从生态位观点评价苏南地区种植业结构调整

从生态位观点评价苏南地区种植业结构调整高德明（南京农业大学农学系,２１００１４）ＥｖａｌｕａｔｉｏｎｏｆＣｒｏｐｐｉｎｇＳｔｒｕｃｔｕｒｅＡｄｊｕｓｔｌｎｅｎｔｓｉｎＳｏｕｔｈｅｒｎＪｉａｎｇｓｕｆｒｏｍｔｈｅＶｉｅｗｐｏｉｎｔｓｏｆＮｉｃｂｅＴｋｅｏｒｙ￥．ＧａｏＤｅｍｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＡｇｒｏｎｏｍｙ,ＮａｎｊｉｎｇＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖｅｒｓｉｔｙ,２１００１４）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥ－ｃｏｌｏｇｙ,１９９３,１２（２）：４３－４４．ＡｃｃｏｒｄｉｎｇｔｏｔｈｅｃｏｎｃｒｅｔｅｃｏｎｄｉｔｉｏｎｓｉｎｓｏｕｔｈｅｒｎＪｉａｎｇｓｕ,ｔｈｅｓｉｇｎｉｆｉｃａｎｃｅ,ｎｅｃｅｓｓｉｔｙａｎｄｐｏｓｓｉｂｉｌｉｔｙｏｆａｄ－ｊｕｓｔｉｎｇｃｒｏｐｐｉｎｇｓｔｒｕｃｔｕｒｅａｒｅｅｖａｌｕａｔｅｄｆｒｏｍｔｈｅｖｉｅｗｐｏｉｎｔｓｏｆｎｉｃｈｅｔｈｅｏｒｙ．Ｔｈｅｅｆｆｉｃｉｅｎｃｉｅｓｏｆｔｗｏｃｒｏｐ－ｐｉｎｇｓｙｓｔｅｍｓｉｎｕｔｉｌｉｚｉｎｇｐａｄｄｙｆｉｅｌｄｎｉｃｈｅｓａｒｅａｎａｌｙｚｅｄａｎｄｔｈｅｒｅｓｕｌｔｓｓｈｏｗｔｈａｔｔｈｅｃｒｏｐｐｉｎｇｐａｔ     

南方丘陵山区农业生态环境的改善：—以五华县新一村为例

南方丘陵山区农业生态环境的改善──以五华县新一村为例钟继洪,唐淑英,谭军（广东省土壤研究所,广州５１０６５０）ＩｍｐｒｏｖｅｍｃｎｔｏｆＡｇｒｏ－ｅｃｏｌｏｇｉｃａｌＥｎｖｉｒｏｎｍｅｎｔｉｎＨＩｉｌｌｙａｎｄＭｏｕｎｔａｉｎｏｕｓＡｒｃａｓｏｆＳｏｕｔｈＣｈｉｎａ：ＴａｋｉｎｇＸｉｎｙｉＶｉｌｌａｇｅｏｆＷｕｈｕａＣｏｕｎｔｙａｓａｎＥｘａｍｐｌｅ￥．ＺｈｏｎｇＪｉｈｏｎｇ,ＴａｎｇＳｈｕｙｉｎｇ,ＴａｎＪｕｎ（ＧｕａｎｇｄｏｎｇＩｎｓｔｉ－ｔｕｔｅｏｆＳｏｉｌＳｃｉｅｎｃｅ,Ｇｕａｎｇｚｈｏｕ５１０６５０）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（４）：５２－５４．ＸｉｎｙｉｖｉｌｌａｇｅｒｅｐｒｅｓｅｎｔｓａｔｙｐｉｃａｌｈｉｌｌｙａｎｄｍｏｕｎｔａｉｎｏｕｓａｒｅａｉｎＧｕａｎｇｄｏｎｇｐｒｏｖｉｎｃｅ．Ａｓａｒｅｓｕｌｔｏｆｐｒｏ－ｌｏｎｇｅｄｅｘｔｅｎｓｉｖｅｅｘｐｌｏｉｔａｔｉｏｎｏｆｎａｔｕｒａｌｒｅｓｏｕｒｃｅｓ,ｉｔｓａｇｒｏ－ｅｃｏｌｏｇｉｃａｌｅｎｖｉｒｏｎｍｅｎｔｗａｓｗｏｒｓｅｎｅｄ．Ｔｈｒｏｕｇｈｈａｒｎｅｓｓｉｎｇｔｈｅｌａｎｄｒｅｓｏｕｒｃｅｓｏｆｔ     

农业生态系统的人类生态学分析模式探讨

农业生态系统的人类生态学分析模式探讨李季（北京农业大学农业生态环境科学系,１０００９４）ＡｎＡｎａｌｙｔｉｃａｌＭｏｄｅｌｏｆＡｇｒｏｅｃｏｓｙｓｔｅｍｆｒｏｍＨｕｍａｎＥｃｏｌｏｇｙＰｅｒｓｐｅｃｔｉｖｅ￥．ＬｉＪｉ（ＤｅｐａｒｔｍｅｎｔｏｆＥｃｏｌｏｇｙａｎｄＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｓ,ＢｅｉｊｉｎｇＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖｅｒｓｉｔｙ１０００９４）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（２）：２３－２４．Ｂａｓｅｄｏｎｔｈｅａｎａｌｙｓｉｓｏｆｏｕｒｃｕｒｒｅｎｔａｇｒｏ－ｅｃｏｌｏｇｉｃａｌｒｃｓｅａｒｃｈ,ａｎｅｗａｎａｌｙｔｉｃａｌｍｏｄｅｌｏｆａｇｒｏ－ｅｃｏｓｙｓｔｅｍｋｅｓｔａｂｌｉｓｈｅｄａｎｄｔｈｅｃｏｎｔｅｎｔｓｏｆｉｔｓｒｅｓｅａｒｃｈａｒｅｒｅｓｔｒｕｃｔｕｒｅｄ．Ｔｈｅａｉｍｏｆｔｈｅｓｅｉｓｔｏｐｒｏｖｉｄｅａｍｏｄｅｌｆｏｒｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｒｅｇｉｏｎａｌａｇｒｉｃｕｌｔｕｒｅ,ｗｈｉｃｈｃａｎｎｏｔｏｎｌｙｅｘｐａｎｄｔｈｅｃｕｒｒｅｎｔｒｅｌａｔｅｄｔｈｅｏｒｉｅｓａｎｄｍｅｔｈｏｄｏｌｏｇｉｅｓ,ｂｕｔ     

THINOPYRUM BESSARABICUM和THINOPYRUM ELONGATUM的基 …

对２个八倍体Ｃ．Ｓ－Ｔｈｉｎｏｐｙｒｕｍ ｂｅｓｓａｒａｂｉｃｕｍ（ＡＡＢＢＤＤＪＪ,２ｎ＝８ｘ＝５６）和Ｇｏｓｈａｗｋ（ＧＨＫ）－Ｔｈｉｎｏｐｙｒｕｍ ｅｌｏｎｇａｔｕｍ（ＡＡＢＢＤＤＥＥ,２ｎ＝８ｘ＝５６）的根尖细胞染色体进行Ｃ－分带,从中分检出Ｔｈ．ｂｅｓｓａｒａｂｉｃｕｍ和Ｔｈ．ｅｌｏｎｇａｔｕｍ的各自染色体进行核型分析,结果表明：Ｔｈ．ｂｅｓｓａｒａｂｉｃｕｍ和Ｔｈ．ｅｌｏｎｇａｔｕｍ的     

Inhibition of GST－π Expression by Retrovirus－mediated Antisense RNA Transfection

ＩｎｈｉｂｉｔｉｏｎｏｆＧＳＴ－πＥｘｐｒｅｓｓｉｏｎｂｙＲｅｔｒｏｖｉｒｕｓ－ｍｅｄｉａｔｅｄＡｎｔｉｓｅｎｓｅＲＮＡＴｒａｎｓｆｅｃｔｉｏｎ￥ＺＨＯＵＺｈｏｎｇ－ｊｕｎ（周中军）；ＪＩＮＳｈｕｎ－ｑｉａｎ（金顺钱）；ＬＵＯＸｉａｎ－ｍａｏ（罗贤懋...     

便携多路环境数据采集系统

便携多路环境数据采集系统姜仕仁，常杰，葛滢（杭州大学生物科学与技术系，３１００１２）ＡＰｏｒｔａｂｌｅＭｕｌｔｉ－ＰａｓｓａｇｅＥｎｖｉｒｏｎｍｅｎｔａｌＤａｔａＡｕｔｏ－ＳａｍｐｌｉｎｇＳｙｓｔｅｍ．￥ＪｉａｎｇＳｈｉｒｅｎ；ＣｈａｎｇＪｉｅ；Ｇｅ...     

利用PE构建免疫毒素

利用ＰＥ构建免疫毒素蒋欣黄华梁（中国科学院遗传研究所,北京１００１０１）ＰＥａｎｄＰＥ－ｄｅｒｉｖｅｄＲｅｃｏｍｂｉｎａｎｔＩｍｍｕｎｏｔｏｘｉｎｓＪｉａｎｇＸｉｎＨｕａｎｇＨｕａｌｉａｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＧｅｎｅｔｉｃｓ,ＣｈｉｎｅｓｅＡｃ...     

联合固氮研究进展

联合固氮研究进展李久蒂安千里（中国科学院植物研究所,北京１０００９３）ＡＤＶＡＮＣＥＳＩＮＡＳＳＯＣＩＡＴＥＤＮＩＴＲＯＧＥＮＦＩＸＡＴＩＯＮＲＥＳＥＡＲＣＨＬｉＪｉｕ－ｄｉＡｎＱｉａｎ－ｌｉ（ＩｎｓｔｉｔｕｔｅｏｆＢｏｔａｎｙ,ＣｈｉｎｅｓｅＡｃ...     

Regulation of C－Fos mRNA Expression in Sertoli Cells by cAMP，Ca~（＋＋），and protein Kinase C－mediated Pathways

ＲｅｇｕｌａｔｉｏｎｏｆＣ－ＦｏｓｍＲＮＡＥｘｐｒｅｓｓｉｏｎｉｎＳｅｒｔｏｌｉＣｅｌｌｓｂｙｃＡＭＰ，Ｃａ~（＋＋），ａｎｄｐｒｏｔｅｉｎＫｉｎａｓｅＣ－ｍｅｄｉａｔｅｄＰａｔｈｗａｙｓ￥ＪＩＡＭｅｎｇ－ｃｈｕｎ；（贾孟春）；ＮｅｅｌａｋａｎｔａＲ?..     

洞庭湖滨湖湿地平原农村生态工程初步研究

洞庭湖滨湖湿地平原农村生态工程初步研究严斧,游有林,刘劲凡,卢源德,周为民（中国科学院生态环境研究中心系统生态室沅江课题组,大庸市４１６６００）ＲｕｒａｌＥｃｏｌｏｇｉｃａｌＥｎｇｉｎｅｅｒｉｎｇｏｎＷｅｔｌａｎｄＰｌａｉｎｏｆＤｏｎｇｔｉｎｇＬａｋｅｓｉｄｅ￥．ＹａｎＦｕ;ＹｏｕＹｏｕｌｉｎ;ＬｉｕＪｉｎｆａｎ;ＬｕＹｕａｎｄｅ;ＺｈｏｕＷｅｉｍｉｎ（ＹｕａｎｊｉａｎｇＲｅｓｅａｒｃｈＧｒｏｕｐ,ＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏ－ｅｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅ,Ａ－ｃａｄｅｍｉａＳｉｎｉｃａ,Ｄａｙｏｎｇ４１６６００）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（２）：４５—４８．ＡｃｃｏｒｄｉｎｇｔｏｔｈｅｍａｉｎｔｙｐｅｓｏｆｒｅｓｏｕｒｃｅｃｏｍｂｉｎａｔｉｏｎｓｏｎｗｅｔｌａｎｄｐｌａｉｎｏｆＤｏｎｇｔｉｎｇｌａｋｅｓｉｄｅ,ｓｅｖｅｒａｌｅｃｏ－ｌｏｇｉｃａｌｅｎｇｉｎｅｅｒｉｎｇｓｉｎｃｌｕｄｉｎｇｌａｋｅｓｉｄｅｒｅｅｄ－ｆｏｒｅｓｔ,ｌｏｗｌａｎｄｒｉｃｅ－ｆｉｓｈ－ｒａｍｉｅ,ｒｎａｎｕｒｅ－ｆｏｒａｇｅ－ｆｕｅｌ,ｆｉｓｈ－ｐｉｇ－ｄｕｃｋａｎｄｆ     

Investigation of ion acceleration in an expanding laser plasma by using a hybrid Boltzmann-Vlasov-Poisson model

The acceleration of ions of different species from a plasma slab under the action of a charge-separation electric field driven by hot and cold electrons is studied by using a hybrid Boltzmann-Vlasov-Poisson model. The obtained spatial and energy distributions of light and heavy ions in different charge states demonstrate that the model can be efficiently used to study the ion composition in a multispecies expanding laser plasma. The regular features of the acceleration of ions of different species are investigated. The formation of compression and rarefaction waves in the halo of light ion impurity, as well as their effect on the energy spectrum of the accelerated ions, is analyzed. An approach is proposed that makes it possible to describe the production of fast ions by laser pulses of a given shape. It is shown that the energy of fast ions can be increased markedly by appropriately shaping the pulse. The effect of heating of the bulk of the cold target electrons on the ion acceleration is discussed.     

棉田节肢动物群落的优势种分析

优势种作为生物群落的基本特征之一 ,是指那些由于其数量多、生物量大及其在食物链中有重要地位而对群落产生重大影响的物种。但在农田昆虫群落优势种分析中 ,通常是以数量的多少而确定其是否为优势种。事实上 ,尽管有些昆虫 (如害虫 )数量不多 ,不具备群落优势种的特征 ,但由于其个体大 ,对作物造成很大的危害。对于这类昆虫是否属于优势种类目前争论较大[1,5] 。棉花 (Ｇｏｓｓｙｐｉｕｍｈｉｒｓｕｔｕｍ )是我国重要的经济作物。其内节肢动物群落物种的组成与优势程度直接影响着棉花的生产。本文拟在系统调查棉田节肢动物群落的基础上 ,…     

晋东豫西旱农试验区农业生态系统能流特征

以晋东豫西旱农试验区－－山西省寿阳县宗艾镇宗艾村农业生态系统为研究对象,分析了农田、果园、林业和畜牧业等亚系统能量流动途径、人工辅助能输入、能量产出,能量结构偏差以及能量转化效率等能流特征。结果表明：（１）由于能量投入低,尽管利用效率较高,但能量产出仍处于低水平阶段。农田生态系统的有机能投入和人工辅助能总投入很低,低于１９７９年全国平均水平,但能量产投比较高,增加人工辅助能投入、提高有机能投入比例     

Energy efficiency of information transmission by electrically coupled neurons

The generation of spikes by neurons is energetically a costly process. This paper studies the consumption of energy and the information entropy in the signalling activity of a model neuron both when it is supposed isolated and when it is coupled to another neuron by an electrical synapse. The neuron has been modelled by a four-dimensional Hindmarsh–Rose type kinetic model for which an energy function has been deduced. For the isolated neuron values of energy consumption and information entropy at different signalling regimes have been computed. For two neurons coupled by a gap junction we have analyzed the roles of the membrane and synapse in the contribution of the energy that is required for their organized signalling. Computational results are provided for cases of identical and nonidentical neurons coupled by unidirectional and bidirectional gap junctions. One relevant result is that there are values of the coupling strength at which the organized signalling of two neurons induced by the gap junction takes place at relatively low values of energy consumption and the ratio of mutual information to energy consumption is relatively high. Therefore, communicating at these coupling values could be energetically the most efficient option.     

Monte Carlo calculations on the conformations of models for the glycopeptide linkage of glycoproteins

In order to search for probable conformations of the peptide, the amino acid side chain, and the carbohydrate linkage in glycoproteins, conformational energy surfaces of glycopeptide model compounds were studied by Monte Carlo methods using the Metropolis algorithm. The potential energies were composed of empirical energy functions which include nonbonded interactions, electrostatics, hydrogen bonding, and torsional energies specified by parameters which have been used for peptides. Calculations were performed on 1-N-acetyl-2-acetamido-beta-D-glucopyranosyl amine and the glycosylated dipeptide N-acetyl-delta-N-(2-acetamido-beta-D-glucopyranosyl)-L-asparaginyl-N'-methyl amide as models for N-glycosylated peptides and on methyl-2-acetamido-alpha-D-galactopyranoside as well as the glycosylated dipeptides N-acetyl-gamma-O-(2-acetamido-alpha-D-galactopyranosyl)-L-threonyl-N'-methyl amide and its seryl analog as models for O-glycosylated glycoproteins. The probable conformations of these compounds were analyzed by single-angle probability tables and by two-dimensional conformation density maps projected from the Markov chains which contained up to six independently varied conformational dihedral angles. The presence of high barriers to rotation required the use of search strategies which resulted in a rather low acceptance rate for new conformations in the Metropolis algorithm in order to avoid trapping of the Markov chain in local energy minima. This problem contributed to the failure of these calculations to attain complete convergence to the thermodynamic limit for the glycosylated dipeptide models in which six dihedral angles were independently varied. Analysis of the results shows that the conformational space available to the highly crowded axial glycosides of the alpha-O-GalNAc type is much more restricted than that for the N-asparaginyl glycopeptides. The most probable conformation for the O-glycosylated peptides is is a beta-turn while N-glycosylated peptides may be either in a beta-turn or an extended conformation.     

甲烷氧化菌研究进展

甲烷氧化菌以甲烷为其唯一的碳源和能源 ,在全球大气甲烷平衡中起着重要的作用 ,它还可以降解卤代化合物 ,在污染治理方面具有潜在价值。本文从甲烷氧化菌的分类出发 ,对甲烷氧化菌氧化甲烷的机理及影响因素、甲烷氧化菌的生理、生态分布及检测方法、甲烷氧化菌降解有机污染物的潜在应用等作一综述 ,分析目前研究中存在的问题 ,并指出今后应加强研究的方面。     

蒲洼农业生态系统能流的稳定性及其动态

在研究生态系统结构及功能的基础上,本文基于１９７５－１９９０年的数据,对蒲洼农业生态系统能流的稳定性及其动态进行了分析。通过建立能流模型,由李雅普诺夫稳定性原理,得出该生态系统能流的平衡态具有渐近稳定性。动态数学模拟表明,目前该系统的能量流动正从不稳定状态向稳定和平衡态过渡,这一过程大约需要７ａ时间。     

免疫能力与动物种群调节和生活史权衡的关系

在生物医学和动物科学领域,免疫能力是指有机体对疾病的抵抗能力.近年来,对野生动物免疫能力的研究是一个新兴的热点领域,它与生态学结合,产生了生态免疫学.本文从生态学的角度,介绍了免疫能力的概念、影响因素及其与动物种群调节机理的关系,概述了与小型哺乳动物种群密度波动有关的免疫衰退假说、免疫能力选择假说和冬季免疫增强假说,总结了免疫能力与能量代谢和内分泌特征之间的关系,并对免疫能力在生活史权衡研究中的最新进展,即有机体生长与免疫、繁殖与免疫之间的权衡关系等进行了阐述,最后结合国际上本学科研究的发展动态,提出了一些未来的研究方向.     

Selective decrease in protein intake following brain serotonin depletion.

The effect of reduced brain serotonin concentration achieved with drugs or raphé lesions on the control of protein intake and energy intake by young rats was examined. All rats were provided an oppurtunity to select from 15% and 55% casein diets provided simultaneously in two food cups. Systemic parachlorphenylalanine, central 5, 7-dihydroxytryptamine or mid-brain raphé lesions reduced by 20–30% the amount of protein consumed from these two diets over a two week study period. Across these same groups total energy intake was not different from the control groups. This decrease in the proportion of dietary energy selected as protein by the treated self-selecting rats was associated with the reduction observed in brain serotonin and its major metabolite, 5-hydroxyindole acetic acid at the completion of the feeding period. These findings support previous work implicating brain serotonin metabolism in the selective control of protein intake.     

干旱区绿洲廊道景观研究——以金塔绿洲为例

干旱区绿洲内主要廊道景观类型包括河流、水渠、田间防护林和公路等 .以金塔绿洲为例 ,介绍廊道景观在绿洲的形成与发展过程中传输物质和能量、阻隔荒漠景观扩展和入侵的基本生态功效 .利用GIS方法分析试验区内的廊道分布状况以及与各类景观之间的空间关系 .在近 10年景观格局的动态变化监测的基础上 ,分析廊道的驱动作用 .结果表明 ,用长度和宽度、周长和面积比、密度和非均匀度来表示廊道的各种特性 ;金塔绿洲廊道总长为 1838.5km ,密度为 2 .1km·km-2 ,以渠道和公路为主 ;水浇地、林地和城镇居民地廊道密度最大 ,受影响程度最高 ;绿洲内沟渠廊道质量的改进是影响水浇地等景观变化的重要驱动力之一 .