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排序方式: 共有454条查询结果,搜索用时 15 毫秒
61.
Haruo Yoshimura Yoshihisa Endo Shigeru Hashimoto 《Journal of the American Oil Chemists' Society》1991,68(8):623-628
Terminal olefins can be converted into the corresponding sulfonates by sulfonation with SO3 followed by hydrolysis, the products are used as detergent ingredients. Although internal olefins were also expected to be
good feed stocks, it was difficult to convert them into the corresponding sulfonates with as good of a yield as that of terminal
olefins under the same synthesis conditions.
Our studies have been carried out in order to clarify the reason for poorer conversion of the internal olefins. It was found
by a nuclear magnetic resonance spectroscopic study that the major components of the sulfonated intermediate of internal olefins
wereβ-sultones, the amounts of which were usually very small in sulfonated terminal olefins. A portion of theseβ-sultones was desulfonated, depending on temperature, to the original olefins and the corresponding sulfate salts during alkaline
hydrolysis. The prevention of desulfonation of theβ-sultones in the hydrolysis process was one of the most important aspects for the production of internal olefin sulfonates.
Finally, by keeping the hydrolysis temperature below 35°C, the conversion of internal olefins into sulfonates was achieved
with the same yield as that of conventional terminal olefins. 相似文献
62.
T Komeno T Itoh Y Shinagawa Y Hattori Y Ohba T Nagasawa T Abe 《Canadian Metallurgical Quarterly》1996,37(6):506-510
The cells of Martinotti are unique neurons of the cerebral cortex with ascending axons. Giovanni Martinotti (1857-1928), professor of anatomic pathology at the University of Bologna, has been claimed to be the discoverer of such cells. Nevertheless, no papers specifically concerning neuroanatomy have been found in his curriculum. The authors have been able to establish that Carlo Martinotti (1859-1918), a pupil of Camillo Golgi (1843-1926) was the legitimate discoverer of the nerve cells carrying his own name. 相似文献
63.
High-performance genetic analysis on microfabricated capillary array electrophoresis plastic chips fabricated by injection molding 总被引:1,自引:0,他引:1
Dang F Tabata O Kurokawa M Ewis AA Zhang L Yamaoka Y Shinohara S Shinohara Y Ishikawa M Baba Y 《Analytical chemistry》2005,77(7):2140-2146
We have developed a novel technique for mass production of microfabricated capillary array electrophoresis (mu-CAE) plastic chips for high-speed, high-throughput genetic analysis. The mu-CAE chips, containing 10 individual separation channels of 50-microm width, 50-microm depth, and a 100-microm lane-to-lane spacing at the detection region and a sacrificial channel network, were fabricated on a poly(methyl methacrylate) substrate by injection molding and then bonded manually using a pressure-sensitive sealing tape within several seconds at room temperature. The conditions for injection molding and bonding were carefully characterized to yield mu-CAE chips with well-defined channel and injection structures. A CCD camera equipped with an image intensifier was used to monitor simultaneously the separation in a 10-channel array with laser-induced fluorescence detection. High-performance electrophoretic separations of phiX174 HaeIII DNA restriction fragments and PCR products related to the human beta-globin gene and SP-B gene (the surfactant protein B) have been demonstrated on mu-CAE plastic chips using a methylcellulose sieving matrix in individual channels. The current work demonstrated greatly simplified the fabrication process as well as a detection scheme for mu-CAE chips and will bring the low-cost mass production and application of mu-CAE plastic chips for genetic analysis. 相似文献
64.
N Ishiguro M Shinagawa S Onoe K Yamanouchi T Saito 《Canadian Metallurgical Quarterly》1998,42(8):579-582
A rapid method to determine the allelic variants of the sheep PrP gene was developed. DNA samples from 128 Suffolk sheep (39 rams and 89 ewes) were screened by using polymerase chain reactions and dot-blot hybridization with 32P-labeled nine allele-specific oligonucleotide probes corresponding to the polymorphic PrP codons 112, 136, 154 and 171. Three allelic variants of the PrP gene, PrP(MARQ), PrP(TARQ) and PrP(MARR), were found in the flocks. Among those variants, nearly half of the ewes had alleles of the 171-Arg variant that is closely associated with resistance to natural scrapie. Assessments of allelic mutations of the PrP gene may help to select the scrapie-resistant progenitors in the flocks. 相似文献
65.
66.
Yoshihisa Kosugi Masato Goto Zhenhong Tan Asaya Fujita Takashi Saito Takashi Kamiyama Wei-Tin Chen Yu-Chun Chuang Hwo-Shuenn Sheu Daisuke Kan Yuichi Shimakawa 《Advanced functional materials》2021,31(25):2009476
Materials which show novel thermal properties can be used to make highly efficient and environmentally friendly energy systems for thermal energy storage and refrigeration through caloric effects. An A-site-ordered quadruple perovskite-structure oxide, NdCu3Fe4O12, is found to release significant latent heat, 25.5 kJ kg−1 (157 J cc−1), at the intersite-charge-transfer transition temperature near room temperature. The transition is first-order and accompanied by an unusual magnetic ordering and a large negative-thermal-expansion-like volume change, and thus, it causes a large entropy change (84.2 J K−1 kg−1). The observed entropy change is comparable to the largest changes reported in inorganic solid materials, and more importantly, it is utilized through a colossal barocaloric effect. The adiabatic temperature change by applying 5.1 kbar pressure is estimated to reach 13.7 K, which means efficient refrigeration can be realized through this effect. 相似文献
67.
Hiroki Tanji Ryo Tanaka Takahiro Murakami Yoshihisa Ishida 《Signal, Image and Video Processing》2016,10(6):1105-1112
In this paper, we propose a nonparametric Bayesian model combined with the Indian buffet process (IBP) for a finite impulse response (FIR) system. We develop an FIR system identification method that can simultaneously estimate the number of FIR taps and coefficients. In the proposed model, each FIR tap consists of a coefficient and a gain, and the gain is a binary value. An infinite-dimensional binary vector is composed of binary values, and we assume that this binary vector is generated by the IBP. To identify the FIR system, we specify the likelihood function and prior distributions of the parameters and derive their posterior distributions. We can simultaneously estimate the number of FIR taps and coefficients by sampling from posterior distributions using the Gibbs sampler. Our simulations demonstrate that although the number of FIR taps is unknown, the identification performance of the proposed method in a high signal-to-noise ratio environment is similar to or better than that of the conventional least square solution. 相似文献
68.
Fujisaki S Fujisaki Y Ishiwara H 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2007,54(12):2592-2594
Characteristics of metal-ferroelectrics-metal (MFM) capacitors and meta -ferroelectrics-insulator-semiconductor (MFIS) diodes with poly(vinylidene fluoridetrifluoroethylene) [P(VDF-TrFE)] copolymer films thinner than 100 nm were investigated. The films were prepared by spin cast process and were annealed at 140 degrees C in air for crystallization. The ferroelectric properties are equivalent to those of oxide ferroelectrics, even under low voltage or high frequency operation. 相似文献
69.
Sugihara T Tsuji Y Sakai K 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(1):18-24
A recent physiological finding of neural coding for border ownership (BO) that defines the direction of a figure with respect to the border has provided a possible basis for figure-ground segregation. To explore the underlying neural mechanisms of BO, we investigated stimulus configurations that activate BO circuitry through psychophysical investigation of the BO-dependent tilt aftereffect (BO-TAE). Specifically, we examined robustness of the border ownership signal by determining whether the BO-TAE is observed when gestalt factors are broken. The results showed significant BO-TAEs even when a global shape was not explicitly given due to the ambiguity of the contour, suggesting a contour-independent mechanism for BO coding. 相似文献
70.
By using the characteristics of a hydrogen-absorbing alloy, the hydrogen produced by catalytic dehydrogenation of saturated
compounds can be absorbed to form metal hydrides, and, vice versa, the resulting metal hydrides are able to hydrogenate efficiently
unsaturated compounds upon dehydriding. Gas-phase reactions between 2-butene and 2-propanol on a hydrogen-absorbing alloy
CaNi5 have been studied in the temperature range of 393–473 K. CaNi5 showed interesting characteristics as an active catalyst for the catalytic transfer hydrogenation of butene from propanol
as a hydrogen donor. 2-propanol was effectively dehydrogenated at 423 K to yield acetone in which the dissociated hydrogen
was completely absorbed by CaNi5 to form the metal hydride. When the alloy was hydrided to some extent, butene was hydrogenated by the absorbed hydrogen in
the metal hydride to produce butane. The overall reaction on CaNi5 was expressed as catalytic transfer hydrogenation of 2-butene from 2-propanol through intermediate formation of metal hydrides,
rather than the direct reaction between butene and propanol on the alloy. Thus, CaNi5 effectively repeated hydriding–dehydriding cycles: hydriding of CaNi5 by 2-propanol dehydrogenation with subsequent dehydriding for the hydrogenation of 2-butene. The use of hydrogen-absorbing
CaNi5 provides a novel reaction system for the catalytic transfer hydrogenation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献