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81.
82.
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease in the world, paralleling the epidemic of obesity and Type 2 diabetes mellitus (T2DM). NAFLD exhibits a histological spectrum, ranging from “bland steatosis” to the more aggressive necro-inflammatory form, non-alcoholic steatohepatitis (NASH) which may accumulate fibrosis to result in cirrhosis. Emerging data suggests fibrosis, rather than NASH per se, to be the most important histological predictor of liver and non-liver related death. Nevertheless, only a small proportion of individuals develop cirrhosis, however the large proportion of the population affected by NAFLD has led to predictions that NAFLD will become a leading cause of end stage liver disease, hepatocellular carcinoma (HCC), and indication for liver transplantation. HCC may arise in non-cirrhotic liver in the setting of NAFLD and is associated with the presence of the metabolic syndrome (MetS) and male gender. The MetS and its components also play a key role in the histological progression of NAFLD, however other genetic and environmental factors may also influence the natural history. The importance of NAFLD in terms of overall survival extends beyond the liver where cardiovascular disease and malignancy represents additional important causes of death. 相似文献
83.
Journal of Chemical Ecology - MACE is an open access collection of electron impact (EI) mass spectra for coupled gas chromatography-mass spectrometry (GC/MS) that serves as an add-on database,... 相似文献
84.
85.
Poly(vinyl chloride)–n-propyl xanthate (PVC–nPX) macroinitiators with 3 to 14 bonded xanthate groups per molecule were synthesized using PVC and potassium n-propyl xanthate. The reaction took place rapidly between 30 and 45°C. Ultraviolet (UV) and nuclear magnetic resonance studies confirmed the presence of xanthyl groups on these macroinitiators. The PVC–nPX macroinitiators were grafted by methyl methacrylate under UV irradiation of 254, 302 and 336 nm producing graft copolymers and homopolymers. The molecular weights increased with increasing conversion, which is consistent with a ‘living’ polymerization process. The active species in these polymerizations are believed to be macroradicals and xanthyl radicals. 相似文献
86.
Anton Polotai Julie Voak Jim Henry David Thoss Yi Yang Sanjay Chitale 《International Journal of Applied Ceramic Technology》2020,17(2):728-733
The need for electronics to operate at temperatures of 200°C and above continues to grow. These applications include avionics, aerospace, automotive, downhole drilling, mining, and many others. To satisfy this demand, a significant amount of research and development has been conducted. Despite the efforts, the number of new electronic components designed specifically for high-temperature operation is still relatively limited. In Low Temperature Co-fired Ceramic (LTCC) packages, LTCC materials are generally used as the host media for a number of pre-fabricated semiconductor components. As a result, reliability of the entire LTCC package largely depends on the performance of the least robust component. Ferro A6M-E and Ferro L8 are the two well-established and recognized LTCC dielectrics widely used for mid and high frequency LTCC applications, including several high reliability aerospace and defense applications that require demanding Mil-Spec qualifications. This study is our first attempt to characterize and understand basic high-temperature dielectric properties of these two commercial LTCC materials. The secondary objective is to initiate a dialogue in attempt to establish reliability requirements for LTCC packages dedicated for high-temperature operation. 相似文献
87.
Helena Valentová Miroslav Kašpar Věra Hamplová Karel Bouchal Michal Ilavský Antonín Sikora Daniel Froelich René Muller 《Polymer Bulletin》1997,38(2):219-226
The dynamic mechanical behaviour of random copolymers of LC monomer-1-(hexyloxycarbonyl)ethyl 4-[4-(methacryloyloxy)benzoyloxy]benzoate
(HB) and octyl methacrylate (OMA) was studied in the main transition and flow regions. Even though the aliphatic end groups
of the side chain of HB and OMA are roughly the same, the T
g temperature of poly(HB) is ∼ 80 K higher than that of poly(OMA); this fact is due to the presence of the stiff phenyl benzoate
mesogenic group in the side chain of HB. With increasing content of OMA in the copolymer the superimposed curves of the storage
G′
p and loss G′′
p moduli at a constant temperature shift towards shorter frequencies. It has been shown that this shift is mainly due to an
increase of the free volume in the copolymers with increasing content of OMA. While HB monomer shows liquid crystalline (LC)
properties, its polymer (poly(HB)) and random copolymers with OMA show only isotropic thermal behaviour because no flexible
spacer is present in the side chain of HB which would decouple the main chain and mesogenic group motions. This means that
neither the homopolymer of HB, nor its copolymers with a flexible comonomer retain the LC properties of the starting LC monomer,
HB.
Received: 26 September 1996/Revised: 7 November 1996/Accepted: 7 November 1996 相似文献
88.
Vladimir S. Derevschikov Janna V. Veselovskaya Anton S. Shalygin Dmitry A. Yatsenko Andrey Z. Sheshkovas Oleg N. Martyanov 《中国化学工程学报》2022,46(6):11-20
Potassium carbonate-based sorbents are prospective materials for direct air capture (DAC). In the present study, we examined and revealed the influence of the temperature swing adsorption (TSA) cycle conditions on the CO2 sorption properties of a novel aerogel-based K2CO3/ZrO2 sorbent in a DAC process. It was shown that the humidity and temperature drastically affect the sorption dynamic and sorption capacity of the sorbent. When a temperature at the sorption stage was 29 ℃ and a water vapor pressure in the feed air was 5.2 mbar (1 bar = 105 Pa), the composite material demonstrated a stable CO2 sorption capacity of 3.4% (mass). An increase in sorption temperature leads to a continuous decrease in the CO2 absorption capacity reaching a value of 0.7% (mass) at T = 80 ℃. The material showed the retention of a stable CO2 sorption capacity for many cycles at each temperature in the range. Increasing PH2O in the inlet air from 5.2 to 6.8 mbar leads to instability of CO2 sorption capacity which decreases in the course of 3 consecutive TSA cycles from 1.7% to 0.8% (mass) at T = 29 ℃. A further increase in air humidity only facilitates the deterioration of the CO2 sorption capacity of the material. A possible explanation for this phenomenon could be the filling of the porous system of the sorbent with solid reaction products and an aqueous solution of potassium salts, which leads to a significant slowdown in the CO2 diffusion in the composite sorbent grain. To investigate the regeneration step of the TSA cycle in situ, the macro ATR-FTIR (attenuated total reflection Fourier-transform infrared) spectroscopic imaging was applied for the first time. It was shown that the migration of carbonate-containing species over the surface of sorbent occurs during the thermal regeneration stage of the TSA cycle. The movement of the active component in the porous matrix of the sorbent can affect the sorption characteristics of the composite material. The revealed features make it possible to formulate the requirements and limitations that need to be taken into account for the practical implementation of the DAC process using the K2CO3/ZrO2 composite sorbent. 相似文献
89.
Weisheng Yue Jeroen Anton van Kan Linke Jian Thomas Osipowicz Frank Watt 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(14):2376-2380
We present an approach to fabricate tall high aspect ratio Au microstructures by means of proton beam direct writing. Combining proton beam direct writing and electroplating, we successfully produced gold structures with sub-micrometer lateral dimensions, structure heights in excess of 11 μm, and aspect ratios over 28. Sidewall quality of the Au structures was improved by lowering the process temperature to 20 °C when developing PMMA patterns with GG developer. The application of such structures as X-ray masks for deep X-ray lithography with synchrotron radiation was demonstrated. 相似文献
90.
Dmitry Oshchepkov Irina Chadaeva Rimma Kozhemyakina Karina Zolotareva Bato Khandaev Ekaterina Sharypova Petr Ponomarenko Anton Bogomolov Natalya V. Klimova Svetlana Shikhevich Olga Redina Nataliya G. Kolosova Maria Nazarenko Nikolay A. Kolchanov Arcady Markel Mikhail Ponomarenko 《International journal of molecular sciences》2022,23(5)