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61.
Elisa Di Fabio Antonia Iazzetti Alessio Incocciati Valentina Caseli Giancarlo Fabrizi Alberto Boffi Alessandra Bonamore Alberto Macone 《International journal of molecular sciences》2022,23(12)
Amine oxidases are enzymes belonging to the class of oxidoreductases that are widespread, from bacteria to humans. The amine oxidase from Lathyrus cicera has recently appeared in the landscape of biocatalysis, showing good potential in the green synthesis of aldehydes. This enzyme catalyzes the oxidative deamination of a wide range of primary amines into the corresponding aldehydes but its use as a biocatalyst is challenging due to the possible inactivation that might occur at high product concentrations. Here, we show that the enzyme’s performance can be greatly improved by immobilization on solid supports. The best results are achieved using amino-functionalized magnetic microparticles: the immobilized enzyme retains its activity, greatly improves its thermostability (4 h at 75 °C), and can be recycled up to 8 times with a set of aromatic ethylamines. After the last reaction cycle, the overall conversion is about 90% for all tested substrates, with an aldehyde production ranging between 100 and 270 mg depending on the substrate used. As a proof concept, one of the aldehydes thus produced was successfully used for the biomimetic synthesis of a non-natural benzylisoquinoline alkaloid. 相似文献
62.
Annika Kempmann Thomas Gensch Andreas Offenhusser Irina Tihaa Vanessa Maybeck Sabine Balfanz Arnd Baumann 《International journal of molecular sciences》2022,23(12)
Calcium (Ca2+) ions play a pivotal role in physiology and cellular signaling. The intracellular Ca2+ concentration ([Ca2+]i) is about three orders of magnitude lower than the extracellular concentration, resulting in a steep transmembrane concentration gradient. Thus, the spatial and the temporal dynamics of [Ca2+]i are ideally suited to modulate Ca2+-mediated cellular responses to external signals. A variety of highly sophisticated methods have been developed to gain insight into cellular Ca2+ dynamics. In addition to electrophysiological measurements and the application of synthetic dyes that change their fluorescent properties upon interaction with Ca2+, the introduction and the ongoing development of genetically encoded Ca2+ indicators (GECI) opened a new era to study Ca2+-driven processes in living cells and organisms. Here, we have focused on one well-established GECI, i.e., GCaMP3.0. We have systematically modified the protein with sequence motifs, allowing localization of the sensor in the nucleus, in the mitochondrial matrix, at the mitochondrial outer membrane, and at the plasma membrane. The individual variants and a cytosolic version of GCaMP3.0 were overexpressed and purified from E. coli cells to study their biophysical properties in solution. All versions were examined to monitor Ca2+ signaling in stably transfected cell lines and in primary cortical neurons transduced with recombinant Adeno-associated viruses (rAAV). In this comparative study, we provide evidence for a robust approach to reliably trace Ca2+ signals at the (sub)-cellular level with pronounced temporal resolution. 相似文献
63.
Fabio Bioletto Martina Bollati Chiara Lopez Stefano Arata Matteo Procopio Federico Ponzetto Ezio Ghigo Mauro Maccario Mirko Parasiliti-Caprino 《International journal of molecular sciences》2022,23(9)
Primary aldosteronism (PA) is a pathological condition characterized by an excessive aldosterone secretion; once thought to be rare, PA is now recognized as the most common cause of secondary hypertension. Its prevalence increases with the severity of hypertension, reaching up to 29.1% in patients with resistant hypertension (RH). Both PA and RH are “high-risk phenotypes”, associated with increased cardiovascular morbidity and mortality compared to non-PA and non-RH patients. Aldosterone excess, as occurs in PA, can contribute to the development of a RH phenotype through several mechanisms. First, inappropriate aldosterone levels with respect to the hydro-electrolytic status of the individual can cause salt retention and volume expansion by inducing sodium and water reabsorption in the kidney. Moreover, a growing body of evidence has highlighted the detrimental consequences of “non-classical” effects of aldosterone in several target tissues. Aldosterone-induced vascular remodeling, sympathetic overactivity, insulin resistance, and adipose tissue dysfunction can further contribute to the worsening of arterial hypertension and to the development of drug-resistance. In addition, the pro-oxidative, pro-fibrotic, and pro-inflammatory effects of aldosterone may aggravate end-organ damage, thereby perpetuating a vicious cycle that eventually leads to a more severe hypertensive phenotype. Finally, neither the pathophysiological mechanisms mediating aldosterone-driven blood pressure rise, nor those mediating aldosterone-driven end-organ damage, are specifically blocked by standard first-line anti-hypertensive drugs, which might further account for the drug-resistant phenotype that frequently characterizes PA patients. 相似文献
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文章指出了印度Amarkantak火电项目1号机组协调控制系统在负荷变动试验中所存在的设计缺陷。通过对系统的分析,针对现场情况对控制策略进行了修改和完善,在试验中获得了较好的结果。 相似文献
67.
阐述了双进双出磨煤机BBD4060 bis分离器结构特性及工作原理,绘出了磨煤机在额定出力附近分离器特性曲线。根据试验数据,分析了各挡板角度下的一次风速及煤粉细度,认为燃用现用煤质应设定相对较粗的煤粉细度,将分离器的挡板角度调整到60°。 相似文献
68.
为减少一次风机故障减负荷(runback,RB)过程中蒸汽温度的波动范围,针对百万千万超超临界机组,对影响超超临界机组RB过程汽温波动的主要因素进行了研究,分析了燃水比、过剩空气系数等影响汽温波动的因素,阐述了机组正常运行时燃料、给水、总风量的调节控制关系,提出了RB过程中的燃料量、给水流量和总风量的控制关系及有效的RB过程汽温控制策略,给出了一次风机RB过程主汽温度、再热汽温度、机组负荷、主汽压力等机组参数的变化结果。大唐潮州电厂4号机组应用及试验结果表明,本文提出的RB控制策略对过热汽温、汽压等参数控制效果良好,对同类机组RB过程的实施具有重要的参考价值。 相似文献
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70.
《Planning》2014,(1)
目的 分析甲状腺及乳腺多原发癌的临床和超声特征。方法 回顾性分析1990年1月至2013年3月在北京协和医院接受诊治且手术病理证实的甲状腺及乳腺多原发癌24例,比较这些患者的甲状腺癌及乳腺癌临床和超声特征。结果 24例患者中9例(37.5%)以甲状腺癌首发,其中2例(22.2%)在1年内出现乳腺癌;15例(62.5%)以乳腺癌首发,其中6例(40.0%)在1年内出现甲状腺癌。甲状腺癌和乳腺癌超声表现均多为实性(86.4%和84.2%)、形态不规则(63.6%和94.7%)、纵横比大于1(50.0%和57.9%)、边界不清(63.6%和78.9%)、低回声或极低回声(90.9%和100%)、点状钙化(50.0%和47.4%)、局部丰富血流(50.0%和68.4%)。结论 甲状腺及乳腺多原发癌的临床和超声特征与单发甲状腺癌及乳腺癌人群相近,超声可有效地筛查甲状腺及乳腺多原发癌,尤其在首发乳腺癌后1年内。 相似文献