一种漂移室定位子性能反常现象的研究

研究了一种漂移室定位子性能的反常现象,它关系到定位子的使用寿命．着重测量了暗电流和随机噪声与时间、高压及温度的关系.     

不良导体热系数和热体散热率测量方法研究(英文)

本文介绍一种直接测量散热率新方法．进而测出不良导体的热系数。该方法，减小了由间接测量散热率所带来的误差，实验装置简单，操作方便，参数少，测量结果的精确性和重复性都有较大提高，更重要的是这一新的实验方法突出了物理思想。     

Polling systems in heavy traffic: Exhaustiveness of service policies

We study the expected delay in cyclic polling models with general ‘branching-type’ service disciplines. For this class of models, which contains models with exhaustive and gated service as special cases, we obtain closed-form expressions for the expected delay under standard heavy-traffic scalings. We identify a single parameter associated with the service discipline at each queue, which we call the ‘exhaustiveness’. We show that the scaled expected delay figures depend on the service policies at the queues only through the exhaustiveness of each of the service disciplines. This implies that the influence of different service disciplines, but with the same exhaustiveness, on the expected delays at the queues becomes the same when the system reaches saturation. This observation leads to a new classification of the service disciplines. In addition, we show monotonicity of the scaled expected delays with respect to the exhaustiveness of the service disciplines. This induces a complete ordering in terms of efficiency of the service disciplines. The results also lead to new rules for optimization of the system performance with respect to the service disciplines at the queues. Further, the exact asymptotic results suggest simple expected waiting-time approximations for polling models in heavy traffic. Numerical experiments show that the accuracy of the approximations is excellent for practical heavy-traffic scenarios. This revised version was published online in June 2006 with corrections to the Cover Date.     

三种胺羧配合物的113Cd NMR研究

该文对Cd-HEDTA(N-(2-羟基乙基)乙二胺-N',N',N'-三乙酸),Cd-PDTA(1,2丙二胺四乙酸)和Cd-DTPA(二乙三胺五乙酸)的¹¹³Cd NMR谱和自旋晶格弛豫时间T₁,及NOE因子进行了研究.结果表明,Cd-HEDTA和Cd-PDTA结构与Cd-EDTA类似,Cd-PDTA双线归因于其可能的两种异构体.Cd-DTPA大的化学位移表明其具有七配位的五角双锥结构.在这种结构中DTPA可用三个氮原子参加配位.对¹¹³Cd自旋晶格弛豫时间分析表明,Cd-DTPA配合物中质子偶极作用机理的贡献较大,这归因于Cd DTPA有更多的乙酸根亚甲基质子参与偶极作用.     

Browder-Petryshyn 型的严格伪压缩映射的粘滞迭代逼近方法

主要研究Browder-Petryshyn型的严格伪压缩映射的粘滞迭代逼近过程,证明了Browder-Petryshyn型的严格伪压缩映射的不动点集F(T)是闭凸集．在q-一致光滑且一致凸的Banach空间中,对于严格伪压缩映射T,利用徐洪坤在2004年引进的粘滞迭代得到的序列弱收敛于T的某个不动点．同时证明了Hilbert空间中Browder-Petryshyn型的严格伪压缩映射的相应迭代序列强收敛到T的某个不动点,其结果推广与改进了徐洪坤2004年的相应结果．     

Analysis method of the effect of fabrication errors on a planar waveguide demultiplexer

The impact of fabrication errors on a planar waveguide demultiplexer is analyzed based on an analytical method. The explicit expression of the transfer function taking into account phase and amplitude errors is presented in order to analyze the loss and crosstalk of the demultiplexer caused by fabrication errors. A basic requirement for the demultiplexer with a certain crosstalk criterion can be easily obtained. Using an etched diffraction grating demultiplexer as an example, it is shown that the analytical results have a good agreement with results from a numerical method.     

四（对-羟基苯基）卟啉氧合配合物的室温固相合成，表征及氧合能力

采用固相反应合成了四羟基苯基卟啉与与Fe^2＋,Co^2＋金属离子的配合物,在室温下,将其与分子O2作用,提纯后得到两种固态氧合配合物．通过元素分析、红外光谱（IR）、核磁共振氢谱（^1HNMR）、电导、热分析（TG／DTA）、紫外光谱（UV）等测试手段确定了氧合配合物的组成为[Co·THPP·O2]（NO3）2·2H2O、[Fe·THPP·O2]Cl2·2H2O]，可知1mol配合物吸收了1molO2,采用失重法测定了氧合配合物中的配位氧,确定1mol金属配合物吸收1molO2形成超氧配合物．     

Effect of nitrogen surface doping on the work function and field emission of hydrogenated amorphous carbon films

The effect of nitrogen surface doping on the electron field emission characteristics of hydrogenated amorphous carbon films was studied. It was found that the emission threshold electric field decreased after nitrogen surface doping which indicated the reduction of the emission barrier at the film surface. It was demonstrated that this improvement arose from the decrease of the effective work function due to the formation of a dipole layer induced by chemical termination and chemical structural change on the film surface. PACS 52.75.Xx; 73.30 +y; 73.61.Jc