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21.
桃金娘科园林植物形态种类丰富,能吸引鸟类、蜂类、蝶类等,对部分桃金娘科引鸟植物的生态效益和景观营造进行评估。结果表明:桃金娘科植物花色艳丽,果实硕大,可作动物食源,能有效吸引具有生态景观价值的野生鸟类如暗绿绣眼鸟、白头鹎、红嘴蓝鹊、红耳鹎、珠颈斑鸠、黑脸噪鹛、乌鸫、领雀嘴鹎等。结合花期吸引传粉昆虫及果期引鸟效果,提出相应的生态景观营造策略,有利于食物网的完善构建,进一步完善绿地生态系统建设。  相似文献   
22.
This study examined the capacity of Japanese spiny lobster Panulirus japonicus phyllosoma larvae to absorb nutrients directly from the surrounding water. For this purpose, 48-, 81-, 124-, 160-, and 264-day-old intermoult larvae were starved for 48 h, held for 30 min to 4 h in 0.05 g L–1 solutions or dispersions of cholesterol, peanut oil, saccharose and horseradish peroxidase in seawater, and subsequently examined by histological and ultrastructural methods. Lipids, carbohydrate, and protein were detected in either the lumen of the midgut gland tubules, the midgut gland cells, the haemolymph or in the cells of the epidermis of all larvae examined after each experimental period, with general improvement of the cell and tissue characteristics over unfed controls. The lipids were also found in the cuticle. Thus, the results provide evidence of nutrient absorption via the digestive tract, and possibly also via the integument. Structural adaptations that may be involved in the process of absorption were tentatively identified. Our observations suggest the possibility that particulate organic matter (POM) and dissolved organic matter (DOM) can be utilized by the P. japonicus phyllosoma larvae, perhaps as supplementary sources of nutrients to macroscopic diets.  相似文献   
23.
The biological activity of the Ireland strain of Choristoneura fumiferana (Clem) nucleopolyhedrovirus (CfMNPV) propagated in different hosts was determined to provide the basis upon which genetically modified CfMNPV, or other naturally occurring isolates, should be compared. Occlusion bodies (OB) derived from CF-203 cells were significantly larger and more pathogenic than those propagated in vivo when tested against the fifth larval instar of C fumiferana (Clem) and C occidentalis Freeman. The dose-responses (LD50 and LD95, expressed as occlusion bodies per larva) of C fumiferana larvae to in vitro-propagated OBs were 274 and 5785, respectively. The values of LD50 and LD95 to C occidentalis larvae were 19 and 118, respectively. There were no significant differences in pathogenicity or size when OBs propagated in C fumiferana larvae were tested against either insect species, nor were there significant differences for OBs propagated in C occidentalis larvae. The LD50 and LD95 of in vivo-produced OBs to C fumiferana were 925 and 61988, respectively. The LD50 and LD95 to C occidentalis were 50 and 453, respectively. OBs propagated in vitro had a mean volume of 13.13 microm3, whereas those propagated in vivo ranged from 0.84 to 1.41 microm3. The median survival time-responses (ST50) of fifth-instar C fumiferana or C occidentalis larvae to OBs propagated in vivo were not significantly different from those propagated in vitro at the dosage levels tested. Values of ST50 of C fumiferana larvae to in vitro- and in vivo-produced OBs at dosages causing less than 50% mortality rangedfrom 9.6 to 9.8 days post-inoculation (dpi), whereas a LD95 dose resulted in ST50 values ranging from 7.3 to 7.7 days. ST50 values of C occidentalis larvae at dosages causing less than 50% mortality ranged from 9.8 to 10.2 dpi, whereas a LD95 dose resulted in ST50 values ranging from 9.5 to 9.8 dpi. The median feeding cessation time-response (FT50) of fifth-instar C fumiferana larvae to OBs propagated in vitro (5.7 days) was not significantly different from the FT50 of those propagated in vivo in either insect species (5.3 and 5.7 days) at the dosage level tested (LD95). No significant differences in FT50 values were observed between OBs propagated in either larval host. The FT50 of C occidentalis larvae to OBs propagated in vitro (7.7 days) was not significantly different from that to those propagated in vivo in C occidentalis larvae (7.6days), but somewhat different (7.2 days) from that to those propagated in C fumiferana larvae. Results indicate that CfMNPV can be propagated in vivo in either C fumiferana or C occidentalis larvae (or sequentially through both) without alteration in infectivity, although the use of the CF-203 cell line yields the most biologically active OBs.  相似文献   
24.
红鳍东方鲀仔鱼期摄食与生长的研究   总被引:8,自引:2,他引:8  
在水温 ( 1 6± 1 )℃条件下 ,红鳍东方 (Takifugurubripes)仔鱼孵出后 4d开始摄食 ,此时其卵黄囊体积由初孵时的 0 636mm3减少到 0 375mm3;1 2d时 ,卵黄完全耗尽。最高初次摄食率出现在卵黄耗尽时 ,可达 1 0 0 % ;仔鱼能维持 9d高达 90 %以上的初次摄食率。初次摄食强度最大值也出现在 1 2d。饥饿不可逆点 (PNR)出现在 1 5~ 1 6d。在内营养期日平均增长率为 0 2 1 7mm/d ;在PNR前的摄食期 ,饥饿仔鱼的日平均生长率为 0 0 1 7mm/d ;而摄食仔鱼的日平均生长率为 0 0 95mm/d ;PNR后至死亡前 ,饥饿仔鱼呈负增长 ,而摄食仔鱼的日平均生长率达 0 41 0mm/d。  相似文献   
25.
玉米是我国主要农作物之一,其生产效率与生产质量的好坏,直接关系着我国粮食安全。传统的玉米播种方式,不仅生产效率、作业质量和标准化程度均比较低,无法实现高效率全自动大面积玉米播种或者套种的实际需求。在新时期,随着城镇化进程加快,农村劳动力日益短缺,加上社会经济发展与科学技术的进步,为我国玉米移栽机自动化技术开发设计提供了必要的支撑条件。为此,对我国东北地区玉米试验田进行相关研究,就自动化玉米移栽机及其送苗装置技术的研发、设计进行探究,并重点阐述其基本工作原理。  相似文献   
26.
用体外产气法测定了桂牧1号象草不同月份、不同高度的产气量及添加聚乙二醇(PEG)对产气量的影响。结果显示:(1)桂牧1号象草各月份的干物质含量比较为:11月〉10月〉9月〉4月。其中,1.0m左右及1.0m以上的象草的干物质含量明显较高(P〈0.01)。(2)在体外产气法实验中添加PEG能显著增加样品12h和24h的产气量(P〈0.01),证明象草中所含有的抗营养因子对黑山羊瘤胃微生物活动有一定的制约作用。(3)9、11月份象草的最佳刈割高度应为1.5m左右,4、10月份象草的最佳刈割高度应为1.0m左右。(4)4月、9月份的象草,添加PEG后产气量提高率较高。利用此时期的象草喂食黑山羊时,适当做PEG处理可以提高象草的饲用价值。  相似文献   
27.
Coexisting natural enemies that share a common host resource in the same guild usually exhibit variation in their life history traits, due to their need to share a similar ecological niche. In this study, we compared the immature development times and adult life history traits of two coexisting, host-feeding parasitoids, Diglyphus isaea Walker and Neochrysocharis formosa Westwood (Hymenoptera: Eulophidae), of which both attack larvae of the same agromyzid leafminers. These two species are both synovigenic, idiobiont parasitoids, whose adults consume host fluids (“host feeding”) and lay anhydropic eggs. Of the two, D. isaea has a larger body but little or no initial egg load, and engages in similar lifetime host-feeding events. However, it achieves higher fecundity, longer adult longevity, and higher host suppression ability than N. formosa, which has a smaller body and higher initial egg load. Although D. isaea engages in similar lifetime host-feeding events with N. formosa, all of its gains in life history traits per host-feeding event of D. isaea were larger than those of N. formosa. The age-specific fecundity and host mortality curves of N. formosa were more skewed in early life than those of D. isaea. In addition, the ovigeny index of N. formosa was negatively correlated to body size. Our results confirmed that two coexisting parasitoids, which share the same host resource, show different immature development patterns and life history traits, suggesting that different resource allocation mode could be a general rule of coexisting species sharing the same habitat or host.  相似文献   
28.
商品猪精细养殖数字化技术平台构建与实现   总被引:1,自引:0,他引:1  
本文全面地介绍了“商品猪精细养殖数字化技术平台”的系统解决方案、系统实现、采用的关键技术和系统实现的特点等,重点阐述了系统采用的技术架构、实现的主要功能和采取的关键技术.平台提供了生产管理、饲料管理、疾病管理和生产监测统计等功能,基本实现了商品猪养殖企业精细养殖过程的数字化管理.  相似文献   
29.
【目的】研究L-肉碱强化卤虫对鲤鱼开口苗脂肪酸组成和C/N比率的影响,为鲤鱼开口苗的饲养提供参考。【方法】分别用质量浓度为0(对照),1,100,1 000 mg/L的L-肉碱强化卤虫无节幼体(Artemiasp.)12和24h,然后投喂给鲤鱼(Cyprinus carpio)开口苗,21 d后测定鱼苗的脂肪酸组成和C/N比率。【结果】投喂L-肉碱强化12 h的卤虫时,1 mg/L L-肉碱处理组鲤鱼开口苗的∑C14-24脂肪酸含量、饱和脂肪酸含量和单不饱和脂肪酸含量较对照组显著降低(P<0.05);1 000 mg/L L-肉碱处理组鲤鱼开口苗的单不饱和脂肪酸含量较对照组显著升高(P<0.05);L-肉碱对鲤鱼开口苗的多不饱和脂肪酸含量、∑n-3+∑n-6和∑DHA+EPA含量均无显著影响(P>0.05);1 000mg/L L-肉碱处理组鲤鱼开口苗的C/N比率显著低于对照组和1 mg/L L-肉碱处理组(P<0.05)。投喂L-肉碱强化24 h的卤虫时,1和100 mg/L L-肉碱处理组鲤鱼开口苗的∑C14-24脂肪酸和饱和脂肪酸含量较对照组显著降低(P<0.05),但2组之间差异不显著(P>0.05);1 000 mg/L L-肉碱处理组鲤鱼开口苗的∑C14-24脂肪酸和饱和脂肪酸含量较对照组显著升高(P<0.05);1 mg/L L-肉碱处理组鲤鱼开口苗的单不饱和脂肪酸含量较其他3组显著降低(P<0.05),多不饱和脂肪酸、∑n-3+∑n-6和∑DHA+EPA含量与对照组差异不显著(P>0.05);100 mg/L和1 000 mg/L L-肉碱处理组鲤鱼开口苗的多不饱和脂肪酸、∑n-3+∑n-6和∑DHA+EP A含量较对照组显著升高(P<0.05),且2组之间差异显著(P<0.05);1,100 mg/L L-肉碱处理组鲤鱼开口苗的C/N比率较对照组和1 000 mg/L L-肉碱处理组显著降低(P<0.05)。【结论】本试验条件下,以质量浓度100 mg/L L-肉碱强化卤虫24 h后再投喂鲤鱼开口苗,可显著改善鲤鱼开口苗的脂肪酸组成和C/N比率。  相似文献   
30.
对铜仁市锦江河采集的野生斑鳜消化系统和食性进行了研究,并对不同年龄斑鳜消化系统特征和食性进行比较分析。结果表明,口裂长和肠长都随着体长的增长而增大,Ⅲ龄以上成鱼口裂长和肠长的增长速度慢于体长;个体越小的斑鳜,其眼径与头长的比值越大;低龄斑鳜的摄食率和摄食强度明显高于成鱼。  相似文献   
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