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排序方式: 共有1397条查询结果,搜索用时 156 毫秒
201.
In the present paper, an accident occurred during a liquefied petroleum gas (LPG) tank filling activity has been taken into consideration. During the transfer of LPG from the source road tank car to the receiving fixed storage vessel, an accidental release of LPG gave rise to different final consequences ranging from a pool fire, to a fireball and to the catastrophic rupture of the tank with successive explosion of its contents. The sequence of events has been investigated by using some of the consequence calculation models most commonly adopted in risk analysis and accident investigation. On one hand, this allows to better understand the link between the various events of the accident. On the other hand, a comparison between the results of the calculations and the damages actually observed after the accident, allows to check the accuracy of the prediction models and to critically assess their validity. In particular, it was shown that the largest uncertainty is associated with the calculation of the energy involved in the physical expansion of the fluid (both liquid and vapor) after the catastrophic rupture of the tank. 相似文献
202.
Karina Donadel Marcos D.V. Felisberto Valfredo T. Fávere Mauricio Rigoni Nelson Jhoe Batistela Mauro C.M. Laranjeira 《Materials science & engineering. C, Materials for biological applications》2008,28(4):509-514
Magnetic particles are extremely interesting for several biomedical applications; amongst these are therapeutic applications, such as: hyperthermia and release of drugs. The use of magnetic particles to induce hyperthermia in biological tissues is an important factor in cancer therapy. The aim of this study was to prepare and characterize iron oxide magnetic particles coated with biopolymer chitosan, and also to produce ferrofluids from the magnetic particles. The iron oxide magnetic particles (IOMP) were coated with chitosan (CS) by spray-drying method using two IOMP/coating ratios (IOMP/CS = 1.6 and IOMP/CS = 4.5). The magnetic particles were characterized by way of scanning electronic microscopy and energy-dispersive X-ray. The analysis by energy-dispersive X-ray was carried out to determine the chemical composition of particles in samples. The size distribution the iron oxide magnetic particles uncoated and coated were evaluated by the laser diffraction analysis and image analysis, respectively. Amongst the prepared ferrofluids, the sample IOMP/CS = 1.6 proved to be the one that has brought about the best results in therapeutics applications, such as in hyperthermia treatment. This sample was placed within an alternating magnetic field during 40 min, it was observed that 1 °C heated in 3 min and underwent a temperature variation of 7 °C, since it varied from 25 °C to 32 °C. Considering that the experiment would be carried out at body temperature 37 °C, probably, the temperature variation would be very close to the one reported at 25 °C. In such a way, the cancerous cells would reach 44–45 °C and at such temperatures the cancer cells generally perish. 相似文献
203.
Becker S Maissen O Ponomarev I Stoll T Meury T Sprecher C Alini M Wilke I 《Journal of materials science. Materials in medicine》2008,19(2):659-665
We investigated the osteopromotive properties of plasmatransglutaminase (F XIII), bone marrow and venous blood on a resorbable
β-tricalcium phosphate (β-TCP) scaffold. A baseline binding and release study of F XIII from the scaffold showed a continuous
release of 18% of the total dose after 48 h. The main study consisted of 18 adult sheep with cylindrical defects in both tibiae.
The defects were filled with a β-TCP cylinder impregnated either with bone marrow, venous blood, F XIII or sheep were treated
with 1250 IU F XIII intravenously over 14 days (n = 4 in each group). The defects were left open in two sheep. QCT and histology was performed after 6 and 12 weeks. The best
bone ingrowth was seen after 6 weeks in the bone marrow group and after 12 weeks in the local F XIII group. The highest ingrowth
on the inside of the cylinder proving the osteopromoting potential of F XIII was found in the local F XIII group. In our opinion
F XIII is a good and readily available osteopromoting agent which can be used with β-TCP in cases of bone deficit to promote
bone regeneration. 相似文献
204.
Seven challenges for nanomedicine 总被引:1,自引:0,他引:1
205.
State‐of‐the‐Art Neutral Tint Multichromophoric Polymers for High‐Contrast See‐Through Electrochromic Devices 下载免费PDF全文
Mauro Sassi Matteo M. Salamone Riccardo Ruffo Giorgio E. Patriarca Claudio M. Mari Giorgio A. Pagani Uwe Posset Luca Beverina 《Advanced functional materials》2016,26(29):5240-5246
Two new multichromophoric electrochromic polymers featuring a conjugated EDOT/ProDOT copolymer backbone (PXDOT) and a reversible Weitz‐type redox active small molecule electrochrome (WTE) tethered to the conjugated chain are reported here. The careful design of the WTEs provides a highly reversible redox behavior with a colorless red switching that complements the colorless blue switching of the conjugated backbone. Subtractive color mixing successfully provides high performing solution processable polymeric layers with colorless neutral tint switchable limiting states for application in see‐through electrochromic devices. Design, synthesis, comprehensive chemical and spectroelectrochemical characterization as well as the preparation of a proof‐of‐concept device are discussed. 相似文献
206.
Zia Abbas Mauro Olivieri 《International Journal of Circuit Theory and Applications》2016,44(7):1400-1424
Process variability, in addition to wide temperature and supply voltage variation ranges, severely degrades the fabrication outcome (yield) of digital cells as for the fulfillment of performance specification bounds. This paper presents the application of mathematical optimization to the design of standard cells that are robust to process variations even in worst‐case operating conditions. The method attains the optimal sizing of individual transistors in the cell for maximizing the statistical yield referring to leakage power and propagation delay bounds, with local and global process variations specified by industrial process development kits (PDKs). The approach is demonstrated for a 40 nm low‐power standard threshold voltage Complementary Metal Oxide Semiconductor (CMOS) technology, for an intended operating temperature range [?40 °C, 125 °C] and supply voltage range [0.95 V, 1.05 V]. The reported optimization results show a yield improvement from an initial 50% to 99.9%, and Simulation Program with Integrated Circuit Emphasis (SPICE)‐level Monte Carlo analysis confirmed the estimated yield of the obtained circuits. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
207.
Mauro Di Marco Mauro Forti Luca Pancioni 《International Journal of Circuit Theory and Applications》2016,44(11):1959-1981
The paper considers a feedback cellular neural network (CNN) obtained by interconnecting elementary cells with an ideal capacitor and an ideal flux‐controlled memristor. It is supposed that during the analogue computation of the CNN the memristors behave as dynamic elements, so that each dynamic memristor (DM)‐CNN cell is described by a second‐order differential system in the state variables given by the capacitor voltage and the memristor flux. The proposed networks are called DM‐CNNs, that is CNNs using a dynamic (D) memristor (M). After giving a foundation to the DM‐CNN model, the paper establishes a fundamental result on complete stability, that is convergence of solutions toward equilibrium points, when the DM‐CNN has symmetric interconnections. Because of the presence of dynamic memristors, a DM‐CNN displays peculiar and basically different dynamic properties with respect to standard CNNs. First of all a DM‐CNN computes during the time evolution of the memristor fluxes, instead of the capacitor voltages as for a standard CNN. Furthermore, when a steady state is reached, the memristors keep in memory the result of the computation, that is the limiting values of the fluxes, while all memristor currents and voltages, as well as all currents, voltages, and power in the DM‐CNN vanish. Instead, for standard CNNs, currents, voltages, and power do not drop off when a steady state is reached. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
208.
A ruthenium oxide hexacyanoferrate (RuOHCF) modified electrode was developed. Hydrodynamic voltammetry was employed to demonstrate the remarkable electrocatalytic activity toward the oxidation of 2'-deoxyguanosine. The RuOHCF modified electrode was used as amperometric detector for 2'-deoxyguanosine determination in a FIA apparatus. The influence of various experimental conditions was explored for optimum analytical performance, and at these experimental conditions, the method exhibited a linear response range to 2'-deoxyguanosine extending from 3.8 to 252 micromol L(-1) with detection limit of 94 nmol L(-1). Applications in DNA samples were examined, and the results for determination of 2'-deoxyguanosine were in good agreement with those obtained by HPLC analysis. Studies on the kinetics of the in vitro consumption of 2'-deoxyguanosine by acetaldehyde were also performed. 相似文献
209.
Campanella L Magrì AL Tomassetti M Rossi V Vecchio S 《Drug development and industrial pharmacy》2007,33(8):830-840
In this paper our previous researches dealing with compatibility, thermoanalytical characterization, the kinetics of thermal degradation of acetaminophen, either pure or contained in some commercial pharmaceutical formulations, have found applications outlets. In a previous investigation the possible interactions between acetaminophen and four excipients contained in the commercial pharmaceutical formulations were tested. As a continuation of this research in the present study an analytical method based on differential scanning calorimetry (DSC) was applied to determine the acetaminophen content of four commercial pharmaceutical formulations. For a fifth drug it was shown that the method is not applicable owing to observed incompatibility with one of the excipients. Finally, the analytical results obtained were compared with those derived from two UV spectrophotometric methods (one, i.e., “direct method,” recommended by the Pharmacopeia and the other based on the first-order derivative UV spectra). 相似文献
210.
We examined the in vivo contribution of insulin, T090137 (T09), agonist of liver X receptor (LXR), fenofibrate, agonist of
peroxisome proliferator activated receptor (PPAR-α) and sterol regulatory element binding protein-1c (SREBP-1c) on the unsaturated
fatty acid synthesis controlled by Δ6 and Δ5 desaturases, compared with the effects on stearoylcoenzyme A desaturase-1. When
possible they were checked at three levels: messenger RNA (mRNA), desaturase protein and enzymatic activity. In control rats,
only fenofibrate increased the insulinemia that was maintained by the simultaneous administration of T09, but this increase
has no specific effect on desaturase activity. T09 enhanced SREBP-1 in control animals and the mRNAs and activity of the three
desaturases in control and type-1 diabetic rats, demonstrating a LXR/SREBP-1-mediated activation independent of insulin. However,
simultaneous administration of insulin and T09 to diabetic rats led to a several-fold increase of the mRNAs of the desaturases,
suggesting a strong synergic effect between insulin and LXR/retinoic X receptor (RXR). Moreover, this demonstrates the existence
of an interaction between unsaturated fatty acids and cholesterol metabolism performed by the insulin/SREBP-1c system and
LXR/RXR. PPAR-α also increased the expression and activity of the three desaturases independently of the insulinemia since
it was equivalently evoked in streptozotocin diabetic rats. Besides, PPAR-α increased the palmitoylcoenzyme A elongase, evidencing
a dual regulation in the fatty acid biosynthesis at the level of desaturases and elongases. The simultaneous administration
of fenofibrate and T09 did not show additive effects on the mRNA expression and activity of the desaturases. Therefore, the
results indicate a necessary sophisticated interaction of all these factors to produce the physiological effects. 相似文献