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991.
青海地处青藏高原生态脆弱区 ,青海经济发展必须以保护和治理环境为根本出发点。根据青海农牧业经济现状和社会经济发展的客观要求 ,必须依靠先进技术为根本手段 ,生态保护为基本目标 ,即走“生态—技术”农牧业发展道路。 相似文献
992.
赤霉素和2,4—D对猴头菇的效应及其机制研究 总被引:4,自引:0,他引:4
用赤霉素和2,4-D处理猴头菇,对改善猴头菇品质,提高其维生素及微量元素含量,增强猴头菇菌丝体酶活性,促进猴头菇子实层细胞分裂、伸长、分化均具有明显效应。 相似文献
993.
用酶标抗体法检测蚕微粒子孢子 总被引:6,自引:0,他引:6
用酶标抗体间接法和酶标抗体PAP法检测蚕微粒子孢子,二种方法检测结果一致,被检材料与阳性对照中的孢子被染成褐色,从而可以确定为蚕微粒子孢子。二种方法比较,间接法相对简单,PAP法敏感性更高,均为重要的蚕微粒子孢子的鉴别诊断方法。 相似文献
994.
We explored land use, fish assemblage structure, and stream habitat associations in 20 catchments in Opequon Creek watershed, West Virginia. The purpose was to determine the relative importance of urban and agriculture land use on stream biotic integrity, and to evaluate the spatial scale (i.e., whole-catchment vs riparian buffer) at which land use effects were most pronounced. We found that index of biological integrity (IBI) scores were strongly associated with extent of urban land use in individual catchments. Sites that received ratings of poor or very poor based on IBI scores had > 7% of urban land use in their respective catchments. Habitat correlations suggested that urban land use disrupted flow regime, reduced water quality, and altered stream channels. In contrast, we found no meaningful relationship between agricultural land use and IBI at either whole-catchment or riparian scales despite strong correlations between percent agriculture and several important stream habitat measures, including nitrate concentrations, proportion of fine sediments in riffles, and the abundance of fish cover. We also found that variation in gradient (channel slope) influenced responses of fish assemblages to land use. Urban land use was more disruptive to biological integrity in catchments with steeper channel slopes. Based on comparisons of our results in the topographically diverse Opequon Creek watershed with results from watersheds in flatter terrains, we hypothesize that the potential for riparian forests to mitigate effects of deleterious land uses in upland portions of the watershed is inversely related to gradient.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
995.
Michel A. Salmon Marina Vendrame Jean Kummert Philippe Lepoivre 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(8):755-762
Real-time PCR with fluorogenic hydrolysis probes (5' nuclease assay) is increasingly used for the detection of pathogens for diagnostic purposes. Nevertheless, the size of the probes, usually 25–40 nucleotides, might limit their use to detect pathogens with high genome variability between isolates, where an identical sequence cannot be found without multiple mismatches. In this report, we describe a 5' nuclease assay, to detect Apple stem pitting virus, based on the use of a shorter probe which is chemically modified with a minor groove binder in order to increase duplex stability and raise the melting temperature to a value suitable for real-time analysis. The short size of the probe, which is critical to target a conserved cluster sequence of 14 nucleotides in the RNA polymerase gene, circumvents the genome variability of the virus. The assay correlates at 96 percent with gel analysis and is more reliable than biological indexing to detect Apple stem pitting virus field isolates. It is fast and fully compatible with automation, and therefore particularly suitable for plant certification. 相似文献
996.
通过比较,研究了粗状假丝酵母诱变株产脂肪酶催化水解不同底物的相对活力,包括低级酯、脂肪酸甘油酯和天然油脂。并对粗状假丝酵母产脂肪酶催化水解猪油反应中的pH值、温度、时间、加酶量、乳化剂用量和Ca2+浓度等因素进行了研究,得出pH值为7.5、温度为45℃、水解反应时间为72h、加8ml粗酶液、2%油的乳化剂、Ca2+浓度为75mmol/l时,猪油有最佳水解率。通过对该酶反应动力学进行研究得出其水解反应的米氏常数Km为12.25×10-3mol/l和最大反应速率Vmax为11.14μmol/min。 相似文献
997.
为探讨耐热木聚糖酶水解自制甘蔗渣木聚糖制备木寡糖的工艺条件和分析水解液的寡糖成分,试验以产耐热木聚糖酶的基因工程菌1020为原料,水解自制的甘蔗渣木聚糖,分别研究水解过程中酶的用量、木聚糖的浓度及酶解温度对酶解反应的影响,并采用高压液相色谱和质谱联用技术对水解液成分进行分析。试验结果表明,2%的木聚糖浓度,水解温度95℃,酶液用量100U/g,酶解3h后DP值可降至2.94,满足生产木寡糖对聚合度的要求;并且水解液的成分主要为木糖、木二糖和木三糖,没能检测到木四糖。耐热木聚糖酶在高温下酶解木聚糖对酶法制备木寡糖具有重要的应用价值。 相似文献
998.
Ameliorative effects of boron on serum profile in buffalo (Bubalus bubalis) fed high fluoride ration
An experiment was undertaken to evaluate the protective role of boron on the serum profile of buffalo calves fed a high fluoride
ration. Twelve male Murrah buffalo (Bubalus bubalis) calves of 6–8 months age, divided into three groups of four calves in each, were fed basal diets and supplemented with sodium
fluoride (NaF, 60 ppm) alone or in combination with borax (Na2B4O7.10H2O, 140 ppm) for 90 days. Boron (B) was added in the ration as borax to make @140 ppm boron (elemental B) on DM basis in treatment
II. Dietary F caused a significant (p < 0.05) depressing effect on serum Ca and Zn on day 90 which was improved with B supplementation. However, serum Fe and Cu
did not show any significant change on F or F+B supplementation. The serum ALP and phosphorus level were increased significantly
(p < 0.05) on F feeding but declined significantly (p < 0.05) when B was fed. The findings suggested beneficial effect of boron on serum minerals and ALP in buffalo calves fed
high fluoride ration. 相似文献
999.
无公害平菇代料栽培标准化生产技术 总被引:2,自引:0,他引:2
本文提出了平菇无公害生产技术及栽培措施,包括母种、原种及栽培种、栽培袋的无公害生产技术,出菇管理技术,病虫害的物理防治与生物防治,产品采收要求,开发的技术完全符合国家相关无公害农产品标准。 相似文献
1000.