Maturity grids as tools for change management

One method to assess organizational capabilities is a maturity grid. MATURITY GRIDS AS TOOLS FOR CHANGE MANAGEMENT A maturity grid assessment is typically structured around a matrix or a grid. It consists of a series of cells where ...

Ultrashort pulse generation in diode laser devices

The generation of ultrashort optical pulses by semiconductor lasers has been extensively studied for many years. A number of methods, including gain-/Q-switching and different types of mode locking, have been exploited for the generation of picosecond and sub-picosecond pulses [1]. However, the shortest pulses produced by diode lasers are still much longer and weaker than those that are generated by advanced mode-locked solid-state laser systems [2]. On the other hand, an interesting class of devices based on superradiant emission from multiple contact diode laser structures has also been recently reported [3]. Superradiance (SR) is a transient quantum optics phenomenon based on the cooperative radiative recombination of a large number of oscillators, including atoms, molecules, e-h pairs, etc. SR in semiconductors can be used for the study of fundamental properties of e-h ensembles such as photon-mediated pairing, non-equilibrium e-h condensation, BSC-like coherent states and related phenomena. Due to the intrinsic parameters of semiconductor media, SR emission typically results in the generation of a high-power optical pulse or pulse train, where the pulse duration can be much less than 1 ps, under optimised bias conditions. Advantages of this technique over mode locking in semiconductor laser structures include potentially shorter pulsewidths and much larger peak powers. Moreover, the pulse repetition rate of mode-locked pulses is fixed by the cavity round trip time, whereas the repetition rate of SR pulses is controlled by the current bias and can be varied over a wide range. © 2012 IEEE.

定量评估豢养长江江豚个体间的优势关系

2000年1—4月和2000年4月—2002年4月,分别连续3个月和2年观察了中国科学院水生生物研究所白鱀豚馆6头长江江豚(3雌3雄,8个不同组合群)个体间发生的3种交互关系,即接近—逃开、接近—接触和接近—尾鳍击打。在累计8,162min的观察时间内,共观察到这些交互关系1,685次。本研究将江豚个体间发生的这3种交互关系作为个体间优势关系的指示,并分别给交互双方赋予不同的分值,采用优势比分矩阵方法定量分析了江豚个体之间的优势关系。结果表明江豚群体内存在优势关系。同性别个体之间,优势关系与年龄和饲养时间

HLA-DRB1、-DQB1基因多态性与食管鳞癌遗传关联性

目的　从基因水平探讨食管鳞癌HLA DRB1 , DQB1等位基因的遗传易感性 ,以阐述其免疫遗传学特征。方法　运用序列特异性引物聚合酶链反应技术 ,检测无亲缘关系湖北汉族健康人 1 36例、食管鳞癌患者 42例的HLA DRB1 , DQB1等位基因。结果　湖北汉族人食管鳞癌患者与正常人比较 ,HLA DRB1 0 90 1等位基因分布频率显著增高 (0 .2 50 0比 0 .1 397,P =0 .0 2 8,OR =2 .0 53 ,病因分数 =0 .1 2 82 ) ,HLA DQB1 0 30

Approximate Bayesian Computation for Smoothing

We consider a method for approximate inference in hidden Markov models (HMMs). The method circumvents the need to evaluate conditional densities of observations given the hidden states. It may be considered an instance of Approximate Bayesian Computation (ABC) and it involves the introduction of auxiliary variables valued in the same space as the observations. The quality of the approximation may be controlled to arbitrary precision through a parameter ε > 0. We provide theoretical results which quantify, in terms of ε, the ABC error in approximation of expectations of additive functionals with respect to the smoothing distributions. Under regularity assumptions, this error is, where n is the number of time steps over which smoothing is performed. For numerical implementation, we adopt the forward-only sequential Monte Carlo (SMC) scheme of [14] and quantify the combined error from the ABC and SMC approximations. This forms some of the first quantitative results for ABC methods which jointly treat the ABC and simulation errors, with a finite number of data and simulated samples. © Taylor & Francis Group, LLC.

暹罗鱼腥藻空间飞行突变株的光合特性分析

对经空间飞行搭载而获得的通罗鱼腥藻突变株的分析发现，与对照相比，它在生长率和光合效率方面明显较高．进一步分析其光合色素的组成，叶绿素荧光及PSII／PSI比值，发现突变株的PC／Chl比值明显低于对照藻株，而叶绿素荧光高于对照，PSII／PSI比值是对照藻株的1.7倍，在其它光合色素的比例上也有差异．分析这些结果表明，突变株与对照株在光合特征上有差异可能是突变株在色素系统的改变引起光能捕捉和光能利用上更为高效的原因．

中国典型地带土壤原生动物食性的观察

报道了中国６个典型地带土壤原生动物的食性观察结果，并就观察结果进行了讨论和分析。根据食性或营养方式，将鉴定到的２９０种土壤原生动物分为８个功能营养类群———自养者、食细菌者、肉食者、食碎屑者、食真菌者、植食者、杂食者和腐生性营养者。对鉴定到的各分类类群的食性进行了讨论和分析。

吸鱼粘体虫在异育银鲫心脏中的孢子发生

吸鱼粘体虫主要寄生在异育银鲫的心肌纤维间。随着营养体的长大,营养体内的两型生殖细胞相聚,小生殖细胞包围大生殖细胞,形成泛孢子母细胞。大生殖细胞进行连续的核分裂,成为产孢体。核分裂达12核时,产孢体内分化为10个细胞:4个成极囊细胞,4个成壳片细胞和2个双核的孢子质细胞。这些细胞均分为两组,从而形成双生孢子型的泛孢子母细胞。

白鱀豚饲养池水质某些理化因子的变动规律

自来水中的低量余氯对白暨豚无明显的刺激作用。豚池水温的变化情况与长江中、下游相似,极温对豚有不利影响。不同温度下,池水中磷酸盐含量的日增加率有显著差异,铵氮和硝酸盐氮的日增加系数相近,分别为0.327和0.2468,而亚硝酸盐氮的日增加系数在0.397—0.539之间,受温度的影响较大。池水有机物耗氧量增加不显著,含量与时间的相关式符合Y=aX~b型。缺少阳光照射是池水无机氮化合物增加较快、有机物分解较慢的原因之一。

ICE Manual of Structural Design

Part of the ICE manuals series, ICE manual of structural design is the essential reference for all structural engineers involved in the design of buildings and other structures.

关于双形藻属和韦氏藻属的分类位置问题

<正> 到目前为止,绿球藻目(chlorococcales)的分类系统是相当混乱的。要整理这一目植物的分类系统,作者认为:首先要建立这一目的分类基础,同时,还要对于在分类系统上作为基本单位的属,尤其是在特征上不明确的,加以整理。这样,才能够确定这些属的分类位置和进一步建立这一目植物的分类系统。