全文获取类型
收费全文 | 1068篇 |
免费 | 22篇 |
专业分类
电工技术 | 3篇 |
综合类 | 3篇 |
化学工业 | 277篇 |
金属工艺 | 14篇 |
机械仪表 | 15篇 |
建筑科学 | 79篇 |
矿业工程 | 28篇 |
能源动力 | 41篇 |
轻工业 | 130篇 |
水利工程 | 13篇 |
石油天然气 | 6篇 |
无线电 | 41篇 |
一般工业技术 | 120篇 |
冶金工业 | 161篇 |
原子能技术 | 7篇 |
自动化技术 | 152篇 |
出版年
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 12篇 |
2019年 | 9篇 |
2018年 | 19篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 17篇 |
2014年 | 11篇 |
2013年 | 80篇 |
2012年 | 28篇 |
2011年 | 54篇 |
2010年 | 33篇 |
2009年 | 30篇 |
2008年 | 54篇 |
2007年 | 42篇 |
2006年 | 40篇 |
2005年 | 30篇 |
2004年 | 25篇 |
2003年 | 24篇 |
2002年 | 39篇 |
2001年 | 14篇 |
2000年 | 25篇 |
1999年 | 20篇 |
1998年 | 30篇 |
1997年 | 18篇 |
1996年 | 25篇 |
1995年 | 22篇 |
1994年 | 22篇 |
1993年 | 15篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 16篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 21篇 |
1982年 | 17篇 |
1981年 | 19篇 |
1980年 | 19篇 |
1979年 | 15篇 |
1978年 | 14篇 |
1977年 | 9篇 |
1976年 | 14篇 |
1975年 | 13篇 |
1974年 | 5篇 |
1973年 | 9篇 |
排序方式: 共有1090条查询结果,搜索用时 15 毫秒
21.
Eileen J. O'Neill Thomas Batey Malcolm S. Cresser 《Journal of the science of food and agriculture》1983,34(6):541-548
The effects of fertiliser N on the growth rate and nitrogen and pigment concentrations of spring barley throughout growth were measured at two locations in north-east Scotland in consecutive years. Inorganic N in soil was also measured as were grain and straw yields at maturity. The results show that plant analysis, as early as 3 or 4 weeks after emergence of barley, was an effective assessment of soil N status. 相似文献
22.
Malcolm Abbott Jeffrey Cotter 《Progress in Photovoltaics: Research and Applications》2006,14(3):225-235
A process using laser‐ablated pits to texture the front surface of monocrystalline and multicrystalline silicon solar cells is described. Optical and electrical characterization demonstrates that the technique performs as well as upright random pyramid texturing and causes no laser‐induced defects or laser shunting. Double‐sided buried contact solar cells fabricated with laser texture performed as well as those fabricated with upright random pyramid textures on 1 Ω cm, p type float‐zoned wafers. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
23.
Xingying Zhang Chen Song Huijia Nong Kaige Xu Xiaozhuo Wu Wen Zhong Malcolm Xing Leyu Wang 《Advanced functional materials》2023,33(32):2300866
A conductive engineered cardiac patch (ECP) can reconstruct the biomimetic regenerative microenvironment of an infarcted myocardium. Direct ink writing (DIW) and 3D printing can produce an ECP with precisely controlled microarchitectures. However, developing a printed ECP with high conductivity and flexibility for gapless attachment to conform to epicardial geometry remains a challenge. Herein, an asymmetrical DIW hydrophobic/hydrophilic membrane using heat-processed graphene oxide (GO) ink is developed. The “Masked spin coating” method is also developed that leads to a microscale GO (hydrophilic)/reduced GO (rGO, hydrophobic) physiological sensor, as well as a macroscale moisture-driven GO/rGO actuator. Depositing mussel-inspired polydopamine (PDA) coating on the one side of the DIW rGO , the ultrathin (approximately 500 nm) PDA-rGO (hydrophilic)/rGO (hydrophobic) microlattice (DrGOM) ECP is bestowed with the flexibility and moisture-responsive actuation that allows gapless attachment to the curved surface of the epicardium. Conformable DrGOM exhibits a promising therapeutic effect on rats' infarcted hearts through conductive microenvironment reconstruction and improved neovascularization. 相似文献
24.
Mussel‐Inspired Conductive Cryogel as Cardiac Tissue Patch to Repair Myocardial Infarction by Migration of Conductive Nanoparticles 下载免费PDF全文
Leyu Wang Junzi Jiang Wenxi Hua Ali Darabi Xiaoping Song Chen Song Wen Zhong Malcolm M. Q. Xing Xiaozhong Qiu 《Advanced functional materials》2016,26(24):4293-4305
The engineered cardiac patch (ECP) is a promising strategy to repair infarct myocardium and restore the cardiac function. An ideal ECP should be able to mimic the primary attributes of native myocardium, which includes a high resilience, good cardiomyocyte adhesion, and synchronous contraction. Here, a mussel‐inspired dopamine crosslinker is used to integrate polypyrrole (Ppy) nanoparticles, gelatin‐methyacrylate, and poly(ethylene glycol) diacrylate into a cryogel form. The dopamine crosslinker and Ppy nanoparticles are coordinated to obtain optimal mechanical and superelastic properties for the ECP. The dopamine facilitates the uniform distribution of the Ppy nanoparticles, which migrate and fuse from the scaffold to the surface of the cardiomyocytes, revealing a potential mechanism for restoring infarct myocardium. The incorporated Ppy nanoparticles thus significantly enhance the functionalization of the cardiomyocytes, resulting in excellent synchronous contraction by increasing the expression of α‐actinin and CX‐43. Cardiomyocytes‐loaded ECP can improve the cardiac function in myocardial‐infarction (MI) affected rat models. The results show that the fractional shortening and ejection fraction are elevated by about 50% and that the infarct size is reduced by 42.6%. Collectively, this study highlights an effective cardiac patch based on mussel‐inspired conductive particle adhesion and a superelastic cryogel promising for the restoration of infarcted myocardium. 相似文献
25.
Preparative isolation of aquatic humic substances 总被引:14,自引:0,他引:14
26.
The treatment of acid rock drainage (ARD) places extraordinary financial burdens on governments and companies worldwide, and
an improved efficiency in treatment by as little as 1% can save many millions of dollars in rehabilitation. We investigated
a system for treating Fe-rich ARD using a three-stage reactor design. In the first reaction cell, Fe-rich ARD was partially
neutralised using rapid periodic carbonate resuspension with a rotating axial mixer. This was followed by an air-sparged oxidation
chamber and then a second reaction cell, with more carbonate periodically resuspended until a pH of 6.3 was reached, which
was followed by a settlement chamber. This reactor design has a high capacity for neutralisation, with an efficiency of ≈70%
of acidity neutralised by the acid neutralising capacity (g of CaCO3 equivalent) added to the reactor. Axial mixers were tested because of their low-energy requirements and their high reliability.
The intermediate chamber effectively removes Fe by oxidising Fe(II) to Fe(III). Given the amount of acidity neutralised, the
sludge volume produced was low compared to other technologies, providing further potential savings in sludge handling. Waste
carbonate rock proved to be an effective neutralising agent, even though it was about 60% dolomite and 40% magnesite, with
minor calcite, and despite the fact that magnesite has substantially slower dissolution kinetics compared to the more dominant
dolomite. The mixed waste carbonates were capable of raising the pH sufficiently to reduce the heavy metal loadings in Fe-rich
ARD by more than two orders of magnitude. The final settlement stage of the process was shown to be essential for metal precipitation,
for the carry-over of fine carbonates, and CO2 loss. This was associated with a rise in pH, from 6.3 to 7.5. In addition, residual slow-reacting magnesite from the mixed
carbonate remains in the sludge from the first reactor and provides acid buffering capacity within the sludge, which is commonly
lacking in the ARD neutralisation sludge of other systems. 相似文献
27.
28.
The application of combined g.c.-m.s. with automated data processing to the rapid analysis of coal solvents has been described. An analytical method, using commercially available data processing routines, has been developed for the automatic quantitative analysis of specific aromatic and hydroaromatic compounds in coal processing solvents. To demonstrate the use of this technique, raw anthracene oil was hydrogenated under different conditions and the resulting hydrogenated anthracene oils were analysed. The results showed correlations between the hydrogen content and the absolute concentrations of specific compounds in the samples. 相似文献
29.
Dunsmore CJ Malone KJ Bailey KR Wear MA Florance H Shirran S Barran PE Page AP Walkinshaw MD Turner NJ 《Chembiochem : a European journal of chemical biology》2011,12(5):802-810
Cyclophilin A (CypA) is a member of the immunophilin family of proteins and receptor for the immunosuppressant drug cyclosporin A (CsA). Here we describe the design and synthesis of a new class of small-molecule inhibitors for CypA that are based upon a dimedone template. Electrospray mass spectrometry is utilised as an initial screen to quantify the protein affinity of the ligands. Active inhibitors and fluorescently labelled derivatives are then used as chemical probes for investigating the biological role of cyclophilins in the nematode Caenorhabditis elegans. 相似文献
30.
Laura Gonzalez-Macia Malcolm R. Smyth Aoife Morrin Anthony J. Killard 《Electrochimica acta》2011,(11):562
The modification of silver paste electrodes with a combination of dodecylbenzenesulfonic acid and KCl has been shown to lead to significant enhancements of the electrochemical reduction of hydrogen peroxide. The catalytic enhancement was shown to be dependent on the concentration of the surfactant/salt solution, which resulted in increases of some 80-fold in amperometric response to hydrogen peroxide at −0.1 V vs Ag/AgCl, pH 6.8 over unmodified silver paste. Physical analysis showed modifications to both the surface morphology and chemical composition of the silver paste electrode surface. However, BET and electrochemical analysis revealed no significant change in surface area. It is suggested that the enhanced catalysis may result from the formation of stabilised surfactant/salt structures at the metal electrode surface. The electrode was also shown to be suitable for the amperometric detection of hydrogen peroxide with a limit of detection of 1.1 × 10−6 M (S/N = 3). 相似文献