电子商务安全保密技术

电子商务是利用计算机网络的信息交换来实现电子交易，大量的经济信息在网上传递，资金在网上划拨流动，因此，网上信息的可靠性和保密性，都必须确保万无一失，足够高的信息安全性是成功发展电子商务的一个关键性因素，本文主要介绍针对网络安全问题所涉及到的几种技术：虚拟专用网技术，信息加密技术，信息认证技术，防火墙技术和计算机应用技术。     

基于虚拟仪器的远程网络虚拟实验室的设计

本文简要介绍了虚拟仪器的概念和特点，提出了一种以虚拟仪器为基础，具有客户端、网络服务器和仪器服务器三层结构的网络虚拟实验室的构建方法。用户通过Internet浏览器远程传送数据，Web服务器接收数据并转化为仪器服务器相应的指令和参数，由仪器服务器运行实验，并返回实验结果。     

虚拟单道—定标器的设计

介绍了采用基于微机数据采集卡的虚拟单道－定标器的设计方法。它综合了传统单道和定标器两种仪器的功能，可用于α射线的能谱测量中，体现了虚拟仪器技术的灵活性和可重构性，扩展了虚拟仪器在核物理实验中的应用。     

面向对象程序设计在数据采集程序中的一种应用

介绍了包含型多态性的概念和在支持多种数据采集硬件数据采集程序中的应用，介绍了应用虚拟函数技术所得到的优点。     

核测控仪器远程控制的研究

首先介绍了几种嵌入式核测控仪器连网的方法及其优缺点,然后给出了其中一种技术上成熟,经济性和市场性都很好的解决方案.此方案利用以太网专用芯片W5100能够使核测控仪器快速接人企业内部的以太网络并可以根据需要通过因特网来实现远程的数据传输.文中分别介绍了应用此方案的核测控仪器的网络部分的硬、软部分的设计,以及上位机程序编写思路.     

基于智能网卡的数据传输实现

智能网卡被应用于网络吞吐量很大的系统中，如现代高能物理实验数据获取系统、网络服务器等。以一种商业化的智能网卡（Intelligent EthernetCard）为例，介绍了基于PMC的智能网卡的架构、原理以及工作过程，通过实验对比分析了智能网卡与一般网卡的工作性能。     

应用于集装箱检查系统的互逆式客户/服务器处理技术

提出一种新型的分布式网络处理技术，即互逆式客户/服务器处理技术，结合该技术在“同方威视”集装箱检查系统中的成功应用，介绍了该技术的特点和优势，阐述了用这种新技术进行网络程序开发的策略和原则，并提出了用该技术进行集装箱检查系统软件开发的一个范例。     

一种无延迟线的恒比定时器

介绍一种无延迟线的恒比定时器的设计方法，其中以低通滤波网络取代恒比定时甄别电路中的延迟线，简化了电路结构，并且具有较高的定时精度，给出了测试结果。     

C系列SYSMAC LINK网

本文介绍了日本欧姆龙Ｃ系列可编程序控制器ＳＹＳＭＡＣ ＬＩＮＫ网络的特点、硬件配置、参数设定及传送时延等。对ＳＹＳＭＡＣ ＬＩＮＫ网络的两种数据传送方式，即数据连接和通信指令命令，作了较为详细的说明。     

基于Multigen的虚拟地质环境构建技术探讨

虚拟地质环境构建技术是改变矿产资源勘查传统方式，实现虚拟找矿与勘探的重要技术。从Multigen虚拟现实平台的技术特点出发，探讨了基于Multigen虚拟现实平台的铀资源勘查虚拟地质环境构建的技术方法和流程，并对流程中的高程数据、属性数据、纹理数据的转换和输入，以及虚拟地质环境驱动等技术环节进行了较详细的阐述，进而初步建立了某铀矿区的虚拟地质环境，为实现建立铀资源数字勘查区的目的，并最终实现铀资源虚拟勘查的“梦想”奠定了初步基础。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

Investigations on landmine detection by BF3 detector

Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.     

Web Services interface of SSRF archive data analysis system

Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

Linear accelerators equipped with multileaf collimators （MLC） are becoming more common and are widely used in the intensity-modulated radiotherapy （IMRT）. There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance （QA） and quality control （QC）. This paper is aimed to investigate the role of AGFA high-energy CR （Computed Radiography） in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.     

微型X射线管空气比释动能和能谱的测量

为研究微型X射线管的特性,通过电离室测量光管出射口30 cm远处的空气比释动能,使用高纯锗探测器分别测量了Ag过滤和Cu过滤下的X射线能谱。结果表明,空气比释动能随电流的增加有线性增加的趋势,能谱图明显的观察到银的两个特征X射线。完成了微型X射线管空气比释动能和能谱的测量方法以及实验测量的工作,为微型x射线管下辐射质的建立提够了条件基础。     

Gamma-ray attenuation technique for measuring void fraction in horizontal gas-liquid two-phase flow

The measurement of void fraction is of importance to the oil industry and chemical industry. In this article, the principle and mathematical method of determining the void fraction of horizontal gas-liquid flow by using a single-energy γ-ray system is described. The γ-ray source is the radioactive isotope of 241Am with γ-ray energy of 59.5 keV. The time-averaged value of the void fraction in a 50.0-mm i.d. transparent horizontal pipeline is measured under various combinations of the liquid flow and gas flow. It is found that increasing the gas flow rate at a fixed liquid flow rate would increase the void fraction. Test data are compared with the predictions of the correlations and a good agreement is found. The result shows that the designed γ-ray system can be used for measuring the void fraction in a horizontal gas-liquid two-phase flow with high accuracy.