debug the execute file step into and step out; locate the overflow points and checking buffer overflow caused by integer overflow. We have implemented our approach in three buffer overflow types: format string overflow, stack overflow and heap overflow. Experiments results show that our approach is effective and efficient. We have detected more than 5 known integer overflow vulnerabilities via buffer overflow.