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1.
针对联合收获机知识缺乏系统化组织与分类、难以在设计时高效获取并应用的问题,应用装备谱系及谱系拓扑图形式对联合收获机知识进行层次化组织;按照联合收获机智能化设计实际应用需求,对知识库系统功能模块进行架构分析;分析了农机装备设计知识的表现形式,综合利用产生式规则和框架表示的混合表示方法对设计过程进行分析和表达,建立了设计体系。以Visual Studio 2015平台为开发工具,在.Net环境下,应用ADO.Net技术、CATIA二次开发技术及SQL Server数据库,将联合收获机设计知识、参数化模型等数字化资源融和,进行组织管理,构建了联合收获机知识库系统。通过人机交互的方式,将知识表达形成的设计体系系统化,应用模糊查询方法、推理机和ADO.Net技术实现系统中知识的查询、推理及编辑功能,并将知识推送的结果传递给关联的参数化模型驱动,在不同需求下快速构建模型,实现了知识的高效获取与应用,提高了设计效率,为联合收获机零部件设计提供了一种通用方法。系统测试表明,该系统具有可行性和有效性,适用于联合收获机系列产品的开发。  相似文献   
2.
Barley (Hordeum vulgare) is cultivated on 49.1 million hectares worldwide with 50.2% of the area located in Europe. Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh), occurs wherever barley is grown. Cultivar resistance plays an important role in global barley production, especially in parts of Europe where high concentrations of both spring and winter types are grown. The aim of this report was to postulate specific resistance genes in barleys from nine European countries registered in the Czech Republic from 2011 to 2015. Thirty‐five spring cultivars and 27 winter barleys were tested with 56 diverse Bgh isolates. Twenty‐five known resistance genes were postulated, and unknown genes were detected in Sandra, Saturn and Zeppelin. Unidentified specific resistance genes were also present in winter hybrids Hobbit and Wootan. Spring cultivars Arthur and Francin consisted of three and two genotypes, respectively. Resistance gene mlo was present in 26 spring cultivars, and the proportion of cultivars with this gene increased from 62.9% in 2006–2010 to 75.7% in 2011–2015. The gene Mlp1 was identified for the first time in German winter cultivar Saturn. Five spring cultivars registered in Slovakia were included in the tests. All the cultivars that were tested contained one or more specific resistance genes to powdery mildew. Adaptability of the pathogen and possibilities for breeding winter barleys are discussed.  相似文献   
3.
旨在设计利用不同信息来源的模型估计荷斯坦后备牛不同月龄体重性状的遗传参数。本研究于2014—2020年测定并收集了7 122头荷斯坦牛32 338条0~12月龄体重数据,分别利用系谱信息(linear mixed model with pedigree relationship matrix, LM_A)和系谱-基因组信息构建亲缘关系矩阵(linear mixed model with genotype-pedigree joint relationship matrix, LM_H),基于母体效应动物模型估计初生重,基于是否考虑初生重作为协变量的单性状动物模型估计2~12月龄各月龄体重遗传力,并利用双性状动物模型估计初生重与其它月龄体重的遗传相关。结果显示,对于初生重,根据赤池信息量准则(Akaike information criterion, AIC),LM_H方法的拟合程度显著优于LM_A方法,但两种方法估计的遗传参数相差不大:直接遗传力分别为0.30和0.32,母体遗传力分别为0.08和0.09,个体直接遗传效应和母体遗传效应遗传相关系数分别为-0.65和-0.64;对于2~...  相似文献   
4.
利用分子标记辅助家系选育进行红鳍东方鲀生长性状的遗传评估,由红鳍东方鲀基础群体中选择性腺发育良好的雌雄亲本各11尾建立全同胞家系11个,每个全同胞家系随机采集10尾个体组建全同胞家系群体,从混合培育的家系中选择相对较大的个体400尾组建混合选育群体。在红鳍东方鲀遗传连锁图谱上挑选44个均匀分布于22个连锁群上的微卫星DNA标记,每个连锁群有2个标记。全同胞家系群体的遗传分析结果显示,10个高亲本排除概率微卫星标记的Excl(1)和Excl(2)为0.58~0.662和0.736~0.797,14个低亲本排除概率标记的Excl(1)和Excl(2)为0.054~0.43和0.177~0.608,剩余20个中等亲本排除概率标记的Excl(1)和Excl(2)为0.467~0.575和0.641~0.732。利用拥有高亲本排除概率的微卫星DNA标记进行混合选育群体的亲权鉴定,结果显示:不同父母本繁殖产生的子代数量存在明显差异,父本M2和母本F4产生了124个子代,占子代个体总数的32.89%。根据亲权鉴定结果建立的系谱估计主要生长性状的遗传参数,不同日龄的体质量和体长遗传力估计值为0.17~0.21和0.15~0.18。研究表明,利用具有高亲本排除概率的微卫星DNA标记能够有效建立红鳍东方鲀系谱,进行生长性状的遗传参数估计,分子标记辅助家系选育可以作为红鳍东方鲀目标性状遗传改良的新方法。  相似文献   
5.
The dispersal ecology of most stream fishes is poorly characterised, complicating conservation efforts for these species. We used microsatellite DNA marker data to characterise dispersal patterns and effective population size (Ne) for a population of Roanoke logperch Percina rex, an endangered darter (Percidae). Juveniles and candidate parents were sampled for 2 years at sites throughout the Roanoke River watershed. Dispersal was inferred via genetic assignment tests (ATs), pedigree reconstruction (PR) and estimation of lifetime dispersal distance under a genetic isolation‐by‐distance model. Estimates of Ne varied from 105 to 1218 individuals, depending on the estimation method. Based on PR, polygamy was frequent in parents of both sexes, with individuals spawning with an average of 2.4 mates. The sample contained 61 half‐sibling pairs, but only one parent–offspring pair and no full‐sib pairs, which limited our ability to discriminate natal dispersal of juveniles from breeding dispersal of their parents between spawning events. Nonetheless, all methods indicated extensive dispersal. The AT indicated unrestricted dispersal among sites ≤15 km apart, while siblings inferred by the PR were captured an average of 14 km and up to 55 km apart. Model‐based estimates of median lifetime dispersal distance (6–24 km, depending on assumptions) bracketed AT and PR estimates, indicating that widely dispersed individuals do, on average, contribute to gene flow. Extensive dispersal of P. rex suggests that darters and other small benthic stream fishes may be unexpectedly mobile. Monitoring and management activities for such populations should encompass entire watersheds to fully capture population dynamics.  相似文献   
6.
Anadromous fishes are frequently restricted by artificial barriers to movement such as dams and culverts, so measuring dispersal helps identify sites where improved connectivity could promote range expansion and population viability. We used a combination of DNA‐based parentage analysis and mark–recapture techniques to evaluate dispersal by juvenile coho salmon (Oncorhynchus kisutch) in a population in the initial stages of colonisation following installation of fish passage structures at a previously impassable dam on the Cedar River, WA, USA. The spatial distribution of individuals within maternal families revealed that dispersal was common. Among the offspring of radio‐tagged mothers, 28% were collected outside the spawning reach and dispersed up to 6.3 km (median = 1.5 km). Most juveniles captured in a tributary (Rock Creek, where few adults spawned) had immigrated from the Cedar River and represented many different families. Juvenile dispersal therefore provided a secondary phase of spatial expansion following initial colonisation by adults. Consistent with the condition‐dependent dispersal hypothesis, juveniles that dispersed farther upstream in the tributary were larger than fish collected near the tributary mouth. Overall, the results demonstrated widespread dispersal in a system with low coho salmon densities, and this might increase the rate of population growth if it reduces the effects of local density dependence. By implication, juveniles can take advantage of rearing habitats reconnected through barrier removal, even when such areas are located several kilometres from adult breeding grounds.  相似文献   
7.
按系统指数(PI:Pedigree Index)的高低将119头北京荷斯坦犊牛分成两组(PI〉500为高组,PI〈500为低组),其中38头犊牛(5头公牛的后代)具有高系谱指数,平均值为718.5,81头犊牛(10头公牛的后代)具有低系谱指数,平均值为400.5。犊牛为3~6月龄,在禁食34~36h状态下采血,检测它们血液中总蛋白(TP)、尿素氮(BUN)、肌酸酐(CRE)、游离脂肪酸(FFA)的  相似文献   
8.
Genome-wide single nucleotide polymorphism (SNP) markers in Japanese Black cattle enable genomic prediction and verifying parent–offspring relationships. We assessed the performance of opposing homozygotes (OH) for paternity testing in Japanese Black cattle, using SNP genotype information of 50 sires and 3,420 fattened animals, 1,945 of which were fathered by the 50 genotyped sires. The number of OH was counted for each sire–progeny pair in 28,764 SNPs with minor allele frequencies of ≥0.05 in this population. Across all pairs of animals, the number of OH tended to increase as the pedigree-based coefficient of relationship decreased. With a threshold of 288 (1% of SNPs) for paternity testing, most sire–progeny pairs were detected as true relationships. The frequency of Mendelian inconsistencies was 2.4%, reflecting the high accuracy of pedigree information in Japanese Black cattle population. The results indicate the utility of OH for paternity testing in Japanese Black cattle.  相似文献   
9.
旨在对广灵县优种驴场保种群体进行调查的基础上构建分子系谱,并对其种群的遗传结构进行分析。本研究采集保种群成年、体况良好的广灵驴(体重350~400 kg)颈静脉血10 mL(n=107),其中公驴13份,母驴94份,抗凝处理后提取全血DNA。采用12个微卫星标记进行荧光PCR扩增后,用ABI3730测序仪进行分型。分型结果采用Cervus 2.0和Pedigraph 2.4软件构建分子系谱,同时采用STRUCTURE2.3和Fstat软件计算群体遗传参数,采用R语言的hclust函数绘制7头公驴及其后代的系统发生NJ树(邻接树)。结果,对107头种驴进行了分子系谱构建,找到了30头子代的父亲和7头子代的母亲,系谱可靠性>90%;微卫星标记的平均观测杂合度(HObs)和多态信息含量(PIC)分别为0.676 5和0.593 9,标记遗传多样性较高;NJ树对7个公驴家系进行了聚类;群体分化系数(FST)为0.184,群体平均近交系数(FIT)为0.033,群体内近交系数(FIS)为-0.238,且群体处于哈代-温伯格平衡状态,存在很弱的近交。本研究建立了广灵驴保种群可靠性较高的分子系谱并对其遗传结构进行了分析,证明该群体遗传多态性较高,群体近交系数较低,处于较好的保种状态,具有较大的品种资源开发潜力。  相似文献   
10.
Investigation of historic population processes using molecular data has been facilitated by the use of approximate Bayesian computation (ABC), which enables the consideration of multiple alternative demographic scenarios. The Lincoln Red cattle breed provides a relatively simple example of two well‐documented admixture events. Using molecular data for this breed, we found that structure did not resolve very low (<5% levels) of introgression, possibly due to sampling limitations. We evaluated the performance of two ABC approaches (2BAD and DIYABC) against those of two earlier methodologies, ADMIX and LEADMIX, by comparing their interpretations with the conclusions drawn from herdbook analysis. The ABC methods gave credible values for the proportions of the Lincoln Red genotype that are attributable to Aberdeen Angus and Limousin, although estimates of effective population size and event timing were not realistic. We suggest ABC methods are a valuable supplement to pedigree‐based studies but that the accuracy of admixture determination is likely to diminish with increasing complexity of the admixture scenario.  相似文献   
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