单纯疱疹病毒Ⅰ型(HSV—1)基因突变株的生物学特性初步研究

应用病毒空斑滴定法及动物LD_(50)法对HSV-1基因插入突变株[HSV-1(RC)]的生物学特性进行了初步研究。发现HSV-1(RC)株在不同的6种细胞系上能够生长繁植,但在BHK-21、Hep-2细胞上较其亲代HSV-1(Δ305)及HSV-1(F)株生长缓慢,且空斑形成单位(pFU)数明显低于亲代株。动物LD_(50)实验结果HSV-1(F)株LD_(50)值为2.9×10~4pFU/0.1ml,而HSV-1(6305)及HSV-1(RC)LD_(50)值为0。实验结果提示:HSV-1基因组BamHI C片段插入突变处不是该病毒在一些细胞培养上生长所必需的基因片段,但对在某些细胞系上的生长仍具有影响作用。HSV-1的TK基因和BamHI C片段插入突变处则是病毒在动物整体上毒力强度的必需基因。在HSV-1基因组BamHI C片段处插入9.7kb大小的外源基因并不影响病毒在细胞上的组装和繁殖,但其毒力降低,建立的实用空斑滴定技术适用于病毒学研究,有推广应用价值。     

考虑结构性的土体本构模型的建模方法

土体的结构性模型是土力学的核心问题.本文根据不同的模型理论和方法,把土体的结构性模型分为复合体本构模型、微观力学本构模型和土体的塑性理论模型,并对各个模型的研究现状、建模的思路与实质进行研究.     

各向异性复合材料内界面裂纹接触区尖端处的应力奇异性问题

在外载荷的作用下,各向异性复合材料内界面裂纹区呈现多种情况。本文应用Stroh公式讨论了裂纹尖端区的应力奇异性。     

悬索桥的非线性自由振动方程

本文给出了悬索桥横向—竖向—扭转耦合非线性自由振动的一般微—积分方程,通过引入无量纲量,得到了无量纲化方程,通过用线性问题主模态来表示解的表达式,得到N—耦合的二阶非线性常微—积分方程的三个方程组。     

Radar Emitter Signal Recognition Based on Complexity Features

Intra-pulse characteristics of different radar emitter signals reflect on signal waveform by way of changing frequency, phase and amplitude. A novel approach was proposed to extract complexity features of radar emitter signals in a wide range of signal-to-noise ratio ( SNR), and radial basis probability neural network (RBPNN) was used to recognize different radar emitter signals. Complexity features, including Lempel-Ziv complexity (LZC) and correlation dimension (CD), can measure the complexity and irregularity of signals, which mirrors the intra-pulse modulation laws of radar emitter signals. In an experiment, LZC and CD features of 10 typical radar emitter signals were extracted and RBPNN was applied to identify the 10 radar emitter signals. Simulation results show that the proposed approach is effective and has good application values because average accurate recognition rate is high when SNR varies in a wide range.     

THE APPLICATION OF STATISTICAL PARAMETERS OF PHASE RESOLVED PD DISTRIBUTION TO AGING EXTENT ASSESSMENT OF LARGE GENERATOR INSULATION

Agingextentassessmentofgeneratorinsulationisofgreatsignificanceinplanninganeffectiveout ageandmaintenance .Inthelastdecade ,agingex tentassessmentoflargegeneratorinsulationwasasubjectresearchedintensively[1-4] .Anumberofpa pershavebeenpublishedonthetechniquesofinsu lationconditiondiagnosisandagingextentassess mentofgeneratorinsulation .Nearlyalleffortsforinsulationdiagnosisandagingassessmenthavereliedonelectricalmeasurementsandmostattentionhasbeenpaidtoanalysisofcharacteristicsofpartialdis cha…     

A MIXED LUBRICATION MODEL MODIFIED BY SURFACES'''' FRACTAL CHARACTERISTICS

Since 1978,theaverageflowlubricationmod el,i .e .Patir Chengequation[1] ,hasbeenwidelyusedinsolvingforthelubrication problemofabearingandthetribology systeminacylinder pis ton .However ,valuesoftheflowfactorsintheequation ,suchaspressureflowfactor ,aremeasuredonthebaseofroughness ,whichisvariablewithmeasuringscale .Since 1980s ,fractalgeometryhasgreatlydeveloped .Fractalistheintrinsicandglobalpropertiesofthematerialismwithfractalandinde pendentofameasuringscale .Also ,itwasverifiedthatsomemac…     

确定双三次Coons曲面边界切矢的一种新方法——三点圆法

双三次Coons曲面是Coons曲面中最有实用价值的一种,给定型值点和边界条件即可绘制该曲面,但在实用中给定边界条件往往很困难,本文提出一种新的方法——三点圆法来确定双三次Coons曲面的边界切矢,该法直接利用已给的型值点确定边界切矢,不仅几何意义明确,而且便于计算,并在IBM微机上用BASIC语言编程实现了这种算法,效果良好。     

ANTITUMOR MECHANISM OF GEM10 BY THE NATURAL KILLER ACTIVITY AND INTERLEUKIN-2 PRODUCTION

Studiesongermaniumcompoundsshowedthattheyhavemanybiologicaleffects ,suchasanti tu mor[1] ,improvingimmunity[2 ] ,reducingthecon centrationofbloodcholestrolandtrilycerides[3] ,in hibitingvirusreproduction ,butthesideeffectsoftoxicrestricttheirclinicaluses[4 ,5] .Therefore ,itisstillnecessarytodevelopothernewcompoundsoforganogermaniums.GeM 10 ,aneworganicgerma niumcompounds alkili metalcomplexcombinedwitheffectiveextractsofsomeChinesetraditionalherbs ,hasbeendemonstratedtobesaferandmorereliable.…     

Distributed Broker-Agent Architecture for Multimedia Communications Traversing NAT／Firewall in NGN

The forthcoming Next Generation Network (NGN) is an all IP network. Multimedia communications over IP networks are a type of bundled session communications, which cannot directly traverse Network Address Translations (NATs) and firewalls even in NGN. To solve the problem that the existing traversal methods are not suitable for service providers to set up a real system in NGN,a Distributed Broker-agent Architecture (DBA) is addressed. DBA is secure and realizable for service providers and enterprises because it is easy to set up and does not need to upgrade the existing devices like Firewalls, NATs or endpoint devices of subscribers.DBA is composed of two-layer distributed agents, the server proxies and the client agents, in which all multimedia communications use shared tunnels to carry signaling messages and media data between broker-agents, and the call signaling is encrypted over Security Socket Layer (SSL) to guarantee the security of calling. Moreover, the function model and multiplexed connection messages format of DBA are designed, which lays a basis for the protocol in the future NGN. In addition, a simple implementation based on H.323 verifyies the main function of traversing firewalls and NATs.