作物耐盐碱性鉴定评价方法

为了提高作物耐盐碱性,减轻盐碱胁迫导致的减产,许多学者广泛开展了作物耐盐碱性的生理生化和遗传等方面研究,并取得了显著成绩。但国内在耐盐碱性鉴定评价方法方面还缺乏统一标准,这影响着作物耐盐碱性研究的深入开展。本文阐述了目前国内所采用的作物耐盐碱性鉴定方法、耐盐碱指标和分级标准等,以期为我国作物耐盐碱性鉴定评价技术规范的制定和遗传育种提供参考依据。     

Facile catalyst separation without water: fluorous biphase hydroformylation of olefins

A novel concept for performing stoichiometric and catalytic chemical transformations has been developed that is based on the limited miscibility of partially or fully fluorinated compounds with nonfluorinated compounds. A fluorous biphase system (FBS) consists of a fluorous phase containing a dissolved reagent or catalyst and another phase, which could be any common organic or nonorganic solvent with limited or no solubility in the fluorous phase. The fluorous phase is defined as the fluorocarbon (mostly perfluorinated alkanes, ethers, and tertiary amines)-rich phase of a biphase system. An FBS compatible reagent or catalyst contains enough fluorous moieties that it will be soluble only or preferentially in the fluorous phase. The most effective fluorous moieties are linear or branched perfluoroalkyl chains with high carbon number; they may also contain heteroatoms. The chemical transformation may occur either in the fluorous phase or at the interface of the two phases. The application of FBS has been demonstrated for the extraction of rhodium from toluene and for the hydroformylation of olefins. The ability to separate a catalyst or a reagent from the products completely at mild conditions could lead to industrial application of homogeneous catalysts or reagents and to the development of more environmentally benign processes.     

活性炭储氢系统充放气过程试验研究

为量化分析充放气压力和充放气流率对活性炭储氢系统充放气过程热效应的影响,选择比表面积为1800m2·g-1的椰壳活性炭SAC-01作吸附剂、容积为540mL的钢制压力容器为储存容器,在室温、4个压力（10．5MPa、8MPa、6MPa、4MPa）下,对容器进行氢的快速充放和通过质量流量控制器（MFC）设定气体流率下充放气试验．结果表明：在充放气的初始阶段,充放气流率较大,储罐中心温度在短时间内升高／降低到最大／最小值;储罐壁温度的变化特点与储罐中心的相似,但变化滞后且变化幅度较小．对比试验结果时发现,充放气流率一定时,充放气压力会影响吸附床的温度波动幅度,但不改变储罐中心上升／下降到温度幅值所需要的时间;充放气流率为影响吸附床温度波动的主要原因;采用慢速充放气可减缓吸附床的温度波动．     

Ergot-induced inhibition of pituitary tumor growth in rats

Daily injections of ergocornine or ergonovine, for 3 weeks, into rats carrying a prolactin- and growth hormone-secreting pituitary tumor (MtW15) induced significant regression or inhibition of tumor growth, whereas ergocryptine had no significant effect. Ergocornine caused a decrease in cells and a disappearance or pycnosis of nuclei in the tumor tissue, and a reduced concentration of prolactin in blood.     

Interanimal "memory" transfer: results from brain and liver homogenates

Sixty mice received either shock or no shock in a shuttle box, or nonspecific stress in another apparatus. Brain and liver homogenates from these animals were then injected into 120 naive recipients, who were all tested in the shuttle box. Subjects receiving brain or liver from shocked or stressed donors had significantly higher latencies than control counterparts. These results are interpreted in terms of stress, rather than a memory transfer hypothesis.     

The use of mobile devices with multi-tag technologies for an overall contextualized vineyard management

This paper describes a Viticulture Service-Oriented Framework (VSOF) which turns around context elements or tags that are placed in the field and which can be decoded by mobile devices such as mobile phones or PDAs. The tags are used to automatically associate a field location to the relevant database tables or records and also to access contextual information or services. By pointing a mobile device to a tag, the viticulturalist may download data such as climatic data or upload information such as disease and pest incidence in a simple way, without having to provide coordinates or any other references, and without having to return to a central office. This work is part of an effort to implement a large-scale distributed cooperative network in the Douro Demarcated Region in Northeast Portugal, a region in which the effort makes particular sense due to the extremely variable topography and mesoclimates. The possibility of exchanging contextualized information and accessing contextualized services in the field, using well-known devices such as cell phones, may contribute to increase the rate of adoption of information technology in viticulture, and contribute to more efficient and closer-to-the-crops practices.     

南荻资源的人工开发利用

对我国特产禾本科植物南荻(Triarrhena lutarioripria L.Liu)的人工开发利用途径进行了综述.南荻具有碳四(C4)植物高光效、生长快速、耐湿耐旱的特性.在湖泊、滩涂荒地种植可固土防浪、净化水体;大面积人工栽培可成为工农业原料生产基地和旅游观光景点;建立人工生境湿地在园林绿地或湿地可作观赏植物少量种植.如在人工处理湿地种植可处理污水污物,在珠江口区域滩涂湿地引种湿地植物南荻,将有助于治理湿地污水污物、绿化美化环境.     

树干喷药环防治松毛虫的研究

本试验选用溴氰菊酯和杀灭菊酯,以柴油和水作稀释剂,用家用手动喷雾器在树干胸高处喷药环防治越冬上下树松毛虫取得了较好的防治效果。持效期可维持40天以上。这是一种局部、微量施药方法,施药时间在秋末或春初,多数有益生物已经停止或尚未开始活动,所以,对森林中许多有益昆虫的影响很小。     

试论英语中形容词的位置

形容词是修饰名词,补充说明它的意思、但又限制了这个名词应用范围的词.因此,形容词在句中的某些细微变化,特别是在句中位置上的变化,会产生令人意想不到的语言效果,甚至会引起歧意。本文着重探讨了形容词在句中的位置.同一个形容词在句中用于不同位置时(定语位置或表语位置,前置定语或后置定语)可能对句子含义产生影响。     

Chemistry and structure of nucleic acids of bacteriophages. Many forms of nucleic acids of bacteriophages show the ways that information is stored and reproduced

The nucleic acids of bacteriophages are characterized by a surprising multiformity. RNA and DNA may occur, the latter in single- or double-stranded form, circular or linear, with or without breaks or single-strand ends. Terminal redundancy may exist and the populations of linear phages may be uniform or randomly permuted. A double-stranded circular DNA does not occur in extracellular bacteriophage, but is often if not always formed after infection of the bacterial host. Phage DNA may be glucosylated or methylated to a certain extent, and the glucose and methyl residues may influence the stability of the DNA inside the host.     

Haldan keffer hartline

By the methods of comparative physiology, or of experimental biology, by the choice of a suitable organ, tissue or process, in some animal far removed in evolution, we may often throw light upon some function or process in the higher animals, or in man.     

叶蝉的食性,为害及为害状探讨

本文对我国叶蝉科昆虫的食性、为害及为害状作了概述。叶蝉均为植食性,与农林业生产关系密切。有过半种类为多食性,近半为寡食性或仅知一种寄主。寄主范围包括草本植物和木本植物。过半叶蝉以草本植物或主要以草本植物为寄主,近半以木本植物或主要以木本植物为寄主。叶蝉的为害包括以取食和产卵方式造成的直接为害,以传毒致病方式造成的间接为害。传毒叶蝉造成的致病经济损失,往往比其直接为害损失要重得多。为害状有三类,近小半为枯萎型,各有一小部分为卷缩凋萎型或白点焦枯型。     

露地草花在杭州西湖风景区的应用

露地草花是园林植物的重要组成部分。杭州西湖风景区在露地草花的应用方面,采用地被、花径等形式种植;选用顶生显露、抗性强、种子易得的品种,并合理利用球宿根花卉;根据花色和花期等主要特点,单植或混种,使之与环境相协调,取得了一定的效果。本文还总结了西湖风景区19科、33种露地草花的花期和主要习性。     

Evoked potential correlates of expected stimulus intensity

The electrophysiological responses to a flash of medium intensity have different wave shapes in trials in which the occurrence of bright stimuli or dim stimuli is expected. When a bright or dim stimulus is signaled, the potentials evoked by the medium stimulus resemble the responses evoked by a real bright or dim flash.     

凉山烟区土壤养分分析及施肥对策

对凉山不同烟区植烟土壤养分含量进行了综合评价分析,明确了土壤养分含量与土壤有机质和pH值的相关关系。结果表明:(1)凉山烟区土壤有机质含量中等偏丰富;氮含量中等偏低;北部烟区磷含量中等,南部烟区磷含量中等偏低;北部烟区钾含量偏低,南部烟区钾含量中等偏丰富;氯、硼含量偏低;铜、锌、铁、锰含量呈中等偏丰富水平;北部烟区钙含量中等偏低,南部烟区钙含量丰富;北部烟区镁含量中等偏低,南部烟区镁含量中等偏丰富;北部烟区阳离子交换量偏低,南部烟区阳离子交换量中等;北部烟区土壤偏酸性,南部烟区各约有1/3的土壤偏酸性和偏碱性。(2)氯、钙、镁、锰与有机质含量呈负相关关系,其余养分含量与有机质呈正相关关系;钙、镁与土壤pH值呈正相关关系,其余养分含量与土壤pH值呈负相关关系。并针对该烟区植烟土壤养分状况提出施肥建议。     

Protein content of seed: increase improves growth and yield

Oat seeds with a higher protein content as a result of chemical applications in 1967 yielded 21 to 42 percent more grain in 1968. Wheat seed, whether from Michigan, Illinois, or Mexico, that contained more protein as a result of field applications of chemicals or nitrogen developed into larger seedlings. The content of protein in the seed correlated with subsequent growth and yield, indicating that the amount of endogenous protein or of a proteinaceous moiety, which can be controlled, may be an important factor in subsequent yield of major agronomic crops.     

星天牛的防治试验研究

星天牛在我国分布较广泛,能危害多种林木,近年来在椒江市木麻黄防护林中发生较严重,主要以幼虫钻蛀木质部,形成弯曲的蛀道,被害木轻则生长衰弱,重则易造成风折、风倒或整株枯死。此虫在椒江1年发生1代,以幼虫在木质部中越冬。对它有效的防治方法主要是:人工捕捉成虫;击杀卵和初龄幼虫;喷洒25％菊乐合酯或40％SN-851乳油1500倍液杀卵和小幼虫,用80％敌敌畏、90％敌百虫或40％SN-851乳油2000倍液,也可用20％杀灭菊酯、2.5％溴氰菊酯乳油2500倍液,将上述药液注入通气孔可收到90％的防治效果,用百部的块根堵塞通气孔,可获得87％左右的防治效果。     

Thermal spectrum of uranus: implications for large helium abundance

An analysis of the infrared spectrum of Uranus' disk between 7 micrometers and 3 millimeters suggests a volume mixing ratio for helium in the atmosphere of 40 +/- 20 percent, more than for the sun, Jupiter, or Saturn. Alternative explanations require even more extreme assumptions regarding gas abundances or aerosol vertical distribution and spectral properties. The most serious difficulty with a model containing large amounts of helium is devising a credible evolutionary or chemical model explaining the absence or segregation of so much hydrogen.     

因子分析在向日葵农艺性状相关研究中的应用

本研究应用R型主因子分析法对1987年和1988年向日葵杂交种的9个主要农艺性状进行了因子分析。结果表明:(1)因子分析结果因环境而异,在实际应用时应特别注意;(2)不同试材、不同环境的因子分析结果或结论又有相当程度的一致性,而育种工作者就是要利用这种一致性指导选择、鉴定以及决策等环节。两年的分析都可把原始性状分解成4个相互独立的性状群即公因子,而其中表现稳定的有单株生产力因子、营养生长势因子和品质因子。如果这些公因子在向日葵群体中真实存在的话,就可以按因子逐步改良从而达到提高产量和改进品质的目的。其改良效果可望超过单个性状的独立选择法。     

Human cloning and our sense of self

This Viewpoint formulates and responds to three lines of argument concerning human reproductive cloning's potential to undermine our sense of self or identity. First, cloning would undermine our sense of individuality or uniqueness. But it could only undermine our genetic uniqueness, not our full individuality. Second, cloning would undermine the value or worth of human beings. But it would not make individuals replaceable or of any less moral worth. Third, a clone's freedom or autonomy to construct his or her own life would be undermined by the presence of an earlier twin. But only a mistaken belief in genetic determinism supports this feared loss of freedom.