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排序方式: 共有898条查询结果,搜索用时 46 毫秒
821.
Yuji Nobuta Yuji Yamauchi Tomoaki Hino Satoshi Akamaru Yuji Hatano Masao Matsuyama Satoshi Suzuki Masato Akiba 《Fusion Engineering and Design》2012,87(7-8):1070-1073
Co-deposited carbon film with different deuterium concentration, D/C, were exposed to tritium gas at the temperature of 423 K, and then the atomic ratio of absorbed tritium to carbon, T/C, was evaluated. The obtained data were discussed with crystal structure of the carbon film. The T/C increased with decreasing D/C of carbon film. The carbon film with low D/C had more defective structure. The reduction of D/C by the heating before tritium exposure led to the increase of absorption amount. These results suggest that carbon film with more defective structure and low D/C film could absorb large amount of tritium. The hydrogen isotope concentration in the present experiment was saturated below the orders of 10?4, which was 3–4 orders of magnitude smaller than that of co-deposited carbon film with hydrogen isotope. 相似文献
822.
The conversion of municipal solid wastes (MSW) to energy for co-combustion with coal may be a viable MSW disposal solution from the view point of suppression of the environmental pollution as well as reduction of coal consumption. This paper describes the application of innovative hydrothermal technology on different kinds of MSW to produce powder-like solid products appropriate for co-combustion with coal. In this work, three kinds of surrogated MSW (Japanese MSW, Indian MSW and Chinese MSW) different in composition and characteristics were subjected to the hydrothermal treatment (HT) at 220 °C and 2.4 MPa for 30 min. After the HT, the combustion behaviors of the samples were determined by investigating the sample weight loss (TG) and the rate of weight loss (DTG) through the thermogravimetric analysis (TGA). In addition, the effects of the HT on the characteristics and the combustion behaviors of the MSW were explored by comparing with three standard samples such as rice, cellulose and polypropylene (PP) both before and after the HT. The results obtained in this study can be drawn as the following: The HT is capable for converting MSW into uniform powder samples with low moisture content, regular shapes and high bulk density. During the HT, the hydrolysis reaction leads to the loss in volatile matter and the carbonization results in the gain in fixed carbon. The higher heating values of the three kinds of MSW after the HT are enhanced by 1.01–1.41 times (energy content per weight) and 6.39–9.00 times (energy content per volume). The combustion behaviors of the MSW in this study before the HT were dominated by the substance major in weight whereas for the ones after the HT, the intrinsic characteristics of the MSW can play an important role in determining the combustion behaviors. 相似文献
823.
Tomoaki Namioka Taichi NaruseRyosuke Yamane 《International Journal of Hydrogen Energy》2011,36(9):5581-5588
In order to determine both the criterion for diagnosing the deterioration of Ni/ScSZ cermet anodes in solid oxide fuel cells (SOFCs) by tar contaminants in wood gas and the tolerance limit of tar in wood gas for such anodes, the influence of tar concentration in wood gas on anode deterioration behavior was examined by means of scanning electron microscopy. We found that the anode degradation mechanism consisted of three phenomena: the disappearance of Ni particles, the destruction of sintered ScSZ, and carbon deposition. Furthermore, the Ni particle disappearance occurred at lower tar concentrations than did sintered ScSZ destruction and apparent carbon deposition. Therefore, we propose that the disappearance of Ni particles be set as the criterion for confirming deterioration of Ni/ScSZ cermet anodes in SOFCs by tar. On the basis of this criterion, the tolerance limit of toluene in fuel gas was determined to be 3 g/Nm3 when the operating temperature, steam to carbon molar ratio, and current density were 1073 K, 1, and 0.5 A/cm2, respectively. The tolerance limit for tar for the fuel cell constructed herein was one to two orders of magnitude higher than that for internal combustion engines. 相似文献
824.
Homo- and copolymerizations of 1,5-hexadiene with ethene and styrene using halfsandwich metallocene catalyst Me2Si(Me4Cp)(N-tert.-butyl)TiCl2/MAO (Cp = cyclopentadienyl, Me = methyl, MAO = methylalumoxane) were investigated. According to 13C-NMR spectroscopic microstructure analysis, cyclopolymerization of 1,5-hexadiene afforded randomly distributed cis- and trans-cyclopentane
rings in the homo- and copolymer backbone. 1,5-hexadiene incorporation reached 52 mol-%. The ratio of vinyl side chains to
cyclopentane rings was controlled by 1,5-hexadiene concentration, where low 1,5-hexadiene concentration promoted cyclopolymerization.
Copolymer glass transition temperatures increased with increasing content of cyclic units in the backbone. Styrene was used
successfully as termonomer in ethene/1,5-hexadiene polymerization, resulting in a semicrystalline terpolymer with cyclic and
styrenic units in the polymer backbone.
Received: 5 September 1996/Accepted: 11 November 1996 相似文献
825.
Radiofrequency (RF) catheter ablation of the slow AV nodal pathway was attempted in 34 patients with common type of AV nodal reentrant tachycardia (AVNRT). Radiofrequency energy of 18-32 watts was applied for 30-60 seconds at sites exhibiting atrial-slow pathway potentials or slow potentials. These potentials were recorded at the mid or posterior septum, anterior to the coronary sinus ostium. A mean of two radiofrequency applications successfully eliminated AVNRT in all patients. The incidence of junctional ectopy was significantly higher during 34 effective applications of radiofrequency energy than during 36 ineffective applications (100% versus 17%). Thus, the recording of atrial-slow pathway potentials or slow potentials, and the development of junctional ectopy can be used as a marker for successful ablation. Slow AV nodal conduction was eliminated in 22 patients and persisted without inducible AVNRT in 12. None of the patients had recurrences of AVNRT over a mean follow-up interval of 12 months, and all had preserved AV conduction. Long-term follow-up studies with an electrophysiological method confirmed that the ablation was effective. Transient AV block was observed in only 1 patient, and no major complications were noted. Thus, radiofrequency catheter ablation of the slow AV nodal pathway is highly effective and safe, with a low rate of complication, for the treatment of common type of AVNRT. 相似文献
826.
A technique for forming shallow boron-doped layers for channel doping using preamorphization (channel preamorphization) is described. An extremely shallow boron-doped layer for shallow channel doping has been formed using preamorphization and rapid thermal annealing. Boron peak concentration around the surface is 3.5×1018 cm -3, and the depth at which the boron concentration becomes 10 17 cm-3 is 450 Å. In contrast, the depth is as large as 900 Å for nonpreamorphized samples. It is found that the shallow boron-doped layer formation is made possible because enhanced diffusion arising from ion implantation damage as well as the channeling in boron ion implantation is suppressed by preamorphization. It is also found that preamorphization does not affect MOS capacitor characteristics so long as the amorphous/crystalline interface is sufficiently deep, which allows that channel preamorphization is readily applicable to channel doping in MOSFET fabrication. To substantiate the experimental results, buried-channel p-MOSFETs with a shallow boron counterdoped layer using channel preamorphization have been successfully fabricated. Channel preamorphization did not degrade carrier mobility and improved MOSFET characteristics in the sub-quarter-micrometer-gate-length region suppressing short-channel effects due to the shallower counterdoped boron profile. High-performance 0.2-μm-gate-length p-MOSFETs with good subthreshold characteristics have been fabricated 相似文献
827.
Akiyama H Isuzugawa K Harikai N Watanabe H Iijima K Yamakawa H Mizuguchi Y Yoshikawa R Yamamoto M Sato H Watai M Arakawa F Ogasawara T Nishihara R Kato H Yamauchi A Takahata Y Morimatsu F Mamegoshi S Muraoka S Honjoh T Watanabe T Wakui C Imamura T Toyoda M Maitani T 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2003,44(5):213-219
Inter-laboratory evaluation studies were conducted for the notified ELISA methods for allergic substances (Egg). Standard extracts of egg spiked in extracts of sausage, sauce, cookie, bread and cereal at a level of 5-20 ng/mL as the sample solution were analyzed in replicate in 10 laboratories. Coefficients of variation (CVs) of all three ELISA methods using an Egg Protein ovalbumin ELISA Kit (ovalbumin kit), an Egg Protein ovomucoid ELISA Kit (ovomucoid kit) and a FASTKIT Egg ELISA kit (Egg ELISA kit) were mostly less than 10%. Mean recoveries of the standard extract of egg were over 40% in the three ELISA methods. Repeatability relative standard deviations of egg standard solution in five food extracts were in the ranges of 18.7-25.5%, 18.6-41.8%, 21.3-43.3% for the ovalbumin kit, the ovomucoid kit and the Egg ELISA kit, respectively. Reproducibility relative standard deviations of egg standard solution in five food extracts were 16.8-35.1%, 19.6-35.8%, 24.7-51.1% for the ovalbumin kit, the ovomucoid kit and the Egg ELISA kit, respectively. The detection limits of all the ELISA methods were 4-5 ng/mL in sample solutions. These results suggested that the notified ELISA methods are reliable and reproducible for the inspection of egg protein levels in extracts of sausage, sauce, cookie, bread and cereal. 相似文献
828.
Ryoichi Kurihara Yasushi Seki Shuzo Ueda Isao Aoki Satoshi Nishio Toshio Ajima Tomoaki Kunugi Kazuyuki Takase Michinori Yamauchi Izumi Hosokai Takashi Okazaki Seiichiro Yamazaki 《Journal of Fusion Energy》1997,16(3):225-230
A vacuum vessel (VV) of a tokamak fusion reactor like the International Thermonuclear Experimental Reactor (ITER) consists the first confinement barrier that includes the largest amount of radioactive materials such as tritium and activation products. The ingress of coolant event (ICE) is a design basis event in the ITER where water is used as the coolant. The loss of vacuum event (LOVA) is also considered as an independent design basis event. Based on the results of ICE and LOVA preliminary experiments, an integrated in-vessel thermofluid test is being planned and conceptual design of the facility is in progress. The main objectives of the integrated test are to investigate the consequences of possible interaction of the ICE and the LOVA and to validate the analytical model of thermofluid events in the VV of the fusion reactor. This paper introduces a conceptual design of the integrated test facility and a testing plan. 相似文献
829.
H Okamoto N Takuwa K Gonda H Okazaki K Chang Y Yatomi H Shigematsu Y Takuwa 《Canadian Metallurgical Quarterly》1998,273(42):27104-27110
In Chinese hamster ovary (CHO) cells transiently transfected with an expression vector for EDG1, but not an empty vector, sphingosine-1-phosphate (SP) at a concentration as low as 10(-10) M caused an increase in the intracellular free Ca2+ concentration ([Ca2+]i) as a result of mobilization of Ca2+ from both intracellular and extracellular pools. In a CHO clone stably expressing EDG1 receptor (CHO-EDG1 cells), SP induced increases in the production of inositol phosphates and the [Ca2+]i and inhibited forskolin-induced increase in the cellular cAMP content, all in a manner sensitive to pertussis toxin. SP also activated mitogen-activated protein kinase in CHO-EDG1 cells in pertussis toxin-sensitive and Ras-dependent manners. To evaluate the spectrum of agonists for EDG1, we used human erythroleukemia (HEL) cells, which at naive state do not respond to SP or structurally related lipids with an increase in the [Ca2+]i. In HEL cells stably expressing EDG1 receptor (HEL-EDG1 cells), SP dose-dependently increased the [Ca2+]i with half-maximal and maximal concentration values of 10(-9) and 3 x 10(-7) M, respectively; sphingosylphosphorylcholine at exclusively high concentrations, but not sphingosine at all, also increased the [Ca2+]i. HEL-EDG1 cells bound 32P-labeled SP, which was displaced dose dependently by unlabeled SP. These results indicate that EDG1, a member of the EDG family G protein-coupled receptors, is a specific, high-affinity SP receptor. 相似文献
830.
5-Hydroxytryptophan (5-HTP) is the intermediate metabolite of the essential amino acid L-tryptophan (LT) in the biosynthesis of serotonin. Intestinal absorption of 5-HTP does not require the presence of a transport molecule, and is not affected by the presence of other amino acids; therefore it may be taken with meals without reducing its effectiveness. Unlike LT, 5-HTP cannot be shunted into niacin or protein production. Therapeutic use of 5-HTP bypasses the conversion of LT into 5-HTP by the enzyme tryptophan hydroxylase, which is the rate-limiting step in the synthesis of serotonin. 5-HTP is well absorbed from an oral dose, with about 70 percent ending up in the bloodstream. It easily crosses the blood-brain barrier and effectively increases central nervous system (CNS) synthesis of serotonin. In the CNS, serotonin levels have been implicated in the regulation of sleep, depression, anxiety, aggression, appetite, temperature, sexual behaviour, and pain sensation. Therapeutic administration of 5-HTP has been shown to be effective in treating a wide variety of conditions, including depression, fibromyalgia, binge eating associated with obesity, chronic headaches, and insomnia. 相似文献