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341.
Background: Various frequencies of sperm aneuploidy are reported in sperms of subfertile patients compared to normal individuals. Moreover, sperm DNA damage is shown to be associated with male infertility. In this study, the rate of DNA damage and frequencies of aneuploidy in sperms of subfertile patients was investigated. Methods: Semen samples were obtained from healthy normal and subfertile (oligozoospermia, asthenozoospermia, and oligoasthenozoospermia) men. The frequency of aneuploidy was assessed using primed in situ labeling (PRINS) analysis with specific primers for chromosomes 18, 21, X, and Y. Sperm DNA damage was assessed using alkaline comet assay. Results: The mean frequencies of disomy for the patients were significantly higher than normal for all chromosomes (P<0.01). The extent of DNA damage in sperms of subfertiles was significantly higher than in normal individuals (P<0.001). The obtained results indicated that higher rate of DNA damages led to higher frequency of chromosomal disomy except for asthenozoospermia samples which exhibited higher rate of DNA damage and lower frequency of chromosomal disomy. Conclusions: These results demonstrate that men with oligozoospermia and oligoasthenozoospermia have an elevated risk for chromosome abnormalities in their sperm, particularly sex chromosomes. DNA damage might be involved in the process of malsegregation of chromosomes.Asthenozoospermia, DNA damage, Primed in situ labeling (PRINS), Comet assay  相似文献   
342.
The effect of different types of processing such as boiling, pressure cooking, puffing, frying, germination, and germination followed by cooking on the protein and carbohydrate digestibility of chickpea, horsegram and cowpea were studied in in vitro systems. In the case of chickpea, the protein digestibility was not significantly improved by any of the treatments. However, for horsegram and cowpea, improvement in protein digestibility was observed after some of the different processing treatments. Frying decreased the protein digestibility in all of the pulses. All of the treatments, except germination, caused a marked increase in in vitro carbohydrate digestibility.  相似文献   
343.
Mycobacterium farcinogenes is the causal agent of bovine farcy, a chronic infectious disease of zebu cattle in some parts of tropical Africa. Whole cell homologous antigen of M. farcinogenes was used in the standardization and evaluation of an enzyme linked immunosorbent assay (ELISA) for the detection of circulating antibodies against bovine farcy using sera from confirmed bovine farcy and from bovine farcy-free cattle. The cut-off optical density (OD) value was decided at 1.8 using filter 405nm after one hour of incubation at 37°C. Accordingly, 115 out of 124 (92.7%) serum samples from clinically proven bovine farcy cattle were reported sero-positive. Sera from cattle infected with M. avium and M. paratuberculosis revealed OD value <1.8, indicating the differential diagnostic ability of M. farcinogenes antigen. Our test sensitivity was 92.7% and specificity was 97%, therefore could be routinely employed to support early clinical diagnosis, epidemiological surveys and for screening animals before exportation to farcy-free regions.  相似文献   
344.
345.
The status of woody plants in dry-land systems is a fundamental determinant of key ecosystem processes. Monitoring of this status plays an important role in understanding the dynamics of woody plants in arid and semi-arid ecosystems. The present study determined the dynamism of the Zagros forests in Iran using Remote Sensing and Geographic Information System techniques and statistical science. The results show that the density of trees varied from 10 to 53 % according to the physiographic and climatic conditions of semi-arid regions. The best and lowest correlation between vegetation indices and forest density were obtained for the global environmental monitoring index (GEMI; R 2 = 0.94) and soil adjust vegetation index (R 2 = 0.81), respectively. GEMI is used to monitor land use changes over a 10-year period. Results show that 2720 ha2 of forest have been destroyed by human interference and tillage on steep slopes during this period which also resulted in the loss of the fertile soil layer. GEMI determined the areas with a biomass of trees and could normally separate border regions with low biomass density of trees from regions without canopy cover. The results revealed that assessment of forest and vegetation cover in arid and semi-arid arduous forest regions using satellite digital numbers and ordinary sampling is subject to uncertainty. A stratified grouping procedure should be established to increase the accuracy of assessment.  相似文献   
346.
347.
Rhizosphere processes have a major impact on Zn desorption and Zn uptake by plant. However, information about Zn desorption characteristics in the rhizosphere of wheat is limited. Therefore, a greenhouse experiment was performed to determine Zn desorption characteristics in the bulk and rhizosphere soil of wheat (Triticum aestivum L.) of 10 soils amended and un-amended with municipal sewage sludge using rhizoboxes. The kinetics of Zn desorption was determined by successive extraction with 10 mM citric acid in a period of 1–504 h at 25 ± 1°C in the bulk and rhizosphere of un-amended and amended soils. The results showed that the Zn amount extracted after 504 h in the rhizosphere soils was significantly (< 0.01) higher than the bulk soils. The mean of Zn desorption in the bulk and rhizosphere of un-amended soils were 10.4 ± 0.34 and 11.4 ± 0.43 mg kg?1, respectively, while the mean of Zn desorption in the bulk and the rhizosphere of amended soils were 13.2 ± 0.48 and 14.8 ± 0.67 mg kg?1, respectively. Desorption kinetics of Zn conformed fairly well to the first-order, parabolic diffusion, power function, and zero-order equations. The results of Zn fractionation indicated that exchangeable Zn and Zn associated with organic matter decreased and Zn associated with iron-manganese oxides and residual Zn increased in the rhizosphere soils compared to the bulk soils. Zinc desorption after 504 h and residual Zn in the bulk and rhizosphere of un-amended and amended soils were significantly positively correlated (< 0.05). Therefore, residual Zn was the main Zn pool that controlled Zn desorption after 504 h in the bulk and rhizosphere soils studied.  相似文献   
348.
Summary The uptake of labelled and unlabelled N by wheat was measured in a field experiment using 15N-labelled ammonium nitrate fertilizer. The dry matter yield and N yields were significantly increased with fertilizer N application compared to those from unfertilized soil. The uptake of applied N by wheat ranged between 25 and 34%. Fertilizer N application increased the uptake of unlabelled soil N which was attributed to a positive priming effect or added N interaction. The added N interaction observed by applying 20, 60, and 120 kg fertilizer N was 11.4, 19.1, and 27.9 kg, corresponding to 26, 44 and 64%, respectively of the N taken up from unfertilized soil. The A values did not alter with the increase in fertilizer N application. The observed added N interaction may have been the result of pool substitution whereby added labelled fertilizer N stood proxy for unlabelled soil N. A significant correlation coefficient (r=0.996**) between the uptake of soil N and the dry matter yield showed that soil N was more important than fertilizer N in wheat production.  相似文献   
349.
Flours from advanced lines or cultivars of six triticales and two prime hard wheats, along with triticale‐wheat blends, were investigated for mixing, extension (excluding blends), and baking properties using microscale testing. Percentage total polymeric protein (PPP) and percentage unextractable polymeric protein (UPP) of flours and doughs, including blends, mixed to optimal dough development were estimated using size‐exclusion HPLC to determine the changes in protein solubility and association with blend composition (BC), mixing properties, and loaf height. Each triticale was blended with flours of each of the two wheat cultivars (Hartog and Sunco) at 0, 30, 40, 50, 60, 70, and 100% of wheat flour. Nonlinear relationships between BC and mixograph parameters (mixing time [MT], bandwidth at peak resistance [BWPR], and resistance breakdown [RBD]) were observed. A linear relationship between BC and peak resistance (PR) was predominant. PPP of triticale flours was mostly higher than PPP of wheat cultivars. UPP of all triticales was significantly lower than wheat cultivars. PPP of freeze‐dried doughs was mostly nonsignificant across the blends and showed a curvilinear relationship with BC. The deviations from linearity of MT and PPP were higher in triticale‐Sunco blends than in triticale‐Hartog blends. UPP of blends was closer to or lower than the lower component in the blend. The deviations from linearity for MT and UPP were greater in triticale‐Hartog blends than triticale‐Sunco blends. A highly significant correlation (P < 0.001) was observed between BWPR and loaf height. This suggested that BWPR in triticale‐wheat flour blends could be successfully used for the prediction of loaf height. Triticale flour could be substituted for wheat flour up to 50% in the blend without drastically affecting bread quality. Dough properties of triticale‐wheat flour blends were highly cultivar specific and dependent on blend composition. This strongly suggested that any flour blend must be tested at the desired blend composition.  相似文献   
350.
 绿洲农业是依靠灌溉发展起来的生态系统。干旱地区地表水资源共同特点是春、秋季供水紧张,夏季相对富裕;但种植业产业结构上用水又集中在春季,水的利用矛盾重重。本文分析新疆策勒绿洲近50年农业统计资料,结合课题组调查收集的第一手资料,在充分分析干旱区绿洲农业结构与水资源利用特点的基础上,用资源最优分配模型和线性优化模型方法,提出了绿洲农业结构、作物布局和水资源利用最佳方案,为干旱区绿洲水资源合理利用、区域经济发展提供科学依据。  相似文献   
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