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781.
Selective lipase-catalyzed synthesis of glucose fatty acid esters in two-phase systems consisting of an ionic liquid (1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF4] or 1-butyl-3-methyl imidazolium hexafluorophosphate [BMIM][PF6]) and t-butanol as organic solvent was investigated. The best enzyme was commercially available lipase B from Candida antarctica (CAL-B), but also lipase from Thermomyces lanuginosa (TLL) gave good conversion. After thorough optimization of several reaction conditions (chain-length and type of acyl donor, temperature, reaction time, percentage of co-solvent) conversions up to 60% could be achieved using fatty acid vinyl ester as acyl donors in [BMIM][PF6] in the presence of 40% t-BuOH with CAL-B at 60 °C. 相似文献
782.
Dorothy Guzowski Alamelu Chandrasekaran Craig Gawel Jacqueline Palma Jonathan Koenig Xue Ping Wang Michael Dosik Mark Kaplan Charles C Chu Sangeeta Chavan Richard Furie Emilia Albesiano Nicholas Chiorazzi Leslie Goodwin 《Journal of biomolecular techniques》2005,16(2):154-166
Interleukin-10 (IL10), an anti-inflammatory cytokine, has been implicated in a variety of immune- and inflammatory-related diseases. We investigated the following SNPs: -1082, -819, -592 in the promoter region of IL10 in a normal (control) population and selected diseases: breast cancer (BrCa), systemic lupus erythematosus (SLE), and B-cell chronic lymphocytic leukemia (B-CLL) by denaturing high-performance liquid chromatography (DHPLC) and found distinct genotype and haplotype patterns. DHPLC was performed using the Transgenomic WAVE instrument, a mutational discovery tool that allows for high throughout analysis of SNPs. The principle of DHPLC is based on separation of homo- and heteroduplex formation of individual polymerase chain reaction products at specific melting temperatures and set gradients. The melting temperature selected for each SNP was based on size and sequence of the polymerase chain reaction product (for -1082, 57 degrees C; for -819, 58 degrees C; and for -592, 59.2 degrees C). Before fragment mutational analysis, all samples were denatured at 95 degrees C and slowly reannealed to allow for reassociation of different strands. Heteroduplex samples were easily distinguished from homoduplex samples. In order to identify wild type from homozygous mutant, two homoduplex polymerase chain reaction samples had to be mixed together, denatured at 95 degrees C and reannealed. The homozygous mutant, when combined with wild type, displayed a double peak on chromatogram. Once distinct chromatograms were established for each of the SNPs and the nucleotide changes confirmed by sequencing, genotype and haplotype frequencies were tabulated for the groups studied. 相似文献
783.
784.
多维色谱-串联质谱联用技术分离和鉴定小鼠肝脏质膜蛋白质 总被引:5,自引:0,他引:5
采用自动在线纳流多维液相色谱 串联质谱联用的方法分离和鉴定蔗糖密度梯度离心法分离和富集的小鼠肝脏质膜蛋白质 .以强阳离子交换柱为第一相 ,反相柱为第二相 ,在两相之间连接一预柱脱盐和浓缩肽段 .用含去污剂的溶剂提取细胞质膜中的蛋白质 ,获得的质膜蛋白质经酶解和适当的酸化后通过离子交换柱吸附 ,分别用 10个不同浓度的乙酸铵盐溶液进行分段洗脱 .洗脱物经预柱脱盐和浓缩后进入毛细管反相柱进行反相分离 ,分离后的肽段直接进入质谱仪离子源进行一级和二级质谱分析 .质谱仪采得的数据经计算机处理后用Mascot软件进行蛋白质数据库搜寻 ,共鉴定出 12 6种蛋白质 ,其中 4 1种为膜蛋白 ,包括与膜相关的蛋白质和具有多个跨膜区的整合膜蛋白 ,为建立质膜蛋白质组学研究的适宜方法和质膜蛋白质数据库提供了有价值的基础性研究资料 . 相似文献
785.
Carlos E. Aragón Maritza Escalona Iris Capote Danilo Pina Inaudis Cejas Roberto Rodriguez Maria Jesus Cañal Jorge Sandoval Sophe Roels Pierre Debergh Justo Gonzalez-Olmedo 《In vitro cellular & developmental biology. Plant》2005,41(4):550-554
Summary The photosynthetic capacity changes and the main enzymatic systems related to carbon metabolism were investigated during the
in vitro culture of plantain shoots (Musa AAB cv. CEMSA 3/4) in temporary immersion bioreactors (TIB) and their subsequent acclimatization.
The maximal rate of photosynthesis (Pn), transpiration, and the activity of the carbon metabolism enzymes phosphoenolpyruvate
carboxylase (PEPC), acid invertase (AI), pyruvate kinase (PK) and sucrose phosphate synthase (SPS) were measured every 7 d
during the 21 d of elongation in TIB, and the following 42 d of acclimatization. Sucrose content in the liquid medium and
in the leaves was also determined. The most significant changes in plant growth were observed during acclimatization. During
the in vitro stage photosynthesis was limited (4–6 μmol CO2m−2s−1); the photosynthetic rate however increases rapidly and significantly as soon as in vitro culture is over during acclimatization. PEPC activity increased during the whole evaluation period. The highest levels were
achieved around days 42 and 56. PK and SPS activities were optimal during the first weeks in acclimatization (28–35 d), while
AI increased at the beginning of the elongation phase (7 d), and later at the end of the acclimatization (49–63 d). The relationships
between morphological parameters, photosynthetic capacity of the plantlets and the carbon metabolism enzymes during both phases
of the culture are discussed. 相似文献
786.
Paralytic shellfish poisoning toxin profiles of dinoflagellate cultures of Gymnodinium catenatum Graham from the Yellow and South Seas in Korea were investigated by high performance liquid chromatography fluorometric detection. Strains from the Yellow Sea had predominantly carbamate toxins, while strains from Sujeongri and Chindong in the South Sea contained the N‐sulfocarbamoyl toxins, Cl,2, as major components including the presence of GTX5 and dcSTX in some strains. Toxin profiles from St. Deukryang Bay strains (South Sea) showed both characteristics of those in the South Sea and those in the Yellow Sea. Thirty strains could be divided into three groups based on cluster analysis of toxin compositions. Group I (Yellow Sea strains) was distinguished from Group II (Sujeongri and Chindong strains) by the absence of GTX5 and dcSTX. Group III comprised Deukryang Bay strains. In conclusion, the Yellow Sea and the South Sea were found to have different dinoflagellate populations with different toxin compositions. 相似文献
787.
788.
The previously prepared trans-[(1,2-diphenyl-1,2-dicyclopentadienyl)ethanediyl] titanium(IV) dichloride, [1,2-(Ph)2C2H2{η5-C5H4}2]Ti(Cl)2, was synthesised using an alternative procedure, from which its crystal structure was determined. Using this compound, a variety of other ansa-titanocene derivatives were synthesised by replacement of the chloride ligands with selected substituents. Thus RTi(X)(Y) systems where R=1,2-(Ph)2C2H2η5-C5H42; X=Y=CH3; X=CH3, Y=Cl; X=Y=NCS; X=Y=NCO; X=Y=OPh and (X/Y)=O have been synthesised and characterised. DFT calculations were performed on the complexes trans-[(1,2-diphenyl-1,2-dicyclopentadienyl)-ethanediyl] titanium(IV) dichloride, bis-(6,6-diphenylfulvene)titanium and bis-(6,6-diphenylfulvene)iron. This demonstrated the role that the metal centre plays in their formation, generating either an ansa-metallocene, a ‘tucked in’ fulvene complex or a metallocene coordinating fulvene anions. 相似文献
789.
魔芋无土栽培营养液配方研究初报 总被引:6,自引:2,他引:4
分别采用全MS、1/2MS、1/5MS、1/10MS(含大量元素、微量元素和铁盐)、1/10MS大量元素营养液(不含微量元素和铁盐)定期浇灌用蛭石栽培的不同级别的魔芋,前50d生长状况没有差异,50-80d以1/2MS-1/10MS营养液为佳,80-110d时1-5MS-1/10MS生长较好;魔芋在缺乏微量元素的营养液中后期生长不良,提前倒苗;产量分析结果表明:35g以上的种芋以1/2MS最高,35g以下的种芋以1/10MS最高,魔芋的耐盐浓度在2.25‰以下,高盐浓度对块茎的形成有毒害作用,造成产量大幅度下降,添加微量元素和铁有较好的增产作用。 相似文献
790.
Ursula Dörner 《生物化学与生物物理学报:生物膜》2004,1667(1):47-55
Detergent extracts of whole cells of the Gram-positive bacterium Tsukamurella inchonensis ATCC 700082, which belongs to the mycolata, were studied for the presence of ion-permeable channels using lipid bilayer experiments. One channel with a conductance of about 4.5 nS in 1 M KCl was identified in the extracts. The channel-forming protein was purified to homogeneity by preparative SDS-PAGE. The protein responsible for channel-forming activity had an apparent molecular mass of about 33 kDa as judged by SDS-PAGE. Interestingly, the protein showed cross-reactivity with polyclonal antibodies raised against a polypeptide derived from MspA of Mycobacterium smegmatis similarly as the cell wall channel of Mycobacterium phlei. Primers derived from mspA were used to clone and sequence the gene of the cell wall channels of T. inchonensis (named tipA for T. inchonensis porin A) and M. phlei (named mppA for M. phlei porin A). Surprisingly, both genes, tipA and mppA, were found to be identical to mspA of M. smegmatis, indicating that the genomes of T. inchonensis, M. phlei and M. smegmatis contain the same genes for the major cell wall channel. RT-PCR revealed that tipA is transcribed in T. inchonensis and mppA in M. phlei. The results suggest that despite a certain distance between the three organisms, their genomes contain the same gene coding for the major cell wall channel, with a molecular mass of 22 kDa for the monomer. 相似文献