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991.
Yang Guo Qiaojuan Yan Zhengqiang Jiang Chao Teng Xinlei Wang 《Journal of industrial microbiology & biotechnology》2010,37(11):1137-1143
The aim of this study is to investigate production of l-lactic acid from sucrose and corncob hydrolysate by the newly isolated R. oryzae GY18. R. oryzae GY18 was capable of utilizing sucrose as a sole source, producing 97.5 g l−1
l-lactic acid from 120 g l−1 sucrose. In addition, the strain was also efficiently able to utilize glucose and/or xylose to produce high yields of l-lactic acid. It was capable of producing up to 115 and 54.2 g l−1 lactic acid with yields of up to 0.81 g g−1 glucose and 0.90 g g−1 xylose, respectively. Corncob hydrolysates obtained by dilute acid hydrolysis and enzymatic hydrolysis of the cellulose-enriched
residue were used for lactic acid production by R. oryzae GY18. A yield of 355 g lactic acid per kg corncobs was obtained after 72 h incubation. Therefore, sucrose and corncobs could
serve as potential sources of raw materials for efficient production of lactic acid by R. oryzae GY18. 相似文献
992.
脂联素调节糖脂代谢相关信号通路的研究进展 总被引:1,自引:0,他引:1
脂联素是一种主要由脂肪组织分泌的脂肪细胞因子,具有调节糖脂代谢、增强胰岛素敏感性、抗炎和抗动脉粥样硬化等多种作用。在脂联素介导的信号通路中,脂联素首先与脂联素受体(AdipoR)位于膜外的羧基端结合,再通过AdipoR膜内的氨基端与信号接头蛋白结合,进而激活下游的多条信号通路,其中腺苷酸活化蛋白激酶(AMPK)是脂联素信号通路中的关键分子,活化的AMPK可以使其下游的乙酰辅酶A羧化酶(ACC)、p38丝裂原活化蛋白激酶(p38 MAPK)、磷脂酰肌醇3激酶(PI3K)等多种胞质信号分子磷酸化,介导细胞能量代谢。本文重点综述了脂联素通过AMPK调节糖脂代谢的信号通路的研究进展。 相似文献
993.
R. K. Varshney M. Baum P. Guo S. Grando S. Ceccarelli A. Graner 《Molecular breeding : new strategies in plant improvement》2010,26(2):229-242
Detection and utilization of genetic variation available in the germplasm collection for crop improvement have been the prime
activities of breeders. Here a set of ICARDA barley germplasm collection comprising of 185 cultivated (Hordeum vulgare L.) and 38 wild (H. spontaneum L.) genotypes originated from 30 countries of four continents was genotyped with 68 single nucleotide polymorphism (SNP)
and 45 microsatellite or simple sequence repeat (SSR) markers derived from genes (expressed sequence tags, ESTs). As two SNP
markers provided 2 and 3 datapoints, a total of 71 SNPs were surveyed that yielded a total of 143 alleles. The number of SSR
alleles per locus ranged from 3 to 22 with an average of 7.9 per marker. Average PIC (polymorphism information content) value
for SSR and SNP markers were recorded as 0.63 and 0.38, respectively. Heterogeneity was recorded at both SNP and SSR loci
in an average of 5.72 and 12.42% accessions, respectively. Genetic similarity matrices for SSR and SNP allelic data were highly
correlated (r = 0.75, P < 0.005) and therefore allelic data for both markers were combined and analyzed for understanding the genetic relationships
among the germplasm surveyed. Majority of clusters/subclusters were found to contain genotypes from the same geographic origins.
While comparing the genetic diversity, the accessions coming from Middle East Asia and North East Asia showed more diversity
as compared to that of other geographic regions. Majority of countries representing Africa, Middle East Asia, North East Asia
and Arabian Peninsula included the genotypes that contained rare alleles. As expected, spontaneum accessions, as compared to vulgare accessions, showed a higher number of total alleles, higher number of alleles per locus, higher effective number of alleles
and higher allelic richness and a higher number of rare alleles were observed. In summary, the examined ICARDA germplasm set
showed ample natural genetic variation that can be harnessed for future breeding of barley as climate change and sustainability
have become important throughout all growing areas of the world, drought/heat tolerance being the most important ones. 相似文献
994.
A major QTL for resistance to Gibberella stalk rot in maize 总被引:1,自引:0,他引:1
Qin Yang Guangming Yin Yanling Guo Dongfeng Zhang Shaojiang Chen Mingliang Xu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(4):673-687
Fusarium graminearum Schwabe, the conidial form of Gibberella zeae, is the causal fungal pathogen responsible for Gibberella stalk rot of maize. Using a BC1F1 backcross mapping population derived from a cross between ‘1145’ (donor parent, completely resistant) and ‘Y331’ (recurrent
parent, highly susceptible), two quantitative trait loci (QTLs), qRfg1 and qRfg2, conferring resistance to Gibberella stalk rot have been detected. The major QTL qRfg1 was further confirmed in the double haploid, F2, BC2F1, and BC3F1 populations. Within a qRfg1 confidence interval, single/low-copy bacterial artificial chromosome sequences, anchored expressed sequence tags, and insertion/deletion
polymorphisms, were exploited to develop 59 markers to saturate the qRfg1 region. A step by step narrowing-down strategy was adopted to pursue fine mapping of the qRfg1 locus. Recombinants within the qRfg1 region, screened from each backcross generation, were backcrossed to ‘Y331’ to produce the next backcross progenies. These
progenies were individually genotyped and evaluated for resistance to Gibberella stalk rot. Significant (or no significant) difference in resistance reactions between homozygous and heterozygous genotypes
in backcross progeny suggested presence (or absence) of qRfg1 in ‘1145’ donor fragments. The phenotypes were compared to sizes of donor fragments among recombinants to delimit the qRfg1 region. Sequential fine mapping of BC4F1 to BC6F1 generations enabled us to progressively refine the qRfg1 locus to a ~500-kb interval flanked by the markers SSR334 and SSR58. Meanwhile, resistance of qRfg1 to Gibberella stalk rot was also investigated in BC3F1 to BC6F1 generations. Once introgressed into the ‘Y331’ genome, the qRfg1 locus could steadily enhance the frequency of resistant plants by 32–43%. Hence, the qRfg1 locus was capable of improving maize resistance to Gibberella stalk rot. 相似文献
995.
Ni-Ni Guo Zong-Ming Zheng Yu-Lin Mai Hong-Juan Liu De-Hua Liu 《Applied microbiology and biotechnology》2010,86(2):701-707
The filtration in 1,3-propanediol (1,3-PD) downstream process is influenced by the large amounts of capsular polysaccharides
(CPS) produced by Klebsiella pneumoniae CGMCC 1.6366. The morphological and fermentation properties were investigated with the CPS-deficient mutant K. pneumoniae CGMCC 1.6366 CPS. Similar biomass was obtained with CGMCC 1.6366, and the mutant strain in batch cultures indicating the
cell growth was slightly inhibited by CPS defection. The viscosity of fermentation broth by mutant strain decreased by 27.45%.
The flux with ceramic membrane filter was enhanced from 168.12 to 303.6 l h−1 m−2, exhibiting the great importance for downstream processing of 1,3-PD fermentation. The products spectrum of mutant isolate
changed remarkably regarding to the concentration of fermentation products. The synthesis of important 1,3-PD and 2,3-butanediol
was enhanced from 9.73 and 4.06 g l−1 to 10.37 and 4.77 g l−1 in batch cultures. The noncapsuled K. pneumoniae provided higher 1,3-PD yield of 0.54 mol mol−1 than that of encapsuled wild parent in batch cultures. The fed-batch fermentation of mutant strain resulted in 1,3-PD concentration,
yield, and productivity of 78.13 g l−1, 0.53 mol mol−1, and 1.95 g l−1 h−1, respectively. 相似文献
996.
淀粉分支酶基因sbe是影响玉米直链淀粉含量的主要因素,淀粉分支酶分为3种即sbeI、sbeIIa和sbeIIb,其中sbeIIb对直链淀粉含量影响效应最大,抑制玉米淀粉分支酶sbeIIb基因的表达可减少支链淀粉的含量,从而达到提高直链淀粉的目的;ADP-葡萄糖焦磷酸化酶(AGPase)是直链淀粉合成的关键酶,通过提高AGP表达量同样可提高玉米直链淀粉含量。以此为目的分别克隆了sbeIIb一段375bp高度保守区,玉米SBE基因一段175bp内含子,AGP完整开放阅读框,大麦胚乳特异启动子和ADPG基因终止子。构建了sbeIIb基因正、反义的hpRNA发夹结构,将该发夹结构与上述基因分别连接到pCAM-BIA3301上;构建得到包含sbeIIb基因干扰结构与AGP基因过表达的pCAMB-RSA多基因胚乳特异表达载体。为此,pCAMB-RSA载体的成功构建将为高直链淀粉玉米的培育奠定基础。 相似文献
997.
998.
Chromosomal rearrangement in pectinidae revealed by rRNA loci and implications for bivalve evolution 总被引:1,自引:0,他引:1
Karyotype and chromosomal localization of major (18-5.8-28S) and minor (5S) ribosomal RNA genes were studied in two species of Pectinidae, zhikong (Chlamys farreri) and bay (Argopecten irradians irradians) scallops, using fluorescence in situ hybridization (FISH). C. farreri had a haploid number of 19 with a karyotype of 3m + 4sm + 7sm-st + 4st + 1st-t, and A. i. irradians had a haploid number of 16 with a karyotype of 5st + 11t. In C. farreri, the major and minor rRNA genes had one locus each and were mapped to the same chromosome-Chromosome 5. In A. i. irradians, the major rRNA genes had two loci, located on Chromosomes 4 and 8, and the 5S rRNA gene was found at a third chromosome-Chromosome 10. Results of this and other studies indicate that karyotype of A. i. irradians (n = 16, 21 arms) is secondary and derived from an ancestral karyotype similar to that of C. farreri (n = 19, 38 arms) through considerable chromosomal loss and rearrangements. The ability to tolerate significant chromosomal loss suggests that the modal karyotype of Pectinidae and possibly other bivalves with a haploid number of 19 is likely tetraploid; i.e., at least one genome duplication has occurred during the evolution of Bivalvia. 相似文献
999.
Meng-Ze Du Feng-Biao Guo Yue-Yun Chen 《Journal of biomolecular structure & dynamics》2013,31(2):391-401
Abstract In this paper, we re-annotated the genome of Pyrobaculum aerophilum str. IM2, particularly for hypothetical ORFs. The annotation process includes three parts. Firstly and most importantly, 23 new genes, which were missed in the original annotation, are found by combining similarity search and the ab initio gene finding approaches. Among these new genes, five have significant similarities with function-known genes and the rest have significant similarities with hypothetical ORFs contained in other genomes. Secondly, the coding potentials of the 1645 hypothetical ORFs are re-predicted by using 33 Z curve variables combined with Fisher linear discrimination method. With the accuracy being 99.68%, 25 originally annotated hypothetical ORFs are recognized as non-coding by our method. Thirdly, 80 hypothetical ORFs are assigned with potential functions by using similarity search with BLAST program. Re-annotation of the genome will benefit related researches on this hyperthermophilic crenarchaeon. Also, the re-annotation procedure could be taken as a reference for other archaeal genomes. Details of the revised annotation are freely available at http://cobi.uestc.edu.cn/resource/paero/ 相似文献
1000.