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91.
Li-Ling Lin Chao-Wen Wang Cheng-Lung Chiu Yung-Chuan Ko 《Paddy and Water Environment》2011,9(2):257-266
In recent years, frequent attacks of heavy rain and typhoon have severely devastated the vulnerable mountains of Taiwan; slopelands
are artificially disturbed by improper development and utilization. People are getting more aware of the importance of slopeland
preservation as well as disaster prevention and mitigation. The government, realizing the criticality of gradually worsened
land safety issues, has also set forth the “Draft of National Land Planning Act” and the “Draft of Regulations on Land Preservation
Act” in the purposes of rehabilitating the excessively explored ecosystems and diminishing the development extent of environmentally
susceptible areas, so as to effectively preserve soil, water, and organism resources and to achieve perpetual development
of national lands. “Classification of Slopeland Utilization Limitations” is a critical link to national land preservation.
The classification is based on four factors, namely average slope, effective soil depth, soil erosion, and parent rock, with
different utilization zones defined as bases of landuse planning. However, current classification results of the environmentally
susceptible and disaster-prone mountain lands are mostly defined as suitable for forestry or husbandry. Scattered allocation
of these lands results in critical issues such as segmented landuse and impaired landscape and ecotype. It is necessary to
re-adjust land resources planning and usage management. Therefore a review of the current standards for classifying slopeland
utilization limitations is proposed to facilitate rational allocation of slopeland use. Jhuoshuei River is selected as the
scope of the case study, with data of debris flows induced by the typhoon Toraji in 2001 as the training data. Eight susceptibility
factors, which include form factor of watershed, integral hypsometric, slope of main stream, density of stream network, density
of road network, area ratio of historical landslide, and area ratio of triggered landslide, together with the total rainfall
of the storm event as the triggering factor, are selected for creating the debris flow susceptibility model by employing the
logistic regression within the multivariate geostatistics analysis. This model interprets the curve of success ratio of debris
flows triggered by typhoon Toraji, of which the area under the curve is as high as 74.3%. The debris flow susceptibility model
created in the study takes the Feng-Chiu section of Sinyi Township, Nantou County, Taiwan within the Jhuoshuei River as the
scope of research. GIS technology has been applied in the feasibility study of classification standards. New concepts have
been further proposed in view of national land preservation addressing the medium and high elevation disaster-prone areas
that are not suitable for agricultural use, for standard revision reference. 相似文献
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93.
Fiorenza Micheli Andrew O. Shelton Seth M. Bushinsky Alice L. Chiu Alison J. Haupt Kimberly W. Heiman Carrie V. Kappel Margaret C. Lynch Rebecca G. Martone Robert B. Dunbar James Watanabe 《Biological conservation》2008,141(4):1078-1090
We evaluated the persistence and possible recovery of two depleted marine mollusks, the red (Haliotis rufescens) and black abalone (H. cracherodii), in central California, USA. Monitoring over 32-years did not reveal increasing or decreasing trends in red abalone abundances and sizes over the past three decades, in the absence of harvesting. Comparisons between marine reserves protected for at least 25 years and sites with open public access showed significant difference in size structure for black abalone, with individuals greater than 8 cm in shell length comprising 14–37% of animals in reserves and 2–11% at open-access sites, and a trend for greater abundances of red abalone within reserves. Despite no increasing trends, protection in one of the no-take reserves, the Hopkins marine life refuge (HMLR), has led to persistence of red abalone populations over multiple generations, at average densities of 0.2 individuals/m2. At other locations, both within the HMLR and elsewhere, red abalone densities are lower than at the location where long-term studies were conducted (av. 0.03 animals/m2), and an order of magnitude lower than for black abalone (av. 0.4 animals/m2). These results suggest that continued fishery closure and protection in no-take reserves are effective tools for allowing persistence of abalone populations, though there are no signs of recovery to levels comparable to those preceding fisheries collapse. Such failure to recover is most likely associated with high natural mortality and possibly continued illegal take, but not with processes underlying low abalone population levels elsewhere, including food or habitat limitation, recruitment failure, or disease. Linking current structure and trends to specific processes is a crucial first step towards devising focused strategies for conserving and re-building depleted marine populations. 相似文献
94.
苦槛蓝对菜青虫的生物活性及生理效应的研究 总被引:7,自引:0,他引:7
应用同位素示踪技术研究了^14C-三唑酮在小麦2-3叶期幼苗上的吸收分布和影响因素。结果表明,根部给药后2-216h小麦幼苗根部放射性和相对强度由54.0%下降为21.7%;在幼苗残存种子上的放射性相对强度由37.5%上升为56.6%,^14C-三唑同传导速度很快,在叶片中的积累与根部给药时间呈正相关,由8.5%上升为21.7%。 相似文献
95.
炔类化合物对亚洲玉米螟拒食活性和电生理反应 总被引:5,自引:0,他引:5
利用饲料柱法测定了人工合成的 9个共轭二炔和 3个单炔类化合物对亚洲玉米螟 Ostrinia furnacalis(Guene'e) 5龄幼虫的拒食活性 ,并利用顶端记录技术 ,诱发该虫栓锥感受器感受细胞的电位脉冲反应。结果表明 :受试的炔类化合物对亚洲玉米螟幼虫具有不同程度的拒食活性 ,特别是化合物 2 (6,6-二甲基-2,4-庚二炔-1-醇、化合物 3(2,4-己二炔-1,6-二醇 )、化合物 9(1-苯基-2 ,4-己二炔 )和化合物 11(3-溴-2-丙炔-1-醇 ) ,实验剂量为 500μg/g饲料时 ,2 4 h非选择性拒食率在 80%左右。电生理测定结果表明 :浓度为 1mg/mL时 ,该系列化合物刺激中栓锥感受器能诱发感受细胞发放不同频率的脉冲和振幅 ,脉冲频率在 8.30~31.00imp/s,振幅在 400~1000μV之间。刺激侧栓锥感受器 ,也能诱发感受细胞发放不同频率的脉冲 ,脉冲频率在 6.00~ 15.66imp/s之间。将化合物诱发中栓锥感受细胞电位脉冲频率与生测拒食活性进行比较 ,发现二者存在一定程度的相关性。在剂量 -发放频率测试中 ,测得化合物 9诱发栓锥感受器脉冲频率具有浓度依赖性。 相似文献
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97.
An external ear lesion designated as auricular chondropathy in aging Crl:CD rats was reported. One hundred eighty (180) of 4,876 rats (3.7%) had ear deformity. Grossly, the ears were thickened, nodular, or disfigured. Both ears were affected in most rats. The lesions primarily involved the cartilaginous plate and were associated with two processes--chondrolysis and granulomatous inflammation. The detailed morphogenesis of the lesions is described, but the etiology of the lesions is unknown. Auricular chondropathy in rats and relapsing polychondritis in man are compared. 相似文献
98.
99.
裘维蕃 《中国农业大学学报》1990,(4):353-356
1 植物病理学的基本任务植物病理学担负着病理和防治两方面的任务。对人医或兽医来说,病理和临床往往是分工的,而植物病理并没有那样的分工,也就是说它必须兼顾病理和临床。另外一个特点便是植物种类繁多,而每一种植物又各有其自己特殊的多种病害。一个植物病理学家最多只能掌握几种主要农作物的重要病害及其防治要点。可是实际上,经常会遇到许多从未见过的新病 相似文献
100.