金针茹组织分离研究

对金针菇(collyba velutipes<CURT.EX FR>)采用组织分离法制作菌种,割取茵柄与茵盖交际处,菌柄上部,茵柄中上部及菌柄中部的组织块在胡萝卜培养基,马铃薯培养基以及综合培养基中进行培养,实验结果得出菌柄中上部为最佳,菌柄中部亦较好,三种培养基中最佳配方为综合培养基.     

An Analysis of the Ballad of the Sad Café from the Perspective of Grei mas’Semiotic Square

Greimas’s Semiotic Square is a new approach in analyzing literary works.Based on Sassure and Jacnson’s claim on binary opposition,Gereimas extends it to four actants and adds contradictory relationships.By assign meanings to the four actants,an analysis of the complicated relationship between the roles in a text can be made and a revelation of the theme of the text can be realized.Previous studies of this novel take it as an excellent work revealing loneliness and isolation is thought to be the basic condition of human existence.Other study covers the effects of the unrequited love.Quiet differently,this paper tries to interpret this novel by Greimas’semiotic square and thereby revealing the widely accepted theme of this novel that isolation and loneliness is the final destiny of human being in modern society.     

隔震大开间密肋复合墙结构地震反应分析

在高地震烈度地区,基础隔震技术为解决大开间密肋复合墙结构的抗震安全性提供了方法。利用大开间密肋复合墙结构与基础隔震相结合技术,采用SAP2000分析软件建立了隔震大开间密肋复合墙结构的计算模型,对比分析了大开间密肋复合墙隔震结构与非隔震结构的地震反应机理,验证了隔震大开间密肋复合墙结构在高烈度地震区应用的可行性。     

电子商务系统网络安全隔离技术的研究

针对目前Internet上的黑客软件、网络病毒针对TCP/IP协议设计的特点及Windows终端与Windows终端服务器之间可以通过IPX协议建立通信连接的技术特征,提出外网Windows终端服务器选用一网卡只加载标准的TCP/IP协议与Internet相连,另一网卡只加载IPX协议仅与内网Windows终端相连的组网方案,阻隔黑客软件攻击与网络病毒传播的通信通道,研究电子商务系统内外网络安全隔离新型应用模式.     

Dimensions of physical punishment and their associations with children's cognitive performance and school adjustment

This study examined how a range of physical punishment measures, ranging from mild corporal punishment to physical abuse, are associated with cognitive performance, school engagement, and peer isolation over a 3- year span among 658 children initially observed between the ages of 8 and 14. Physical punishment was captured in three groups: mild corporal punishment, harsh corporal punishment, and physical abuse, and both caregiver- and child-reported punishment measures were considered. After accounting for socioeconomic and demographic characteristics, only Ninitial exposure to physical abuse was significantly associated with declines in cognitive performance. However, all forms of physical punishment were associated with declines in school engagement, and harsh corporal punishment was associated with increased peer isolation. Our findings were relatively consistent regardless of whether physical punishment was reported by the child or caregiver. Overall, our findings suggest that the prevention of physical abuse may enhance children's cognitive performance, but that alone may not be sufficient to ensure children are engaged and well-adjusted in school.     

土与结构动力相互作用隔震体系的MB计算方法

采用刚性地基假定是目前结构控制研究的基本条件,此假定忽略了土与结构相互作用效应的影响。但由于土与结构相互作用效应对结构振动特性有一定的影响,进而影响结构控制的效果,因此有必要研究土与结构动力相互作用的简化计算方法。基于上述原因,进行了线性体系土与结构相互作用效应对隔震体系的MB计算方法的研究。     

Absence of postzygotic isolating mechanisms: evidence from experimental hybridization between two species of tropical sea urchins

Two reef margin species of tropical sea urchins, Echinometra sp. C (Ec) and Echinometra oblonga (Eo), occur sympatrically on Okinawa intertidal reefs in southern Japan. Hybridization between these species was examined through a series of cross-fertilization experiments. At limited sperm concentrations, where conspecific crosses reached near 100% fertilization, both heterospecific crosses showed high fertilization rates (81%–85%). The compatibility of the gametes demonstrated that if gamete recognition molecules are involved in fertilization of these species, they are not strongly species-specific. We found that conspecific crosses reached peak fertilization levels much faster than did heterospecific crosses, indicating the presence of a prezygotic barrier to hybridization in the gametes. Larval survival, metamorphosis, and juvenile and adult survival of hybrid groups were nearly identical to those of their parent species. Hybrids from crosses in both directions developed normally through larval stages to sexually mature adults, indicating that neither gametic incompatibility nor hybrid inviability appeared to maintain reproductive isolation between these species. In adults, Ec×Ec crosses gave the highest live weight, followed by Eo (ova)×Ec (sperm), Ec (ova)×Eo (sperm), and Eo×Eo. Other growth performance measures (viz., test size, Aristotle’s lantern length, and gonad index) of hybrid groups and their parental siblings showed the same trends. The phenotypic color patterns of the hybrids were closer to the maternal coloration, whereas spine length, tube-foot and gonad spicule characteristics, pedicellaria valve length, and gamete sizes showed intermediate features. Adult F₁ hybrids were completely fertile and displayed high fertilization success in F₁ backcrosses, eliminating the likelihood that hybrid sterility is a postzygotic mechanism of reproductive isolation. Conversely, intensive surveys failed to find hybrid individuals in the field, suggesting the lack or rarity of natural hybridization. This strongly suggests that reproductive isolation is achieved by prezygotic isolating mechanism(s). Of these mechanisms, habitat segregation, gamete competition, differences in spawning times, gametic incompatibility or other genetic and non-genetic factors appear to be important in maintaining the integrity of these species.     

从空间组织角度看新冠肺炎疫情隔离管控中的问题及对策建议

隔离管控是遏制新冠肺炎疫情传播蔓延的有效手段,但在隔离管控中暴露出来的城市管理、社会民生等方面问题值得深思。文章首先梳理了近期新冠肺炎疫情隔离管控中出现的5类问题,并在扼要回顾了国内外相关研究后提出从结合系统论思维的空间组织角度展开研究是契合的方向;进而从空间组织与系统科学的客观规律出发探究问题背后的原因,指出了从理论上缺乏对隔离管控决策的系统化考量,从实践上缺乏常态到非常态切换的准备是造成问题的根源。最后,文章从空间组织体系的优化、基础设施与能力建设、后备演练机制等3方面提出了建议。     

Laugh so you don't cry: teachers combating isolation in schools through humour and social support

The structure of the teaching profession leaves teachers professionally and personally isolated from other adults. This article will discuss the results of an ethnography focused on the rare informal social interaction that occurs among teachers in a United States’ school, with a particular focus on the lunch hour. Specifically, this article explores the reciprocal nature of support provided within self-generated congregational spaces. This study demonstrates the positive use of humour in combating stress in the teaching profession, and how these relationships support Hochschild's (1983) theory of emotional labour.     

纤维素分解菌的分离筛选和产酶条件优化

目的：研究纤维素分解菌的分离及产酶条件优化.方法：以含菌秸秆、腐木叶和玉米地土壤为原料,经富集、初筛培养后,根据水解圈直径/培养天数进行纤维素分解菌的复筛培养,测定CMC酶活和FPA滤纸酶活,并进行了产酶条件的单因素优化实验.结果：采集的样品中共分离到4个菌株,均为细菌,其中H-3的羧甲基纤维素（CMC）酶活和滤纸（FPA）酶活最高,分别是0.5401U.m l-1、0.2923U.m l-1.结论：H-3菌分解纤维素的能力最强,最佳产酶条件为温度30℃,pH4.5.不含尿素,葡萄糖和纤维素含量为0.4%和0.6%.