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放牧研究中的术语及其定义

草原与草坪 1981年第1期 65-66+64页

作者： j·hodgson 胡自治

草层1、草层(Sward)——草本植物群体地上和地下部分的总称。它的特点是具有相对较矮的生长习性和相对连续的地面覆盖。2、草层植冠(Sward Canopy)——草本植物群体的地上部分,它涵有植物各部分的排列和分布的意义。3、牧草(Herbage)—... 详细信息

草层1、草层(Sward)——草本植物群体地上和地下部分的总称。它的特点是具有相对较矮的生长习性和相对连续的地面覆盖。2、草层植冠(Sward Canopy)——草本植物群体的地上部分,它涵有植物各部分的排列和分布的意义。3、牧草(Herbage)——单本植物群体的地上部分,是一种具有数量和营养价值特征的植物物质的积累,但不涵植物学组成和结构的意义。4、放牧地(Pasture)——草本植物群体的地上部分,通常有围栏为界,是放牧的一种功能单位。5、牧草量(Herbags mass)——单位土地面积的牧草总量,通常指地上的水平。但需指出,地上的水平只具一定的参考意义。

关键词：采食动物行为农产品动物产品农畜家畜土地面积草本植物单位面积地上部分放牧季放牧时期时间长度动物生产

草地状况对母牛和绵羊采食习性影响的比较研究

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草原与草坪 1987年第1期 31-35页

作者： T.D.A.Forbes j.hodgson 丁文广田有凤

引言在对放牧的反刍家畜采食习性的研究中,发现草地结构的差异对单口采食量的变化有很大影响。随着单口采食量的下降,采食口数有所增加,放牧时间延长。但这种变化并不稳定,而且单口采食量的减少很难获得补偿,很少有文献报道关于牛和绵... 详细信息

引言在对放牧的反刍家畜采食习性的研究中,发现草地结构的差异对单口采食量的变化有很大影响。随着单口采食量的下降,采食口数有所增加,放牧时间延长。但这种变化并不稳定,而且单口采食量的减少很难获得补偿,很少有文献报道关于牛和绵羊对草地状况的变化在习性方面反应的比较研究。本文对此问题作了专门研究,比较了在整个放牧期间牛和绵羊对不同类型草地和草地结构变化的反应。

关键词：草地家畜农畜放牧周期牧草产量绵羊草层高度采食量采食时间母牛

不同生长阶段群体数量特征对产草量作用的分析

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草地学报 1997年第1期5卷 48-53页

作者：杨锦忠董宽虎夏景新 C.Matthew j.hodgson 山西农业大学山西太谷030801 中国农业大学北京100094 新西兰梅西大学

在相同的光、温、水、肥条件下，同时对营养生长期的高羊茅和生殖生长期的多年生黑麦草人工草地的产草量和群体数量特征的定量关系进行研究。在营养生长期，参数的变异程度小于生殖生长期。营养生长期各因子对产草量直接作用的程度排序... 详细信息

在相同的光、温、水、肥条件下，同时对营养生长期的高羊茅和生殖生长期的多年生黑麦草人工草地的产草量和群体数量特征的定量关系进行研究。在营养生长期，参数的变异程度小于生殖生长期。营养生长期各因子对产草量直接作用的程度排序为：叶面积指数＞草丛高度＞分蘖密度；生殖生长期为：草丛高度＞叶面积指数＞分蘖密度。因子的直接作用和间接作用的格局则因生长阶段而异。上述各种差异在评价草地状况时应加以充分考虑，以获得对草地系统的全面认识。

关键词：牧草产量营养生长群体数量特征黑麦草

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Storing Freshwater Versus Storing Electricity in Power Systems with High Freshwater Electric Demand

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journal of Modern Power Systems and Clean Energy 2024年第2期12卷 323-333页

作者： Mubarak j.Al-Mubarak Antonio j.Conejo Department of Electrical and Computer Engineering The Ohio State UniversityColumbusOHUSA Department of Electrical Engineering Kuwait UniversityP.O.Box 5969Safat 13060Kuwait Department of Integrated Systems Engineering and the Department of Electrical and Computer Engineering The Ohio State UniversityColumbusOH 43210USA IEEE

We consider a power system whose electric demand pertaining to freshwater production is high(high freshwater electric demand),as in the Middle East,and investigate the tradeoff of storing freshwater in tanks versus storing electricity in batteries at the day-ahead operation *** storing freshwater and storing electricity increase the actual electric demand at valley hours and decrease it at peak hours,which is generally beneficial in term of cost and ***,to what extent?We analyze this question considering three power systems with different generation-mix configurations,i.e.,a thermal-dominated mix,a renewable-dominated one,and a fully renewable *** generation-mix configurations are inspired by how power systems may evolve in different countries in the Middle *** production uncertainty is compactly modeled using chance *** draw conclusions on how both storage facilities(freshwater and electricity)complement each other to render an optimal operation of the power system.

关键词： Power system operation freshwater production and transportation coordination day-ahead scheduling

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Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： David j.Bottjer Department of Earth Sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Global weirding at mass extinction horizons

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National Science Review 2024年第1期11卷 10-12页

作者： Gregory j.Retallack Department of Earth Sciences University of Oregon

A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].

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Decoding the genetic program of micronucleus formation: linking chromosomal instability to human disease

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Signal Transduction and Targeted Therapy 2024年第7期9卷 2840-2842页

作者： jörg Fahrer Division of Food Chemistry and Toxicology Department of ChemistryRPTU Kaiserslautern-Landau67663 KaiserslauternGermany

A recent study by Adams and colleagues published in Nature unveiled more than one hundred genes that are involved in micronucleus formation,1 which is a biomarker for genomic instability and associated with aging,cancer,and other disorders.2 As an outstanding achievement,the authors identified DSCC1(DNA Replication And Sister Chromatid Cohesion 1)as a critical gene protecting against early developmental defects,genomic instability,reduced proliferative capacity,cohesinopathy-related phenotypes,and tumor development in vivo.

关键词： chromosomal linking Replication

Necrotic enteritis and antibiotic-free production of broiler chickens:Challenges in testing and using alternative products

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Animal Nutrition 2024年第1期16卷 288-298页

作者： Robert j.Moore School of Science RMIT University

The global trend towards raising broiler chickens without the use of in-feed antibiotics(IFAs) means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously provided. IFAs supported the productivity performance of chickens and played a key role in maintaining their health. Necrotic enteritis(NE) is an important disease of broilers that affects health,productivity, and welfare, and was previously well controlled by IFAs. However, with the reduction in IFA use, NE is resurgent in some countries. Vaccines and various feed additives, including pre-, pro-, and postbiotics, phytobiotics, fatty acids, and phage therapies have been introduced as alternative methods of NE control. While some of these feed additives have specific activity against the NE pathogen, Clostridium perfringens, most have the more general goal of reinforcing gut health. Extensive reviews of the effects of many of these feed additives on gut health have been published recently. Hence, rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production settings. The review is based on the author's particular experience,reading, thoughts, and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these issues. It is put forward to stimulate thinking and discussion on the issues covered.

关键词： Necrotic enteritis Clostridium perfringens Vaccines Feed additive Farm management

Are hydrides under high-pressure-high-temperature superconductors?

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National Science Review 2024年第7期11卷 9-12页

作者： j.E.Hirsch Department of Physics University of California

Contrary to the current consensus, I argue that the existing evidence for high-temperature superconductivity in hydrides under high pressure is not compelling. I suggest that the focus of the field should urgently shift to establish unequivocally experimentally whether or not superconductivity in pressurized hydrides exists, instead of continuing to search for new materials that might show elusive signals of unproven superconductivity at ever higher temperatures. The implications of a negative finding for the theoretical understanding of superconductivity are discussed.

关键词： Hydrides