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921.
为加强对高校实验室安全管理,对HACCP系统在实验室中的应用进行研究和探讨.以浙江医药高等专科学校为例.通过对实验室特点的分析,把HACCP体系引入到实验室安全的日常监管中来.通过危害分析,确定关键控制点,提出相应的控制措施.通过对实验室实施HACCP计划,显著提高了实验室的安全,为HACCP体系在高校实验室安全管理提供了可行的实践依据. 相似文献
922.
本文对贵州高校图书馆数字信息资源建设现状进行了调查,分析了贵州高校图书馆数字信息资源建设存在的问题.论文指出,要在提高对贵州高校图书馆数字信息资源建设重要性认识的基础上,加强贵州科技文献共享平台建设,重视开放存取资源的开发和利用. 相似文献
923.
924.
稻褐飞虱实验种群致害性变异 总被引:1,自引:0,他引:1
以蜜露排泄量为稻褐飞虱致害性指标对稻褐飞虱实验种群的致害性变异进行了研究。首先测定了褐飞虱3个实验种群(TN1种群、Mudgo种群和ASD7种群)[分别用水稻品种TN1、Mudgo和ASD7强迫饲养82代,其中TN1种群(T)为弱致害力种群,Mudgo种群(M)和ASD7种群(A)为强致害力种群]分别在感虫和抗虫品种上的蜜露排泄量。结果表明,寄主表现感虫还是抗虫,与褐飞虱致害力之间存在交互作用。将不同致害力的褐飞虱种群接在抗虫品种上,才可能观察到较大的致害性差异,据此比较了杂交F1代与亲本种群个体、自交F2代与杂交F1代种群个体在抗虫品种上的致害性差异,以分析褐飞虱致害性变异规律。杂交F1代(包括T♀×M♂,A♀×T♂两种处理)雌成虫的平均致害力均介于两个亲本之间,其值与强致害力亲本的更为接近;杂交F1代雌成虫致害力的变异程度均显著地大于弱致害亲本,而与强致害性的亲本相比几乎无明显的差异;表明相对于弱致害性,褐飞虱的强致害性可能为一显性性状。与杂交F1代相比,T♀×M♂处理中自交F2代雌成虫的致害力无显著变化,而A♀×T♂处理中自交F2代雌成虫的致害力显著大于杂交F1代;两种处理中,自交F2代的方差或显著小于杂交F1代,或稍大于杂交F1代,表明自交F2代种群个体未增加新的遗传分离。 相似文献
925.
Molecular cloning of MDA5, phylogenetic analysis of RIG‐I‐like receptors (RLRs) and differential gene expression of RLRs,interferons and proinflammatory cytokines after in vitro challenge with IPNV,ISAV and SAV in the salmonid cell line TO 下载免费PDF全文
I‐K G Nerbøvik M A Solheim H Ø Eggestøl A Rønneseth R A Jakobsen H I Wergeland G T Haugland 《Journal of fish diseases》2017,40(11):1529-1544
The RIG‐I receptors RIG‐I, MDA5 and LGP2 are involved in viral recognition, and they have different ligand specificity and recognize different viruses. Activation of RIG‐I‐like receptors (RLRs) leads to production of cytokines essential for antiviral immunity. In fish, most research has focused on interferons, and less is known about the production of proinflammatory cytokines during viral infections. In this study, we have cloned the full‐length MDA5 sequence in Atlantic salmon, and compared it with RIG‐I and LGP2. Further, the salmonid cell line TO was infected with three fish pathogenic viruses, infectious pancreatic necrosis virus (IPNV), infectious salmon anaemia virus (ISAV) and salmonid alphavirus (SAV), and differential gene expression (DEG) analyses of RLRs, interferons (IFNa‐d) and proinflammatory cytokines (TNF‐α1, TNF‐α2, IL‐1β, IL‐6, IL‐12 p40s) were performed. The DEG analyses showed that the responses of proinflammatory cytokines in TO cells infected with IPNV and ISAV were profoundly different from SAV‐infected cells. In the two aforementioned, TNF‐α1 and TNF‐α2 were highly upregulated, while in SAV‐infected cells these cytokines were downregulated. Knowledge of virus recognition by the host and the immune responses during infection may help elucidate why and how some viruses can escape the immune system. Such knowledge is useful for the development of immune prophylactic measures. 相似文献
926.
sten Jensen Anders Sunde Wroldsen Pl Furset Lader Arne Fredheim Mats Heide 《Aquacultural Engineering》2007,36(3):272-284
Aquaculture is the fastest growing food producing sector in the world. Considerable interest exists in developing open ocean aquaculture in response to a shortage of suitable, sheltered inshore locations and possible husbandry advantages of oceanic sites such as increased water quality and oxygen supply, which improve production efficiency and the quality of fish. The extreme weather conditions experienced offshore leads to a focus on new structure concepts, remote monitoring and a higher degree of automation in order to keep the cost of constructions with an economically viable range. This paper proposes tensegrity structures in the design of wave compliant structures for offshore aquaculture. The objective of this paper is to study several different combinations of pre-stress and stiffness and determine how they influence the stiffness of the tensegrity structure. The finite element analysis program ABAQUS™ has been used to investigate the load carrying capacity of a tensegrity beam structure. The stiffness properties of the tensegrity beam were observed to be highly non-linear and dependent on pre-stress and spring stiffness. When designing a tensegrity beam, both pre-stress and spring stiffness should be considered to ensure the desired structural properties. A large strength to mass ratio and promising properties with respect to control of geometry, stiffness and vibration could make tensegrity an enabling technology for future developments. The suggested concept, the tensegrity beam, shows promising stiffness properties in tension, compression and bending, which are relevant for development of open ocean aquaculture construction for high energy environments. 相似文献
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928.
M. P. C. ENGLER R. CICHOTA Q. DE JONG VAN LIER E. M. BLOEM G. SPAROVEK E. SCHNUG 《土壤圈》2008,18(3):328-334
A new laboratory method was proposed to establish an easily performed standard for the determination of mobile soil water close to real conditions during the infiltration and redistribution of water in a soil. It consisted of applying a water volume with a tracer ion on top of an undisturbed ring sample on a pressure plate under a known suction or pressure head. Afterwards, soil water mobility was determined by analyzing the tracer-ion concentration in the soil sample. Soil water mobility showed to be a function of the applied water volume. No relation between soil water mobility and applied pressure head could be established with data from the present cxperiment. A simple one- or two-parameter equation can be fitted to the experimental data to parameterize soil water mobility as a function of applied solute volume. Sandy soils showed higher mobility than loamy" soils at low values of applied solute volumes, and both sandy and loamy soils showed an almost complete mobility at high applied solute volumes. 相似文献
929.
930.
以海沃德猕猴桃无菌苗为材料,在培养基中添加次氯酸钠溶液,利用响应面法对其增殖培养基进行优化。在单因素的试验基础上,以NAA、6-BA、蔗糖为试验因子,增殖系数为响应值,进行三因素三水平的试验设计。结果表明:三因素对植株增殖系数的影响力大小为NAA>6-BA>蔗糖,最终得到的增殖培养基优化结果为MS+2.0mg/L6-BA+0.1mg/LNAA+30g蔗糖+3g琼脂+0.013%次氯酸钠。在此条件下,最佳增值效率预测值为4.706,实际增殖结果为4.39,说明该方程预测与实际试验拟合度较好,该优化方案可行。 相似文献