CONVERGENCE ON RANDOMLY TRIMMED SUMS WITH A DEPENDENT SAMPLE

§１．ＩｎｔｒｏｄｕｃｔｉｏｎａｎｄＲｅｓｕｌｔｓＬｅｔ｛Ｘｎ，ｎ１｝ｂｅａｓｅｑｕｅｎｃｅｏｆｒａｎｄｏｍｖａｒｉａｂｌｅｓｗｉｔｈａｃｏｍｍｏｎｄｉｓｔｒｉｂｕｔｉｏｎｆｕｎｃｔｉｏｎＦ（ｘ）ａｎｄｌｅｔＸｎ１Ｘｎ２…Ｘｎｎｂｅｔｈｅｏｒ...     

Coboundaries of irreducible markov operators onC(K)

LetK be a compact Hausdorff space, and letT be an irreducible Markov operator onC(K). We show that ifgεC(K) satisfies sup _N ‖Σ _j ^=0N T ^j g‖<∞, then (and only then) there existsfεC(K) with (I − T)f=g. Generalizing the result to irreducible Markov operator representations of certain semi-groups, we obtain that bounded cocycles are (continuous) coboundaries. For minimal semi-group actions inC(K), no restriction on the semi-group is needed.     

金催化化学发光新体系——苯并吡喃化学发光分析法测定金矿中的痕量金

本文提出了一种测定矿样中痕量金的化学发光分析法,氯化6,7-二羟基-2,4-二甲基苯并吡喃-H_2O_2化学发光体系,方法的检出限为7ppb。工作曲线线性范围是10～1000ppbAu,测定的相对标准偏差小于7％。应用本法测定矿样中的金,结果良好。     

Sensitive monitoring of humic acid in various aquatic environments with acidic cerium chemiluminescence detection.

In this research, a simple, sensitive chemiluminescence (CL) method for the determination of humic acid (HA) in water samples was first developed based on the redox reaction between humic acid and cerium(IV) in the acidic condition. Different with the former redox CL reaction which occurred in alkaline solution, no enhancers were needed and neither precipitation nor a second contamination would occur in the present CL system. Comparing with other spectrometric methods, we find that the proposed analysis system had better applicability and accuracy. Under the optimal experiment conditions, the CL peak height was linear with the concentration of HA in the range of 0.03 to 10.0 microg mL(-1). The detection limit is 0.01 microg mL(-1) (S/N = 3), and the relative standard deviation was 2.3% for 0.5 microg mL(-1) HA solution with eleven repeated measurements. The present CL method was successfully applied to the determination of HA in tap water, spring water and river water samples with good recovery from 90.0 to 110.0%. A possible CL mechanism was proposed based on the results of UV and fluorescence spectrometry and the CL spectrum of HA. It was speculated that the semi-quinone radicals in the excited state were the emitters.     

逆序数的应用

本文通过“1 4-1 5”智力玩具和最优戴断切割问题两个实例 ,讨论了逆序数在解决实际问题中的应用     

带W权Drazin逆的一种新算法

利用矩阵A的带W权Drazin逆的一个性质特征,对任意的矩阵A∈Cm×n,W∈Cn×m,建立了带W权的Drazin逆Ad,w的一种新的表示式,给出了具体的算法步骤,并且在文末给出了算例.     

PERMANENCE AND GLOBAL STABILITY TO A NONAUTONOMOUS NONLINEAR DISCRETE SINGLE SPECIES SYSTEM

In this paper,we study some permanence and global stability to a nonau- tonomous nonlinear discrete single species system,and obtain some sufficient condition of global stability to the system.     

2‐Cyanoprop‐2‐yl dithiobenzoate mediated reversible addition–fragmentation chain transfer polymerization of acrylonitrile targeting a polymer with a higher molecular weight

The reversible addition–fragmentation chain transfer (RAFT) polymerization of acrylonitrile (AN) mediated by 2‐cyanoprop‐2‐yl dithiobenzoate was first applied to synthesize polyacrylonitrile (PAN) with a high molecular weight up to 32,800 and a polydispersity index as low as 1.29. The key to success was ascribed to the optimization of the experimental conditions to increase the fragmentation reaction efficiency of the intermediate radical. In accordance with the atom transfer radical polymerization of AN, ethylene carbonate was also a better solvent candidate for providing higher controlled/living RAFT polymerization behaviors than dimethylformamide and dimethyl sulfoxide. The various experimental parameters, including the temperature, the molar ratio of dithiobenzoate to the initiator, the molar ratio of the monomer to dithiobenzoate, the monomer concentration, and the addition of the comonomer, were varied to improve the control of the molecular weight and polydispersity index. The molecular weights of PANs were validated by gel permeation chromatography along with a universal calibration procedure and intrinsic viscosity measurements. ¹H NMR analysis confirmed the high chain‐end functionality of the resultant polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1272–1281, 2007     

河南省城市居民消费结构比较研究

本文主要应用聚类分析方法 ,对河南省 17个地市级城市居民的消费结构进行了比较统计分析 ,从而得到了各城市居民消费结构的一些特点和规律 ,并进一步探讨了其消费结构、可支配收入与总消费支出之间的关系     

睾酮类兴奋剂测定中一些β-葡萄糖醛酸甙酶酶解能力的比较

睾酮是国际奥委会规定禁用的99种兴奋剂之一,由于睾酮是内源性激素,因此不能靠定性来判断运动员是否服用了睾酮,在人体激素代谢中,产生睾酮差向异构体——表睾酮,在男性黄种人中睾酮与表睾酮浓度比约为1:1,白种人中略高一些,根据这一情况,国际奥委会规定,人尿中睾酮与表睾酮之间浓度比不得超过6:1,尿中排泄出的睾酮和表睾酮是以葡