超关系Ri的性质

In this paper we discuss the basic properties of hyper relation Ri， which is upgraded from the base relation R. The relationship between Ri and R is considered.     

用迁移实现局域网由低版本向高版本升级

Novell网络以其安全性好、硬件投资少、易于维护的特点而著称,但随着公司的不断发展,原有系统已经不能满足实际的需要,因此,许多企业已对其原有网络系统进行了升级或正准备升级。在这种情况下,介绍本单位对网络系统升级的一种方法供大家参考。     

域名系统在校园网中的应用探讨

介绍了域名系统及其在校园网中的作用 ,并结合笔者在校园网网管的工作经验 ,针对校园网域名系统在运行过程中遇到的问题进行了分析     

分布式环境下 C/S模式客户端软件自动在线升级的设计与实现

通过分布环境下C/S模式软件在线自动升级的实现,揭示了在必须采用C/S模式实现业务应用时进行软件及时的自动升级的可行性。在具体应用环境下克服了C/S模式部署困难,升级不方便,维护成本高几个不利的因素,将客户端描述文件中的程序最近一次更新日期或版本号与服务器端升级程序的最近一次更新日期或版本号进行比较,使系统自动感知新程序的存在,在设计上采用首启动探寻式最新版本更新,克服了定时探索新版所带来的网络资源的消耗,对打造多元化综合软件应用架构进行了积极的探索与应用。     

Online upgrading of organic vapors from the fast pyrolysis of biomass

The online upgrading process that combined the fast pyrolysis of biomass and catalytic cracking of bio-oil was developed to produce a high quality liquid product from the biomass. The installation consisted of a fluidized bed reactor for pyrolysis and a packed bed reactor for upgrading. The proper pyrolysis processing conditions with a temperature of 500℃ and a flow rate of 4m3·h-1 were determined in advance. Under such conditions, the effects of temperature and weight hourly space velocity (WHSV) on both the liquid yields and the oil qualities of the online catalytic cracking process were investigated. The results showed that such a combined process had the superiority of increasing the liquid yield and improving the product quality over the separate processes. Furthermore, when the temperature was 500℃, with a WHSV of 3h-1, the liquid yield reached the maximum and the oxygenic compounds also decreased obviously.     

无线网络控制器升级引发信令负荷过载的解决方案

针对无线网络控制器(RNC)升级重启后导致核心网出现2次信令负荷过载现象,分析造成信令过载的原因,并对各端口进行测算,最后对规避过载情况提出了有效的解决方案.     

矿区地上下三维信息模型构建算法与系统开发

研究了地上三维场景模型与地下三维矿体模型的构建方法,提出了基于散点构网的地质实体充填算法模型.结合地理信息系统的建设方法,以辽宁某铁矿为原型,开发了其地上下三维可视化信息系统,实现了各类三维模型的创建、三维显示与浏览、空间属性查询、交互操作、测量与空间分析等功能.系统既实现了地上下三维模型的快速建立,又解决了以往三维模型中只能显示,不能查询、量测、编辑等问题,可以宏观地把握、微观地洞察矿区地上下整体地形地质特征和地理信息空间分布,更客观全面地表达矿山三维地理信息实体,可作为数字矿山、智能采矿的基础.     

加快建设东莞现代产业体系研究

现代产业体系是一个历史的和区域的概念。未来广东现代产业体系将是第三产业比重较快提高;传统产业与现代产业同时并存,融合生长;产业集群协调配合;社会市场环境配套的产业体系．现在东莞基本上建成了现代产业体系的基础。表现为三次产业结构快速改善;技术创新能力有一定基础;优势传统产业品牌逐步建立;产业集群已经形成;配套环境基本具备。要建成东莞现代产业体系还必须在技术、成本、新增长点、市场营销、人居环境、人才、创业、制度等方面创造新的竞争优势。     

NSCL-Ongoing activities and future perspectives

Michigan State University’s NSCL (National Superconducting Cyclotron Laboratory) is funded by the US National Science Foundation to operate the premier rare isotope user facility in the US. Beams of rare isotopes at NSCL are produced via projectile fragmentation or fission and separated in-flight. The current NSCL facility capabilities and main research directions will be outlined. The laboratory is currently expanding its capabilities by building an efficient gas-stopping and reacceleration capability initially up to 3.2 MeV per nucleon. For the longer term future, NSCL is proposing to replace the existing superconducting cyclotrons with a high-intensity, 200 MeV per nucleon superconducting heavy-ion linac.     

Oligomerization,Isomerization and Carboxylation of Alkanes and Alkenes with Galvanostatically Generated Superoxide in the Al/O2 Electrochemical Cell

Conversion of low‐value, but thermodynamically stable chemical byproducts such as alkanes or CO₂ to more valuable feedstocks is of broad‐based interest. These so‐called up‐conversion processes are expensive because they require energy‐intensive and catalytic interventions to drive reactions against thermodynamic gradients. Here we show that the nucleophilic characteristics of superoxides, generated galvanostatically in an Aluminum/O₂ electrochemical cell, can be used in tandem with the intrinsic catalytic properties of an imidazolium/AlCl₃ electrolyte to facilely upgrade alkanes (n‐decane), alkenes (1‐decene), and CO₂ feedstocks. The aluminum/O₂ electrochemical cell used to generate the superoxide intermediate is also reported to deliver large amounts of electrical energy and therefore offers a system for high‐energy density storage and for chemical up‐conversion of low‐value compounds. Chronopotentiometry, mass spectrometry and nuclear magnetic resonance were used to investigate the electrochemical features of the system and to analyze the discharge products. We find that even at room temperature, alkanes and alkenes are facilely oligomerized and isomerized at high conversions (>97 %), mimicking the traditionally produced refined products. Incorporating CO₂ in the alkane feed leads to formation of esters and formates at moderate yields (21 %).