一类重随机Poisson过程的等待时间的分布密度公式及其在害虫预测预报中的应用

对具有强度过程λｔ（Ｘ）＝Ｘ＾αＶ（ｔ）（α∈Ｒ＋）的重随机Ｐｏｉｓｓｏｎ过程「Ｎｔ：ｔ≥ｔ０」,推导出其等待时间Ｗｎ的分布密度函数ｆＷｎ（ｔ）的表达式;讨论了进一步推广所得结果的途径;利用所得结果解决了一个预测害虫最适防治时刻的问题。     

小叶锦鸡儿人工固沙区植被恢复生态过程的研究

主要研究了流动沙兵采用草方格固沙结合播种小叶锦鸡儿后,上锦鸡儿人工群落形成和发展过程,尤其对群落中物种侵入过程和群落组织结构在３５年间的变化情况做了详细分析。结果表明,人工小叶锦鸡儿群落不同发育阶段植物丰富度发生降有大的变化,从５种增加到２３种;在生活型组成结构上,一年生植物占约对优势,但所占比例随着时间的变化有８逐渐减少的趋势,地面芽植物和地下芽植物的种类数 和个体数所占比例均逐渐增加;物种多样     

Lipase-catalyzed reaction in the packed-bed reactor with continuous extraction column to overcome a product inhibition

The resolution of rac-α-methyl-β-propiothiolactone (rac-MPTL) was performed in a packed-bed reactor (PBR) using Pseudomonas cepacia lipase (PCL) in organic media to produce enantiopure (R)-MPTL. By comparing enzyme stability of three enzyme forms, i.e. commercial PCL powder, Celite-immobilized PCL, and cross-linked enzyme crystals of PCL (CLECs-PCL), Celite-immobilized PCL was chosen for the construction of PBR because of its comparable stability to that of CLEC and easy handling. Owing to the severe product inhibition by 3-mercapto-α-methylpropionic acid (MMPA), the batch reaction system was inappropriate for the hydrolysis with PCL at high concentration of rac-MPTL. To overcome these problems, PBR with a continuous extraction column was used. The product inhibition was successfully overcome by incorporating an aqueous extraction unit. However, the yield of (R)-MPTL (enantiomeric excess, ee>99%) was only about 20% based upon the initial concentration of rac-MPTL, due to the concomitant partitioning of rac-MPTL to the aqueous phase in the extraction column as well as the subsequent auto-hydrolysis of rac-MPTL to rac-MMPA during extraction. To reduce the undesired partitioning of rac-MPTL to aqueous phase, various salts were screened to modulate the partitioning coefficient of the reaction components. Using 1 M ammonium sulfate solution as the aqueous phase of the extraction column, the yield of (R)-MPTL (ee>99%) was enhanced to 40%.     

土壤-植物系统污染生态学研究与展望

为了促进土壤-植物系统污染生态学这门新兴学科的进一步健康发展与学科建设并在今后国家层面上发挥越来越重要的作用,本文回顾了该领域一些具有开端意义的工作与早期研究,并对其学科定义与内涵的发展和基本原理与研究方法的进展给予了追踪,进而就该学科的主要任务和主体研究内容以及今后进一步发展进行了阐述与展望．     

大鹏湾夜光藻赤潮发生风险率的随机过程分析

本文以春季大鹏湾夜光藻种群等间隔采样序列作为随机过程变量,运用随机过程理论,构造了夜光藻种群超阈值风险的成丛随机点过程复合模型,对夜光藻赤潮风险率的随机过程进行分析,得到夜光藻赤潮的风险估算,并进行拟优合度检验.认为研究结果对预测夜光藻赤潮发生具有一定的指导意义.     

夏天无药材提取工艺研究

采用正交试验法,以原阿片碱转移率为指标,考察乙醇浓度(A)、乙醇用量(B)、提取时间(C)和提取次数(D)4个因素对夏天无提取工艺的影响。结果表明,优化的夏天无提取工艺为A₃B₁C₃D₃,即取夏天无药材粉碎成粗颗粒,以90%乙醇加热回流提取3次,每次加6倍量乙醇,第一次提取2 h,第二次提取1 h,第三次提取1 h。     

Simple Nonparametric Inference for Monotonic Processes

A scoring system for possibly censored monotonic processes is presented which allows to analyze such processes by means of standard parametric or nonparametric tests. In either case the analyses are invariant to monotonic transformations of time. Such analyses are of relevance whenever changes in degree of function are observed rather than the single and 100% loss of function of survival analysis. An example of gradually increasing function after particular reconstructive surgery is supplied.