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71.
72.
RFLP tagging of a new semidwarfing gene in rice 总被引:6,自引:0,他引:6
C. Z. Liang M. H. Gu X. B. Pan G. H. Liang L. H. Zhu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(6-7):898-900
A new rice semidwarfing gene which is not allelic tosd1, temporarily designated assdg, might be of use as a new source of semidwarfism in rice breeding programs. We report here the identification of a DNA marker closely linked to this gene. The DNA marker was identified by testing 120 mapped rice RFLP makers as hybridization probes for Southern analysis of a pair of nearly isogenic lines with or withoutsdg. Linkage association of the marker with the gene was verified using a F2 population segregating for semidwarfism. RFLP analysis showed thatsdg is closely linked to a single-copy DNA clone RZ182 on chromosome 5, with a distance of 4.3 centiMorgans between them. This marker may facilitate early selection for the semidwarfing gene in rice breeding programs 相似文献
73.
Expression of mouse metallothionein-I gene confers cadmium resistance in transgenic tobacco plants 总被引:8,自引:0,他引:8
Aihua Pan Meizhu Yang Feng Tie Lingyua Li Zhangliang Chen Biggen Ru 《Plant molecular biology》1994,24(2):341-351
Transgenic tobacco plants containing a mouse metallothionein-I (MT-I) gene fused to the cauliflower mosaic virus 35S (CaMV 35S) promoter and nopaline synthase (nos) polyadenylation site were obtained by transforming tobacco leaf discs with an Agrobacterium tumefaciens strain carrying the chimaeric gene. Transformants were directly selected and rooted on medium containing cadmium and kanamycin. A total of 49 individual transgenic tobacco plants were regenerated. Among them 20% showed a very high expression level and their growth was unaffected by up to 200 M cadmium, whereas the growth of control plants was severely affected leaf chlorosis occurred on medium containing only 10 M cadmium. The concentration of MT-I in leaves of control and transgenic tobacco was determined with Cd/haemoglobin saturation assay, a polarographic method and western blotting. In addition, seeds from self-fertilized transgenic plants were germinated on medium containing toxic levels of cadmium and scored for tolerance/susceptibility to this heavy metal. The ratio of tolerant to susceptible plants was 3:1 indicating that the metallothionein gene is inherited as a single locus. 相似文献
74.
In order to study the differentiation of Asian colobines, fourteen variables were analysed in one way, on 123 skulls, includingRhinopithecus, Presbytis, Presbytiscus, Pygathrix, andNasalis with both cluster and differentiated functions tests. Information on paleoenvironment changes in China and South-East Asia
since late Tertiary have been used to examine the influences of migratory habits and the distribution range in Asian colobines.
The cladogram among different Asian colobines genera was made from the results of various analysis. Some new points or revisions
were suggested: 1. Following the second migratory way, ancient species of Asian colobines perhaps passed through Xizang along
the northern bank of Tethis sea and Heng-Duan Shan regions, across Yunnan into Vietnam, since the ancient continent between
Yunnan and Xizang was already located in on eastern bank of Tethis sea. Thus, during the evolution, Asian colobines must have
had two original centres, i.e. “Sundaland” and Heng-Duan Shan Chinese regions; 2. Pygatrix possesses a lot of cranial features
more similar toPresbytiscus than toRhinopithecus. The small difference from the modification combinesPygatrix with other two genera as shown by Groves (1970), but it is better to putPygatrix andPresbytiscus together as one genus; 3.Nasalis (2n=48) may be the most primitive genus within Asian colobines. Some features shared withRhinopithecus, for example body size, terrestrial activities, limb proportion etc. ...seem to be considered as a common inheritance of
symlesiomorphus characters; 4.Rhinopithecus, with reference to cranioface and cranium or to its origin, is a special genus of Asian colobine. It may represent the highest
level of evolutionary position within various genera (Peng et al., 1985). 相似文献
75.
Six cases of mother-cub relationships in wild giant pandas (Ailuropoda melanoleuca) were observed in the Qinling Mountains, China. It was found that panda cubs are normally left alone in the den for 4–8 h while mothers forage. The mother's absence during bouts of foraging should be considered when rescuing abandoned cubs in order to avoid adding to the decline of the wild population. © 1994 Wiley-Liss, Inc. 相似文献
76.
Zn对细胞保护作用机理的研究 总被引:16,自引:0,他引:16
应用扫描质子微探针和同步辐射x荧光分析技术测定了细胞中元素的分布和组成,为确定Zn是细胞结构成分提供了直接的实验依据.用上述核技术结合有关生化指标,分析测定了正常和损伤细胞(脂质过氧化损伤)中Fe,Zn和丙二醛、SH基含量变化的相互关系.实验结果表明,当细胞发生脂质过氧化损伤时,Fe含量和丙二醛含量同步增高,而Zn含量和SH基量则降低.给细胞补充Zn后,提高了细胞质膜中的Zn含量,SH基量也随之增加,同时丙二醛量降低.提示Zn保护细胞完整性的作用机理之一是控制脂质过氧化作用.Zn可保护膜蛋白的SH基,减少和阻止被Fe所催化的过氧化反应. 相似文献
77.
T. C. Pan T. H. Lin C. L. Tseng M. H. Yang C. W. Huang 《Biological trace element research》1993,39(2-3):117-128
Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Though extensive epidemiological
study has implicated that high arsenic content in artesian well water of the endemic area, bears some important connection
with the disease, the etiology of the disease is still unknown. In this study, attention is paid to multielement determination
in order to find out whether the trace elements in hair of Blackfoot disease patients are different from those of the controls.
Experimental results indicate that the concentrations of As and Se in hair of patients are significantly higher than those
of the controls, but Ca and Zn are significantly lower than those of the controls. The possible connection of these elements
with the etiology of the disease is discussed. 相似文献
78.
Sarah Grant Andreas Houben Boris Vyskot Jiri Siroky Wei-Hua Pan Jiri Macas Heinz Saedler 《Genesis (New York, N.Y. : 2000)》1994,15(3):214-230
Most flowering plant species are hermaphroditic, but a small number of species in most plant families are unisexual (i.e., an individ-ual will produce only male or female gametes). Because species with unisexual flowers have evolved repeatedly from hermaphroditic progenitors, the mechanisms controlling sex determination in flowering plants are extremely diverse. Sex is most strongly determined by genotype in all species but the mechanisms range from a single controlling locus to sex chromosomes bearing several linked locirequired for sex determination. Plant hormones also influence sex expression with variable effects from species to species. Here, we review the genetic control of sex determination from a number of plant species to illustrate the variety of extant mechanisms. We emphasize species that are now used as models to investigate the molecular biology of sex determination. We also present our own investigations of the structure of plant sex chromosomes of white campion (Silene latifolia - Melan-drium album). The cytogenetic basis of sex determination in white campion is similar to mammals in that it has a male-specific Y-chromosome that carries dominant male determining genes. If one copy of this chromosome is in the genome, the plant is male. Otherwise it is female. Like mammalian Y-chromosomes, the white campion Y-chromosome is rich in repetitive DNA. We isolated repetitive sequences from microdissected Y-chromosomes of white campion to study the distribution of homologous repeated sequences on the Y-chromosome and the other chromosomes. We found the Y to be especially rich in repetitive sequences that were generally dispersed over all the white campion chromosomes. Despite its repetitive character, the Y-chromosome is mainly euchromatic. This may be due to the relatively recent evolution of the white campion sex chromosomes compared to the sex chromosomes of animals. © 1994 Wiley-Liss, Inc. 相似文献
79.
Pan Aihua Tie Feng Duau Zhenwen Yang Meizhu Wang Zhenxing Li Lingyuan Chen Zhangliang Ru Binggen 《Molecular genetics and genomics : MGG》1994,243(6):666-673
We have introduced a genetically marked Dissociation transposable element (Ds HPT ) into tomato (Lycopersicon esculentum) by Agrobacterium tumefaciens-mediated transformation. Probes for the flanking regions of the T-DNA and transposed Ds HPT elements were obtained with the inverse polymerase chain reaction (IPCR) technique and used in RFLP linkage analyses. The RFLP map location of 11 T-DNAs carrying Ds HPT was determined. The T-DNAs are distributed on 7 of the 12 tomato chromosomes. To explore the feasibility of gene tagging strategies in tomato using Ds HPT , we examined the genomic distribution of Ds HPT receptor sites relative to the location of two different, but very closely linked, T-DNA insertion sites. After crosses with plants expressing Ac transposase, the hygromycin phosphotransferase (HPT) marker on the Ds element and the excision markers β-glucuronidase (GUS) and Basta resistance (BAR) facilitated the identification of plants bearing germinally transposed Ds HPT elements. RFLP mapping of 21 transposed Ds HPT elements originating from the two different T-DNA insertions revealed distinct patterns of reintegration sites. 相似文献
80.
蕉类的细胞遗传学研究 总被引:18,自引:1,他引:17
本文对芭蕉属正蕉组内的一些有代表性的野生种和包括香蕉,大蕉在内的二倍体和三倍体食用栽培蕉,共18个材料进行了核型比较分析,对其中5个重要的栽培蕉品种的花粉母细胞减数分裂进行了观察,从核型、染色体配对以及染色体 特殊分离行为等3个方面得到的证据表明,并非所有香蕉才同源三倍体,有一些香蕉品种的3个染色体组之间同源程度很低, 通过对一些特征染色体的分析,推测这种香蕉的单染色体组很可能来自BB野生蕉、大蕉 相似文献