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991.
A ternary Al–Mg–Si alloy was prepared by co-evaporation technique and tested with respect to hydrogen entry behaviour as an alternative to conventional zinc coating on steel. Hydrogen entry behaviour evaluated using Devanathan cell showed a smaller hydrogen entry for this new coating than conventional zinc coating. Compared to an unscratched surface, hydrogen entry increased by more than 100 times in the scratched surface, but it was lower than that for the zinc coating with a scratched surface owing to the moderate galvanic corrosion potential of the new coating. This new coating is proposed especially for high-strength steel application. 相似文献
992.
993.
Diblock and miktoarm star-shaped thermoresponsive copolymers composed of single-stranded DNA (ssDNA) and poly(N-isopropylacrylamide) were successfully synthesized with combination of atom transfer radical polymerization (ATRP) and click chemistry. This approach should be generalizable to other DNA-functionalized copolymers. Such copolymers self-assemble into spherical micelles with ssDNA corona in aqueous solution above the lower critical solution temperature. The micellar size can be tuned from the macromolecular architecture. These DNA-encoded micellar particles are able to encapsulate and release hydrophobic guest molecules upon changing temperature. 相似文献
994.
Muhammad Aziz Yasuki Kansha Atsushi Tsutsumi 《Chemical Engineering and Processing: Process Intensification》2011,50(9):944-951
Brown coal drying based on self-heat recuperation (SHR) technology which recovers effectively both latent and sensible heat was developed to reduce energy consumption which is required during drying. A fluidized bed dryer (SHR–FBD) with heat exchanger immersed inside the bed was adopted as the evaporator. To evaluate the energy efficiency of the proposed SHR–FBD system, a comparison to the available mechanical vapor recompression (MVR) based drying system concerning the effect of the fluidization velocity and bed aspect ratio to the required energy input for brown coal drying was conducted. From the results, the proposed SHR–FBD system was found to be able to drastically reduce the drying energy consumption at all evaluated fluidization velocities and bed aspect ratios. Numerically, the proposed system reduced the energy consumption to about 15% and 75% of that required in hot air and MVR drying systems. 相似文献
995.
Public infrastructure has long been faced with difficulty in financing. Available public resources are often limited in many countries. Competitive bidding in public procurement systems is an important instrument to contain the public investment costs. But competition is often limited in the infrastructure sector. In such circumstances, better public procurement design can save a lot of public resources. There is a general tradeoff between the competition effect and economies of scale and scope; large contracts can benefit from the scale and scope effects but have to compromise competition. The unbundling approach can foster competition but may suffer from diseconomies of scale and scope. Using procurement data from water supply and sewage projects in developing countries, the paper analyzes the effects of the (un)bundling strategy on bidders’ entry and bidding behavior. It shows that the bidder cost structure exhibits significant diseconomies of scope between two main public works in this sector, i.e., treatment plant construction and distribution network installation. There is no clear evidence of the competition effect. Therefore, there is no rationale of bundling these two works into a single contract. Unbundling can help governments to contain public infrastructure costs. 相似文献
996.
Kento Imajo Masato Yoneda Takaomi Kessoku Yuji Ogawa Shin Maeda Yoshio Sumida Hideyuki Hyogo Yuichiro Eguchi Koichiro Wada Atsushi Nakajima 《International journal of molecular sciences》2013,14(11):21833-21857
Research in nonalcoholic fatty liver disease (NAFLD), including nonalcoholic steatohepatitis (NASH), has been limited by the availability of suitable models for this disease. A number of rodent models have been described in which the relevant liver pathology develops in an appropriate metabolic context. These models are promising tools for researchers investigating one of the key issues of NASH: not so much why steatosis occurs, but what causes the transition from simple steatosis to the inflammatory, progressive fibrosing condition of steatohepatitis. The different rodent models can be classified into two large groups. The first includes models in which the disease is acquired after dietary or pharmacological manipulation, and the second, genetically modified models in which liver disease develops spontaneously. To date, no single rodent model has encompassed the full spectrum of human disease progression, but individual models can imitate particular characteristics of human disease. Therefore, it is important that researchers choose the appropriate rodent models. The purpose of the present review is to discuss the metabolic abnormalities present in the currently available rodent models of NAFLD, summarizing the strengths and weaknesses of the established models and the key findings that have furthered our understanding of the disease’s pathogenesis. 相似文献
997.
Youhei Numata Surya Prakash Singh Ashraful Islam Munetaka Iwamura Atsushi Imai Koichi Nozaki Liyuan Han 《Advanced functional materials》2013,23(14):1817-1823
A novel Ru π‐expanded terpyridyl sensitizer, referred to as HIS‐2, is prepared based on the molecular design strategy of substitution with a moderately electron‐donating 4‐methylstyryl group onto the terpyridyl ligand. The HIS‐2 dye exhibits a slightly increased metal‐to‐ligand charge transfer (MLCT) absorption at around 600 nm and an intense π–π* absorption in the UV region compared with a black dye. Density functional theory calculations reveal that the lowest unoccupied molecular orbital (LUMO) is distributed over the terpyridine and 4‐methylstyryl moieties, which enhances the light‐harvesting capability and is appropriate for smooth electron injection from the dye to the TiO2 conduction band. The incident photon‐to‐electricity conversion efficiency spectrum of HIS‐2 exhibits better photoresponse compared with black dye over the whole spectral region as a result of the extended π‐conjugation. A DSC device based on black dye gives a short‐circuit current (JSC) of 21.28 mA cm?2, open‐circuit voltage (VOC) of 0.69 V, and fill factor (FF) of 0.72, in an overall conversion efficiency (η) of 10.5%. In contrast, an HIS‐2 based cell gives a higher JSC value of 23.07 mA cm?2 with VOC of 0.68 V, and FF of 0.71, and owing to the higher JSC value of HIS‐2, an improved η value of 11.1% is achieved. 相似文献
998.
Minako Karahashi Fumiko Ishii Tohru Yamazaki Koichi Imai Atsushi Mitsumoto Yoichi Kawashima Naomi Kudo 《Lipids》2013,48(5):457-467
The Goto-Kakizaki (GK) rat is an animal model for spontaneous-onset, non-obese type 2 diabetes. Despite abundant evidence about disorders in metabolism, little information is available about fatty acid metabolism in the liver of GK rats. This study aimed to investigate the characteristics of the fatty acid profile, particularly MUFA, and the mechanism underlying the alterations in fatty acid profiles in the liver of GK rats. The activities of enzymes that participate in the biosynthesis of MUFA, expressions of genes encoding these enzymes, and the fatty acid profile in the liver were compared with those of obese Zucker (fa/fa) (ZF) rats, which are obese and non-diabetic. Stearoyl-CoA desaturase (SCD) activity and SCD1 gene expression were considerably up-regulated in GK rats, and these levels were largely comparable to those in ZF rats. However, the proportions and contents of oleic acid and palmitoleic acid were very low considering the highly elevated activity of SCD in the liver of GK rats, when compared with ZF rats. Palmitoyl-CoA chain elongation (PCE) activity and fatty acid elongase (Elovl6) gene expression were markedly up-regulated in ZF rats, whereas PCE activity was up-regulated much less and Elovl6 gene expression was unchanged in GK rats. These results suggest the possibility that up-regulation of gene expression of Elovl6 along with SCD1 is indispensable to elevate the proportions and contents of oleic acid in the liver. 相似文献
999.
A cellulose model compound, methyl β-D-glucopyranoside (MGP), was subjected to oxygen-alkali treatment in the presence of various kinds of lignin model compounds. Only in the presence of a lignin model compound reactive with oxygen, a significant degradation of MGP was observed and the rate and the extent of its degradation were strongly dependent on the structure and the amount of a lignin model compound. Depression of MGP degradation was found to be achieved by two clearly distinguished mechanisms. One is an enhancement of the degradation of a lignin model compound without the acceleration of MGP degradation and the other is a depression of MGP degradation without significantly deteriorating the degradation of a lignin model compound. An increase in oxygen pressure and a 10% methanol addition belonged to the former case and a change in the ratio of metal ions and a 1% methanol addition belonged to the latter case. The addition of magnesium sometimes resulted in the acceleration of MGP degradation, depending on its ratio to iron. 相似文献
1000.
In this paper, a novel position sensorless control method for interior permanent magnet synchronous motors (IPMSMs) that is based on a novel ?ux model suitable for maximum torque control has been proposed. Maximum torque per ampere (MTPA) control is often utilized for driving IPMSMs with the maximum e?ciency. In order to implement this control, generally, the accurate motor parameters are required. However, the inductance varies dramatically because of magnetic saturation, which has been one of the most important problems in recent years. Therefore, the conventional MTPA control method fails to achieve maximum e?ciency for IPMSMs because of parameter mismatches. In this paper, ?rst, a novel ?ux model has been proposed for realizing the position sensorless control of IPMSMs, which is insensitive to Lq. In addition, in this paper it is shown that the proposed ?ux model can approximately estimate the maximum torque control (MTC) frame, which is a new coordinate aligned with the current vector for MTPA control. Next, in this paper, a precise estimation method for the MTC frame has been proposed. By this method, highly accurate maximum torque control can be achieved. A decoupling control algorithm based on the proposed model is also addressed in this paper. Finally, some experimental results demonstrate the feasibility and e?ectiveness of the proposed method. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(3): 55–66, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22380 相似文献