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931.
对宁夏吴忠市利通区4个奶牛场和10户农户进行奶牛产奶期铜营养状况进行了调查,分别测定了奶牛盛乳期、产奶中期、产奶后期血清和毛铜的含量和血清中铜蓝蛋白、SOD的活性.结果表明:在盛乳期、产奶后期,散户(产奶后期)、中户奶牛血液铜、毛铜含量偏低,但未出现明显缺乏症状,处于亚临床缺乏状态;产奶中期各户奶牛各项指标均在正常范围之内,混合料中的铜符合标准.各期小户奶牛各项指标基本正常,饲喂状况良好.产奶各期血液铜蓝蛋白、SOD的活性变化范围较小,处于正常范围之内. 相似文献
932.
ZHOU Gao ZHAO GuangjieCollege of Material Science Technology Beijing Forestry University Beijing P.R.China 《中国林业科技(英文版)》2004,3(4):76-80
The use of more and more electron products requires interior wood products to have the performance of electromagnetic shielding. One of the ways to realize it is to introduce the chemical plating which has already been developed in electron industry into wood processing. The paper clarifies the mechanism of electroless copper and gold plating and its application to wood. It emphasizes the development and technology of electroless copper and gold plating on wood. Meanwhile, it points out that it is highly feasible to take this technology into effect. 相似文献
933.
Changes in some blood micronutrients, leukocytes and neutrophil expression of adhesion molecules in periparturient dairy cows. 总被引:3,自引:0,他引:3
Dairy cows are highly susceptible to infectious diseases, like mastitis, during the period around calving. Although factors contributing to increased susceptibility to infection have not been fully elucidated, impaired neutrophil recruitment to the site of infection and changes in the concentrations of some micronutrients related with the function of the immune defence has been implicated. Most of the current information is based on studies outside the Nordic countries where the conditions for dairy cows are different. Therefore, the aim of the study was to evaluate changes in blood concentrations of the vitamins A and E, the minerals calcium (Ca), phosphorous (P), and magnesium (Mg), the electrolytes potassium (K) and sodium (Na) and the trace elements selenium (Se), copper (Cu) and zinc (Zn), as well as changes in total and differential white blood cell counts (WBC) and expression of the adhesion molecules CD62L and CD18 on blood neutrophils in Swedish dairy cows during the period around calving. Blood samples were taken from 10 cows one month before expected calving, at calving and one month after calving. The results were mainly in line with reports from other countries. The concentrations of vitamins A and E, and of Zn, Ca and P decreased significantly at calving, while Se, Cu, and Na increased. Leukocytosis was detected at calving, mainly explained by neutrophilia, but also by monocytosis. The numbers of lymphocytes tended to decrease at the same time. The mean fluorescent intensity (MFI) of CD62L and CD18 molecules on blood neutrophils remained constant over time. The proportion of CD62L+ neutrophils decreased significantly at calving. The animals were fed according to, or above, their requirements. Therefore, changes in blood levels of vitamins, minerals and trace elements were mainly in response to colostrum formation, changes in dry matter intake, and ruminal metabolism around calving. Decreased levels of vitamins A and E, and of Zn at calving might have negative implications for the functions of the immune defence. The lower proportion of CD62L+ neutrophils at calving may result in less migration of blood neutrophils into the tissues, and might contribute to the increased susceptibility to infections at this time. 相似文献
934.
运用混合交设计摸清了羽毛回流酸解制备复合氨基酸的最佳方法,使产生了氨基酸单体总量占羽毛蛋白氨基酸总量的86%以上。通过PH滴定曲线紫外-可见光谱证明了复合氨基酸铜络合反应和络合物的形成。 相似文献
935.
何斌 《广西农业生物科学》1995,(4)
本文报道了铜试剂与铜(Ⅱ)在水相中的显色反应。结果表明,在非离子表面活性剂乳化剂OP存在下,于pH5.4~9.5的水溶液中,铜试剂与铜(Ⅱ)形成黄色的配合物,其最大吸收波长为454nm,表观摩尔吸光系数为1.38×104L/mol·cm,铜(Ⅱ)浓度在0~2.4μg/mL范围内符合比耳定律。在柠檬酸铵和EDTA二钠的存在下,方法具有较高的选择性,用于植物中微量铜的测定,结果令人满意。 相似文献
936.
The concentrations of copper, zinc and molybdenum were measured in the liver of goats from western and south-eastern Norway. The mean copper concentrations in the liver of goats from these two districts were 23±19 µg Cu/g and 59±31 µg Cu/g wet weight, respectively. As for zinc and molybdenum, no difference was found between the two groups of animals. No correlations were detected between copper and zinc, zinc and molybdenum, or copper and molybdenum. The copper levels in Norwegian goat liver are considerably lower than in sheep liver, and the ranges are significantly more narrow. The concentrations of molybdenum in goat liver are at the same levels as in sheep and swine, while the levels of zinc are somewhat lower. 相似文献
937.
The solubility of Cu and Zn binding proteins was studied in liver samples from clinically healthy and chronic copper poisoned sheep (CCP). Homogenized liver was divided by ultracentrifugation into cytosol and pellet. The cytosol was gelfiltrated, Cu and Zn contents were determined in the eluates as well as in the pellet. Liver homogenate, cytosol and pellet were treated with 2-mercaptoethanol (ME). The resulting clear solutions were fractionated by gel filtration followed by determination of the contents of the two metals in the eluates.In CCP sheep the solubility of Cu containing proteins from the liver homogenate and pellet increased after incubation with ME.The results suggest that in CCP sheep a considerable amount of Cu containing proteins are present in an insoluble form, which to some extent is resolubilized by ME. 相似文献
938.
Dynamics of the Cumulation of Iron, Copper and Sodium During Development to Maturity of Soybean Seed
The dynamics of the cumulation of iron, copper and sodium with four genotypes of soybean cultivated in the same topographical and agrotechnical conditions during three years was followed. Sampling was done in weekly intervals until complete maturity of seed. It was found out that the most intense cumulation took place during the seed development stages III and IV at the time of mostly expressed metabolic activity of the seed. The absolute values of the contents were increasing along with seed maturing and maximums were reached by the end of the stage IV or rather by the beginning of the seed development stage V. Although the dynamics of cumulation regardless of the year of investigation was equal with all the genotypes the analysis of the impact of climatic factors showed that higher precipitation at the period of seed development along with moderate air temperature affected mineral cumulation. Similarly, the highest contents of iron, copper and sodium observed with the genotypes Srecka and Maksimirka point out that the cumulation of the investigated minerals in soybean seed is affected by genetic particularity. 相似文献
939.
Eduardo Hidalgo Roy Bateman Ulrike Krauss Martijn ten Hoopen Adolfo Martínez 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(9):953-961
This paper describes a factorial trial designed to investigate the delivery systems of fungal biological agents (Clonostachys rosea), applied as single strain or as strain mixture, in comparison with copper hydroxide as a chemical standard against Moniliophthora roreri in cocoa. Application techniques compared were motorised mistblowers fitted with rotary atomisers and hydraulic sprayers fitted with cone nozzles giving a narrow angle of spray. The third factor was the presence or absence of an emulsifiable rape-seed adjuvant oil in the tank mixture. Copper fungicide was the best agent for moniliasis control and resulted in the highest yield. Both the mycofungicides reduced sporulation of the pathogen. Net reduction of inoculum was best for the hydraulic sprayer-applied copper fungicide and the motorised mistblower-applied single-strain biocontrol agent. Overall, directional hydraulic sprays were found to be somewhat superior to the motorised mistblower technique, with its dissipated cone of spray. Addition of the adjuvant oil was the least important of the factors, but efficacy depended on the agent used, with a significant enhancement in the efficacy of copper with oil but a detrimental effect on C. rosea. 相似文献