全文获取类型
收费全文 | 1288篇 |
免费 | 85篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 478篇 |
金属工艺 | 19篇 |
机械仪表 | 26篇 |
建筑科学 | 33篇 |
能源动力 | 36篇 |
轻工业 | 295篇 |
水利工程 | 8篇 |
石油天然气 | 4篇 |
无线电 | 52篇 |
一般工业技术 | 178篇 |
冶金工业 | 83篇 |
原子能技术 | 9篇 |
自动化技术 | 145篇 |
出版年
2024年 | 4篇 |
2023年 | 24篇 |
2022年 | 85篇 |
2021年 | 103篇 |
2020年 | 40篇 |
2019年 | 43篇 |
2018年 | 36篇 |
2017年 | 39篇 |
2016年 | 51篇 |
2015年 | 52篇 |
2014年 | 53篇 |
2013年 | 99篇 |
2012年 | 69篇 |
2011年 | 88篇 |
2010年 | 73篇 |
2009年 | 80篇 |
2008年 | 72篇 |
2007年 | 48篇 |
2006年 | 35篇 |
2005年 | 26篇 |
2004年 | 30篇 |
2003年 | 21篇 |
2002年 | 15篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1971年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1375条查询结果,搜索用时 0 毫秒
221.
Hadiseh Taheri Mehmet Altay Unal Melike Sevim Cansu Gurcan Okan Ekim Ahmet Ceylan Zois Syrgiannis Konstantinos C. Christoforidis Susanna Bosi Ozge Ozgen Manuel Jos Gmez Mine Turktas Erken igdem Soydal Zafer Erolu Ceylan Verda Bitirim Umut Cagin Fikret Ar Asuman Ozen Ozlem Kuuk Lucia Gemma Delogu Maurizio Prato
nder Metin Aelya Yilmazer 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(10)
222.
Hadiseh Taheri Mehmet Altay Unal Melike Sevim Cansu Gurcan Okan Ekim Ahmet Ceylan Zois Syrgiannis Konstantinos C. Christoforidis Susanna Bosi Ozge Ozgen Manuel Jos Gmez Mine Turktas Erken igdem Soydal Zafer Erolu Ceylan Verda Bitirim Umut Cagin Fikret Ar Asuman Ozen Ozlem Kuuk Lucia Gemma Delogu Maurizio Prato
nder Metin Aelya Yilmazer 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(10)
223.
Corvin Rive Giacomo Reina Prerana Wagle Emanuele Treossi Vincenzo Palermo Alberto Bianco Lucia Gemma Delogu Matthias Rieckher Bjrn Schumacher 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(45)
Graphene oxide (GO) holds high promise for diagnostic and therapeutic applications in nanomedicine but reportedly displays immunotoxicity, underlining the need for developing functionalized GO with improved biocompatibility. This study describes adverse effects of GO and amino‐functionalized GO (GONH2) during Caenorhabditis elegans development and ageing upon acute or chronic exposure. Chronic GO treatment throughout the C. elegans development causes decreased fecundity and a reduction of animal size, while acute treatment does not lead to any measurable physiological decline. However, RNA‐Sequencing data reveal that acute GO exposure induces innate immune gene expression. The p38 MAP kinase, PMK‐1, which is a well‐established master regulator of innate immunity, protects C. elegans from chronic GO toxicity, as pmk‐1 mutants show reduced tissue‐functionality and facultative vivipary. In a direct comparison, GONH2 exposure does not cause detrimental effects in the wild type or in pmk‐1 mutants, and the innate immune response is considerably less pronounced. This work establishes enhanced biocompatibility of amino‐functionalized GO in a whole‐organism, emphasizing its potential as a biomedical nanomaterial. 相似文献
224.
Ladislao Salmerón Pablo Delgado Lucia Mason 《Journal of Computer Assisted Learning》2020,36(6):1038-1051
Interventions to promote students' source evaluations have used various methods designed for the classroom context. In the present study, we tested an approach that is easily adaptable to online courses, based on eye movement modelling examples (EMME), that is, short videos displaying an expert student's eye gaze while s/he reads multiple pages on the Internet to learn about a conflicting topic. Using an eye-tracking methodology in a pre–post design, we analysed how an intervention using EMME changed students' attention to source information, and how this processing affected their learning. EMME increased participants' attention to the search engine results page, author information and decreased attention of texts from untrustworthy pages. In addition, EMME increased the number of participants who cited at least one document source at post-test. We discuss the potential benefits and limitations of EMME in teaching complex literacy strategies, and the importance of measuring processing data in educational research studies. 相似文献
225.
226.
Mario Gleria Francesco Minto Lucia Flamigni Pietro Bortolus 《Journal of Inorganic and Organometallic Polymers and Materials》1992,2(3):329-344
The synthesis and photochemical behavior both in solution and in the solid state of poly[bis(4-isopropylphenoxy)0.8 (4-benzoylphenoxy)1.2 phosphazene] is described. The main reaction of this material under illumination with light of a wavelength longer than 340 nm is the intramolecular abstraction of an hydrogen atom by the excited benzophenone substituent from the 4-isopropylphenoxy moiety geminally substituted on the same phosphorus of the phosphazene chain. In this way highly reactive radical species are produced which induce very efficient photo-cross-linking of the phosphazene copolymer and insolubilization. The efficiency of this process in the solid state is examined in view of the potential application of this material as a polyphosphazene-based negative photoresist. 相似文献
227.
Marek Jelemenský Csenger Kovcshzi Kristína Ferenczyov Monika Hofbauerov Bernadett Kiss va Pllinger gnes Kittel Viktor Nabil Sayour Anik Grbe Csilla Pelyhe Szabolcs Hambalk Lucia Kindernay Miroslav Baran
ík Pter Ferdinandy Monika Bartekov Zoltn Giricz 《International journal of molecular sciences》2021,22(19)
Helium inhalation induces cardioprotection against ischemia/reperfusion injury, the cellular mechanism of which remains not fully elucidated. Extracellular vesicles (EVs) are cell-derived, nano-sized membrane vesicles which play a role in cardioprotective mechanisms, but their function in helium conditioning (HeC) has not been studied so far. We hypothesized that HeC induces fibroblast-mediated cardioprotection via EVs. We isolated neonatal rat cardiac fibroblasts (NRCFs) and exposed them to glucose deprivation and HeC rendered by four cycles of 95% helium + 5% CO2 for 1 h, followed by 1 h under normoxic condition. After 40 h of HeC, NRCF activation was analyzed with a Western blot (WB) and migration assay. From the cell supernatant, medium extracellular vesicles (mEVs) were isolated with differential centrifugation and analyzed with WB and nanoparticle tracking analysis. The supernatant from HeC-treated NRCFs was transferred to naïve NRCFs or immortalized human umbilical vein endothelial cells (HUVEC-TERT2), and a migration and angiogenesis assay was performed. We found that HeC accelerated the migration of NRCFs and did not increase the expression of fibroblast activation markers. HeC tended to decrease mEV secretion of NRCFs, but the supernatant of HeC or the control NRCFs did not accelerate the migration of naïve NRCFs or affect the angiogenic potential of HUVEC-TERT2. In conclusion, HeC may contribute to cardioprotection by increasing fibroblast migration but not by releasing protective mEVs or soluble factors from cardiac fibroblasts. 相似文献
228.
Apparent chemical composition of nine commercial or semi-commercial whey protein concentrates, isolates and fractions 总被引:2,自引:0,他引:2
Carl Holt Deborah McPhail Ian Nevison Tommy Nylander Jeanette Otte Richard H. Ipsen Rogert Bauer Lars gendal Kees Olieman Kees G. de Kruif Joëlle Léonil Daniel Mollé Gwénaële Henry Jean Louis Maubois M. Dolores Pérez Pilar Puyol Miguel Calvo Stella M. Bury George Kontopidis Iain McNae Lindsay Sawyer Laura Ragona Lucia Zetta Henriette Molinari Bert Klarenbeek Margrethe J. Jonkman Jacques Moulin & Dereck Chatterton 《International Journal of Food Science & Technology》1999,34(5-6):543-556
Summary Analytical results are given for whey powders prepared on a commercial or semi-commercial scale by three companies. Altogether, five preparations enriched in β-lactoglobulin, four whey protein isolates and a fraction enriched in α-lactalbumin were analyzed for protein composition, including %β-lactoglobulin, α-lactalbumin, bovine serum albumin, casein (glyco) macropeptide and the main triglycerides. Protein composition was determined by high pressure gel permeation and reversed phase liquid chromatography and by capillary zone electrophoresis. The extent of modification of the native β-lactoglobulin structure was also measured through the degree of lactosylation and the fraction of accessible free sulphydryl groups. One significant finding was that the calculated recovery of protein following quantitation of the chromatogram or electropherogram was seldom above 90% and occasionally below 60% of that loaded onto the column or capillary, raising doubts as to the reliability of the analytical results. Extrapolation by linear regression to 100% recovery allowed estimates to be made of the true β-lactoglobulin composition of the samples. The nine samples could be placed into three distinct groups with estimated true β-lactoglobulin weight % of 70.9 ± 1.1, 62.0 ± 3.4 and 39.5 ± 4.9. Physico-chemical properties of the group of samples are reported elsewhere (Holt et al ., 1999). 相似文献
229.
Lucia Natarelli Fabio Virgili Christian Weber 《International journal of molecular sciences》2021,22(22)
Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is characterized by important respiratory impairments frequently associated with severe cardiovascular damages. Moreover, patients with pre-existing comorbidity for cardiovascular diseases (CVD) often present a dramatic increase in inflammatory cytokines release, which increases the severity and adverse outcomes of the infection and, finally, mortality risk. Despite this evident association at the clinical level, the mechanisms linking CVD and COVID-19 are still blurry and unresolved. Noncoding RNAs (ncRNAs) are functional RNA molecules transcribed from DNA but usually not translated into proteins. They play an important role in the regulation of gene expression, either in relatively stable conditions or as a response to different stimuli, including viral infection, and are therefore considered a possible important target in the design of specific drugs. In this review, we introduce known associations and interactions between COVID-19 and CVD, discussing the role of ncRNAs within SARS-CoV-2 infection from the perspective of the development of efficient pharmacological tools to treat COVID-19 patients and taking into account the equally dramatic associated consequences, such as those affecting the cardiovascular system. 相似文献
230.
Helen Sheldon John Alexander Esther Bridges Lucia Moreira Svetlana Reilly Koon Hwee Ang Dian Wang Salwa Lin Syed Haider Alison H. Banham Adrian L. Harris 《International journal of molecular sciences》2021,22(20)
ELTD1 is expressed in endothelial and vascular smooth muscle cells and has a role in angiogenesis. It has been classified as an adhesion GPCR, but as yet, no ligand has been identified and its function remains unknown. To establish its role, ELTD1 was overexpressed in endothelial cells. Expression and consequently ligand independent activation of ELTD1 results in endothelial-mesenchymal transistion (EndMT) with a loss of cell-cell contact, formation of stress fibres and mature focal adhesions and an increased expression of smooth muscle actin. The effect was pro-angiogenic, increasing Matrigel network formation and endothelial sprouting. RNA-Seq analysis after the cells had undergone EndMT revealed large increases in chemokines and cytokines involved in regulating immune response. Gene set enrichment analysis of the data identified a number of pathways involved in myofibroblast biology suggesting that the endothelial cells had undergone a type II EMT. This type of EMT is involved in wound repair and is closely associated with inflammation implicating ELTD1 in these processes. 相似文献