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81.
Agricultural productivity may be raised in a sustainable way by many different technologies such as biological fertilizers,
soil and water conservation, biodiversity conservation, improved pest control, and changes in land ownership and distribution.
Of these measures, biotechnology applications probably hold the most promise in augmenting conventional agricultural productivity,
because biotechnology applications give not only the need to increase production, but also protect the environment and conserving
natural resources for future generations. Biotechnology applications will have the possibilities to increase productivity
and food availability through better agronomic performance of new varieties, including resistance to pests; rapid multiplication
of disease-free plants; ability to obtain natural plant products using tissue culture; diagnosis of diseases of plants and
livestock; manipulation of reproduction methods increasing the efficiency of breeding; and the provision of incentives for
greater participation by the private sector through investments. Insect resistance through the transfer of a gene for resistance
fromBacillus thuringiensis (Bt) is one of the most advanced biotechnology applications already being commercialized in many parts of the world. This paper
reviews the development and the status ofBt technology and application ofBt transgenic plants in current agriculture, and discusses specific issues related to the transfer of the technology to the
future of genetic engineered trees with emphasis on conifers.
Biography: Tang Wei (1964-), male, Ph. Doctor, Research associate, Department of Biology, Howell Science Complex, East Carelina University,
Greenville, NC 27858-4353, USA.
Responsible editor: Chal Ruihai 相似文献
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SiteandmethodThesiteislocatedintheSuiIingDistrictofHeiIong-jiangProvincefromN47"26'toN48"o6',E127"37'toE128"28'.TheaveragesIopeis15".Themeanelevationis349m.ThemeanannuaItem-peratureis-o.4t.TheaccumuIatedtemperatureof31ooCis1986C-Theamountofprecipitationisfrom6ooto8oomm.Thefrost-freeseasonisabout13od.ThemainsoilisdarkbrownsoiI.The17plots(o.o4hm')fordifferentages,differ-entsitesweremeasured.OnesampletreewasseIectedineverypIot,ThefalIenstemanalysistreesweredividedwithonemeterortwometer… 相似文献
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ABSTRACTThe relationship between stand attributes and biomass accumulation pattern in a mangrove forest has been intensively studied in this study. We assessed above (AGM) and belowground mass (BGM) and examined the relationship between forest attributes and aboveground mass in the Sundarbans, Bangladesh. The study was conducted with 18 plots having total area of 1.08 ha. The mean AGM and BGM of the study sites were 234.08 and 132.85 Mg ha?1 respectively. H. fomes contributed the highest amount (82.9% of total AGM and 80.53% of total BGM) of above (193.56 Mg ha?1) and belowground mass (107.09 Mg ha?1) at the study site. Our study revealed structural attributes (tree diameter, height, and basal area) positively correlated with AGM. In contrast, species richness and species diversity negatively correlated with AGM. Our study indicated that lack of positive relationship between species diversity and AGM which may be attributable to high AGM of the dominant species (H. fomes) and may have a considerable consequence in AGM of the study area. Thus, maintaining large trees (DBH and height) rather than species diversity in the Sundarbans mangrove forest might be an effective approach for increasing aboveground mass. 相似文献
87.
Xu Wei Deng Jun-tao Sun Bao-ping Zhu Guo-ping 《中国林学(英文版)》2005,7(4):49-54
The general situation of the total land resources in Wulushan, West China was studied by field investigations with the aid of a GIS software, called Region Manager. The current status of land use in Wulushan is described. The potential land productivity was evaluated by a fuzzy comprehensive method, We take each plot as a basic unit of evaluation on the basis of an index system of land resources in Wulushan which was developed from the investigation data. Evaluation of potential land productivity is the key part of land management. A guideline is presented in this paper for a proper utilization of the land resources and to develop the productive capacity of the land. 相似文献
88.
不同密度30年生马尾松林分生产结构与现存量的研究 总被引:1,自引:1,他引:1
对不同密度30年生马尾松人工林调查的结果表明:平均胸径随立木密度的增大而减少,平均树高受立木密度的影响较小;干、枝、叶和根等林分现存量随立木密度的增大而减少;单位叶量的材积生产力随立木密度的增大呈抛物线状态。 相似文献
89.
杨树混交林地土壤微生物与酶活性的变异研究 总被引:39,自引:2,他引:39
对北京大兴县林场和河南省民权国营林场2块试验林,面积分别为1.86hm ̄2和3.2hm ̄2,连续四年(1992-1995)进行土壤微生物与酶活性定位观测和定量分析,研究杨树不同混交模式土壤微生物和土壤酶活性的变异及其对土壤营养元素含量和林木生长的影响。结果表明:(1)杨树混交可以提高林地土壤微生物数量,5种处理间存在差异(P=79%)。(2)不同混交处理,土壤酶活性存在差异(P=87%),其中转化酶、磷酸酶在A、C处理中增长较明显;5种酶活性之间差异极显著(P>99%)。(3)杨树混交林的土壤营养元素、土壤微生物、酶活性与林地生产力关系密切。 相似文献
90.
在对我国桉树、落叶松及樟子松主要栽培区进行实地调查的基础上,利用有关地区森林资源二类调查及样地测定资料,以气候生产力为指标,比较评价了广东和海南桉树人工林、广西桉树人工丰产林和黑龙江省国有林区落叶松、樟子松人工林现实生产力。结果表明,广东粤西、海南省桉树人工林现实生产力分别是当地气候生产力的22.81%和41.08%;广西速丰林平均达73.78%。落叶松、樟子松分别达当地气候生产力的25.70%-41.68%和28.45%-51.55%。以典型局、场或丰产林项目为基础,对各研究树种人工林生产潜力进行了系统分析,提出在现有技术与经济条件下,桉树人工速丰林应达到气候生产力的80.00%以上;落叶松在≥14指数、樟子松在≥12指数立地上的生产力应分别达气候生产力的70%和80%以上。 相似文献