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1.
牧草价值综合评价的定量方法探讨   总被引:7,自引:0,他引:7  
以模糊数学集合理论为基础,试用综合评判法,建立了牧草价值综合评价的因素层次结构、等级标准和数学模型,应用该模型对吉林省西部天然草地28种野生牧草做了实际牧草价值的定量化综合评价。结果表明该方法简便、灵敏、能以定量化形式反映牧草价值大小,有益于不同牧草种质的评定、比较和筛选培育。  相似文献   

2.
10kV的配电线路的带电作业具有一定的危险性,而且这种线路的作业环境也比较复杂,本文利用层次分析法以及模糊综合评价法对10kV配电线路带电作业的安全性进行了综合评价,在对该线路带电作业进行综合评价时要建立有效的安全评价指标体系,这些指标包括作业环境、人员素质、现场管理等等。本文对这些指标的定量以及危险因素进行了分析,确定了10kV配电线路带电作业的安全等级,以供参考。  相似文献   

3.
文畅平  白银涌  苏伟  孙政  陈宗辉 《草业科学》2016,33(12):2425-2433
基于未确知数学理论和属性数学理论,研究了土壤肥力综合评价方法,建立了城市绿地土壤肥力综合评价及分级的未确知属性测度分析法。该方法首先需要确定城市绿地土壤肥力状况的评价指标及分类标准,以及土壤肥力状况级别组数;然后构建单指标的未确知属性测度函数,以计算单指标的未确知属性测度函数值和样本的综合未确知属性测度值;最后应用置信度准则对城市绿地土壤样本进行识别,以确定土壤样本肥力状况的级别属性。基于两个城市绿地土壤样本的模糊综合评价结果,以及13个城市绿地土壤样本的全排列多边形图示指标法、物元可拓法以及改进的人工神经网络法的评价结果进行了验证,本研究方法的评价结果与模糊综合评价法、全排列多边形图示指标法、物元可拓法以及改进的人工神经网络法的一致性分别为100%、84.62%、92.31%和100%。实例评价表明,采用该方法对城市绿地土壤肥力状况进行评价是可行的,为城市绿地土壤肥力综合评价提供了新的途径和方法。  相似文献   

4.
草地生态承载力研究进展及展望   总被引:1,自引:0,他引:1  
从承载力的起源、演化与发展着手,重点阐述了国内外关于生态承载力的研究进展;论述了目前常用的生态承载力评价方法,包括自然植被净第一性生产力估测法、资源与需求的差量法、综合评价法、状态空间法、生态足迹法等,并对各种评价方法进行了比较评述;指出今后生态承载力研究的发展方向:加强生态承载力基础理论的研究,加强学科交叉融合,应用先进科学技术手段获取数据,实现资源共享。  相似文献   

5.
重庆市都市区城镇土地集约利用现状评价与分析   总被引:2,自引:0,他引:2  
采用多因索综合评价法,从经济、社会、生态效益3方面建立综合指标体系,对重庆市都市区城镇土地集约利用现状进行科学评价。量化城镇土地集约利用水平。并从评价结果中分析出该研究区域城镇土地集约利用的特征和存在的主要问题。  相似文献   

6.
兴凯湖自然保护区生态质量模糊综合评价   总被引:1,自引:0,他引:1  
刘芳芳  于洪贤 《野生动物》2009,30(3):152-155
在综合自然保护区生态评价指标体系研究成果的基础上,选取自然性、代表性、多样性、稀有性、适宜性、稳定性和人类威胁等7项指标,运用层次分析法和模糊评价法对兴凯湖自然保护区湿地生态系统进行了生态质量评价。计算得出兴凯湖自然保护区生态系统的综合评价分值为0.7386。评价结果表明该保护区生态质量较好。最后就该保护区目前存在的问题进行分析并提出相应的建议。  相似文献   

7.
农村供水水源地水质的好坏可以影响到地下水功能是否能够发挥其应有的作用。因此,对地下水水质评价问题一直是环境科学研究的热点问题。本文在调研分析常用水质评价方法的基础上,提出了用灰色系统理论中的灰色加权关联度法进行地下水水质评价,把水体环境作为一个灰色系统,以岷县供水水源地为研究对象,对供水水源地的水质检测数据进行评价分析。通过与传统的等权灰色关联度法的评价结果对比表明,灰色加权关联度法是一种切实可行的水环境质量综合评价法,对于其他环境质量的评价也有一定的参考价值。  相似文献   

8.
本文主要对建设项目项目后评价进行介绍,探讨了建设项目后评价常用的方法,并着重介绍了模糊层次分析法。  相似文献   

9.
本试验选取苗期抗旱性表现不同的12份紫花苜蓿(Medicago sativa L.)材料,采用防雨棚田间模拟干旱法,开展了苜蓿全生育期抗旱性鉴定中干旱环境的设置、鉴定指标与评价方法选取的研究。结果显示:紫花苜蓿从苗期开始进入胁迫状态,胁迫周期为全年生长季;筛选出适宜的鉴定指标为:生物量、株高和分枝数;采用抗旱指数法对苜蓿全生育期抗旱性进行评价的结果与苗期评价结果一致性较好,采用隶属函数法对全生育期进行评价的结果与苗期的评价结果存在一定的差异性。苗期抗旱性鉴定周期短,便于操作,适合大量材料的抗旱性鉴定,有一定的科学性。而全生育期鉴定评价结果更直观、准确,可靠性强,可用于苜蓿实际抗旱能力的评价。  相似文献   

10.
体外产气法在动物营养学中应用的研究进展   总被引:1,自引:0,他引:1  
动物生产中饲料营养价值的高低直接影响动物的生产性能及畜产品的品质,实验室常用体外法来评价和估测饲料降解率。体外法主要通过测定底物如饲料降解后的残余量和发酵产物生成量(微生物数量、挥发性脂肪酸)或气体的产量来评价饲料营养价值。体外产气法是基于瘤胃发酵与产气高度相关的一种瘤胃体外模拟技术,该法具有简便、经济、快速、费用低等优点,目前在国内外多用于评价反刍动物饲草的饲用价值。作者主要综述了体外产气法在反刍动物生产中的应用及体外产气法中较为经典的发酵动力学模型。  相似文献   

11.
Robust procedures for estimation of breeding values were applied to multiple‐trait random regression test‐day (TD) model to reduce the influence of outliers on inferences. Robust estimation methods consisted of correcting selected observations (defined as outliers) in the process of solving mixed‐model equations in such a way that ‘new’ observations gave residuals (actual observation minus predicted) within k residual standard deviations for a given day in milk in 305‐day lactation. Data were 980 503 TD records on 63 346 Canadian Jersey cows. Milk, fat, protein and somatic cell score in the first three lactations were analysed jointly in the model that included fixed herd‐TD effect and regressions within region–age–season of calving, and regressions with random coefficients for animal genetic and permanent environmental effects. All regressions were orthogonal polynomials of order 4. Robust procedures for k = 1.5, 2.0, 2.5, 2.75 and 3.0 were contrasted with the regular best linear unbiased prediction (BLUP) method in terms of numbers and distributions of outliers, and estimated breeding values (EBV) of animals. Distributions of outliers were similar across traits and lactations. Early days in milk (from 5 to 15) were associated with larger frequency of outliers compared with the remaining part of lactation. Several, computationally simple, robust methods (for k > 2.0) reduced the influence of outlier observations in the model and improved the overall model performance. Differences in rankings of animals from robust evaluations were small compared with the regular BLUP method. No clear associations between changes in EBV (rankings) of top animals from different methods and the occurrence of outliers were detected.  相似文献   

12.
农药对家蚕的毒性和安全性评价研究   总被引:2,自引:0,他引:2  
陈伟国  鲁兴萌 《蚕业科学》2012,38(2):329-336
农药对家蚕的毒性和安全性评价研究是预警蚕区农药使用对养蚕生产存在的潜在危害风险的一项基础性工作。回顾近20多年来该领域的研究进展,重点介绍当前桑园及周围农作物常用农药对家蚕的急性、慢性毒性以及农药残毒期的测定方法,比较参比法、毒性比法和定级法等毒性分级方法的特点和适用范围,针对农药对家毒的毒性和安全性评价中的测定目标全面性、测定方法规范性和评价指标综合性等提出改进和完善意见,并就建立该领域的协作研究网络,制定试验规程与综合评价技术体系,预防家蚕农药中毒的综合减灾措施等提出改进意见和建议。  相似文献   

13.
Criteria and testing procedures with regard to the suitability of dogs as guide dogs for the blind were developed on the basis of a literature study and own observations. A profile of the guide dog comprising physical characteristics, skillfulness, behaviour, and obedience was drawn up. As a rule, the testing procedures concern health and skills of the dogs. In the skill test some elements of the behavioural and obedience test were included. The final evaluation is based on the results of physical examination and the skill test, unless testing of behaviour and/or obedience appears necessary as well. A method for evaluating the performance of the dogs as objectively as possible is described. Some implications of using and testing guide dogs are discussed.  相似文献   

14.
Radiographic evaluation of uterine enlargement is discussed and illustrated. Normal (pregnancy) and abnormal (pyometra, complications of pregnancy, neoplasma) causes of uterine enlargement are addressed. Special radiographic procedures for uterine evaluation are described.  相似文献   

15.
Diagnostic cytology in avian medicine provides a means for better disease definition in the avian patient, which allows for a more specific therapeutic regimen. It is important that cytologic specimens are from fresh sources, since cells degenerate rapidly following the death of the bird or the tissue. Cytologic evaluation is an adjunct to other diagnostic procedures. A definitive diagnosis often requires information from the clinical history, physical examination, evaluation of samples obtained from the bird, radiographs, surgical procedures, necropsy, and histopathology.  相似文献   

16.
A review of the clinical and pathologic evaluation of allogeneic bone grafts is presented with particular emphasis upon partial joint replacement. The histologic evaluation of cortical bone transplantation is reviewed. Radiographic evaluation of cortical bone transplants is presented in an attempt to understand the normal events that take place in incorporation of the graft by the host. The histologic and radiographic correlation is related to the healing process. Current methods of graft collection and storage are reviewed. While collection of the graft is fairly uniform, there are many varied treatment and storage procedures. General surgical procedures used in performing full cortical bone grafts are reviewed. The clinical use of an osteoarticular allogeneic bone graft in the elbow of a dog is presented, with a review of the operative and postoperative evaluation of the clinical patient.  相似文献   

17.
Bone marrow evaluation provides valuable diagnostic and prognostic information about neoplastic, metabolic, and inflammatory diseases. Bone marrow biopsies should be done only after examination of peripheral blood, to avoid performing unnecessary biopsies. A blood sample should be taken at the time of the bone marrow biopsy, for complete hematopoietic evaluation. It is preferable to take both an aspiration and core biopsy simultaneously. A good sample is mandatory for accurate evaluation and interpretation. The method of evaluation should be systematic, complete, and cover the following points: adequacy of specimens; estimation of cellularity; identification of number, maturation pattern, and morphology of megakaryocytes, myeloid cells, and erythroid cells; estimation of M:E ratio; and identification of abnormal cells, cellular reactions, infectious agents, or abnormal stromal reactions. Bone marrow findings should be interpreted in conjunction with signalment, history, physical findings, and laboratory results. Reference or institutional laboratories should be contacted for proper handling of bone marrow specimens for special procedures, such as histopathology, cytochemistry, immunopathology, and electron microscopy.  相似文献   

18.
Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.  相似文献   

19.
Real-time, B-mode ultrasonography provides the opportunity to improve the methods of evaluation of ovarian function and diagnoses of pregnancy in beef cattle. Determination of the sex of a fetus early in pregnancy (d 55 to 85) and verification of embryo viability by monitoring fetal heartbeat are unique methods involving ultrasound scanning. These techniques and a method for evaluating the technique of artificial insemination can be used to improve reproductive management of cattle. The way in which ultrasound technology may have its greatest impact is as a tool for improving on the method of palpation per rectum for monitoring ovarian function and pregnancy in beef cows and heifers. Determination of fetal sex and monitoring embryo mortality are less likely to be applied regularly in herd management, but these procedures will be valuable in conducting research in reproductive physiology of beef cattle.  相似文献   

20.
Computational procedures were developed to compute within-herd phenotypic, genetic and environmental trend lines on a breed-wide basis by using best linear unbiased estimates of fixed effects and predictors of random sire and dam genetic effects. Procedures were demonstrated by using weaning weight performance records from 20 herds participating in the American Angus Herd Improvement Program. Current evaluation procedures used by several beef breed associations make it possible to provide such information to breeders on a routine basis, along with within-herd breeding values. The within-herd genetic trends are relative to the national genetic evaluation base. Procedures are summarized in addition to presentation of within-herd trend lines for four of the 20 herds, demonstrating the utility of such information to breeders, along with a discussion of several alternative presentation formats.  相似文献   

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