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121.

Development of rangeland inventory and monitoring was initiated as early as in 1908. The early efforts were simple methods to establish rangeland stocking rates. With advancing scientific methodologies and the recognition for moitoring needs, the evaluation of range conditions and management planning increase well after WWII by a number of US federal agencies. By 1970s the environmental protection measures were first emphasized in the USA and were applied also to rangeland utilization. Since then the approaches and methodologies for evaluation of rangelands have changed periodically by accommodating the tenets of federal administrations. The methodologies applied have been geared either to support the environmental preservation or to support economic exploitation. There is still no system, however, for national or regional reporting on range conditions and trends. Local monitoring and management systems often lack scientific and objective basis. Local surveys, however, are important for evaluating existing conditions and should not be based on national reporting requirements. The ecological site concept has been adopted as the toxonomic unit for rangeland classification. It is important that monitoring methods are not biased, based on sufficient sample sizes, and not based on "estimations". The forage allocation based on one-time inventories are seriously flawed and the methods for evaluating stocking rates must be reevaluated. The same applies to the evaluating the rangeland "health." A unified national reporting system must be developed on scientific and objective basis.  相似文献   
122.
Flavonoids in Food and Their Health Benefits   总被引:17,自引:6,他引:17  
There has been increasing interest in the research of flavonoids from dietary sources, due to growing evidence of the versatile health benefits of flavonoids through epidemiological studies. As occurrence of flavonoids is directly associated with human daily dietary intake of antioxidants, it is important to evaluate flavonoid sources in food. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. However, there is still difficulty in accurately measuring the daily intake of flavonoids because of the complexity of existence of flavonoids from various food sources, the diversity of dietary culture, and the occurrence of a large amount of flavonoids itself in nature. Nevertheless, research on the health aspects of flavonoids for humans is expanding rapidly. Many flavonoids are shown to have antioxidative activity, free-radical scavenging capacity, coronary heart disease prevention, and anticancer activity, while some flavonoids exhibit potential for anti–human immunodeficiency virus functions. As such research progresses, further achievements will undoubtedly lead to a new era of flavonoids in either foods or pharmaceutical supplements. Accordingly, an appropriate model for a precise assessment of intake of flavonoids needs to be developed.Most recent research has focused on the health aspects of flavonoids from food sources for humans. This paper reviews the current advances in flavonoids in food, with emphasis on health aspects on the basis of the published literature, which may provide some guidance for researchers in further investigations and for industries in developing practical health agents.  相似文献   
123.
Within a given free-range flock, some hens prefer to spend the majority of their time in the shed (stayers), while others frequently access the range (rangers). Laying performance has been associated not only with the development of these sub-populations but also with different body weights (BW). The purpose of this study was to determine if range usage, BW or a combination of both is associated with energy metabolism and as such contribute to improved hen performance. Forty-eight Lohmann Brown hens at 74 wk of age were selected from a commercial free-range farm based on their BW and range usage over a 56-week period. Using a 2 × 2 factorial arrangement, hens were either classified as heavy (mean ± SEM; 2.01 ± 0.02 kg, n = 24) or light (1.68 ± 0.01 kg, n = 24), and also classified as rangers (accessed the range for 84.1% of available days, 242 ± 3.75 d; n = 24) or stayers (accessed the range for 7.17% of available days; 23.4 ± 6.08 d, n = 24). Stayers had significantly higher metabolizable energy (ME) intake per metabolic BW per d (0.852 vs. 0.798 MJ/kg BW0.75 per d; P = 0.025), higher heat production (0.637 vs. 0.607 MJ/kg BW0.75 per d; P = 0.005), higher heat increment (0.267 vs. 0.237 MJ/kg BW0.75 per d; P = 0.005) and retained more nitrogen (1.59 vs. 1.46 g/hen per d; P = 0.023) compared to the rangers. Light hens had significantly higher metabolic energy intake per metabolic BW (0.854 vs. 0.796 MJ/kg BW0.75 per d; P = 0.018), net energy (NE) intake (0.595 vs. 0.551 MJ/kg BW0.75 per d; P = 0.032), and retained energy (0.225 vs. 0.181 MJ/kg BW0.75 per d; P = 0.032), as well as lower heat production (0.936 vs. 1.003 MJ/hen per d; P = 0.002) compared to heavier hens. An interaction was observed across levels of analysis i.e. between light stayers and light rangers. The light rangers had significantly higher NE intake compared to the light stayers (9.77 vs. 9.27 MJ/kg BW0.75 per d; P = 0.024). In conclusion, light hens were more energy efficient compared to heavy hens. Moreover, light rangers had a more efficient feed utilisation compared to the light stayers.  相似文献   
124.
人性化的居住区景观设计   总被引:1,自引:1,他引:1  
闫晓俊  陈其兵 《安徽农业科学》2007,35(32):10280-10281
提出了居住区景观设计应对居民的综合需求进行深入理性思考,并从自然与和谐、文化与美感、健康与交流3个方面对人性化的居住区景观设计进行了探讨。  相似文献   
125.
为进一步开展欧洲输华粮谷中有害生物风险分析,该文整理和统计2003—2017年我国自欧洲输华粮谷中截获的有害生物数据,并采用SPSS 20软件分别对所截获的主要杂草和昆虫进行了聚类分析、相关分析和主成分分析,确定其截获次数的主控因子。结果显示,我国自欧洲输华粮谷中截获的主要有害生物为杂草,截获记录数为7 905次,占总截获记录的79.99%;我国自欧洲输华大麦中截获的有害生物次数均最多,截获次数为57 843次,占总截获次数的51.39%;我国自乌克兰输华粮谷中截获的杂草和昆虫次数最多,分别为39 026次和678次;我国自欧洲输华粮谷中截获的杂草和昆虫分别为479种和61种;自乌克兰和大麦中截获的杂草和昆虫的Shannon-Weiner指数均相对较高;我国自欧洲输华大麦和玉米中截获的杂草和昆虫分别单独聚为一类,我国自乌克兰和法国输华粮谷中截获的杂草和昆虫分别单独聚为一类;欧洲输华粮谷贸易额是有害生物杂草和昆虫截获次数的主控因子。建议我国进一步做好有害生物截获数据收集工作,加强欧洲输华粮谷中有害生物风险分析,根据风险对不同国家和粮谷采取相应的检疫措施。  相似文献   
126.
海湾在生态系统中占有重要地位,其健康状况研究受到越来越多的关注。该研究回顾了生态系统健康的定义和进展,阐述了海湾生态系统健康评价的两种方法,其中指示物种法从单物种和多物种指示物种法2个方面进行对比分析,多指标综合指数法从综合指数法、活力组织恢复(Vigor-organization-resilience,VOR,结构功能)法和压力状态响应(Pressure-State-Response,PSR模型)法3个方面进行阐述。同时,讨论了海湾生态系统健康评价在近海水产增养殖中的应用,展望了海湾生态系统健康评价的研究方向。  相似文献   
127.
[目的]监测浙江海域中虾姑的重金属镉的含量,并对其健康风险进行评估。[方法]以浙江附近海域捕获的虾姑为材料,根据GB5009.12-2010中的石墨炉原子吸收光谱法测定其体内的重金属镉含量,并利用健康风险指数的方法对多个菜场或码头采来的虾姑中镉的健康风险进行评估。[结果]试验发现,所采集的海捕虾姑样品中镉含量都符合国家规定标准,各个虾姑样品的健康风险指数均小于1,按照平均摄入量来计算,每个虾姑都是处于安全水平的。[结论]浙江海域虾姑镉含量未超标,健康风险指数也在安全范围内,且营养丰富,但摄入也应有一定的限值。  相似文献   
128.
Dietary intake of whole-grain foods is associated with a decreased risk of chronic diseases such as diabetes, obesity and heart disease. In addition to dietary fibre, various phytochemicals have been suggested to contribute to the health effects of whole grain products. This review focuses on phenolic compounds in rye (Secale cereale L.), which is one of the major bread grains in Europe. Data on phenolic concentrations in rye grain and foods, their bioavailability to tissues and effects in vivo, and their potential contributions to health are presented. Phenolic compounds in rye, such as phenolic acids, alkylresorcinols and lignans, are concentrated in the outer layers of the grain. Phenolic acids are the major phenolic compounds in whole grain rye (103–300 mg/100 g grain), ferulic acid being the most abundant. Rye lignans are present at concentrations of 2 mg/100 g grain and had been shown to be converted by the intestinal microflora to the mammalian lignans enterodiol and enterolactone in human intervention studies. Alkylresorcinols (36–320 mg/100 g grain), which have been found to be incorporated into human erythrocyte membranes, are of particular interest due to their potential use as biomarkers of the intake of rye and wheat.  相似文献   
129.
黄芪·蒲公英等中草药配伍对肉仔鸡生长保健性能的影响   总被引:2,自引:0,他引:2  
[目的]探讨黄芪、蒲公英等中草药对肉仔鸡生长保健性能的影响。[方法]将黄芪、蒲公英等中草药分别以配伍形式加入艾维因肉仔鸡基础日粮,测定对其生长保健性能的变化情况。[结果]添加中草药配伍A组(0.8%黄芪,0.4%山楂,0.4%陈皮,0.4%苍术)、中草药配伍B组(1.2%蒲公英,0.8%乌梅,0.8%黄柏,0.4%黄芪)肉仔鸡体重分别提高6.12%(P<0.01)及0.64%(P>0.05);肉仔鸡采食量分别改变-7.95%、9.99%;肉仔鸡料肉比分别改变-14.04%、9.35%,中草药配伍B组替代抗生素添加剂使肉仔鸡成活率和对照组保持相当水平。[结论]黄芪配伍中草药对艾维因肉仔鸡生长性能有较好改善作用;蒲公英配伍中草药则使其生长性能有所下降,但可替代日粮中抗生素添加剂的防病保健作用。  相似文献   
130.
种猪场健康养殖网络管理系统的研制   总被引:1,自引:0,他引:1  
一个基于C#、VB.NET和JavaScript编程语言,以SQL2005为数据库,以Windows2003为服务器平台的种猪场健康养殖网络管理系统,包括基础数据的维护、生产管理、猪群繁殖、饲养与饲料、疾病与防疫、销售管理、统计图表、场内管理和系统维护共九大模块.  相似文献   
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