全文获取类型
收费全文 | 4851篇 |
免费 | 229篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 72篇 |
综合类 | 14篇 |
化学工业 | 1238篇 |
金属工艺 | 95篇 |
机械仪表 | 88篇 |
建筑科学 | 287篇 |
矿业工程 | 23篇 |
能源动力 | 114篇 |
轻工业 | 632篇 |
水利工程 | 25篇 |
石油天然气 | 5篇 |
无线电 | 459篇 |
一般工业技术 | 892篇 |
冶金工业 | 538篇 |
原子能技术 | 56篇 |
自动化技术 | 548篇 |
出版年
2023年 | 45篇 |
2022年 | 89篇 |
2021年 | 111篇 |
2020年 | 81篇 |
2019年 | 109篇 |
2018年 | 106篇 |
2017年 | 110篇 |
2016年 | 141篇 |
2015年 | 128篇 |
2014年 | 150篇 |
2013年 | 193篇 |
2012年 | 222篇 |
2011年 | 237篇 |
2010年 | 150篇 |
2009年 | 168篇 |
2008年 | 167篇 |
2007年 | 183篇 |
2006年 | 178篇 |
2005年 | 130篇 |
2004年 | 115篇 |
2003年 | 95篇 |
2002年 | 99篇 |
2001年 | 79篇 |
2000年 | 62篇 |
1999年 | 75篇 |
1998年 | 152篇 |
1997年 | 118篇 |
1996年 | 78篇 |
1995年 | 75篇 |
1994年 | 68篇 |
1993年 | 55篇 |
1992年 | 64篇 |
1991年 | 54篇 |
1990年 | 46篇 |
1989年 | 54篇 |
1988年 | 53篇 |
1987年 | 65篇 |
1986年 | 55篇 |
1985年 | 51篇 |
1984年 | 62篇 |
1983年 | 54篇 |
1982年 | 45篇 |
1981年 | 53篇 |
1980年 | 46篇 |
1979年 | 44篇 |
1978年 | 46篇 |
1977年 | 50篇 |
1976年 | 61篇 |
1973年 | 35篇 |
1971年 | 34篇 |
排序方式: 共有5086条查询结果,搜索用时 15 毫秒
1.
Dr. Yibin Zhang Dr. Shuai Xia Shulin Wan Tessa E. Steenwinkel Tara Vohs Prof. Rudy L. Luck Prof. Thomas Werner Prof. Haiying Liu 《Chembiochem : a European journal of chemical biology》2021,22(13):2282-2291
Abnormal levels of glutathione, a cellular antioxidant, can lead to a variety of diseases. We have constructed a near-infrared ratiometric fluorescent probe to detect glutathione concentrations in biological samples. The probe consists of a coumarin donor, which is connected through a disulfide-tethered linker to a rhodamine acceptor. Under the excitation of the coumarin donor at 405 nm, the probe shows weak visible fluorescence of the coumarin donor at 470 nm and strong near-infrared fluorescence of the rhodamine acceptor at 652 nm due to efficient Forster resonance energy transfer (FRET) from the donor to the acceptor. Glutathione breaks the disulfide bond through reduction, which results in a dramatic increase in coumarin fluorescence and a corresponding decrease in rhodamine fluorescence. The probe possesses excellent cell permeability, biocompatibility, and good ratiometric fluorescence responses to glutathione and cysteine with a self-calibration capability. The probe was utilized to ratiometrically visualize glutathione concentration alterations in HeLa cells and Drosophila melanogaster larvae. 相似文献
2.
Liangtao Yang Liang-Yin Kuo Juan Miguel López del Amo Prasant Kumar Nayak Katherine A. Mazzio Sebastian Maletti Daria Mikhailova Lars Giebeler Payam Kaghazchi Teófilo Rojo Philipp Adelhelm 《Advanced functional materials》2021,31(38):2102939
A known strategy for improving the properties of layered oxide electrodes in sodium-ion batteries is the partial substitution of transition metals by Li. Herein, the role of Li as a defect and its impact on sodium storage in P2-Na0.67Mn0.6Ni0.2Li0.2O2 is discussed. In tandem with electrochemical studies, the electronic and atomic structure are studied using solid-state NMR, operando XRD, and density functional theory (DFT). For the as-synthesized material, Li is located in comparable amounts within the sodium and the transition metal oxide (TMO) layers. Desodiation leads to a redistribution of Li ions within the crystal lattice. During charging, Li ions from the Na layer first migrate to the TMO layer before reversing their course at low Na contents. There is little change in the lattice parameters during charging/discharging, indicating stabilization of the P2 structure. This leads to a solid-solution type storage mechanism (sloping voltage profile) and hence excellent cycle life with a capacity of 110 mAh g-1 after 100 cycles. In contrast, the Li-free compositions Na0.67Mn0.6Ni0.4O2 and Na0.67Mn0.8Ni0.2O2 show phase transitions and a stair-case voltage profile. The capacity is found to originate from mainly Ni3+/Ni4+ and O2-/O2-δ redox processes by DFT, although a small contribution from Mn4+/Mn5+ to the capacity cannot be excluded. 相似文献
3.
4.
5.
Forschung im Ingenieurwesen - Lkw-Überholmanöver auf Autobahnen können Konfliktsituationen provozieren. Das lange Blockieren der Überholspur und plötzliche Ausscheren kann... 相似文献
6.
Raffael Ott Xenia Pawlow Andreas Weiß Anna Hofelich Melanie Herbst Nadine Hummel Cornelia Prehn Jerzy Adamski Werner Rmisch-Margl Gabi Kastenmüller Anette-G. Ziegler Sandra Hummel 《International journal of molecular sciences》2020,21(24)
Shared metabolomic patterns at delivery have been suggested to underlie the mother-to-child transmission of adverse metabolic health. This study aimed to investigate whether mothers with gestational diabetes mellitus (GDM) and their offspring show similar metabolomic patterns several years postpartum. Targeted metabolomics (including 137 metabolites) was performed in plasma samples obtained during an oral glucose tolerance test from 48 mothers with GDM and their offspring at a cross-sectional study visit 8 years after delivery. Partial Pearson’s correlations between the area under the curve (AUC) of maternal and offspring metabolites were calculated, yielding so-called Gaussian graphical models. Spearman’s correlations were applied to investigate correlations of body mass index (BMI), Matsuda insulin sensitivity index (ISI-M), dietary intake, and physical activity between generations, and correlations of metabolite AUCs with lifestyle variables. This study revealed that BMI, ISI-M, and the AUC of six metabolites (carnitine, taurine, proline, SM(-OH) C14:1, creatinine, and PC ae C34:3) were significantly correlated between mothers and offspring several years postpartum. Intergenerational metabolite correlations were independent of shared BMI, ISI-M, age, sex, and all other metabolites. Furthermore, creatinine was correlated with physical activity in mothers. This study suggests that there is long-term metabolic programming in the offspring of mothers with GDM and informs us about targets that could be addressed by future intervention studies. 相似文献
7.
8.
Jasmin Kuhn Philipp M. Klein Nader Al Danaf Joel Z. Nordin Sren Reinhard Dominik M. Loy Miriam Hhn Samir El Andaloussi Don C. Lamb Ernst Wagner Yoshitsugu Aoki Taavi Lehto Ulrich Lchelt 《Advanced functional materials》2019,29(48)
Phosphorodiamidate morpholino oligomers (PMOs) are oligonucleotide analogs that can be used for therapeutic modulation of pre‐mRNA splicing. Similar to other classes of nucleic acid‐based therapeutics, PMOs require delivery systems for efficient transport to the intracellular target sites. Here, artificial peptides based on the oligo(ethylenamino) acid succinyl‐tetraethylenpentamine (Stp), hydrophobic modifications, and an azide group are presented, which are used for strain‐promoted azide‐alkyne cycloaddition conjugation with splice‐switching PMOs. By systematically varying the lead structure and formulation, it is determined that the type of contained fatty acid and supramolecular assembly have a critical impact on the delivery efficacy. A compound containing linolenic acid with three cis double bonds exhibits the highest splice‐switching activity and significantly increases functional protein expression in pLuc/705 reporter cells in vitro and after local administration in vivo. Structural and mechanistic studies reveal that the lipopeptide PMO conjugates form nanoparticles, which accelerate cellular uptake and that the content of unsaturated fatty acids enhances endosomal escape. In an in vitro Duchenne muscular dystrophy exon skipping model using H2K‐mdx52 dystrophic skeletal myotubes, the highly potent PMO conjugates mediate significant splice‐switching at very low nanomolar concentrations. The presented aminoethylene‐lipopeptides are thus a promising platform for the generation of PMO‐therapeutics with a favorable activity/toxicity profile. 相似文献
9.
Hal Philipp 《今日电子》2006,(9):60-61
好像在突然之间,电容式传感器就无处不在了。它被安装在汽车座位里以控制气囊配置和安全带预紧装置,在洗碗机和干燥机中以校正旋转桶的状态,甚至冰箱也使用其来控制自动去冰过程。但是直到现在,它最大的潜在应用领域还是触摸开关,触摸开关已越来越多地出现在消费电子产品中。 相似文献
10.