一种用于野战通信的多功能程控交换系统

本文介绍一种具有话音和数据交换功能且具有多种用户接口的多功能交换系统。着重介绍该系统在结构上与一般空分程控用户交换机的不同之外,以及实现本系统的技术难点和所采取的技术措施。     

Radiative forcing due to dust aerosol over east Asia-north Pacific region during spring, 2001

Atmosphericaerosolsinfluencetheradiationbudgetoftheatmosphere-terrestrialsystem,andthereforeinflu-encetheclimate.Dustaerosolisconsideredtobeacriticalfactortoclimateforcingamongotherkindsofaerosols,whichaccountsfor30percentofaerosolloadingandop-ticaldepth[1].Therearelargeuncertaintiesinthequantita-tiveassessmentsoftheradiativeeffectofdustatthepre-sentday,involvingvariousfactors:refractiveindices,par-ticlesizedistribution,atmosphericaerosolloading,parti-cleshape,etc.[2].Dustaerosolgenerallyorigi…     

3,5—二甲氧基苯甲醛的合成

以对硝基甲苯为原料,经化还原,溴化,重氮化去氨基,甲氧基化反应制得到３,５－二甲氧苯甲醛,总收率在５１％以上。     

危害新疆西瓜的一种线状病毒的研究

从新疆染病的西瓜分离到一种线状病毒,该病毒可经汁液传播侵染属于６个科的１７种草本植物;染病的西瓜、哈密瓜和西葫芦引起植株生长阻滞、叶片皱缩、褪绿、泡斑、黄花叶以至坏死等系统侵染症状;该病毒可经桃蚜以非持久性方式传播;该病毒的病毒粒子为长约７５０ｍｍ的线形病毒粒子,在染病组织中形成风轮状内含体,证明该病毒属于马铃薯Ｙ病毒组;染病组织粗汁液提纯病毒制备物在ＳＤＳ双向免疫扩散试验中与小西葫芦黄花叶病毒抗     

永磁钡铁氧体制备的新途径

以炼钢烟尘为原料制作永磁钡铁氧体,通过掺杂改善制备中的固相反应;通过控制气氛与温度控制物料间的相反应;通过对原料的活化和晶型转化使形成永磁钡铁氧体所需要的晶型,采用Ｘ射线分析,电子衍射和显微形貌分析等方法,阐述了永磁钡铁氧体在制备过程中各种因素的作用和相互影响。     

饭豆铜锌超氧物歧化酶的纯化及性质

饭豆种子粗提液中有６条Ｃｕ·Ｚｎ—ＳＯＤ活性谱带，经氯仿－乙醇混合液处理，硫酸铵盐析，ＳｅｐｈａｄｅｘＧ－１００凝胶过滤和ＤＥＡＥ－纤维素柱层析被分离，获得了两组ＳＯＤ同工酶组分（ＳＯＤ—１，ＳＯＤ—２）．它们在酶分子结构上可能存在一定差异．ＳＯＤ－１含与粗提液相对的、电泳迁移率较小的活性谱带，它在聚丙烯酰胺凝胶电泳（ＰＡＧＥ）图谱上的活性染色带和蛋白染色带相互对在；在ＳＤＳ－ＰＡＧＥ和等电聚焦电泳图谱上均呈现单一区带，说明该酶已纯化到均一程度．该酶分子量为３１３００，亚基分子量为１６５００，等电点为４．２，在紫外区的吸收值为２６４．０ｎｍ．该必在０—７５℃范围内稳定．纯化的ＳＯＤ—１比活性为１７８９Ｕ／ｍｇ，ＳＯＤ—２比活性为２８４Ｕ／ｍｇ，ＳＯＤ活力回收率为３２％．     

有保护膜的Bi_2O_3基稀土固体电解质

用在掺有Ｙ￣（３＋），Ｇｄ￣（３＋）稀土离子的Ｂｉ＿２Ｏ＿３基电解质陶瓷样品表面镀氧化钇稳定的氧化锆膜，改善电解质的性能。制作了能在中温下工作的固体电解质燃料电池。     

不可压缩粘性流体同阶插值有限单元的讨论

本文讨论了有限元分析中粘性不可压缩流体原始变量法构造同阶插值单元的困 难，应用通常构造单元的方法，速度和压力采用同阶插值时，直接违反了ＬＢＢ条件 中秩的必要条件，从而出现伪压力横式和整体离散线性方程组不定解等问题，针对 这些问题，本文提出一种构造单元的方法，以六节点三角形单元（ＭＰ－）为例，通 过若干数值算例和部分理论分析，说明了这种方法用于构造同阶插值单元是有效的。     

Interaction of hepatitis B virus with tumor suppressor gene p53: its significance and biological function

The mechanism of the interaction of hepatitis B virus (HBV) with tumor suppressor p53 and its role in the hepatocar-cinogenesis have been studied by PCR-directed sequencing, gel shift assays and in situ ultraviolet cross-linking assay. The biological function of the interaction of HBV with p53 gene was investigated by co-transfection of chloramphenicol acetyltransferase ( CAT) reporter gene. p53 and HBV DNA. and quantitative PCR. Among the 16 primary hepatocellular carcinoma (PHC) samples. 13 were HBV-DNA positive. 10 HBxAg positive and 9 p53 protein positive. The p53 gene point mutation was found in 5 samples, one of which had a G to T substitution located at codon 249. After analyzing the HBV genome by a computer program, a p53 response element binding sequence was found in HBV genome at upstream of enhancer I. from 1047 to 1059 nucleotides. This sequence could specifically bind to p53 protein, increase p53 protein accumulation in the PHC cells and stimulate the transactivating activity of p53 and HBV replication . The results also revealed that HBxAg could combine with p53 protein to form a complex in the cells and enhance CAT expression. Immunocytochemical staining showed that p53 protein complex was located in the cytoplasm and the process of p53 entry to nuclei was. in part, blocked. From our results, we conclude that the mutation of p53 gene at codon 249 is infrequent in HBV-associated PHC. the DNA-protein binding between HBV and p53. and the protein-protein binding between HBxAg and p53 might lead to the reduction or inactivation of p53 protein, which in turn resulting in HBV-associated hepatocarcinogenesis.     

当前三大主流磁盘阵列系统的技术比较

在介绍当前三大主流磁盘阵列系统：DASraid、SANraid和NASraid的基础上，把SANraid分别与DASraid、NASraid作技术比较，得出DASraid安全性高、造价低，但连接距离短、工作效率和业务持续性不高；NASraid技术成熟、成本低廉、安装配置快捷方便，但性能略逊于SANraid；SANraid有长距离连接、容错容灾、高可用性、集群共享、高伸缩性、扩充性及保障投资等特性，但造价高昂。然后结合广西发展计划委员会电子政务系统建设，说明SANraid更适合投入大且性能要求高的行业，NASraid则适用于性能要求次一级的行业，而DASraid目前在国内许多一般性的行业中仍得到广泛的应用。