全文获取类型
收费全文 | 1385篇 |
免费 | 91篇 |
国内免费 | 26篇 |
专业分类
1502篇 |
出版年
2023年 | 10篇 |
2022年 | 19篇 |
2021年 | 40篇 |
2020年 | 39篇 |
2019年 | 49篇 |
2018年 | 41篇 |
2017年 | 31篇 |
2016年 | 36篇 |
2015年 | 35篇 |
2014年 | 48篇 |
2013年 | 61篇 |
2012年 | 39篇 |
2011年 | 49篇 |
2010年 | 51篇 |
2009年 | 76篇 |
2008年 | 74篇 |
2007年 | 67篇 |
2006年 | 55篇 |
2005年 | 43篇 |
2004年 | 51篇 |
2003年 | 38篇 |
2002年 | 45篇 |
2001年 | 26篇 |
2000年 | 21篇 |
1999年 | 32篇 |
1998年 | 27篇 |
1997年 | 22篇 |
1996年 | 39篇 |
1995年 | 33篇 |
1994年 | 18篇 |
1993年 | 18篇 |
1992年 | 34篇 |
1991年 | 24篇 |
1990年 | 20篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 25篇 |
1986年 | 17篇 |
1985年 | 13篇 |
1984年 | 17篇 |
1983年 | 9篇 |
1982年 | 21篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 11篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有1502条查询结果,搜索用时 0 毫秒
11.
Atrial Septal Defect was detected at autopsy in a subadult bonnet macaque (Macaca radiata). Case history and autopsy findings were described. 相似文献
12.
禄丰古猿化石地点的植物叶化石 总被引:2,自引:0,他引:2
1987年,在云南禄丰古猿化石地点D剖面第4层(薄层黑色炭质粘土与灰色细砂互层)发现植物叶部印痕化石,经鉴定属壳斗科绝灭的雷龙潭槲叶(Dryophyllum relongtanense Colani),该种植物常参与组成亚热带至暖温带的常绿阔叶林或常绿与落叶阔叶混交林。 相似文献
13.
Klaus Zuberbühler Lorenz Gygax Nerida Harley Hans Kummer 《Primates; journal of primatology》1996,37(1):1-12
In a captive group of long-tailed macaques, tool-using behavior by a single competent individual had a significant effect on the synchronous manipulative behavior of naïve animals. Group members engaged in manipulations on the same object class more frequently during times when the model was working than when it was not. The form of their behavior, however, in no way resembled the technique used by the model. All three animals that later became successful tool users were among the few subjects that exhibited a significant increase in manipulations on the same object class while the model was working. Possible causal relationships between this stimulus enhancement and the transmission of the new behavior to other group members are analyzed and discussed. 相似文献
14.
C.G. Rodriguez N. Makori M. A. Cukierski A. G. Hendrickx 《Journal of medical primatology》1996,25(2):122-132
Abstract: Formation of the definitive kidney in Macaca fascicularis embryos was investigated using light and electron microscopy. Appearance of the definitive kidney at stage 14 was indicated by the ureteric bud invading the metanephrogenic blastema. Glomerular capillaries originate from the connective tissue that surrounds the developing renal vesicle. At 46–100 days gestational age the more developed glomeruli show thinning of the capillary endothelium, thickening of the basal membrane, and presence of pedicels, suggesting a capability of renal function. 相似文献
15.
Alexandra M. Birrell Annemarie Hennessy Adrian Gillin John Horvath David Tiller 《Journal of medical primatology》1996,25(4):287-293
Abstract: Baboons are widely used in biomedical research. Although it is widely held that Papio hamadryas breed well in captivity, each established colony has a different reproductive success often hypothesised to be due to husbandry practices. The National Baboon Colony in Australia is a unique colony that houses Papio hamadryas to mimic that structure seen in the wild. In this article; we have analysed their reproductive parameters and neonatal outcomes. The success of the colony husbandry practices was demonstrated by lack of maternal mortality, low foetal morbidity, and known maternal and paternal linage. 相似文献
16.
Ten species of non-human primates are indigenous to Bioko; half of these are endangered and between five and eight are endemic subspecies. Recent data on their status and distribution have been lacking. In 1986, a ten-week survey of the island was carried out to determine the distribution and status of the primates and the natural vegetation, and to evaluate the effects of man on them. This paper presents the results of that survey, gives an update of conservation achievements since 1986, and highlights current concerns. Between 1974 and 1986 it is probable that numbers of all Bioko primates rose as a result of an increase in habitat and of reduced hunting. At the time of the survey there was considerably more natural, undisturbed, vegetation remaining in Bioko tran expected. Much of this vegetation occurs within two large blocks that are of outstanding importance to the conservation of species in tropical Africa, particularly of plants and primates. 相似文献
17.
I. W. J. Debyser 《International journal of primatology》1995,16(6):889-907
I review literature on juvenile mortality of captive prosimians in order to evaluate the available information on captive
breeding. Juvenile mortality includes abortion, premature mortality, stillbirth, and death of the unweaned young. Prosimian
juvenile mortality ranges between 25 and 45% in captive populations. It is generally lower in the Lemuroidea, particularly
the Cheirogaleidae, than in the Lorisoidea. Mortality is particularly high in the Lorisinae. Most mortality, including a high
stillbirth rate, occurs on the first day and during the first 10 days thereafter. Stress, maternal neglect and traumatic insults,
not infrequently linked to each other, are the most frequently reported causes of death. The percentage of congenital malformations
tends to be high in some colonies. Sex of the infant and parity seem to be important risk factors for juvenile mortality,
whereas litter size does not appear to be important. Based on few data, wild- caught females appear to have higher breeding
success than those born in captivity. Synchronized births in lemuroids and isolated births in Galagoare more likely to result in successfully weaned infants. 相似文献
18.
Nuclear counterparts of the cytoplasmic mitochondrial 12S rRNA gene: A problem of ancient DNA and molecular phylogenies 总被引:10,自引:0,他引:10
Antoinette C. van der Kuyl Carla L. Kuiken John T. Dekker Wladimir R. K. Perizonius Jaap Goudsmit 《Journal of molecular evolution》1995,40(6):652-657
Monkey mummy bones and teeth originating from the North Saqqara Baboon Galleries (Egypt), soft tissue from a mummified baboon in a museum collection, and nineteenth/twentieth-century skin fragments from mangabeys were used for DNA extraction and PCR amplification of part of the mitochondrial 12S rRNA gene. Sequences aligning with the 12S rRNA gene were recovered but were only distantly related to contemporary monkey mitochondrial 12S rRNA sequences. However, many of these sequences were identical or closely related to human nuclear DNA sequences resembling mitochondrial 12S rRNA (isolated from a cell line depleted in mitochondria) and therefore have to be considered contamination. Subsequently in a separate study we were able to recover genuine mitochondrial 12S rRNA sequences from many extant species of nonhuman Old World primates and sequences closely resembling the human nuclear integrations. Analysis of all sequences by the neighbor-joining (NJ) method indicated that mitochondrial DNA sequences and their nuclear counterparts can be divided into two distinct clusters. One cluster contained all temporary cytoplasmic mitochondrial DNA sequences and approximately half of the monkey nuclear mitochondriallike sequences. A second cluster contained most human nuclear sequences and the other half of monkey nuclear sequences with a separate branch leading to human and gorilla mitochondrial and nuclear sequences. Sequences recovered from ancient materials were equally divided between the two clusters. These results constitute a warning for when working with ancient DNA or performing phylogenetic analysis using mitochondrial DNA as a target sequence: Nuclear counterparts of mitochondrial genes may lead to faulty interpretation of results.Correspondence to: A.C. van der Kuyl 相似文献
19.
Immunogenetic investigations on two serum beta-lipoprotein allotypes of rhesus monkeys (Macaca mulatta) are reported. The allotypes, designated Lmb1 and Lmb11, are associated with the main lipoprotein family, LP-B or beta-lipoprotein, expressed on independent beta-molecules, and classify rhesus monkeys into three phenotypes: Lmb1, Lmb11, and Lmb1,11. Genetic and molecular studies indicate that the allotypes are encoded by two codominant autosomal allelic genes, Lmb1 and Lmb11. Anti-Lmb1 cross-reacts with the sera of two other macaque species, whereas anti-Lmb11 with sera of all Old World monkeys. Heteroimmune sera, antihuman apo-B and antirhesus LP-B, showed high but diversified degrees of cross reactivity with other primates. 相似文献
20.
Biopterin, 6-hydroxymethyl-pterin, isoxanthopterin, neopterin and, pterin were quantified in stress-free collected spontaneous morning urine samples from Callithrix jacchus, Saguinus fuscicollis, Saguinus labiatus, Saimiri sciureus, Presbytis entellus, Cercopithecus albogularis, Cercocebus torquatus, Macaca fascicularis, Hylobates concolor, Pongo pygmaeus, and Gorilla gorilla. In most species, biopterin was the most frequent urinary pteridine followed by neopterin. Sex differences in biopterin and neopterin excretion were observed in Gorilla gorilla and Pongo pygmaeus. Pterin and isoxanthopterin were only present in minor concentrations. 6-hydroxymethyl-pterin was barely detectable and not present in the urine of Saguinus labiatus, Saimiri sciureus, and both male Gorilla gorilla and Pongo pygmaeus. 相似文献