瑞替普酶溶栓治疗急性心肌梗死的疗效观察

目的:研究ST段抬高的急性心肌梗死(STEMI)发病后不同时间溶栓的疗效和不良反应.方法:对86例住院的STEMI患者用瑞替普酶行溶栓治疗,依据发病到溶栓开始的时间将86例患者分为三组:A组≤lh (n=28),B组>lh,但<6h(n=36),C组>6h,但≤12h(n=22),观察梗塞相关动脉(IRA)的开通率、5周病死率和溶栓副作用.结果:IRA开通率:A组92.9%(26/28),B组86.1%(31/36),C组45.5%(10/22),C组与A、B两组差异性显著(P<0.01),A、B两组间无显著性差异(P>0.05).病死率:A组、B组和C组的5周病死率分别为0%(0/28),2.77%(1/36)和4.54%(1/22).A、B两组间无显著性差异[0%(0/28)vs 2.77%(1/36),P>0.05],A组与C组有显著性差异[0%(0/28)VS 4.54%(1/22),P<0.01],B组与c组有显著性差异[2.77%(1/36)V8 4.54%(1/22),P<0.01],三组中均无包括脑出血在内的重大出血并发症.结论:瑞替普酶溶栓治疗STEMI疗效好、安全性高.     

外国游客在华停留时间及人数变化的动态数学模式研究

用可靠性统计分析方法，给出外国游客在华旅游停留时间和人数变化的数学模型．建立了停留时间的概率分布密度形式及人数变化的波哇松过程，对区间型数据进行参数估计，提出了建立线性回归模型研究旅游服务对停留时间和人数变化影响情况的分析方法，从而可分析国内可控因素对转移强度的影响．     

Margin optimization algorithm for digital subscriber lines based on particle swarm optimization*

The margin maximization problem in digital subscriber line (DSL) systems is investigated. The particle swarm optimization (PSO) theory is applied to the nonconvex margin optimization problem with the target power and rate constraints. PSO is a new evolution algorithm based on the social behavior of swarms, which can solve discontinuous, nonconvex and nonlinear problems efficiently. The proposed algorithm can converge to the global optimal solution, and numerical example demonstrates that the proposed algorithm can guarantee the fast convergence within a few iterations.     

Convergence and stability of the Newton-Like algorithm with estimation error in optimization flow control

The Newton-Like algorithm with price estimation error in optimization flow control in network is analyzed.The estimation error is treated as inexactness of the gradient and the inexact descent direction is analyzed.Based on the optimization theory,a sufficient condition for convergence of this algorithm with bounded price estimation error is obtained.Furthermore,even when this sufficient condition doesn't hold,this algorithm can also converge,provided a modified step size,and an attraction region is obtained.Based on Lasalle's invariance principle applied to a suitable Lyapunov function,the dynamic system described by this algorithm is proved to be global stability if the error is zero.And the Newton-Like algorithm with bounded price estimation error is also globally stable if the error satisfies the sufficient condition for convergence.All trajectories ultimately converge to the equilibrium point.     

STUDY OF CARBOXYL METHYL STARCH ON PAPER STRENGTH

INTRODUCTIONIn China, there is not abundant of wood resourceNon-wood fiber materials, especially like wheastraw and reed, would still be considerably used araw materials of papermaking in a long period ofuture. However, wheat straw pulp and reed pulwith the problem of short fiber and many mixed celllead to the paper in low strength. So in thmanufacture of papermaking, more and moradditives are added to make up the deficiency. Ipapermaking industry, different types of starch anstarch deri…     

LIGNIN ADSORPTION AND KAPPA NUMBER IN ETHANOL PULPING

INTRODUCTIONIt was reported that organic-solvent pulping process emerged in 1893,and then kleirert, proved that the lignin delignfied in the cooking was soluble in the ethanol water (EW) more than in the ethanol only, obtained a correlative patent in 1932.Diebold who worked in Paper association of Canada prompted the process, and pronounced a patent in the 1978[1-2]. In addition, non-wood fiber material occupies a much higher proportion to the material used in papermaking of china, so lo…     

基于块体体积和岩体波速的岩体力学参数估算方法

岩体力学参数的准确取值是岩土力学与工程领域关键科学问题之一.首先引入可考虑节理间距与数量的块体体积（Vb）参数,提出了基于Vb的地质强度指标（GSI）的计算公式,并将基于岩体波速（Vp）的岩体扰动参数（D）代入Hoek-Brown强度准则,提出了基于Vb和Vp的岩体力学参数估算方法.然后通过与已有GSI计算方法对比,验证了基于Vb计算GSI的正确性,并将基于Vb和Vp的岩体力学参数估算方法应用于田西高速的参数取值,同时将数值计算结果与现场调查、监测结果进行对比分析,验证了所提方法的可行性和准确性.该方法推广了Hoek-Brown强度准则的适用范围,并为工程建设初期试验资料不足情况下的参数取值提供了一种新的思路.     

沉淀方法对聚醚酮酮的结构和铝含量的影响

研究了几种不同的沉淀方法对聚醚酮酮析出的影响.实验表明,不同的沉淀方法对聚醚酮酮的特性粘度和红外光谱无明显影响,但对聚醚酮酮中铝含量却有明显的影响.     

高活性N_2O分解催化剂BaCo_6Al_(2.3)研究

用共沉淀法制备了BaCO3修饰的NiO和Co3O4,用于N2O分解反应的催化剂.研究发现,有最佳组成的BaCo6催化剂比BaxNi6(x=0~2)催化剂活性更高.对于BaCo6催化剂,加入了适量作为黏结剂的勃姆石以增加催化剂的力学强度.所得BaCo6Al2.3催化剂,既有很好的力学强度又有较高的催化活性.在450℃,该BaCo6Al2.3催化剂在含0.2%N2O、5%O2、2%H2O、0.01%NO的Ar气氛中,表现出非常稳定的催化活性.     

添加剂对烷基多苷脱色效果的影响

以Ｈ２Ｏ２为主要脱色剂，以可见光的吸光系数为指标，对烷基多苷粗产品进行脱色研究。实验证明该方法简单可行，同时，实验得出：三种物质组成的复合汪厍剂国２体系中能显著提高脱色效果，消除单纯Ｈ２Ｏ２脱色产生的异味；且，脱色后产品对碱，热的稳定性良好。