Characterization of thick epitaxial silicon detectors from different producers after proton irradiation

Epitaxial (EPI) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of thick EPI silicon diodes irradiated with protons up to a fluence of has been performed by means of Charge Collection Efficiency (CCE) measurements, investigations with the Transient Current Technique (TCT) and standard CV/IV characterizations. The aim of the work was to investigate the impact of radiation damage as well as the influence of the wafer processing on the material performance by comparing diodes from different manufacturers. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. While the generation of leakage current due to irradiation is similar in all investigated series of detectors, a difference in the effective doping concentration can be observed after irradiation. In the CCE measurements an anomalous drop in performance was found even for diodes exposed to very low fluences in all measured series. This result was confirmed for one series of diodes in TCT measurements with an infrared laser. TCT measurements with a red laser showed no type inversion up to fluences of for n-type devices whereas p-type diodes undergo type inversion from p- to n-type for fluences higher than .     

CCE组合抑制剂用于铜锌分离浮选生产实践

CCE组合抑制剂在铜锌分离中对在矿床中被铜离子活化了的锌是一种去活剂，在该药剂作用下同时添加硫酸锌、亚硫酸钠即能使锌矿物在铜锌分离中得到很好地抑制，从而达到铜锌分离的目的。     

继续工程教育投资的优化

发展科学技术,振兴经济的重要支柱的继续工程教正在全世界蓬勃发展,相形之下,继续工程教育经济学目前尚处于萌芽状态,通过对cobb-Douglas出式的推广,本文首先导出继续工程教育投资的数学模型,继而运用系统辩识方法获取总产出对继续工程教育投资的两个弹性系数γ和δ.最后根据极大值原理找到继续工程教育投资最优化的条件.本文结果有助于从宏观上定量描述继续工程教育投资(脱产学时和继教经费)的经济效益,并对企业继续工程教育投资作企业总资源的比例给出了优化方向.     

Special Report on Electrical Standards: New Internationally Adopted Reference Standards of Voltage and Resistance

This report provides the background for and summarizes the main results of the 18th meeting of the Consultative Committee on Electricity (CCE) of the International Committee of Weights and Measures (CIPM) held in September 1988. Also included are the most important implications of these results. The principal recommendations originating from the meeting, which were subsequently adopted by the CIPM, establish new international reference standards of voltage and resistance based on the Josephson effect and the quantum Hall effect, respectively. The new standards, which are to come into effect starting January 1, 1990, will result in improved uniformity of electrical measurements worldwide and their consistency with the International System of Units or SI. To implement the CIPM recommendations in the U.S. requires that, on January 1, 1990, the value of the U.S. representation of the volt be increased by about 9.26 parts per million (ppm) and the value of the U.S. representation of the ohm be increased by about 1.69 ppm. The resulting increases in the U.S. representations of the ampere and watt will be about 7.57 ppm and 16.84 ppm, respectively. The CCE also recommended a particular method, affirmed by the CIPM, of reporting calibration results obtained with the new reference standards that is to be used by all national standards laboratories.     

大话务并发场景下语音质量提升方法的研究

LTE大话务语数并发场景的特点是业务类型多、分优先级调度和资源受限,是现阶段的优化难点.本文结合浙江移动通信网络分布于资源分配现状,通过一些语音质量提升方法的实践,提出了一种基于语音编码的网络优化方案.结合压力测试经验,分析了语数感知拐点,并提出了相应的优化解决方案,有效降低了大话务小区分组丢失率和DTX比例,从而成功实现了语音质量提升.通过这种方式对浙江移动通信网络设备进行优化,经过测试,发现结果满足原定的提升语音质量的目标.     

星载相控阵校准方法的性能分析

现有研究表明,为保证星载相控阵的工作性能,必须对其进行通道间幅相校准,然而常规方法难以在星载环境中适用。因此国外已开发出REV、CCE与UTE等算法。文章对UTE与CCE算法的性能进行理论分析与仿真,结果表明CCE算法的性能优于UTE。通过对相应算法的分析研究,可为将来的工程应用提供良好借鉴。     

Renewable-surface sol-gel derived carbon ceramic-modified electrode fabricated by a newly synthesized polypyridil and phosphine Ru (II) complex and its application as an amperometric sensor for hydrazine

A chemically modified carbon ceramic composite electrode (CCE) containing Dichloro{(8, 9-dimethyl-dipyridio [2,3-a;2′,3′-c] phenazine-κ²-N,N′) bis(triphenylphosphine-κ-P)}ruthenium (II) complex which synthesized newly was constructed by the sol-gel technique. Electrochemical behavior and stability of modified CCE were investigated by cyclic voltammetry. The electrocatalytic activity of CCE was investigated and showed a good effect for oxidation of hydrazine in phosphate buffer solution (PBS). A linear concentration range of 6 μM to 1.2 mM of hydrazine with an experimental detection limit of 1 μM of hydrazine was obtained. The diffusion coefficient of hydrazine and its catalytic rate constant for electrocatalytic reaction along with the apparent electron transfer rate constant (k_s) and transfer coefficient (α) were also determined.The modified carbon ceramic electrode doped with this new Ru-complex showed good reproducibility, short response time (t < 2 s), remarkable long-term stability (>3 month) and especially good surface renewability by simple mechanical polishing.The results showed that this electrode could be used as an electrochemical sensor for determination of hydrazine in real water samples used in Fars Power Plant Station, including its heat recovery steam generator (HRSG) water (at different operational condition), cooling system and clean waste water.     

凝析气藏气-液-液体系相态特征模拟研究

针对凝析气藏中凝析气-反凝析油-地层水之间的相态变化极其复杂,常规相平衡计算只考虑了凝析气与反凝析油之间相态变化的问题,开展了流体组成中考虑气态凝析水组分的流体PVT实验.模拟计算了过饱和水凝析气体系的CCE和CVD实验过程,研究认为:过饱和水的存在会对体系的CCE和CVD过程造成明显的相态影响.对多相流体复杂相平衡研究具有重要意义.     

LTE系统中保证CCE分配公平性的算法

在LTE系统中,CCE是传输控制信息所用的物理资源,被上行调度和下行调度共用,若上行调度中所需CCE资源多并且调度快,那么下行调度中将没有或者只有很少的CCE资源可以使用,导致PDSCH中的RB浪费大,反过来PUSCH中RB浪费大。为了避免这个问题的发生,采取限制上下行调度中分配CCE的最大UE数目的方法来保证其公平性,同时提出计算上下行调度中分配CCE最大UE数目的算法,最后通过仿真证明该方法是可行的。