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51.
USM模块式家具源自于瑞士.钢制的球是USM家具的主要连接器。球和钢管的精密结合是USM品牌的独创,由此就可演变出不同规格.不同造型的USM家具。 相似文献
52.
1“居山”与”隐贵山居“
回想一下人类的聚居行为颇为有趣,当年我们的祖先拼命从险山恶水的自然环境中挣脱出来,为的是得到更加安全和便利的聚居条件,但似乎从那一刻起本能式的回归意识便时刻魂牵梦绕,隐隐作响。其实无论是脱离自然还是回归自然,对于现实而言两者皆是虚幻和理想的。 相似文献
53.
Xinsheng Zhu Hansong Xu Jianmei Lu Juying Wang Shunhua Zhou 《Journal of Polymer Research》2008,15(4):295-300
Poly(ethylene terephthalate) (PET) is of excellent mechanical properties and melt processability and is widely used as raw
material for textile fibers. However, the flame retardant properties of PET were rather poor, and both reactive and additive
phosphorus- and halogen-containing compounds have been employed to enhance the reaction-to-fire properties while the meltdripping
behaviour during burning hasn’t been handled properly with the flame retardants. In this work, fluoropolymer was blended with
both pure PET (pPET) and reactive phosphorus-containing flame retarded copolyester (fPET), and the flame retardance and char
formation and mechanical properties of the resulted pPET and fPET blends were investigated. The tensile strengths of modified
pPET samples were worsen whereas those of modified fPET samples were improved at low concentrations. The initial thermal degradation
in nitrogen was accelerated remarkably for the two polyesters with fluoropolymer. The oxygen indices of the all modified samples
were reduced while char formation and meltdripping suppression were encouraged. The apparent melt viscosity and elasticity
for the two polyesters were gained much with antidripping agent. Therefore, fluoropolymer improved char formation of the two
polyesters based on the gaseous phase mechanism while the partial suppression of meltdripping behavior and the decrease of
mechanical properties mainly originated from the increase of melt viscosity via fibrillation for pPET. 相似文献
54.
浅谈集成电路的废气处理 总被引:1,自引:1,他引:0
集成电路的工业废气有含氟化物、硫酸雾的酸性废气,含氨的碱性废气,含异丙醇、光刻胶的有机废气,含SiO_2的含尘废气,以及含硅烷、磷烷的工艺尾气等,这些工业废气中大部分成分是有毒有害的,必须进行有效的处理才能排入大气中。主要讨论上述工业废气的分类、处理方式、应用范围及应用实例等。 相似文献
55.
56.
Guiying Li Ze He Taicheng An Xiangying Zeng Guoying Sheng Jiamo Fu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(7):1019-1026
BACKGROUND: To investigate the microbial degradation performance of organic pollutants in the atmosphere using a biotrickling filter, two microorganism strains, Bacillus cereus S1 and Bacillus cereus S2, were selected, identified and inoculated into a twin biotrickling filter for comparison. RESULTS: Both strains showed good performance towards the degradation of model organic pollutants when gas flow rates ranged from 100 to 600 L h−1. For S1, the total maximum removal efficiency (RE) of toluene was maintained nearly 100% not only at gas flow rates of 100 L h−1 corresponding to empty bed residence time (EBRT) 199.44 s, but also at gas flow rates of 200 L h−1 (EBRT = 99.72 s) and 300 L h−1 (EBRT = 66.48 s). However, S2 had a much lower degradation capability; near 100% removal efficiency was obtained only at the gas flow rate of 100 L h−1 although both bacteria belong to the same Bacillus cereus. With further increase in gas flow rate, the total REs for both S1 and S2 decreased slightly at first and then dropped sharply to 46% and 35%, respectively, at an EBRT of 33.24 s, corresponding to a gas flow rate of 600 L h−1. Starvation for between 2 and 10 days resulted in the re‐acclimation times of both strains ranging between 1.0 and 15.5 h. CONCLUSION: Strain S1 would be a better choice for inoculation into a biotrickling filter than strain S2, because of its much higher toluene removal capacity and rapid recovery to full performance. Copyright © 2008 Society of Chemical Industry 相似文献
57.
Sodium sulfonate‐terminated dendritic poly(ester‐amine) (SPEA) was synthesized by sulfonation of acrylic double bond‐terminated dendritic poly(ester‐amine) (APEA) with sodium hydrogen sulfite (NaHSO3) in mixture of diglycol and 2‐butanone under normal pressure. The structure of SPEA was characterized by IR, 1H‐NMR, and elemental analysis. SPEA was water‐soluble. 1.0–40.0% (mass) SPEA aqueous solutions appeared as dilatant fluid. When pH value varied from 1.5 to 12.0, the viscosity of 1–5% (mass) SPEA aqueous solutions changed very small, and the electric conductivity almost kept stable within pH 3.0–10.0. The relationship between the viscosity and the concentration of SPEA water solutions was similar to that of NaCl water solutions. The surface tension of SPEA water solutions was lower than that of polyethylene glycol 2000 water solutions with the same concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
58.
Methylmethacrylate (MMA) and octadecyl acrylate (OA) were grafted to poly(methylhydrosiloxane) (PMHS) by hydrosilylation, respectively, with hexachloroplatinic acid as catalyst, and the former was further hydrolyzed to prepare methacrylic acid (MAA)‐graft‐PMHS under the alkaline condition. Through orthogonal experiment, main factors affecting the graft reaction between OA and PMHS were discussed and arranged in a decreasing order according to their abilities of the effect on the hydrosilylation of OA with PMHS: catalyst dosage, reaction temperature, reaction time, material ratio, and solvent dosage. It was found that the hydrosilylation of OA with PMHS was easier to that of MMA with PMHS. Under optimal conditions, the grafting ratios of MMA with PMHS and OA with PMHS reached about 90 and 95%, respectively. FTIR and 1H NMR spectra indicated that the hydrosilylation reactions followed the Markovnikov's rule and played a strong preference toward β‐1,2‐addition. The test of contact angle indicated that surface energy of a system was mainly dependent on the polar groups. The surface energy of OA‐graft‐PMHS (35.07 mN/m) was similar to those of PMHS (35.62 mN/m) and polyoctadecyl acrylate (36.57 mN/m), and lower than that of MAA‐graft‐PMHS (43.50 mN/m). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 相似文献
59.
The phase structures and transition behaviors of a series of side-chain liquid crystalline (LC) polymethacrylates based on p-methoxyazobenzene (PMnAzs, n = 6, 8, 10, 12) were studied using differential scanning calorimetry, one- and two-dimensional (1D and 2D) wide-angle X-ray diffraction, and Fourier transform infrared spectroscopic experiments. The LC phase transition of PMnAz follows the sequence of smectic A (SmA) ? nematic (N) ? isotropic (I). For PM10Az and PM12Az, the transition of SmA-to-N is not complete upon heating. In the low-temperature SmA phase, the polymers adopt a fully interdigitated side-chain packing with the smectic layer period almost identical to the side-chain length. For all the four samples, the first-order diffraction of the SmA structure only renders when the temperature approaches the transition of SmA ? N, with the intensity much lower than that of the second-order diffraction. The absence of the first-order diffraction at low temperatures is ascribed to the possible matching of the electron densities between the center portion of the side-chain sublayer and the main-chain sublayer of the SmA structure. Since only the mesogens from the same main-chain sublayer can stack parallel together, the distribution of the azobenzene domains may cause some sort of density undulation within the smectic layer. Among the samples, PM6Az presents the strongest undulation with some additional orders. We also examined the annealing effect on the H-aggregation of PMnAzs. It is found that isothermal annealing at a temperature slightly higher than the Tg of PM8Az and PM10Az can significantly enhance the UV absorption at 326 nm, indicating a further development of H-aggregation. However, for PM6Az and PM12Az, the UV–vis spectrum of the annealed sample is nearly identical to that without annealing. 相似文献
60.
A novel monomer containing pyridylazo-2-naphthoxyl group, 1-(1-(4-vinylbenzyloxy)naphthalen-2-yl)-2-(pyridin-2-yl)diazene (VBNPA), was successfully synthesized and copolymerized with styrene (St) in N,N-dimethyl formamide (DMF) via reversible addition–fragmentation chain transfer (RAFT) polymerization using 2-cyanoprop-2-yl-1-dithionaphthalate (CPDN) as RAFT agent. The polymerization behavior exhibited “living”/controlled characters. The obtained copolymer, poly(St-co-VBNPA), with pre-determinable molecular weight and narrow molecular weight distribution can be used as a carrier in metal ion detection and analysis via pre-concentration technique. The copolymer–metal ion (copper (Cu) and europium (Eu)) complexes were prepared and characterized. 相似文献