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1.
IntroductionSteelingot.steelslabbecomest6elproductsafterheatingandrollingorforging.Steelproductsofforgingneedtobeheattfeatedinheattreatingfumace,fOrexampleannealingnormalization.Heattreatinentcandecreasestress,reducehydrogenconcentrationandimprovetheorganizationandperformanceofsteel.Everyprocessofproductionthatsteelingotschangeilltosteelproductsisaprocessofthermalcycleofsteel.Thisprocesswillconsumealargeamountofeneasmaterialandequipment.Inthepast,inmetallurgicalenterpriseofourcountrythetimeo…  相似文献   

2.
<正>1.LEF1和Jagged1在人结直肠癌组织中的表达及其意义.王文娟,南克俊,王淑红,胡婷华,姜丽丽,马婕群.2013,34(4):508-511.2.β-榄香烯对体外培养人直肠癌细胞株Colo320的放射增敏作用.陈进才,佘军军,王光辉,韩水平,郑烈瑞.2013,34(3):346-348.3.miR-143和miR-145与肿瘤的研究进展.张林,高林波.2013,34(1):1-6.4.结直肠癌肝转移的危险因素分析.李海军,车向明,贺仕才,龙厚隆.2012,33(4):525-526.5.同时性结直肠癌肝转移同期与分期手术疗效的Meta分析.李宇杰,车向明,甘建新,CHAUDHARY Prakash,廖新华,张丹杰,毕铁强.2012,33(3):365-369.  相似文献   

3.
Introductionetcllneers,recent1.remotelydescribetheirproblemtoagenuinelyproductionsimulationenvironmentfromtheirlocalPC,2.submittheircomptltationaltaskstoapoolofcollaborativecomputerslocatedanywhereinthecountry,3.monitortheircomputationaltasksinteractively,then,4.examinetheirfinalreslllt8locallyfromremotelyavailablegraphicsutilities.ThisisexactlytheenvironmentthatPICMSSaim8toprovide.Todeliversuchcapabilities,thisprojectwillintegrateinnovativesoftwaredesign,computationa1mechanicstheoryandpara…  相似文献   

4.
MyocardiallschemiaandreperfusiondamagehavebeenstudiedfordecadesandmanyexperimentshavetestifiedthatOFRandoverloadofcalciumincellsarethemajorreasonsofthedamage.Seleniumisakindofactiveantioxidantwhereasmagnesiumisthenaturalantagonistofcalcium.SeleniumandmagnesiumcanreducethemyocardialdamagecausedbyOFRandoverloadofcalciumincells.Themodelbe.lugresearchedinthisarticleissetupbyisolatedperfusionofrat'shearts.ActivityofGPXandSODandquantityofMDA,selenium,magnesiumandcalciumintheliquidcollectedfrom…  相似文献   

5.
Lumbardischerniationisthemostcommoncauseoftheachingwaistsandlegs.Anaccuratediagnosisisnecessarytorighttreatment.Beforeoperation,electrophysiologicalexaminationisthebestsupplementarytoimageology.Itcanhelpustodiagnosetheradiculopathycausedbytheoccupativediseasesorthenon--occupativediseases.andtoevaluatetheprognosis.Magneticstimulation,asanon-invasiveelectrophysiologictechniquehasbeenusedintheclinicaldiagnosisoflumbardischerniationtl~4).Yetuptonow,therehasbeennounanimousviewpointuponthelocationo…  相似文献   

6.
Introduction Inthresholddecryptioncryptosystems,the powertodecryptissharedamongasetofdecryp-tionservers.In2001,D.BonehandM.Franklin proposedapracticalidentity-basedencryption(IBE)schemefromtheweilpairing.Combining thetwoconceptstogether,some“ID-basedthresh-olddecryption”schemeshavebeenconstructed.In suchschemes,anentity'spublickeyisderiveddi-rectlyfromitsidentity.Atrustedthirdparty calledtheprivatekeygenerator(PKG)usesthe masterkeytogenerateprivatekeysforallentities.Eachdecryptionserve…  相似文献   

7.
(按栏目编排)专家述评胡海涛,董炜疆.阿尔茨海默病防治研究的现状与展望.2007,28(1):1杜晓军,周娟.松弛素在心血管疾病中的作用及临床治疗展望.2007,28(2):117朱本章,蒲丹.自身免疫病的生物学治疗进展.2007,28(3):233邱曙东,周党侠.男性不育机制部分研究热点的探讨.2007,28(4):349石景森,孙学军.原发性胆囊癌诊治的历史、现状及展望.2007,28(5):473龚均,张茹.胆汁反流与食管黏膜上皮损伤的研究进展.2007,28(6):605论著杨蓬勃,王唯析,张建水,等.Meynert核毁损大鼠海马结构内胆囊收缩素阳性神经元的变化.2007,28(1):6刘朝晖,杨宇,庄鹏辉,等.…  相似文献   

8.
<正> 患者,男,26岁.左上腹包块2月.于1987年8月20日住院.既往体健.查体:一般情况可.肝脏剑下3cm,轻压痛.脾脏上界在左锁骨中线第5肋间,下界甲乙线8cm.甲丙线12cm,质韧.B超检查:肝脾增大.胸部X线片无异常.实验室检查:血色素69g/L,红细胞2×10~4个/L,白细胞6.1×10~9个/L,中性64%.免疫功能检查无异常.骨髓呈贫血性改变.初步诊断:脾功能亢进,行脾切除术.  相似文献   

9.
ThisprojectissupportedbyChineseMedicalBoard(U.S.A)In1990,EisenbergisolatedacDNAfromthehumanmonocytelibrary,expressionofthecDNAinE.coltyieldedtheproteinthatcouldhinderIL--lbindingIL--lreceptor,hetermedtheproteininterleukin--1receptorantagonist(IL--lra)ti.23.IL--lraisauniquecytokinethatcanstronglybindthecellsurfacereceptorsofIL--Iwithoutinducinganydetectableintracellularresponses"'.SinceitisaneffectivecompetitiveinhibitorofIL--lbothinvitroandinvivot'3,IL--lraisausefultooltodetermineth…  相似文献   

10.
Rotavirusisonekindofintestinalviruswhichmaycausechildrendiarrhea.Thegenemapofro-tavirusconsistsof11RNAhelix.RotavirusA,BandCtypesaremainlyetiologycausingdiarrheainhuman.TheimmunomethodsofELISAandRIAhavebeenappliedinclinictodetectrotavirusformanyyears"'-Recently,mo1ecularbiologytech-niqueshavebeendeveloped,andrnoresensitivemethodssuchasacidhybridizationandPCRhavebeenappliedtodetectrotavirus.PCRisconsideredasthemostsensitivemethod.Ithasbeendemon-stratedthatPCRhas5OOOtimessensitivethan…  相似文献   

11.
为抵御虫洞攻击,改善定位性能,提出了一种基于安全邻居发现的抗虫洞攻击DV-HOP (distance vector-Hop)算法(secure neighbor discovery based DV-HOP, NDDV).该算法基于虫洞攻击时网络节点间通信跳数出现的异常,依据节点间路径跳数差异检测虫洞,通过搜索发现、滤除各虚假链路,以保障DV-HOP跳数跳距的准确性,减轻虫洞攻击的影响,提升节点定位精度.以变化参考节点比例的方式,对144个节点进行150次定位仿真实验,结果表明,平均节点度数达到5以上,NDDV即能有效滤除虫洞链路,提升节点定位精度;同等定位精度的情况下相比LBDV (label-based DV-HOP localization against wormhole attacks)算法所需的参考节点比例平均低约17.5%.   相似文献   

12.
为了解决无线传感器网络定位过程中的常见安全问题,提出了一种抗攻击的定位方法.该方法通过高效的认证机制和检测机制帮助待定位节点验证信标节点的合法性及检测定位信息的可靠性,筛选出值得信赖的定位信息用于节点的定位计算,能够有效抵御定位过程中的女巫攻击和虫洞攻击.实验结果验证了该方法能够在存在安全威胁的网络环境下,有效提高无线传感器节点的定位精度.  相似文献   

13.
针对移动自组网复杂多变的无线信道,提出基于接收信号功率强度的链路层发送功率控制方法,通过在物理层和链路层添加针对信号功率的分析和交互功能,实现通信双方自适应的功率协调控制,确保节点的接收功率处在合理的区间,以实现良好的通信性能。通过在NS-2环境下进行仿真实验,分析了该功率控制方法在功率节省和网络性能提升上的有效性。  相似文献   

14.
为克服大部分现有的认证群密钥协商(AGKA)协议的不足,基于双指数挑战-应答数字签名(DCR签名)和BD方案,提出了具有常数轮AGKA协议.该协议除具有相关AGKA协议的安全性外,还有抗临时秘密指数泄露攻击能力,效率也有所提高.  相似文献   

15.
IntroductionIn many modern collaborative and distributedapplications such as multicast communication, au-dio-video conference and collaborative tools, scal-able and reliable group communication is one of thecritical problems. A group key agreement (GKA)protocol allows a group of users to share a key,which may later be used to achieve some crypto-graphic goals. In addition to this basic tool an au-thentication mechanism provides an assurance ofkey shared with intended users. A protocol achiev…  相似文献   

16.
随着客运专线网络的逐渐完善,人们对其可靠性也提出了更高要求。利用复杂网络理论对客运专线网络的可靠性进行分析,有利于发现网络中的关键节点及薄弱环节,从而有针对性地对网络进行完善。基于复杂网络理论,建立客运专线网络模型,并计算该复杂网络模型的静态统计特征,包括度分布、聚类系数和平均路径长度,得出客运专线网络是典型的无标度复杂网络。分别在随机性攻击和选择性攻击两种模式下,从网络的全局效率和最大连通子图的相对大小两个指标,对客运专线网络的可靠性进行分析,得知客运专线网络对随机性攻击的抗破坏能力较强,而对选择性攻击的抗攻击能力较弱,最后提出了提高客运专线网络可靠性的建议。  相似文献   

17.
This paper proposed two modifications on IKE protocol with pre-shared key authentication. The first modification can improve its immunity against DDoS attack by authenticating the initiator before the responder generates the computation-intensive Diffie-Hellman public value. The second modification can improve its efficiency when the attack on messages occurs because it can detect the attack quickly by replacing the centralized authentication in origical IKE protocol with immediate authentication. In addition, the two modifications can be integrated into one protocol compactly.  相似文献   

18.
具有可追查性的抗合谋攻击(t,n)门限签名方案   总被引:5,自引:0,他引:5  
在分析王斌和李建华的无可信中心门限签名方案(王-李方案)以及X ie-Yu改进方案安全缺陷的基础上,提出了一种新的具有可追查性的抗合谋攻击(t,n)门限签名方案;对新方案的安全性进行了分析,并与现有方案的效率进行了比较.结果表明:该方案不仅能够从根本上抵抗合谋攻击和伪造签名攻击,而且在保证匿名性的前提下,能够真正实现签名成员身份的可追查性,同时通过构造安全的分布式密钥生成协议保证群私钥的不可知性,因此比现有方案具有更高的安全性.此外,新方案的计算量和通信量与王-李方案接近,但优于X ie-Yu方案.  相似文献   

19.
An improved scalar Costa scheme (SCS) was proposed by using improved Watson perceptual model to adaptively decide quantization step size and scaling factor. The improved scheme equals to embed hiding data based on an actual image. In order to withstand amplitude scaling attack, the Watson perceptual model was redefined, and the improved scheme using the new definition can insure quantization step size in decoder that is proportional to amplitude scaling attack factor. The performance of the improved scheme outperforms that of SCS with fixed quantization step size. The improved scheme combines information theory and visual model.  相似文献   

20.
With increased cyber attacks over years,information system security assessment becomes more and more important.This paper provides an ontology-based attack model,and then utilizes it to assess the information system security from attack angle.We categorize attacks into a taxonomy suitable for security assessment.The proposed taxonomy consists of five dimensions,which include attack impact,attack vector,attack target,vulnerability and defense.Afterwards we build an ontology according to the taxonomy.In the ontology,attack related concepts included in the five dimensions and relationships between them are formalized and analyzed in detail.We also populate our attack ontology with information from national vulnerability database(NVD)about the vulnerabilities,such as common vulnerabilities and exposures(CVE),common weakness enumeration(CWE),common vulnerability scoring system(CVSS),and common platform enumeration(CPE).Finally we propose an ontology-based framework for security assessment of network and computer systems,and describe the utilization of ontology in the security assessment and the method for evaluating attack efect on the system when it is under attack.  相似文献   

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