399 resultados para AK15-1363


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目的:比较大蹼铃蟾抗菌肽- 2 (Maximin 2) 与肿瘤坏死因子2α(TNF2α) 、干扰素2α22b ( IFN2α22b) 对不同膀胱癌细胞株的抑制杀伤作用。方法:采用细胞培养及MTT 比色法,检测Maximin 2 、TNF2α及 IFN2α22b 对3 个不同膀胱癌细胞株的抑制作用及作用特点,计算量效回归曲线及50 %抑制率。结果: Maximin 2 对不同的膀胱癌细胞株在100μgPmL 左右(48 h) 即达到50 %抑制率浓度( IC50) ,并呈剂量相 关性,与TNF2α、IFN2α22b 抑制作用的表现形式不同。Maximin 2 抑制率最高表现在第48 h ,以后逐渐减 弱, TNF2α、IFN2α22b 则在前24 h 作用较弱,以后逐渐增强。结论:Maximin 2 对不同的膀胱癌细胞株均 有较强的抑制作用,同TNF2α、IFN2α22b 比较其作用机制有所不同,Maximin 2 对膀胱癌细胞株的杀伤作 用可能主要是通过对肿瘤细胞的直接抑制,并且相对容易失活。

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应用CB-HRP溶液注入母鸡输卵管子宫部浆膜下,四甲基联苯胺(TMB)组织化学呈色,以探察母鸡输卵管子宫部初级感觉神经元的定位。结果表明:母鸡输卵管子宫部的初级感觉神经元位于双侧T1-LS13脊神经节、颈静脉神经节和结状神经节。标记细胞数分布不均,在体左侧多于体右侧,在脊神经节多于颈静脉神经节和结状神经节。在脊神经节内标记细胞有T5-LS1和LS8-LS11前后两个相对集中区,峰值分别在T7和LS11。说明尽管母鸡输卵管子宫部是单侧发育成熟脏器,但其感觉沿双侧脊神经和迷走神经传入中枢,以体左侧传入为主;且

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Web services can be seen as a newly emerging research area for Service-oriented Computing and their implementation in Service-oriented Architectures. Web services are self-contained, self-describing modular applications or components providing services. Web services may be dynamically aggregated, composed, and enacted as Web services Workflows. This requires frameworks and interaction protocols for their co-ordination and transaction support. In a Service-oriented Computing setting, transactions are more complex, involve multiple parties (roles), span many organizations, and may be long-running, consisting of a highly decentralized service partner and performed by autonomous entities. A Service-oriented Transaction Model has to provide comprehensive support for long-running propositions including negotiations, conversations, commitments, contracts, tracking, payments, and exception handling. Current transaction models and mechanisms including their protocols and primitives do not sufficiently cater for quality-aware and long running transactions comprising loosely-coupled (federated) service partners and resources. Web services transactions require co-ordination behavior provided by a traditional transaction mechanism to control the operations and outcome of an application. Furthermore, Web services transactions require the capability to handle the co-ordination of processing outcomes or results from multiple services in a more flexible manner. This requires more relaxed forms of transactions—those that do not strictly have to abide by the ACID properties—such as loosely-coupled collaboration and workflows. Furthermore, there is a need to group Web services into applications that require some form of correlation, but do not necessarily require transactional behavior. The purpose of this paper is to provide a state-of-the-art review and overview of some proposed standards surrounding Web services composition, co-ordination, and transaction. In particular the Business Process Execution Language for Web services (BPEL4WS), its co-ordination, and transaction frameworks (WS-Co-ordination and WS-Transaction) are discussed.

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本文概述了吸收压缩复合式热泵及制冷技术的发展现状和最新研究结果,着重论述了这种新兴能量转换技术的构成方式和特点,以及该技术的优越性能、经济性和应用前景。表明这种复合式逆向能量转换技术必将在制冷空调行业以及能量回收再利用领域扮演不可缺少的重要角色。

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The corrosion inhibition behavior of benzotriazole, Na3PO4 and their mixture on carbon steel in 20 wt.% (0.628 mol l(-1)) tetra-n-butylammonium bromide aerated aqueous solution was investigated by weight-loss test, potentiodynamic polarization measurement, electrochemical impedance spectroscopy and scanning electron microscope/energy dispersive X-ray techniques. The inhibition action of BTA or SP or inhibitors mixture on the corrosion of carbon steel is mainly due to the inhibition of anodic process of corrosion. The results revealed that inhibitors mixtures have shown synergistic effects at lower concentration of inhibitors. At 2 g l(-1) BTA and 2 g l(-1) SP showed optimum enhanced inhibition compared with their individual effects.

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本文用加拿大国立研究院(National Research Council of Canada) Fuhrer等人编制的FORTRAN语言程序(以下简称NRCC程序),对两个冠醚类化合物进行了简正坐标分析,这两个化合物分子是二氧六环(C_4H_8O_2)和12-冠-4(C_8H_(16)O_4)。作者用Synder和Zerbi提出的一般价力场,计算了二氧六环的36个简正振动频率,精化四次后的结果误差为14.04 cm~(-1),得到了二氧六环的精化力场和势能分析矩阵;做了12-冠-4-的中红外光谱(3200-5000cm~(-1))。远红外光谱(500-70cm~(-1))和拉曼光谱(3200-50 cm~(-1),从而归属出12-冠-4的78个简正振动频率实验值;利用二氧六环的精化力场作为初始力场,计算了12-冠-4的简正振动频率,对78个简正振动频率进行了精化计算,精化三次后的结果误差为13.99 cm~(-1),精化后得到12-冠-4的精化力场和势能分布矩阵;将NRCC程序以BASIC语言移至TRS-80微型机上,对二氧六环进行了计算,结果良好,首次给出二氧六环一般价力场的势能分布。一、对二氧六环的处理 二氧六环分子式C_4H_8O_2,合14个原子,有3N-6=36个简正振动频率。分子结构系由二个乙氧基(-CH_2-CH_2-O-)单元组成的含有四个碳,两个氧的六元环,平衡态分子为椅式构象,属于C_(2h)点群,36个简正振动频率分为四个对称类Ag、Au、Bg和Bu,分布是:Ag 10个,Bg 8个,Au 9个,Bu9个。二氧六环的分子结构及坐标示意图见28而图5,定义了14个伸缩内坐标,26个弯曲内坐标,6个扭曲内坐标,共46个,C-C键长1.54A,C-O键长1.41 A,C-H键长1.096A,键角都用109°28'。用CART程序(NRCC程序之一)计算二氧六环14个原子的笛卡尔坐标,用GMAT程序(NRCC程序之二)计算其B矩阵和G矩阵,用FPERT程序(NRCC程序之三)计算其简正振动频率、精化力场,计算用一般价力场,引入V矩阵对称化,将46个坐标化为46个(内)对称坐标,10个多余坐标在FPERT程序计算中除去。二、对12-冠-4的处理 12-冠-4分子式C_8H_(16)O_4,含28个原子,共3N-6=78个简正振动频率,分子结构为四个乙氧基(-CH_2-CH_2-O-)单元组成的含八个碳、四个氧的12元环,自由分子的12-冠-4属于C点群。结构数据引自Groth的X光衍射分数和坐标,自己编制了BASIC语言程度将分数坐标化为笛卡尔坐标,用GMAT程序计算B矩阵和G矩阵,FPERT程序计算78个简正振动频率、精化力场、计算势能分布矩阵,引入U矩阵将92个内坐标化为92个对称坐标,14个多余坐标在FPERT程序中自动除去。三、结果 势能分布矩阵给出分子的振动归属,对这两个冠醚类分子的3N-6个简正振动频率,可以划分为五个振动区域。1.C-H伸缩振动区(3000-2800 cm~(-1)) 在该区中,二氧六环有八个值:2974、2966、2854和2867 cm~(-1)各两个,12-冠-4有16个值:2935、2923、2915和2907 cm~(-1)各两个,2860 cm~(-1)8个,高于2900 cm~(-1)者为反对称伸缩振动,低于2900 cm~(-1)者为对称伸缩振动。2.亚甲基弯曲振动之一(1500-1400 cm~(-1)) 该区的主要振动是亚甲基剪式振动(Scissor),其它振动小于10%二氧六环在该区有四个频率:1443、1461、1451和1457 cm~(-1),12-冠-4有八个频率:1466、1450、1450和1405 cm~(-1)各两个。3.亚甲基弯曲振动区二(1400-1200 cm~(-1))该区的主要振动模式为亚甲基的颤动(wag)、卷曲(twist)和摆动(rock)振动,其它振动小于13%。二氧六环在该区有八个频率:1334、1303、1396、1216、1367、1264、1377和1296 cm~(-1),12-冠-4有十六个频率:1388、1363、……1229 cm~(-1)(其中1288、1307cm~(-1)非简并,其余皆两重简并)。4.环的骨架伸缩振动区(1200-600 cm~(-1))该区振动模式复杂,除环的骨架伸缩振动外,还有亚甲基的wag、twist、rock以及环的骨架弯曲振动,而且这些振动的势能分布值都不小。二氧六环在该区有十一个频率,从1127至610 cm~(-1),12-冠-4有二十个频率,从1135至184 cm~(-1)且大都是二重简并的。5.低频区(600-50cm~(-1))这两个分子在低频区的势能分布略有差别。二氧六环在该区有五个频率:503、486、427、276和224 cm~(-1),主要振动模式为骨架弯曲振动和扭曲振动,C-O、C-C的扭曲振动在三个最低频率中分布占10-30%。12-冠-4在该区有18个频率,除570和547cm~(-1)处,都是二重简并的,六个最低频率的振动模式完全属于C-O、C-C键的扭曲振动,其它振动小于10%,所以200 cm~(-1)以下可称为12-冠-4的扭曲振动区,在600-200cm~(-1)之间的12个频率主要是骨架的弯曲振动,也有一定量的亚甲基wag、twist、rock振动。12-冠-4的简正坐标分析尚未有人做过。二氧六环的计算结果与Snyder和Zerbi的分析相吻合,12-冠-4和二氧六环两分子势能分布的相对一致性证明了对12-冠-4的简正坐标分析基本是正确的。本文比较了二分子的力常数和振动频率,探讨了环的大小对振动光谱的影响。四、NRCC程序简介 NRCC程序由CART、GMAT和FPERT三个程序组成,即可联一起运用,亦可分开独立进行运算。该程序功能强,所占内存大,适于大、中型计算机使用。CART程序之名字取自Cartisian Co-or-dinates的前四个字母,功能系由分子结构参数(键长、键角)计算分子内各原子的笛卡尔坐标。GMAT程序之名字取自G matrix的前四个字母,功能系由分子内各原子的笛卡尔坐标,原子质量和内坐标定义计算分子内各原子的坐标交换矩阵B和Wilson振动动能矩阵G。FPERT程序之名字取自F Perturbation的前五个字母,功能系由分子振动功能矩阵G、势能常数即力常数矩阵F计算分子的简正振动频率和势能分布矩阵,再通过实验频率精化势能矩阵F。NRCC程序可对含30个原子、60个内坐标的分子进行简正坐标分析,扩充后容量增大一倍。该程序可选用一般价力场(General Valence Force Field, 简称GVFF)和UBS力场(Urey-Bradley-Shimanouchi Force Field),简称UBSFF或UBFF)。可选用对称化U矩阵,可自行决定力场精化次数和阻尼常数以限制精化结果的收敛性。五、NRCC程序在TRS-80微型机上移植试尝(该部分曾在第三届长春夏季化学讨论会上宣读)针对NRCC程序占内存空间大、难以在微型机上实现的情况,作者将NRCC程序改编为BASIC语言,改变程序的原来结构,形成一组BASIC语言程序:CART/BAS、GMAT/BAS和VIFR/BAS,改编后的BASIC程序在TRS-80微型机调试通过,TRS-80机字长8位,New Dos系统内存32K。改写后的程序只保持了原程序的基本原理,在内存,语句上改动很大,以适于微型机使用。数据在程序中直接嵌入,利于修改替换,且BASIC语言简单易学,便于操作。CART/BAS程序可计算含30个原子以内的分子的笛卡尔坐标,GMAT/BAS程序可计算含20个原子、45个内坐标的分子的G矩阵,VIFR/BAS程序可计算含15个原子的分子的简正振动频率。利用这组程序,作者以二氧六环分子为例做了一些试尝运算,误差14.4 cm~(-1),相对误差1.8%,结果较理想。

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A new technology for fabrication of silica on silicon arrayed waveguide grating (AWG) based on deep etching and thermal oxidation is presented.Using this method,a silicon layer is remained at the side of waveguide.The stress distribution and effective refractive index of waveguide fabricated by this approach are calculated using finite element and finite difference beam propagation method,respectively.The results of these studies indicate that the stress of silica on silicon optical waveguide can be matched in parallel and vertical direction and AWG polarization dependent wavelength (PDλ) can be reduced effectively due to side-silicon layer.

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A new kind of shock capturing method is developed. Before applying the high order accurate traditional scheme which is called as base scheme in this paper the fluid parameters are preconditioned in order to control the group velocity. The newly constructed scheme is high order accurate, simple, has high resolution of the shock, and less computer time consumed.