Water Vapor Maser "Turn-On" in the HII Region W3 (OH)

A line in the water vapor maser spectrum of the HII region W3(OH) was observed to increase in brightness over an 8-day period and then decline to its original intensity over the following 4 weeks. The intensity variation can be explained by a simple maser model, with an impulse of energy suddenly applied. The observed time scale and energy output are consistent with a maser on the outskirts of a dust cocoon surrounding an O5 star, with a momentary "leak," lasting a day or. two, supplying the necessary energy.     

"Where" and "what" in vision

The mixture of a few horizontal and vertical line segments embedded in an aggregate of diagonal line segments can be rapidly counted and their positions rapidly determined by a parallel (preattentive) process. However, the discrimination between horizontal and vertical orientation (that is, discrimination of a single conspicuous feature) requires serial search by focal attention. Under recent theories of attention, focal attention has been assumed to be required for the recognition of different combinations of features. According to the findings of this experiment, knowing "what" even a single feature is requires time-consuming search by focal attention. Only knowing "where" a target it is mediated by a parallel process.     

An examination of "transfer of learning" by nucleic Acid

Nucleic acid extracted from brains of trained animals and injected intraperitoneally into naive animals produced no "transfer of learning" effect on several tasks under many conditions. P(325)-Labeled RNA was not found in the brain after intraperitoneal administration. Even intraventricular injections of nucleic acid produced no "transfer" effect.     

SQL Server数据库"置疑"的原因及解决方法

SQL Server数据库因为软件,硬件或人为因素,常常被标记为"置疑",而导致数据库不能正常访问.文中给出了SQL Server数据库"置疑"的几种原因,以及由这些原因引起而采用相应的解决方法.这些解决方法均通过实践证明,简便可行,安全可靠,能够达到恢复数据库的目的.     

Hippocampectomy and behavior sequences

Four monkeys with bilateral hippocampal lesions were trained to respond sequentially to visual stimuli, presented with an automated discrimination apparatus. Two different sequential tasks were presented. The experimental animals were significantly inferior on both problems to six control animals. Since no impairment appeared on simple visual discriminations presented with intertrial intervals from 5 seconds to 6 minutes, simple sensory deficits and "short-term" memory impairments appear unlikely. The results strengthen the interpretation that bilateral hippocampal lesions interfere with the acquisition of those behaviors which involve the execution of sequential responses.     

从“民工潮”到“民工荒”——我国农村剩余劳动力转移的制度瓶颈探析

通过阐述二元经济理论的三阶段特性及其对中国工业化和城市化进程的现实意义,并将＂刘易斯拐点＂的重要评判标准与中国农村剩余劳动力市场的现状进行对比分析发现：我国农村存在大量剩余劳动力,农民收入的提高是政府外在干预的结果,我国的人口红利并未结束,这些现象与＂刘易斯拐点＂理论相违背,从而证实中国的＂刘易斯拐点＂并未到来。造成我国＂民工荒＂与劳动力过剩并存的现状主要因素包括：一是劳动力市场的结构性矛盾的结果;二是劳动力市场供求规律作用的结果;三是阻碍劳动力自由流动户籍、社会保障等制度性障碍的结果。因此,实现农村剩余劳动力的顺利转移和中国工业化、城市化的目标,必须从宏观层面促进产业结构升级转变经济增长方式,实现区域经济的协调发展;从微观层面消除阻碍农村剩余劳动力转移的制度性障碍。     

GRAPES不同参数化方案对新疆“4．18”寒潮降雪的敏感试验

利用我国新一代数值预报模式GRAPES,选择Kessler、NCEP3-class simple ice和simple ice微物理过程参数化方案和Kain—Fritsch、Betts-Miller-Janjic积云参数化方案形成6个组合,对新疆“4．18”寒潮天气的降雪过程进行预报试验,并与实况资料进行比较、检验。结果表明,就降雪个例而言,预报效果相对好的参数化方案存在不确定性,积云参数化方案对降雪的影响比微物理过程参数化方案对降雪的影响大。NCEP3-class simple ice与Kain-Fritsch方案组合对“4．18”寒潮天气降雪量的预报较好。     

"Hypersexuality" in male cats without brain damage

During 5 years of observation in a cat colony where mating tests are routinely conducted, the spontaneous occurrence of distortions of sexual activity in male cats has been recorded. Many of the behavioral patterns encountered have previously been described only in brain-damaged animals when they have been used as an index of "hypersexuality." Identical behavior occurs in normal males as a simple training effect.     

High-resolution microwave images of saturn

An analysis of high-resolution microwave images of Saturn and Saturn's individual rings is presented. Radio interferometric observations of Saturn taken at the Very Large Array in New Mexico at wavelengths of 2 and 6 centimeters reveal interesting new features in both the atmosphere and rings. The resulting maps show an increase in brightness temperature of about 3 K from equator to pole at both wavelengths, while the 6-centimeter map shows a bright band at northern mid-latitudes. The data are consistent with a radiative transfer model of the atmosphere that constrains the well-mixed, fully saturated, NH(3) mixing ratio to be 1.2 x 10(-4) in a region just below the NH(3) clouds, while the observed bright band indicates a 25 percent relative decrease of NH(3) in northern mid-latitudes. Brightness temperatures for the classical rings are presented. Ring brightness shows a variation with azimuth and is linearly polarized at an average value of about 5 percent. The variations in ring polarization suggest that at least 20 percent of the ring brightness is the result of a single scattering process.     

American Jurassic symmetrodonts and Rhaetic "pantotheres"

The molar morphology of the symmetrodonts Tinodon and Eurylambda from the late Jurassic of North America is virtually identical to that of so-called "pantotheres" from the Rhaetic of Wales. Therefore a primitive symmetrodont molar pattern was probably present in the phylogeny of pantotherian and tribosphenic molars. Occlusion of Tinodon and Eurylambda produced complex wear facets unlike the simple trigon-trigonid shear surfaces of Spalacotherium and Peralestes.     

Nucleotide sequence of the "denaturable" leucine transfer RNA from yeast

The nucleotide sequence of " denaturable"leucine acceptor transfer RNA (tRNA(Leu)(3)) from baker's yeast was determined on (32)P-labeled material. The molecule is 85 nucleotides long and can be folded into the "cloverleaf" model for secondary structure. The basis on which the sequence was deduced from the products of complete enzymatic digestion, prior to its unambiguous determination, is presented.     

《寻找母亲花园》的黑人女性主义传统--兼谈爱丽丝·沃克的黑人女性主义观

爱丽丝·沃克在<寻找母亲花园>中揭示了奴隶制和种族歧视的政治、经济和社会的约束,历史性地扼杀了黑人妇女的创造性这一事实,追寻了黑人女性主义传统,用动人的笔调把黑人妇女受到压制的创造力追溯到像缝制被子和培育鲜花这种无语的艺术形式,运用这种无语的艺术形式所蕴含的隐喻来寻找黑人文学母系.沃特对传统的挖掘这一工作对美国黑人女性文学、黑人文学以及整个美国文学都具有重大意义.     

本溪动物园药用“百草园”开发利用探讨

通过简单介绍本溪动物园的基本情况,就本溪动物园药用“百草园”开发利用的可行性进行了较为详细的分析,并对开发利用的成效、成功经验及存在的问题做了初步探讨.     

治理“空心村” 提高土地复耕率对策研究

自古以来,土地就是一切经济活动的基础,是人类生存与发展的基本条件,但近年来,在我国由于"空心村"问题的存在,造成了大量土地浪费的现象。文章从"空心村"的现状入手,分析了其缺乏法律规范、村级规划滞后、城乡人口流动、缺乏土地流转机制以及村民思想意识尚未转变等形成原因,并依此提出了提高土地复耕率的对策。     

The life and death of "Bare" viscous bubbles

Air bubbles collect and explode at the surface of many viscous liquids, as observed with polymer foams, in glass furnaces, and during volcanic eruptions. The liquid film separating the bubble from bulk air can have a long lifetime (if it is viscous) even if it is not protected by a surfactant. These "bare" films display unusual dynamic behaviors in drainage and rupture. Two different model systems were studied: a polymer melt (silicone oil) and a molten (borosilicate) glass of comparable viscosity. Although the two systems differ greatly in their relaxation time, they are described by the same set of laws, which can be understood from a relatively simple hydrodynamic model.     

Probabilistic integrated assessment of "dangerous" climate change

Climate policy decisions are being made despite layers of uncertainty. Such decisions directly influence the potential for "dangerous anthropogenic interference with the climate system." We mapped a metric for this concept, based on Intergovernmental Panel on Climate Change assessment of climate impacts, onto probability distributions of future climate change produced from uncertainty in key parameters of the coupled social-natural system-climate sensitivity, climate damages, and discount rate. Analyses with a simple integrated assessment model found that, under midrange assumptions, endogenously calculated, optimal climate policy controls can reduce the probability of dangerous anthropogenic interference from approximately 45% under minimal controls to near zero.     

"退耕还林"英译管见

“退耕还林”的本质是把一度为了生产粮食而毁林开垦的土地,停止耕种,重新造林,恢复森林。目前不少译文把“退耕还林”译为grain for green(绿化),或returning farmland toforestland(把农地转为林地)等,使人易误认为是荒山造林绿化(荒山→森林)或把现有农业用地转变为林业用地(农地→林地)。文章认为,要把“退耕还林”译得科学规范,必须抓住其本质。通过分析比较,给出了conversion of farmland back to forests,transfer of farmland back toforests和forest rehabilitation from slope agriculture等几种参考译法。参17     

Changing the acceptor identity of a transfer RNA by altering nucleotides in a "variable pocket"

The specificity of tRNA(Arg) (arginine transfer RNA) for aminoacylation (its acceptor identity) were first identified by computer analysis and then examined with amber suppressor tRNAs in Escherichia coli. On replacing two nucleotides in tRNA(Phe) (phenylalanine transfer RNA) with the corresponding nucleotides from tRNA(Arg), the acceptor identity of the resulting tRNA was changed to that of tRNA(Arg). The nucleotides used in the identity transformation occupy a "variable pocket" structure on the surface of the tRNA molecule where two single-stranded loop segments interact. The middle nucleotide in the anticodon also probably contributes to the interaction, since an amber suppressor of tRNA(Arg) had an acceptor identity for lysine as well as arginine.     

农村土地“三权分置”研究综述

近年来,农村土地“三权分置”这一相关研究逐渐受到各界学者的重视,本文旨在更好 的渗透三权分置相关理论,并对其进行宏观的掌握。登录中国知网检索相关关键字,将文章从 检索现状分析;三权分置的起源与发展;三权分置的意义;三权分置的防范机制四个方面进行梳 理,接下来,“三权分置”的相关研究可以更多地从微观个体（如土地流转的交易双方等）、流转意 愿等主观因素、地域发展不平衡等客观因素对“三权分置”的影响这几方面入手。     

农民工“候鸟式”流动就业对农村经济的影响解析

在农村和城市的推拉力的作用下,中国农民工呈现＂候鸟式＂流动就业模式。农民工的这种＂候鸟式＂流动就业模式,是在中国城市化和现代化进程中所特有的现象,不同于西方国家的农村劳动力转移模式,这种＂候鸟式＂流动对中国农村经济带来一系列重要的、深刻的影响。