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31.
布鲁菌外膜蛋白OMP10表达及其抗原性的研究   总被引:2,自引:2,他引:0  
设计1对特异性引物对羊布鲁菌16M总DNA进行外膜蛋白omp10的PCR扩增,得到了一个大小为330 bp的目的基因片段(去掉17个氨基酸编码的信号肽),测序证实它与国外报道的羊布鲁菌omp10基因完全一致.将其克隆到表达载体PET-30a中,经酶切、PCR扩增和测序分析,表明重组表达载体构建成功.将此重组质粒转化入大肠埃希菌BL21(DE3)中,IPTG诱导表达,该基因以包涵体的形式在大肠埃希菌中表达,经过包涵体的变性、复性和亲和层析纯化,成功获得大小为14.2 ku的融合蛋白,与理论推测的蛋白分子质量一致;Western blot和间接ELISA试验证明,纯化之后的OMP10重组蛋白可以被布鲁菌阳性血清识别.  相似文献   
32.
J. Luo  F.R. Huang  C.L. Xiao  W. Chen  S.W. Jiang  J. Peng   《Livestock Science》2009,126(1-3):286-291
The present study was designed to investigate the effect of dietary fish oil supplementation on piglet T helper cells (Th) polarization in relation to its impact on piglet serum interferon γ (IFN-γ) and interleukin 10 (IL-10) concentrations and splenic expression of Th1/Th2 characteristic genes. The diets of 18 gestating sows were supplemented with 7% lard (C) (n = 10) or 7% fish oil (T) (n = 8) from 10 d before parturition to weaning. At weaning, a split plot experiment was designed, 56 piglets, 28 each from sows fed with fish oil diet or lard diet, were divided into four groups of 7 replicates (one female and one castrated male per replicate) based on both sow diet during lactation and post-weaning piglet diet (C had 7% lard and T had 7% fish oil): CC, CT, TC, TT, and were fed the 7% fish oil or lard diet from day 35 to day 70. Serum concentrations of IFN-γ and IL-10, and Th1/Th2 related genes expression levels in spleen were measured and analyzed. The results showed that piglets fed with fish oil diet during post-weaning tended to have higher serum IFN-γ/IL-10 ratio (P = 0.09) than lard diet fed piglets. Lactation fish oil feeding increased splenic IL-12b, IL-12 receptor β2 (IL-12Rβ2), IL-2 and IFN-γ genes expression (P < 0.05 or P < 0.01) and post-weaning fish oil feeding increased splenic IL-12b (P = 0.06), IL-2 (P < 0.01) and IFN-γ (P = 0.08) mRNA expression than that in lard diet fed piglets at the end of this experiment. On the other hand, IL-4 gene expression (P = 0.01) in spleen was lower in weaned piglet from fish oil diet fed sows than that from lard diet fed sows. However, post-weaning piglets fed fish oil diet had higher splenic IL-4 (P = 0.06), IL-6 (P < 0.01) and IL-10 (P = 0.05) mRNA abundances than that fed with lard diet. These results indicated that dietary fish oil during lactation could increase Th1 polarization and accelerate immune maturation; while 7% fish oil in weaned piglets' diet was likely to increase Th2 cytokines expression.  相似文献   
33.
川西南常绿阔叶林土壤呼吸及其对氮沉降的响应   总被引:2,自引:0,他引:2  
通过原位进行低氮(LN,50 kg N/hm2.a)、中氮(MN,100 kg N/hm2.a)和高氮(HN,150 kg N/hm2.a)处理,研究了川西南天然常绿阔叶林土壤呼吸及其对模拟N沉降的响应。结果表明:(1)该森林土壤呼吸速率最大值612.21±77.82 mg CO2/m2.h出现在7月份,最小值108.95±17.01 mg CO2/m2.h出现在2月,年均土壤呼吸速率为348.00±157.83 mg CO2/m2.h,年均土壤呼吸通量为8.31±3.77 t C/hm2.a。采用双因素关系模型(Rs=aebTWc),土壤温度和土壤湿度共同解释了该常绿阔叶林2005年10月~2006年7月土壤呼吸速率季节变化的68.6%~73.9%,其拟合结果优于以土壤湿度或温度为参数的单因素关系模型。影响土壤呼吸速率的主导因子是温度,其地表温度变化响应的敏感程度Q10值为2.12,以土壤5 cm深处的温度为参数时,Q10值为2.51。(2)N沉降处理3个月后,该森林中HN和MN处理的土壤呼吸速率(309.43±17.24 mg CO2/m2.h,303.82±11.50 mgCO2/m2.h)均显著高于CK(269.28±13.78 mg CO2/m2.h)(P<0.05);处理4个月后,HN的土壤呼吸速率(272.42±13.25 mg CO2/m2.h)均显著高于MN(239.65±10.33 mg CO2/m2.h)、LN(229.10±9.90 mg CO2/m2.h)和CK(234.51±12.77 mg CO2/m2.h)(P<0.05);但处理7~10个月时,各处理之间无显著差异。研究表明,N沉降初期明显促进了常绿阔叶林土壤呼吸,后期无明显影响。  相似文献   
34.
(pp. 59–66)
In order to understand the detailed soil distribution of a terrace with a diluvial deposit, the method to draw a large-scale soil map was studied in Urausu Town of Sorachi district by combinig soil survey and digital elevation data for a 10 m grid.
The results are summarized as follows:
  • 1) 

    From a soil survey, soils in the research area were classified into 3 soil series groups according to Classification of Cultivated Soils in Japan, Third Approximation, which were Skeletal Terrace Brown Forest Soils, Fine-textured Aquic Brown Forest Soils and Fine-textured Haplic Gray Upland Soils. In addition, Fine-textured Haplic Gray Upland Soils · were classified into 2 categories based on the abundance of gravel in the subsoil.

      相似文献   
35.
厦门市2001-2002年PM10浓度时间序列变化分析   总被引:6,自引:0,他引:6  
在厦门市环境大气污染物中,PM10是其首要的大气污染物。厦门市大气中的日PM10浓度受天气和气候以及土地利用类型、地表植被覆盖度等诸多因素的共同影响而呈现出一定的周期性,应用时间序列方法对厦门市2001~2002年的PM10浓度进行周期性和趋势性的分析,揭示了厦门市大气环境中PM10浓随时间变化的周期性规律。同时讨论了部分气候因素对PM10浓度年内变化的影响。  相似文献   
36.
Plot trenching and root decomposition experiments were conducted in a warm-temperate oak chronosequence (40-year-old, 48-year-old, 80-year-old, and 143-year-old) in China. We partitioned total soil surface CO2 efflux (RS) into heterotrophic (RH) and rhizospheric (RR) components across the growing season of 2009. We found that the temporal variation of RR and RH can be well explained by soil temperature (T5) at 5 cm depth using exponential equations for all forests. However, RR of 40-year-old and 48-year-old forests peaked in September, while their T5 peaks occurred in August. RR of 80-year-old and 143-year-old forests showed a similar pattern to T5. The contribution of RR to RS (RC) of 40-year-old and 48-year-old forests presented a second peak in September. Seasonal variation of RR may be accounted for by the different successional stages. Cumulative RH and RR during the growing season varied with forest age. The estimated RH values for 40-year-old, 48-year-old, 80-year-old and 143-year-old forests averaged 431.72, 452.02, 484.62 and 678.93 g C m−2, respectively, while the corresponding values of RR averaged 191.94, 206.51, 321.13 and 153.03 g C m−2. The estimated RC increased from 30.78% in the 40-year-old forest to 39.85% in the 80-year-old forest and then declined to 18.39% in the 143-year-old forest. We found soil organic carbon (SOC), especially the light fraction organic carbon (LFOC), stock at 0-10 cm soil depth correlated well with RH. There was no significant relationship between RR and fine root biomass regardless of stand age. Measured apparent temperature sensitivity (Q10) of RH (3.93 ± 0.27) was significantly higher than that of RR (2.78 ± 0.73). Capillary porosity decreased as stand age increased and it was negatively correlated to cumulative RS. Our results emphasize the importance of partitioning soil respiration in evaluating the stand age effect on soil respiration and its significance to future model construction.  相似文献   
37.
中国摩托车第三阶段排放标准中增加了关于排放限值和耐久性试验的要求,对电喷系统的空燃比控制及尾气后处理装置的空燃比"催化窗口"的高温稳定性提出了更高要求。文章提出了氧传感器自适应控制策略并采用了新研制的基于高性能稀土储氧材料的新型三元催化剂。高性能稀土储氧材料具有高的比表面和高的储氧量以及优异的高温稳定性。整车试验结果表明,新型三元催化剂不仅具有优异的初始活性,而且具有良好的抗老化特性,能够满足电喷发动机排放耐久试验的苛刻要求。  相似文献   
38.
基于铜,邻二氮菲和溴酚兰形成Cu:phen:BPB为1:3:1的三元配合物且丁基罗丹明B与溴酚兰形成经BPB:BRB为1:3的等色染料离子对,建立了等色染出子对萃取法测Cu的新方法,该法摩尔吸光系数为2.86×10^5L.mol^-1.cm^-1线性9.44×10^-7-8.65×10^-5mol.L^-1。  相似文献   
39.
成纤维细胞生长因子10(fibroblast growth factor 10,FGF10)是一种极其重要的生长因子,能促进小鼠(Mus musculus)和人(Homo sapiens)前体脂肪细胞的分化.为了获得山羊(Capra hircus)FGF10基因序列,研究其组织表达特性,确定其在肌内前体脂肪细胞分化过程中的表达模式,并分析FGF10mRNA表达水平与肌内脂肪沉积的关系,本研究以简州大耳羊(C.hircus)为实验动物,采用反转录聚合酶链式反应(RT-PCR)技术克隆FGF10基因,采用Ⅱ型胶原酶消化获得山羊原代肌内前体脂肪细胞,利用实时荧光定量PCR(qPCR)技术检测FGF10在成年山羊不同组织中的表达差异及其在肌内前体脂肪细胞分化过程中的表达水平,并将基因表达水平与肌内脂肪(intramuscular fat,IMF)含量进行关联分析.结果显示,克隆得到山羊FGF10基因(GenBank登录号:KT899958)序列1 252 bp,其中开放阅读框642 bp,编码213个氨基酸,与绵羊(Ovis aries)和牛(Bos taurus)的该基因同源性达100%,具有跨膜结构域和信号肽结构.FGF10 在山羊肺脏中表达水平最高,显著高于其他组织(P<0.05),在脾脏和脂肪中也存在较高水平的表达.FGF10 mRNA在成年羊背最长肌中表达量显著高于羔羊与育成羊(P<0.05),相关性分析结果显示,FGF10 mRNA表达量与山羊背最长肌IMF含量呈显著正相关(P<0.05).FGF10 mRNA在肌内前体脂肪细胞中表达水平最低,在诱导分化后2d达到最高.本研究结果为进一步阐明FGF10基因在山羊肌内脂肪沉积中的分子机制提供了理论依据.  相似文献   
40.
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