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911.
Being a kind of MWR, the orthogonal colloacation method can be conveniently used to reduce the initial-boundary value problems of the partial differential equations to initial value problems of ordinary differential equations. In this paper, the orthogonal collocation method is introduced in detail and by using it the dynamic characteristics of a steam-water heater are investigated.  相似文献   
912.
冬小麦各生育期~(14)C-光合产物的分配与再分配   总被引:4,自引:0,他引:4  
利用示踪同位素碳~(14)研究了冬生长阶段光合产物的分配以及冬后各阶段的连续分配情况.结果表明,光合产物生成后,分配并不停止.在冬后各阶段观察到存在着连续再分配.连续分配中心从地下根系、分蘖节、主茎叶,逐渐向上,直至穗部.然而,除了该中心外,其它器官或组织也能获得一定数量的光合产物.  相似文献   
913.
A partial genetic linkage map was constructed on 71 doubled-haploid lines derived from a cross between the barley lines Tadmor and WI2291 with 181 molecular markers. The segregating population was used to detect markers linked to the gene Mlg conferring resistance to powdery mildew (Erysiphe graminis f. sp. hordei) and to genes for quantitative resistance to scald (Rhynchosporium secalis). The gene Mlg on chromosome 4H was flanked by two AFLP markers at a distance of 2.0 and 2.4 cM, respectively. QTLs for resistance to scald were detected on chromosomes 2H and 3H. This association of molecular markers with qualitative and quantitative disease resistance loci represents a valuable starting-point for marker-assisted selection. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
914.
There are more than two power source in Hybrid Electrical Vehicle(HEV). By using of assist accelerating, power regeneration, Idle stop and power management, HEV gains more acceleration performance and more fuel economy and better gas emission than Conventional Vehicle(CV). With Integrated Starter and Generator(ISG) as a auxiliary power source, batteries and battery control module and power manage module as a Load leveling Device (LLD), two prototype HEV separately equipped Manual Transmission (MT) and Continuously Variable Transmission (CVT) was successfully developed.  相似文献   
915.
Cotton (Gossypium spp) is the world's leading natural fiber crop. Genetic manipulation continues to play a key role in the improvement of fiber quality properties. By use of DNA-based molecular markers and a polymorphic mapping population derived from an inter specific cross between TM-1 (G. hirsutum) and 3-79 (G. barbadense), thirteen quantitative trait loci (QTLs) controlling fiber quality properties were identified in 3-79, an extra long staple (ELS) cotton. Four QTLs influenced bundle fiber strength, three influenced fiber length, and six influenced fiber fineness. These QTLs were located on different chromosomes or linkage groups and collectively explained 30% to 60%of the total phenotypic variance for each fiber quality property in the F2 population. The effects and modes of action for the individual QTLs were characterized with 3-79 alleles in TM-1 genetic background. The results indicated more recessive than dominant, with much less additive effect in the gene mode. Transgressive segregation was observed for fiber fineness that could be beneficial to improvement of this trait. Molecular markers linked to fiber quality QTLs would be most effective in marker-assisted selection (MAS) of these recessive alleles in cotton breeding programs. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
916.
This paper studies the fundamental theory of the generalized minimal residual algorithm(GMRES(m))in Krylov subspace and specially the relationship between residual vector and Krylov subspace.The relationship of the algorithm convergence and the subspace be selected is further researched according the linear system about residual vector.It is posed that the convergence can be slowed down because there are so many very small eigenvalue in magnitude.And a accelerated method(AGMRES(m)) is proposed to improve the convergence of the GMRES(m).Theoretical analysis and numerical results show the reliability and efficiency of the algorithm.  相似文献   
917.
In chemistry and many related fields, electronegativity (EN) is an important fundamental concept and its scale is a useful physcochemical parameter. Here, calculations of both ionization potentials and electron affinities are extended toward 107 elements and done by density functional theory at the local density approximation(LDA) level and the LDB level, i.e., the local density approximation level with further non-local corrections for exchange and correlation included self-consistently as well as the modified Slater transition-state method. The definite-differentiation method is employed into calculations of the electronegativity scale and the related parameters of 107 elements with very good results due to the consideration of relativistic effects. The calculation presented is to examine both the LDA and LDB approximations in calculations for the ionization potential and electron affinity of the elements with an improved or modified Slater transition-state method, and relativistic effects have also been taken into account for 107 elements compared with 103, 86 or less in the previous report under a spin polarized density function theory with some approximations to the exchange-correlation function. The calculation results for the various quantities represent an obviously improvement over some previous calculations. It is shown that the results calculated by the extended technique and the improved Slater transition-state method in general agree well with experimental values presented by Pearson, and are better than the reported values in many previous literatures. The developed new electronegativity scale will widely be applicable in many fields such as molecular structural parameterization expression, chemobiological activity optimization prediction, structure-activity quantitation modeling, functional chemical adaptization designing, and so on.  相似文献   
918.
干旱胁迫下斑茅消减文库的构建及分析   总被引:6,自引:0,他引:6  
以干旱胁迫下斑茅(Saccharum arundinaceum Retz.)叶片组织的cDNA为Tester,正常生长条件下斑茅叶片组织cDNA为Driver,利用抑制性消减杂交技术(Suppression Subtractive Hybridization, SSH)构建斑茅干旱胁迫消减文库。文库克隆总量约为30 000个,克隆重组率为99.2%;随机从文库中挑取3500个克隆分析表明,插入片断长度主要集中在200~1 000 bp之间,500 bp以上的有463个克隆,500 bp以下的有3 037个克隆,平均长度约450 bp; 通过随机对16个文库阳性克隆的测序及分析,3个克隆与ATP-NAD kinase、Aldo/keto reductase和锌指蛋白高度同源,3个克隆没有同源性,10个与逆境相关,是功能未知的EST。选择编号为EL0149和EL0145两个克隆进行Northern杂交验证,结果表明EL0149克隆为干旱胁迫上调表达的EST序列,而EL0145在正常供水和干旱条件下均无明显的的杂交信号。说明本研究克隆的SSH文库质量较高,可以进一步利用SSH文库结合芯片表达谱分析解析作物水分胁迫下的相关抗旱基因网络。  相似文献   
919.
报导了南瓜水溶性多糖的水提醇沉优化工艺。在单因素试验的基础上,选取南瓜水溶性多糖提取时间、提取温度和水料比3个因素进行Box-Benhnken中心组合设计,利用响应面分析法对其提取工艺参数进行优化研究。利用Design-Expert软件对南瓜水溶性多糖得率的二次多项数学模型解逆矩阵分析表明,在提取温度为72.41℃,提取时间为3.02h,水料比为33.48∶1时,南瓜水溶性多糖得率最高,最大得率预测值为2.463%,与实测值2.447%相符。利用优化工艺参数提取南瓜水溶性多糖时,具有最大的提取效果。  相似文献   
920.
药剂处理对瓜尔豆种子低温萌发和活力的影响   总被引:2,自引:0,他引:2  
用不同的药剂分别在20℃、15℃条件下浸泡瓜尔豆种子24h,放入15℃的发芽箱中发芽。结果表明:400ml/kg乙烯利、10mg/kgAMP、20mg/kg6-BAl5℃浸种显著或极显著的提高种子活力,促使种子低温萌发;而20℃浸种时对种子萌发没有显著影响。0.1%水杨酸钠在15℃条件下能显著提高种子的发芽率,较长时间的维持种子活力。0.1%甲醛处理完全杀死种子。20mg/kgIAA20℃浸种、30mg/kg2,4-D15℃浸种抑制种子的萌发。200ml/kgCCC、500mg/kgGA3、0.1mol/LKNO3、25ml/kg肌醇15℃或20℃浸种效果均不明显。  相似文献   
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