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41.
David M.Piscitello 《信息安全与通信保密》2005,(11):48-49
对于在计算机上秘密和恶意地安装spyware(间谍软件)所带来的安全风险、隐私泄露以及绩效损失,许多用户都只是有一些含糊的认识。只有极少数用户知道spyware所具有的多种形式以及它们所采取的一些非常恶劣的行动,除了泛泛地知道spyware是一种不请自来的、恶意的软件之外,普通用户对其知之甚少。直到最近,人们还是认为spyware的危害比不上病毒和垃圾邮件。但是,我认为Spyware具有比病毒和垃圾邮件更大的威胁。相较于电子邮件信用卡诈骗(phishing),spyware对金融所产生的威胁不仅范围要大得多,也要严重得多。另外, 相似文献
42.
介绍一种双异质结InGaAsP/InP双极晶体管,它包括一层用溅射淀积制备的作宽禁带发射区的CdO膜。电流增益已高达40。用CdO层作集电区时,晶体管还能以相反方式工作。该管的主要特点是在结构方面与可作单片集成的1.5μmDH激光器相容。 相似文献
43.
44.
M.I.Gil' 《Annals of Differential Equations》2004,20(2):145-154
The nonlocal initial problem for nonlinear nonautonomous evolution equati-ons in a Banach space is considered. It is assumed that the nonlinearities havethe local Lipschitz properties. The existence and uniqueness of mild solutionsare proved. Applications to integro-differential equations are discussed.The main tool in the paper is the normalizing mapping (the generalizednorm). 相似文献
45.
M Grupen Shemansky 《电子设计技术》2003,10(10):72-79
随着高速数据接入、传输和存储从高端计算设备和远程SONET(同步光纤网)设备转向便携式计算设备和以太网LAN(局域网)应用的日益广泛.半导体器件在满足日益苛刻的性能要求的同时必须变得更加经济实惠.目前,能以通常高于2.5Gbps速率传输数据的集成电路品种繁多,从数据复用信号发射器到高速物理层结构开关(fabric-switchjng)器件不一而足.前者的信号线、电源线和接地线总共不超过200条,而后者则需要2000多条连接线.在这设备范围的两端,互连电路的衬底的电磁特性会影响产品的总性能.人们追求的目标是价格最低廉、体积最小、性能最可靠的封装,这使这些电磁效应更加严重,并使设计细节更加重要. 相似文献
46.
Confined thin film melt polymerization (CTFMP) of naphthalene chloride/hydroquinone (NCMQ, 1/1, molar)mixtures at polymerization temperatures (T_p) below ca. 300℃ resulted in relatively thick, elongated crystals. Polymerizationof NC/HQ above 300℃ between glass yielded well-formed lamellar crystals ca. 100 A thick. Phase Ⅰ and Ⅱ [001] EDpatterns were obtained for all T_p, the relative amount of phase Ⅰ increasing with T_p. Polymerization of naphthalenedicarboxylic acid/hydroquinione diacetate 1/1 mixtures at high T_p also yielded lamellar crystals that "curled up" off of thesubstrate. When the high temperature CTFMP polymerization was conducted between mica, aggregates of lamellae on-edgedeveloped but epitaxial growth did not occur. Epitaxial growth of lamellae between mica could be obtained, however, byconfined thin film solution polymerization, with both of the latter samples yielding apparently related ED patterns from adifferent unit cell than phase Ⅰ or Ⅱ. Fiber patterns, obtained from sheared samples, indicated considerably greater crystaldisorder than in the nascent crystals. Refinement of the phase Ⅰ unit cell parameters, based on the [001] and [01 1] EDpatterns, with modeling based on Cerius~2, suggests a monoclinic phase Ⅰ unit cell with a = 7.76, b = 5.71, c = 14.99 A, α = γ= 90°, β= 99.7°, ρ = 1.47 g/cm~3, space group P12_1/al. 相似文献
47.
C.M.Lin C.T. Chia Y.J. Shu Y.K. Tseng 《光散射学报》2005,17(3):216-218
Weperformedthehigh-pressureRaman measurementofthethreenanosizedZnOcrystals. Wefoundthesmallerthesize,thehigherthe pressuretoinducethephasetransitionfrom w櫣rzitetorock-saltstructure. High-pressureRamanmeasurementsof nona-shapedZnOcrystalswerepreformed.The… 相似文献
48.
One of the Prussian blue analogs, molecular magnet Cu3^Ⅲ [Fe^Ⅲ (CN)6]2.11.6H2 O, was investigated by Moessbauer spectroscopy. It was found that transition temperature was around Tc = 18.5 K from paramagnetic phase to ferromagnetic phase. The β value of the critical exponent is around 0.338 at magnetic ordering temperature.Therefore, the ferromagnetic coupling interaction of Cu-Fe cyanide could be clearly explained by spin wave theory. 相似文献
49.
Solichová D Melichar B Klejna M Jurašková B Královská L Bláha V Zd'ánský P Zadák Z 《Talanta》2003,60(2-3):459-465
Twelve self-sustaining nonagenarians, 10 women and two men, aged 94+/-3 years, and eight institutionalised nonagenarians, eight women, aged 91+/-1 year as well as 11 control subjects, seven women and four men, aged 84+/-5 years entered the study. Urinary neopterin, an indicator of systemic immune activation, and serum thiobarbituric acid reactive substances (TBARS), a marker of lipoperoxidation, were determined initially, and collection of the blood and urine samples was repeated at 3-month interval. Neopterin was measured in the urine specimens by reversed-phase high performance liquid chromatography. A C(18) reversed-phase column 3.3x150 mm, 5 mum-diameter packing Separon SGX was used. Potassium phosphate buffer (15 mmol l(-1), pH 6.4) at flow rate of 0.8 ml min(-1) was used as mobile phase. After centrifugation (5 min, 1300xg) and diluting 100 mul of urine specimens with 1.0 ml of mobile phase containing 2 g of disodium-EDTA per litre, a 20 mul sample was injected on a column. Neopterin was identified by its native fluorescence (353 nm excitation, 438 nm emission). Creatinine was determined by Jaffé kinetic reaction after dilution of sample 1:50 (v/v). The concentration of neopterin in urine was expressed as neopterin/creatinine ratio (mumol mol(-1) creatinine). TBARS were determined spectrofluorometrically using LS-5 spectrofluorimeter (excitation wavelength 528 nm, emission wavelength 558 nm) after extraction with n-butanol treatment with thiobarbituric acid. The significance of differences between nonagenarians and control group was examined by ANOVA-Kruskal-Wallis tests, using statistical software NCSS 6.0.21 (Kaysville, UT, 1996). The decision on significance was based on P=0.05. Urinary neopterin was significantly higher in institutionalised compared to self-sustaining subjects and controls (625+/-565 vs. 203+/-63 mumol mol(-1) creatinine, and 198+/-128 mumol mol(-1) creatinine, respectively, P=0.006). The serum TBARS were higher in both groups of nonagenarians (3.23+/-1.16 mumol l(-1) and 2.69+/-0.39 vs. 2.12+/-0.83 mumol l(-1) for the self-sustaining, institutionalised and controls, respectively, P=0.023). We conclude that the fluorimetric determinations of urinary neopterin and serum TBARS can be useful for the monitoring health status in the elderly patients. 相似文献
50.