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41.
The golden hamster (Mesocricetus auratus) is one of the most frequently used laboratory animals, particularly in chronobiological studies. One reason is its very robust and predictable rhythms, although the question arises whether this is an inbreeding effect or rather is typical for the species. We compared the daily (circadian) activity rhythms of wild and laboratory golden hamsters. The laboratory hamsters were derived from our own outbred stock (Zoh:GOHA). The wild hamsters included animals captured in Syria and their descendants (F1). Experiments were performed under entrained (light: dark [LD] 14h:10h) and under free-running (constant darkness, DD) conditions. Locomotor activity was recorded using passive infrared detectors. Under entrained conditions, the animals had access to a running wheel for a certain time to induce additional activity. After 3 weeks in constant darkness, a light pulse (15 min, 100 lux) was applied at circadian time 14 (CT14). Both laboratory and wild hamsters showed well-pronounced and very similar activity rhythms. Under entrained conditions, all hamsters manifested about 80% of their total 24h activity during the dark portion of the LD cycle. The robustness of the daily rhythms was also similar. However, interindividual variability was higher in wild hamsters for both measures. All animals used the running wheels almost exclusively during the dark portion of the LD cycle, although the wild hamsters were three times more active. The period length, measured in constant darkness, was significantly shorter in wild (23.93h ± 0.10h) than in laboratory hamsters (24.06 ± 0.07h). The light-induced phase changes were not different (about 1.5h). In summary, these results indicate that the laboratory hamster is not much different from the wild type. (Chronobiology International, 18(6), 921-932, 2001)  相似文献   
42.
To investigate which component of the plasma membrane of the hamster egg plays the central role in the sperm–egg fusion, the egg membrane was treated with a variety of proteolytic, carbohydrate-hydrolyzing, lipid-hydrolyzing, and other enzymes. The only enzyme that markedly effected the ability of the egg membrane to fuse with spermatozoa was phospholipase C. The lipid moieties of the egg plasma membrane (and possibly of the sperm membrane) must be of primary importance in sperm–egg fusion at fertilization.  相似文献   
43.
Egg white proteins, hemoglobin, serum proteins and enzymes from Phasianus colchicus have been examined by starch gel electrophoresis. All three genetic parameters, mean proportion of loci polymorphic per population (P), mean numbers of alleles per locus (A), and mean proportion of loci heterozygous per individual (H), are given. Comparison were made between the proteins of the related species Coturnix coturnix japonica, and the variation of pheasant proteins is discussed in connexion with the genetic structure of the population studied.  相似文献   
44.
《Ostrich》2013,84(3):281-284
Golden Nightjar Caprimulgus eximius is an apparently sedentary sub-Saharan species with a breeding range extending from Senegal and Mauritania to Sudan. Although genetic studies of nightjars and related Caprimulgiformes have been published previously, none has included Golden Nightjar. In this study, mitochondrial and nuclear DNA of a Golden Nightjar found dead in Western Sahara in April 2016 was sequenced and compared with other species in the genus Caprimulgus. It was concluded with strong support that Golden Nightjar is closely related to Egyptian Nightjar C. aegyptius. It is hypothesised that Golden and Egyptian Nightjars may have arisen by splitting of a single ancestral species into migratory and sedentary populations.  相似文献   
45.
目的探讨通过随访观察金双歧辅助治疗小儿扁桃体炎患儿的远期效果。方法选取2013年1月至2014年7月在本院儿科住院诊断为扁桃体炎患儿300例,采用随机数字表法,按入院先后顺序分为对照组和观察组,对照组常规给予抗生素(包括抗病毒药)和(或)对症治疗;观察组在对照组治疗的基础上,给予金双歧口服辅助治疗,出院后继续服用金双歧4周;两组患儿分别在出院后1个月、2个月、3个月均进行电话随访,3个月后均通过家庭访视进行观察,比较两组患儿出院后发生呼吸道感染和肠道感染的差异。结果观察组患儿在出院后3个月内呼吸道感染和肠道感染的发生率低于对照组,差异具有统计学意义(P0.05)。结论出院扁桃体炎患儿继续服用金双歧,可提高患儿机体免疫力,降低呼吸道和肠道感染的发生率;随访为观察患儿出院后健康状态,进行健康指导以及收集资料的重要手段。  相似文献   
46.
Reciprocal immunization between parents of an Illinois family of ring-necked pheasants, Phasianus colchicus, resulted in antisera detecting two pairs of alloantigens segregating among 13 progeny. The four alloantigens were tentatively designated as 1 and 2, transmitted antithetically by the sire, and 3 and 4, transmitted antithetically by the dam. Genetic segregation occurring in second-generation progeny demonstrated that these two pairs of antigens belonged to a single genetic system. This alloantigen system was shown to correspond serologically to the major histocompatibility complex (MHC) of the chicken by cross-reactivity of the antigens of this system with specific subregional chicken MHC reagents, appropriately absorbed with erythrocytes of individual pheasants. These four haplotypes of the pheasant MHC were subsequently designated as MhcPhco-B1, MhcPhco-B2, MhcPhco-B3 and MhcPhco-B4. Traditional immunogenetic analysis of 30 pheasant families produced in this study disclosed a minimum of 14 pheasant haplotypes of this alloantigen system (MHC) to be segregating in the population under evaluation.  相似文献   
47.
通过对西藏4个不同生态型区‘金冠’苹果果实品质相关指标进行测定,并对果实品质与主要气象因子进行相关性分析及回归分析,以确定西藏‘金冠’苹果栽培主要气象因子评价体系。结果显示,在西藏4个不同生态型区‘金冠’苹果品质差异显著,其中,林芝‘金冠’综合表现较好。在西藏高海拔地区,年均温、7月均温、昼夜温差、≥10℃年均积温、年日照时数、年降水量及海拔是影响‘金冠’果实品质的主要气象因子。其中,海拔2857.9 m、年均气温13.2℃、7月平均气温15.9℃、年均昼夜温差12.7℃、≥10℃年均积温2310.5℃、年均日照时数2532.6 h、年均降水量636.7 mm是‘金冠’苹果形成最佳果实品质的适应气象因子,并且在一定范围内,昼夜温差越大,果实品质越好。本研究建立了西藏‘金冠’苹果栽培主要气象因子评价体系,并提出昼夜温差是影响西藏高海拔地区‘金冠’苹果品质的最主要评价因子。  相似文献   
48.
49.
It was shown previously in infant rats (Rattus norvegicus) that the ability to produce heat in the cold using brown adipose tissue (BAT) is closely related to the ability to maintain cardiac rate. When the limits of BAT thermogenesis were exceeded, interscapular temperature (which reflects the temperature of the interscapular BAT depot) and cardiac rate fell together. As an extension of this earlier study, the relation between BAT thermogenesis and cardiac rate was examined here in the golden hamster (Mesocricetus auratus), a species whose young do not exhibit BAT thermogenesis until the end of the 2nd week postpartum. It was found that 3 to 12-day-old hamsters were unable to increase shivering or nonshivering thermogenesis in the cold and exhibited decreases in cardiac rate that proceeded in lock-step with decreases in interscapular temperature. In contrast, as the thermogenic capability of hamsters increased after 12 days of age, cardiac rate was maintained within narrow limits across a wide range of air temperatures. These results support the hypothesis that heat produced by BAT helps to warm the heart and thus aids in the maintenance of cardiac rate during cold exposure. Accepted: 16 August 1997  相似文献   
50.
白冠长尾雉的越冬生态   总被引:6,自引:0,他引:6  
白冠长尾雉的越冬生态方成良丁玉华(河南省信阳林业学校,464031)Over_WinteringEcologyoftheWhite_crownedLong_TailedPheasant.FangChengliang,DingYuhua(Xinyang...  相似文献   
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