信息链视角下情报实现再认识

在计算机技术、大数据、云计算、人工智能及数据科学等环境下,情报研究再次引起了人们的极大关注。对信息链视角下情报研究再认识具有较大的理论和现实意义。在梳理和分析信息链、情报以及它们之间的关系的基础上,构建了信息链视角下情报实现和服务系统模型。研究发现在新的时代背景下,信息链的每个转化环节将会直接或间接转化为情报,且信息链与情报的属性、人的认知、管理和技术等因素对情报的实现有较大的影响。最后提出了提升情报实现的相关建议。     

利用RGA-PCR方法进行水稻抗瘟基因分子标记

用28对RGA引物对LTH近等基因系品种进行PCR扩增，其中11对引物扩增出特异性条带。将扩增到的33个特异性片段回收并进行重扩增，有11个片段产生单一条带。选择2个片段HS-1和HS-19进行探针标记。经Southern杂交发现。探针HS-1在含有Pi—ta^2抗瘟基因品种F-128—1、NO4中有特异杂交信号，表明该片段可能与抗瘟基因Pi—ta^2连锁或是其一部分。对特异性片段HS-1进行克隆、测序，全长为478bp，与Mago等从水稻中克隆的一个抗病基因同源序列RGA29有95％同源性。     

农业技术创新链的超循环理论与机理研究

农业技术创新链循环是指从农业技术创新链的某一基本构成环节出发,顺次经过其他基本环节,最后回复到起始环节的过程,它包括反应循环、催化循环和超循环三个等级。其循环机理是:同一农业技术创新链中每一环节的反应循环,推动同一或不同农业技术创新链中同一或同类环节之间的催化循环,再由催化循环推动同一或不同农业技术创新链中各环节之间的超循环。农业技术发明和农业技术首次商业化使用的超循环,使二者耦合成共生的结合体;通过农业技术首次商业化使用和农业技术扩散的超循环,完成农业技术创新链的一次循环;通过农业技术扩散和农业技术发明的超循环,使整个农业技术创新链在新的需求起点上开始循环,如此循环往复。     

Human prion protein cDNA: molecular cloning, chromosomal mapping, and biological implications

A human complementary DNA whose protein product is considered to be the major component of scrapie-associated fibrils in Creutzfeldt-Jakob disease, kuru, and Gerstmann-Straussler syndrome has been identified and characterized. The extensive homology of this gene sequence to the hamster PrP 27- to 30-kilodalton prion protein complementary DNA clone, and its existence as a single copy in the human genome, leads to the conclusion that this is the human prion gene. This human prion gene has been mapped to human chromosome 20, negating a direct link between the prion protein and Down's syndrome or the amyloid of Alzheimer's disease.     

大节距链条木材输送机链速调节问题研究

用单个十字联轴节和一对圆柱齿轮能对林业生产中广泛应用的大节距链条木材输送机链速不均匀问题进行有效调节，方法简便。其相应的理论证明、计算方法和结论也一并给出。     

食物链长度远因与近因研究进展综述

食物链长度是生态系统的基本属性,其变化决定着群落结构和生态系统功能。稳定同位素分析技术的进步推进了生态系统中食物链长度决定因子相关研究的开展。尽管近期的研究证明了食物链长度与资源可利用性、生态系统大小、干扰等远因之间的关系,但是对于食物网内部结构变化这一近因对食物链长度的影响作用关注较少。综述了边界明确和开放类型淡水生态系统中食物链长度的相关研究进展;探讨了远因和近因机制在决定食物链长度中的作用;给出了判断不同层次和尺度上决定食物链长度机制的概念框架;为今后更好的开展不同生态系统间食物链长度的比较研究提出了建议。     

国内外土地利用／土地覆盖变化研究综述

土地利用／土地覆盖变化是目前全球变化研究的核心主题之一。它不仅影响到了人类生存与发展的自然基础,而且影响到地球生物化学圈层的结构、功能及地球系统能量与物质循环等方面。本文通过分析国内外土地利用／土地覆盖变化,以便为推动我国在土地利用和土地覆被变化领域研究工作的进展,促进我国土地利用变化研究工作与世界全球变化研究相衔接发挥积极作用。     

Requirement for the SLP-76 adaptor GADS in T cell development

GADS is an adaptor protein implicated in CD3 signaling because of its ability to link SLP-76 to LAT. A GADS-deficient mouse was generated by gene targeting, and the function of GADS in T cell development and activation was examined. GADS- CD4-CD8- thymocytes exhibited a severe block in proliferation but still differentiated into mature T cells. GADS- thymocytes failed to respond to CD3 cross-linking in vivo and were impaired in positive and negative selection. Immunoprecipitation experiments revealed that the association between SLP-76 and LAT was uncoupled in GADS- thymocytes. These observations indicate that GADS is a critical adaptor for CD3 signaling.     

Solar neutrinos--from puzzle to paradox

The solar neutrino puzzle is deepening into a paradox that refutes the basic logic of the reaction chain that powers the sun by the fusion of protons into heavy elements. Experiments now reveal a serious anomaly in the relative neutrino fluxes from the different steps in the chain. Neutrinos from boron-8 at the end of the chain are seen but hardly any are seen from beryllium-7, without which the observed boron-8 cannot be made. The only apparent way to avoid a paradoxical "missing link" in the sun's energy chain is a nonzero neutrino mass, an idea that can be tested in future experiments.     

Three-dimensional structure identified from single sections

Errors in the identification of objects have been made frequently because of faulty interpretation of their flat images or sections. Such errors are perpetuated through a strange psychological chain reaction. 1) The first author who observes sections of an object, although presenting faithful pictures of sections of it, identifies its shape incorrectly. Such an initial mistake may be due to identification of the flat image with the object itself or to failure to consider the shape of the image as a function of the shape of the real object and the angle and level of cutting. 2) The first author describes verbally his personal concept of the object. 3) The reader reads the text of a publication before or without examining the pictorial evidence. 4) The reader's belief in the authority of the printed word immunizes him against critical evaluation of the evidence. 5) The reader regards a published opinion as a "fact." 6) A mechanism of suppression of new evidence is set up in the brain of the reader in favor of previously published, verbalized concepts. His brain unconsciously rejects new concepts that might arise intracerebrally. The printed word supersedes visual evidence. 7) A secondary mechanism parallels steps 3 to 6. An observer notices an unfamiliar figure in the microscope. Following established procedures for scientific investigations, he refrains from forming an opinion about his observation. Instead he rushes to the library searching for similar, published observations. If he finds a previous report about a similar shape, he accepts it as a "fact" and he "confirms" the previously printed viewpoint. Let me interject a personal experience concerning this mechanism. I investigated the arrangement of blood vessels in the human liver by means of corrosion preparations. The work was divided between an assistant and me. He was assigned the task of preparing drawings of two specimens. In his drawings he showed a structure which was absent from the specimens but had been described in a previous publication. This article shows simple ways for correct initial identification of shape and structure and for the breaking of the reverberating circuit of erroneous thinking.     

网格-下一代互联网络

本文在论述因特网给人们的工作、生活带来巨大变革的基础上,指出网络未能实现资源共享的问题,说明网格的问世是发展的必然;介绍网格含义和特征;介绍网格的发展,网格将把人类带入理想的“三元世界”,就像拿起电话能通话、插上电源能用电…一样,用户一旦接入网格就能根据需要取用各种IT资源.     

SOME REFLECTIONS CONCERNING VALENCE VARIATION AND ATOMIC STRUCTURE

In bringing to a conclusion these few scattered reflections concerning valence variation and atomic structure, may I be permitted to say this: He who is experimentally inclined may henceforth take heart and he need not be quite so timid in interpreting strange chemical reactions on the assumption of possible anomaly in the valence of the reactants. The physicist has no hesitation in speaking of the temporary existence, at the higher temperature employed in spectroscopic work, of such molecules as BaCl, AlO, (HO), CH(+), CH(2), MgF, etc. Is it not possible that under the influence of surface forces somewhat similar valence variation may not be excluded even at lower temperatures? That these strange compounds are thermodynamically unstable may be true. Nevertheless, they may function as the mysterious catalysts, or as initiators of chain reactions.     

土壤和植物硒素研究综述

硒是人体必需的微量元素,硒与人体健康密切相关。土壤硒是植物硒的直接来源,植物在自然界硒生态链转化中占有重要地位,植物硒是决定食物链硒水平的关键环节。综述了土壤和植物中的硒含量状况,对影响植物吸收硒的因素进行了分析,并阐述了土壤和植物中硒的测定方法。     

土壤作物系统中重金属污染的植物修复技术研究现状与前景

土壤与作物作为一个密不可分的系统通过食物链与人类健康问题总是息息相关,土壤作物系统中重金属污染是全球面临的一个急待解决的环境问题.近年来新兴的污染土壤植物修复技术,利用绿色植物来固定、提取土壤中的重金属以降低或清除其对环境的毒害.此方法与传统的土壤污染治理技术相比,具有成本低、不破坏环境、保护人类健康和易为大众接受等优点.本文在系统地介绍植物修复技术的类型、机理、研究现状及存在的主要问题的基础上,对当前比较流行的分子生物技术、基因工程技术在提高植物修复能力中的应用进行了探讨,并对植物修复技术今后发展的方向、需要解决的问题及其应用前景进行了展望.     

Sterol precursors of cholesterol in adult human brain

Adult human brain contains cholestanol and two series of cholesterol precursors having 30, 29, 28, and 27 carbon atoms; one has an unsaturated steroid nucleus, and the other is unsaturated in both nucleus and side chain. The ability of preparations of brain to incorporate a specific precursor into cholesterol, as well as into these sterol metabolites in vitro, indicates that cholesterol synthesis continues long after brain maturation ceases.     

论礼的有意味的形式--以荀子的饰论为例

礼是荀学的核心观念.荀子从礼的外在形式与内在本质两个方面论证了礼的合法性依据.礼的外在形式具有缘饰人性的功能,它既可以满足人性对审美的欲求,又符合政治生活中辨异目的.通过对礼义的学习,以及礼对人恶劣情欲的抑制,在逐渐积善和化恶中,促使人的气质发生变化,从而使理想人格得以养成.     

茶叶茶多酚的浸取方法概述

茶多酚作为茶叶中特有的一类化合物,对油脂的抗氧化作用、抗菌作用及消除体内自由基、抑制肿瘤生长的作用已被越来越多的研究证实。以茶多酚为主体的茶提取物也已进入了商品化生产,研究茶多酚的浸取方法在茶多酚制品方面有着重大的意义。目前,已报道的浸取方法有：溶剂萃取法、离子沉淀法、吸附分离浸取法、树脂法、超临界CO2萃取法、微波浸取法、超滤膜法及超声辅助浸取法等。本文就各种方法的基本原理、流程及优缺点作一综述。     

土壤农药残留的生物修复初探

采用从当地农田土壤中筛选出的两种农药降解菌，通过初步的生物修复试验，证明所筛选的降解菌的降解效果好于农药的自然降解，并将农药残留的气相色谱分析方法用于生物修复的结果检测。     

Bt基因和Bt蛋白检测技术研究进展

通过转基因技术将可表达杀虫特性蛋白的Bt基因转入大豆、水稻等农作物中,培育出优良的抗虫品种,从而在不使用农药等有害物质的前提下,对病虫害起到高效防治作用。然而动物试验及临床研究发现,Bt蛋白可能导致哺乳动物的免疫器官和免疫细胞损伤,也可能影响基因库的遗传结构及群体遗传多样性,对土壤特异生物类群功能、土壤生物多样性以及土壤酶活性等也有不同程度的影响,且Bt蛋白有可能沿着食物链在人体内富集,对人体形成潜在的危害。因此,开展对Bt基因和Bt蛋白的监控研究是必要的,该文对Bt的相关研究现状作一简要综述。     

Quantum low-temperature limit of a chemical reaction rate

The radiation-induced polymerization of formaldehyde has been studied in the solid state. The time of addition of one new link to a polymer chain increases exponentially in accordance with the Arrhenius law at 140 to 80 K, but approaches a constant value (approximately 10(-2) second) at temperatures below 10 K. Thus, a low-temperature limit to a chemical reaction rate has been observed. It is interpreted as a quantum effect caused by tunneling from the zero vibration level of the initial state, and a semiquantitative theory is given. The phenomenon should be taken into account for understanding tunneling of electrons in biological systems when such tunneling is accompanied by conformational changes. It could also be significant in slow, exothermic chemical reactions at low and ultralow temperatures, which may have had a role in chemical and biological evolution (cold prehistory of life?).