基于校园网VPN选型方案的研究与应用

在介绍VPN相关知识的基础上,结合IPSec VPN与SSL VPN各自的优缺点,提出了针对校园网的不同需求,采用不同模式的校园网VPN技术,选择适合校园网应用的最佳模型,并对VPN技术在校园网中的应用前景进行了展望。     

影响VPN技术在高职图书馆数字资源共享中的因素剖析

总结、归纳了影响VPN技术在高职图书馆数字资源共享中的不利因素,指出了实现数字资源共享是一个涉及面广、关系复杂交错的系统工程。强调只有消弱VPN技术层面以外的不利因素,创造数字信息共享条件,高职图书馆数字资源共享才能成为现实。     

VPN技术在高校校区互联中的应用

VPN是采用隧道和加密技术以及身份认证方法,在公共网络上建立私有数据传输通道,从而构建企业网络的技术。本文在系统分析了VPN技术原理的基础上,提出了一种应用VPN实现多校区互联的解决方案。     

SoftEther VPN技术在高校图书馆数字资源访问中的应用

近几年来,随着VPN技术逐步趋向成熟,构建基于Internet的校园VPN网络,能够实现校外师生对图书馆数字资源的远程访问。提出了基于SoftEther VPN的解决方案,介绍了SoftEther VPN的工作原理,阐述了在服务器上设置用户权限的步骤,以及客户端安装SoftEther设置参数的过程。     

VPN和pcAnywhere在气象远程管理中的应用

在气象网络中利用VPN技术和pcAnywhere远程控制软件构建的计算机远程控制平台,既能确保气象网络信息安全,又能实现气象业务计算机的远程管理维护。     

高校校园网PPTP VPN的配置应用实践

本文通过网络管理的应用实践，提供了在防火墙实现PPTP VPN的功能的思路及方法，特别探讨的配置过程的注意点，以供校园网管理员设计配置方案进行操作时参考。     

基于ASP.NET技术的数据处理研究

本文通过ASP.NET技术及安全性算法（如SSL、MD5、SHA1等）确保数据处理的安全性,在动态Web页面数据处理方面,基本实现应用程序数据处理的过程;使用IIS组件、Framework和动态Web框架实现数据的交互性处理;ASP.NET技术、加密算法I、IS组件、Framework及Windows操作系统是实现数据安全性及数据处理的重要方法与手段;为今后充分利用功能强大的AJAX、SQL Express等新技术工具,开发出高效处理数据的应用程序平台,提供强大的技术支持。     

基于点对点隧道协议的虚拟专网的实现及应用

本文简述了虚拟专用网技术在高校校园网的应用,并结合实际应用情况详细阐述了如何在Linux系统中架设基于PPTP的VPN服务器,解决了校外老师访问校园网资源速度缓慢的具体问题。     

基于VRML的3D虚拟景区系统的设计与实现

虚拟景区漫游是虚拟现实在旅游领域的一个应用,是利用虚拟现实技术和计算机图形学等技术实现对景区场景的仿真再现、对景区进行交互式的浏览,是旅游宣传中的有效手段。本研究对虚拟景区系统的三维建模方法、渲染、实现动态与互动的过程提出了见解,并实现了3D虚拟清明上河园系统的设计。     

基于Struts和Hibernate框架的本科生管理信息系统的开发

阐述了MVC模式以及Struts框架、Hibernate构架结构的原理实现过程。在此基础上,探讨了Struts和Hibernate相结合的关系及其系统开发的特点,设计了整合Struts和Hibernate框架技术的本科生管理信息系统的J2EE架构,最后以系统中一个模块的实现为例说明系统开发过程。     

全球河流输沙量分布格局及其影响因素

研究河流输沙量具有重要的理论和实践意义。近60年在气候变化和人类活动日益增强的背景下,全球众多河流输沙量都发生显著变化。基于全球河流输沙量数据库和区域河流输沙量研究成果,从全球尺度对全球河流输沙量现状、输沙量空间分布格局及其影响因素、输沙量变化及其影响因素3方面进行分析研究。结果表明:(1)全球河流年均总输沙量在2×10~(10) t左右,对全球主要36条河流输沙量数据分析表明大多数河流输沙量显著减少;(2)地质地貌条件是河流输沙量控制性因素,气象水文条件和人类活动对河流间输沙量差异的贡献大致相当;(3)对各气候带的代表性河流研究表明,相比较气候变化,全球河流输沙量变化主要受人类活动的影响。未来全球河流总输沙量会因人类活动尤其是大坝建设的影响而继续减少。     

Addition of Sodium Stearoyl Lactylate to Corn and Sorghum Starch Extrudates Enhances the Performance of Pregelatinized Beer Adjuncts

Double mashing for wort production is a time‐consuming process that can be reduced if pregelatinized adjuncts are used. Optimal extruding conditions were determined to obtain brewing adjuncts from corn and sorghum starch. For corn starch extrusion, a Box–Behnken design was devised in which moisture, screw speed, temperature of the barrel, and concentrations of sodium stearoyl lactylate (SSL) were varied, and sorghum starch was extruded according to a 2³ model in which the modified variables were moisture, SSL concentration, and temperature. The aim was to maximize starch damage and minimize resistant starch and final viscosity as determined with a Rapid Visco Analyzer. The treatments that satisfied these requirements were mashed, and wort extract yield was determined. Glucose, maltose, and maltotriose concentrations in the resulting worts were determined by HPLC with a refractive index detector. Feedstock tempering and SSL content were the most important factors affecting the response; for corn starch, treatments with lower moisture (20%) and middle levels of SSL (0.5%) or with high levels of both moisture (40%) and SSL (1%) produced the most desirable samples for mashing, whereas for sorghum starch the best treatment was tempering to 20% moisture and containing middle levels of SSL (0.5%). No statistical differences were found between these experimental treatments and the control.     

乌兰布和沙漠绿洲农田不同土地利用方式地表风蚀特征研究

土壤风蚀是干旱地区绿洲农田开发的一个突出生态问题,如何针对不同的立地单元采取保护性措施是人们长久以来关注的重点。本文选择乌兰布和沙漠绿洲农田流沙地、沙质耕地、黏质耕地、撂荒耕地及留茬地5种典型土地利用方式,对其风速特征、地表蚀积量进行野外原位测定,并分析了不同下垫面的地表粗糙度和沉积土壤粒径特征。结果表明:研究区土壤颗粒组成以细砂含量占主导地位,粉粒、中砂与粗砂含量相对较低。与对照相比,各土地利用方式均能有效增加地表粗糙度,表现为:留茬地(0.32 cm)撂荒耕地(0.29 cm)沙质耕地(0.25 cm)黏质耕地(0.19cm)流沙地(0.02 cm)。土壤风蚀深度整体表现为流沙地沙质耕地撂荒耕地黏质耕地留茬地,5种利用方式下,留茬地风蚀程度最轻,风蚀深度仅为0.04 cm/d,分别较流沙地、沙质耕地、黏质耕地及撂荒耕地降低了99.03%、96.83%、94.29%与90.24%。因而,留茬地具有较好的防风蚀效益,是一种值得推广的土壤风蚀防治措施。     

An emerging energetic soil contaminant,CL-20, can affect the soil invertebrate community in a sandy loam soil

We investigated the effects of nitramine explosive CL-20 (China Lake compound 20) on the indigenous soil invertebrate community in Sassafras sandy loam (SSL) soil using a 12-week soil microcosm assay. Freshly collected SSL soil was amended with CL-20 to prepare multiple treatment concentrations ranging from 0 (acetone control) to 10,300 mg kg⁻¹. The selected concentration range of CL-20 adequately assessed the concentration–response relationships for total microarthropods, and for individual microarthropod groups. The overall composition of microarthropod community in SSL soil was not affected by exposure to CL-20, based on the number of taxonomic groups present in the individual treatments after 12 weeks. However, community structure analysis revealed greater sensitivity to CL-20 by predatory mesostigmatid mites. Microarthropod and nematode communities showed contrasting sensitivities to CL-20 in SSL soil. Total numbers of nematodes were either unaffected or significantly (p < 0.05) increased in CL-20 treatments compared with control. Only predator group among nematodes was consistently adversely affected by exposure to CL-20. The abundance of predatory nematodes decreased in a concentration-dependent manner throughout the 12-week exposure. Microcosm assay with corresponding community structure analysis can provide the means for validating the ecotoxicity data from standardized laboratory tests, both complimenting and expanding upon the ecotoxicological significance of data from standardized single-species toxicity tests.     

Toxicity of chemical-warfare agent HD to Folsomia candida in different soil types

We investigated the ecotoxicity of the chemical-warfare agent (CWA) HD (Mustard) using Collembola reproduction test with numbers of adults and juveniles as measurement endpoints. Toxicity tests were conducted using soils with contrasting parameters to investigate the effects of soil properties on chemical toxicity. These included standard artificial soil (SAS; 10% OM; 6 pH), O’Neill-Hall sandy loam (OHSL; natural soil with 4.3% OM; 5.1 pH), and Sassafras sandy loam (SSL; natural soil with 2% OM; 4.9 pH). Soils were individually spiked with HD concentrations ranging from 1 to 125 mg kg^–1. Lowest observed effect concentrations (LOECs) for adult mortality were 25, 50, and 6.97 mg kg^–1 for SAS, OHSL, and SSL, respectively. The LOECs for reproduction were 6.97, 6.25, and 1.9 mg kg^–1 for SAS, OHSL, and SSL, respectively. HD toxicity to both adults and juveniles was greater in SSL. These results show that soil toxicity testing should not rely solely on the adult acute endpoints using artificial soils, but should include assays with reproductive endpoints using natural soils with varying physical and chemical parameters to adequately assess toxicity to test species.     

Toxicity of chemical warfare agent HD (mustard) to the soil microinvertebrate community in natural soils with contrasting properties

A microcosm technique was used to determine the ecotoxicity of the chemical warfare agent HD (mustard) to the indigenous soil microinvertebrate communities. HD was thoroughly incorporated into Sassafras sandy loam (SSL) soil (4.9% OM) and an oak-beech forest silt loam soil (FS, 16% OM) at nominal HD concentrations ranging from 6 to 1076 mg kg⁻¹. After a 7-day incubation period, microarthropods were extracted from soils using a high-gradient extractor and sorted to Acari suborders Prostigmata, Mesostigmata, and Oribatida, and the insect order Collembola. Nematodes were extracted using Baermann funnels and were sorted into bacterivore, herbivore, fungivore and omnivore/predator trophic groups. Microarthropods were more sensitive to HD in both soil types compared with nematodes. The EC₅₀ values for total numbers of microarthropods in SSL and FS were similar (65 and 71 mg kg⁻¹, respectively). The EC₅₀ values for total numbers of nematodes were 130 and 235 mg kg⁻¹, respectively. Toxicity of HD to nematodes was significantly greater in SSL soil compared to FS, based on 95% confidence intervals. Results show that community-level assessment of chemical toxicity in soil using a microcosm assay is sufficiently robust and can provide the means for validating the ecotoxicity data from standardized laboratory single-species toxicity tests.