中国农业生态的能流能值分析

应用最新能值分析理论和方法,以能值为共同尺度,定量分析中国农业生态系统的能物流,包括自然环境资源、石化补助能和可更新有机能的能值投入,以及农牧渔业的产出能值;计算得出一系列反映生态与经济的能值综合指标体系,绘制了中国农业总体生产系统能流能值模型图;评估了国家农业环境资源基础、能投结构和能值产出,并与一些发达国家比较分析,评价了中国农业的生态经济效益,分析了农业总体结构、能投结构,为农业生产的持续、     

辽宁省朝阳市农业生态经济系统能值分析

应用能值分析的方法,研究了以辽宁省朝阳市为代表的辽西半干旱区农业生态经济系统的能值投入及产出结构,并通过计算、对比能值评价指标,分析了朝阳市农业生态经济系统的发展现状。结果表明,对自然资源的过度利用造成了当地生态环境条件的恶化,由此产生不可更新自然资源的流失以及产出能值的损失;对可更新有机能的不充分利用也是造成当地资源浪费和环境破坏的重要原因。     

黄土高原-青藏高原过渡带农户生产系统的能值分析——以通渭-渭源-夏河样带为例

通渭-渭源-夏河样带位于黄土高原向青藏高原过渡的生态区,是我国典型农牧交错带。长期以来,不合理的农业生产结构带来生态、经济等一系列问题,制约了该地区草地农业的持续发展。为此,从能值角度分析区域农业生产结构,可为农(牧)户决策提供理论依据,为优化区域农业生产结构提供科学依据。收集研究区农户作物和家畜生产的投入-产出数据,用能值方法分析农户生产系统结构特征、农户生产决策行为及生产系统耦合作用,用结构方程模型(SEM)分析农户生产系统能量的组分间流动。研究发现,随海拔增高,农户作物生产活动减少,作物总产出能值递减;尽管作物生产主要投入和产出要素相同,但同一作物不同地点的同一要素投入、产出能值和能值收益率均存在显著差异(P0.05);同一地点不同作物的同一要素投入、产出能值和能值收益率均差异显著(P0.05);作物生产投入要素中,有机肥能值在通渭和渭源均有较高贡献;作物投入和产出能值的农户生产决策阈值自东向西递减,在能值投入初始增加时,夏河农户作物生产规模扩增最为迅速。家畜养殖规模、能值投入和产出自东向西递增;通渭和渭源,小麦秸秆和苜蓿作为中间投入,能值贡献率达到80%;夏河家畜生产投入要素中,补饲粮食能值贡献率高达90%;家畜投入和产出能值的农户生产决策阈值点自东向西递增;能值收益率随耦合度的增加呈指数上升,通渭和渭源能值收益率的增加速度,随耦合度的增加趋于缓慢,而夏河能值收益率增速随耦合度的增加而上升。调整作物生产内部粮、经、饲产品比例结构,加强作物生产与家畜生产耦合作用,优化天然草地利用方式,实现生态效益最大化;阈值点调控农户生产决策行为,实现该区域农业生产结构优化。     

四川省农业生态系统能值评价及动态计量分析

农业生态系统是人类生存的最基本系统,对其结构和功能进行分析是破解农业生态环境问题的关键.本文应用能值分析理论并借助数据包络分析法、协整检验、误差修正模型等经济计量方法,对1997-2009年四川省及其21个地级市农业生态系统的运行动态、环境承载情况、运行效率、投入产出关系进行定量分析.结果表明:研究期间,四川省处在由传统农业向现代农业过渡阶段,农业机械化水平不断提高,资源利用效率不断加强,结构优势度总体情况较好,而过度依赖经济能值的投入使系统可持续性能力逐年减弱;区域间农业生态系统发展状况的差异较大,成都平原区和川西高原区要么资源开发过度,要么资源利用不足,而四川丘陵地区农业生态系统富有活力和发展潜力,属于四川农业未来发展的重点区域;四川省农业生态系统总体运行效率较低,各地状况不一,既包括技术效率较低因素,也有规模不当的原因;四川省农业生态系统经济能值指标与产出能值之间存在长期均衡动态关系,但短期内的能值投入远未达到理想的产出状态.     

广西恭城月柿生态农业旅游能值分析

应用奥德姆（H.T.Odum）创立的生态经济系统能值（emergy）分析理论和方法,定量分析广西恭城瑶族自治县月柿生态农业旅游经济系统的物流和能流,以期为当地和中国欠发达地区的可持续发展提供科学依据。研究结果表明：2004年,该县红岩月柿生态“农业-旅游”经济系统经济投入为12.74×10^5$,经济产出为35.47×10^5$,实现经济净收益22.73×10^5$。与原生态农业系统相比,复合系统在经济投入增加17.2%的情况下,经济产出增加126%以上,经济净收益约为原生态农业系统的4.75倍,经济产投比由原系统的1.44变为复合系统的2.78。发展生态旅游之后,当地新的生态农业旅游系统在环境投入不变的情况下,增加对环境资源的经济反馈9.24×1017sej,使能值产出增加9.79×10^18sej,新系统净效益是原生态农业系统的4.74倍,净能值产出率为原生态农业系统的1.94倍,能值投资率比原生态农业系统提高17%。研究结果还指出：目前恭城县红岩月柿生态农业旅游经济系统正处于发展的初级阶段。     

四川省汶川县生态经济系统能值分析

基于能值理论和分析方法,应用统计和实地调查数据,对四川省汶川县1982-2002年的生态经济系统进行了分析.结果表明:汶川县的经济水平较低,规模较小;主要能值投入为可再生资源;能值产出中不可再生资源能值占大部分,主要来自矿产资源和水泥生产;研究区输出大量能值,项目包括矿产资源和木材资源,大量的能值输出,特别是木材能值输出已使得研究区脆弱的生态环境出现生态问题;汶川县的人均能值消费水平较低,生活水平不高;研究区应注意经济与生态的协调发展.     

湖南省农业生态系统能值演变与趋势

应用能值分析方法,对1999-2008年湖南省农业生态系统的能值总量、投入和产出结构以及各能值指标的变化进行趋势分析.结果表明:研究期间,湖南省农业生态系统总能值使用投入量基本保持平稳,但能值投入结构有变化,其中,不可更新工业辅助能值投入量由4.00E+22 sej增至5.53E+22 sej,可更新有机能值投入量由1.32E+23 sej降至1.20E+23 sej;系统能值产出总量和产出效率均有较大幅度的提高,2008年总能值产出达1.69E+23 sej,比1999年提高23.8％,净能值产出率由0.79升至0.96;由于环境负载率也呈不断上升的趋势(由1.12上升到1.79),可持续发展指数呈缓慢下降趋势,由0.71降至0.54,说明湖南省农业总体属于高消费驱动型生态系统,具有较明显的粗放式发展特征.     

基于能值分析的深圳市三个小型农业生态经济系统研究

应用能值分析方法,通过能值转换率,把深圳市3个农场生态经济系统的能量流、物质流、货币流和信息流转化为统一量纲———能值。在绘制能值系统概图和编制能值分析表的基础上,建立能值评价指标体系对3个系统的能值输入结构、生产效率、环境负载和可持续发展状况等进行分析和比较。此外,比较经济指标与能值分析结果,并采用情景分析对农场未来发展做出预测。能值分析方法不仅考虑环境及其服务功能对经济生产的贡献,同时能值交换率和能值产出率把系统经济流入和产出纳入分析过程,结合环境和经济评价,可用于综合分析农场生态效益和经济效益。研究结果表明:西丽果场是可持续发展能力最高的农场,碧岭现代农业科技园次之,而山海农场的可持续发展能力最低。都市农场应该大比例利用可更新资源,努力发展农业生产,并且积极提升农业的技术含量。在此基础上,控制规模合理地发展旅游经济,走高科技农业生态旅游之路。     

毛乌素沙地县域典型农、牧户单元生态经济系统能值分析

农、牧户单元生态经济系统作为最基层的生产单位,关系着国家大政方针政策的落实和实施.运用能值理论及其分析方法,选择毛乌素沙地偏牧区的内蒙古自治区乌审旗苏力德苏木典型牧户生态经济系统和偏农区的陕西省榆阳区牛家梁镇典型农户生态经济系统作为研究对象,对两种不同产业偏重区产业模式的能值投入、产出结构状况进行对比分析,结合净能值产出率、能值投资率、环境负荷力、能值功率密度、单位面积生产力、人均能值用量、人均能值占有量、系统生产优势度、系统稳定性指数和系统可持续性指数共10项能值分析综合指标体系,全面系统地对农、牧户单元生态经济系统进行比较研究,定量描述典型农、牧户单元生态经济系统格局及其发展的总体特征.旨在为毛乌素沙地偏牧区和偏农区农、牧户经营层面的产业模式优化及发展提供策略选择.     

基于能值的天山北坡经济带农牧系统可持续性评估

应用能值分析理论和方法,对新疆天山北坡经济带农牧业生态经济系统进行了分析和评价,通过一系列的能值指标定量分析了该地区的农牧业系统的能值流动。结果表明:环境资源对农牧业系统的贡献很大,环境资源能值占总能值利用的79.2%,高于全国农业系统平均值(13%);净能值产出率为4.81,高于我国平均值(0.27),说明该区域农牧系统生产有一定的竞争优势;农牧业产品的宏观经济价值大于市场价值,这是由于农牧业生产中有相当大一部分环境资源无偿投入所致;环境负载率指标为0.373,低于我国农业系统的环境负载率(2.8),环境压力较小;可持续发展指数为12.90,有较好的发展潜力,据此,提出了一系列促进区域农业可持续发展的产业结构调整措施。     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

History of the discovery of the mode of transmission of yellow fever virus

This essay documents and examines the historical circumstances and events surrounding the discovery of the mode of transmission of yellow fever virus in Cuba. Close scrutiny of the articles published by Walter Reed and his colleagues in 1900, 1901 and 1902 reveals their limitations as historic documents. Fortunately, other sources of information from that period survive in letters and documents written by individuals involved in the quest for the mode of transmission. Examination and comparison of those sources of information unveiled a fascinating story which reveals that misunderstandings engendered by published articles accorded merit where it was not fully due.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。