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91.
Yuichi Sawai Yuji Iwamoto Sachiko Okuzaki Yoshiyuki Yasutomi Koichi Kikuta Shin-ichi Hirano 《Journal of the American Ceramic Society》1999,82(8):2121-2125
A chemically modified polycarbosilane (PC) containing organofluoric groups (PCOCF) has been synthesized from PC and fluoroalkylmethyldimethoxysilane. PCOCF acts as an efficient compaction binder for SiC powders and as a coating material with excellent oxidation resistance in wet air. PCOCF-coated SiC powders also show excellent packing properties because of the organofluoric side chains, which give highly dense green compacts. PCOCF provides a high ceramic yield of 75% and highly dense SiC ceramics. Four-point bending strength increases and the scatter in strength values decreases significantly by PCOCF coating. 相似文献
92.
Teruo Matsushita Shin-ichi Inoue Ryusuke Tanaka 《Journal of the American Oil Chemists' Society》2010,87(9):963-972
A method for the determination of the total lipid content in fish meat was established using a 2-thiobarbituric acid (TBA) reaction, which had previously been used for the determination of lipid peroxides in animal tissues. In this method, an unspecific peroxidation of fish oils was created by omitting the addition of antioxidant to the reaction mixture during the TBA reaction, because fish meat is more sensitive to the TBA reaction due to its higher concentration of polyunsaturated fatty acids, especially docosahexaenoic acid and eicosapentaenoic acid, which can easily react artificially with TBA in the absence of an antioxidant in the assay system. As for a practical application of this method, we tried to optimize the assay procedures in the sampling, reaction, and detection steps of this method, and finally proposed a new standard procedure recommended for determining the total lipid content of fish using a TBA reaction. In order to confirm the accuracy of the new procedure, comparative evaluations for the lipid contents of commercially available fish, i.e., chub mackerel (Scomber japonicus) and saury (Cololabis saira) were made between the conventional procedure and the recommended TBA method. The lipid contents obtained by the two methods coincided well with high correlation. This method is relevant for total lipid content analysis of fish meat under restricted laboratory conditions. 相似文献
93.
94.
Yu-Wei Wang Shin-ichi Sasaki Taojun Zhuang Hitoshi Tamiaki Jian-Ping Zhang Toshitaka Ikeuchi Ziruo Hong Junji Kido Xiao-Feng Wang 《Organic Electronics》2013,14(8):1972-1979
Two ambipolar chlorophyll derivatives, namely, 32,32-dicyano-pyropheophorbide-a (Chl-1) and methyl 131-deoxo-131-(dicyanomethylene) pyropheophorbide-a (Chl-2), were synthesized for use as either the electron acceptor or the electron donor in organic planar-heterojunction solar cells. Despite the higher electron mobilities of these chlorophyll derivatives compared with their hole mobilities, devices using them as the electron donor with fullerene C70 give much better photovoltaic performance than when they are used as the electron acceptor with copper phthalocyanine. In these Chl-based solar cells, the energy gap between the LUMO levels of the donor and acceptor molecules substantially affects the charge separation and resultant photocurrent and photovoltaic performance. The highest solar energy-to-electricity conversion efficiency of up to 2.3% has been achieved using the Chl-2/C70 solar cell, under AM1.5 solar illumination (100 mW/cm2) after thermal annealing of the device. It was also confirmed that the electron mobility of blend films containing Chls and fullerene derivative PC70BM was determined not only by the electron mobility of PC70BM but also by that of Chls. 相似文献
95.
Shin-ichi Yasueda Masayo Higashiyama Masazumi Yamaguchi Akiharu Isowaki Akira Ohtori 《Drug development and industrial pharmacy》2013,39(8):805-811
The cornea is a solid barrier against drug permeation. We searched the critical barrier of corneal drug permeation using a hydrophobic drug, dexamethasone (DM), and a hydrophilic drug, lomefloxacin hydrochloride (LFLX). The activation energies for permeability of DM and LFLX across the intact cornea were 88.0 and 42.1 kJ/mol, respectively. Their activation energies for permeability across the cornea without epithelium decreased to 33.1 and 16.6 kJ/mol, respectively. The results show that epithelium is the critical barrier on the cornea against the permeation of a hydrophobic drug of DM as well as a hydrophilic drug of LFLX. The activation energy of partition for DM (66.8 kJ/mol) was approximately 3-fold larger than that of diffusion (21.2 kJ/mol). The results indicate that the partition for the hydrophobic drug of DM to the corneal epithelium is the primary barrier. Thermodynamic evaluation of activation energy for the drug permeation parameters is a good approch to investigate the mechanism of drug permeability. 相似文献
96.
Satoshi Sakauchi Makoto Hattori Tadashi Yoshida Takahiro Yagishita Koichi Ito Shin-ichi Akemitsu Koji Takahashi 《Journal of food science》2010,75(2):C177-C183
ABSTRACT: The particular effect of 4 kinds of amino acid and peptide-rich food material (APRM) containing different charged amino acid contents on the gelatinization and retrogradation behavior of potato starch granules and on the water-vaporization behavior was analyzed by differential scanning calorimetry, rapid viscoanalysis, x-ray diffractometry, thermal gravimetry-differential thermal analysis, and pulsed NMR. APRM with a high-charged amino acid content produced unique gelatinization and retrogradation behavior in terms of an elevated gelatinization temperature, reduced viscosity, higher setback, and lower retrograded starch melting enthalpy. The recovered x-ray diffraction intensity decreased with increasing charged amino acid content. APRM with high-charged amino acid content could provide an improved paste having easy vaporization of external water in the swollen starch granules due to the reduced swelling. 相似文献
97.
Shin-ichi Ito Tadashi Kasuya Junya Inoue 《Science and Technology of Advanced Materials》2013,14(1):857-868
We propose a method to predict grain growth based on data assimilation by using a four-dimensional variational method (4DVar). When implemented on a multi-phase-field model, the proposed method allows us to calculate the predicted grain structures and uncertainties in them that depend on the quality and quantity of the observational data. We confirm through numerical tests involving synthetic data that the proposed method correctly reproduces the true phase-field assumed in advance. Furthermore, it successfully quantifies uncertainties in the predicted grain structures, where such uncertainty quantifications provide valuable information to optimize the experimental design. 相似文献
98.
Ariga K Nakanishi T Kawanami S Kosaka T Kikuchi J 《Journal of nanoscience and nanotechnology》2006,6(6):1718-1730
In this research, we synthesized six kinds of oligopeptide-carrying lipids which possessing glycine, diglycine, triglycine, alanine, dialanine, and trialanine residues (see Figure 1 for their formulae), and systematically investigated their phase transition behaviors both at the air-water interface and in aqueous bilayer vesicles. pi-A Isotherms of Langmuir monolayers of these lipids were measured at the air-water interfaces under varied temperature conditions and were analyzed based on compressibility of the monolayers. Above the specific temperature, the transition pressure from its expanded phase to condensed phase is not distinguishable with the collapse pressure of the monolayer, i.e., the monolayer collapses directly from the expanded phase without forming the condensed phase. This temperature was defined as the phase transition temperature of the monolayer, which was compared with the phase transition temperature of the corresponding bilayer vesicle in water. The phase transition temperatures of the oligoglycine-carrying lipids and oligoalanine-carrying lipids are significantly different at the air-water interface, while the corresponding difference is not obvious in their aqueous bilayer vesicles. Consideration based on molecular structures suggests necessity of the water mediation for effective formation of hydrogen bonding between the oligopeptide residues directly connected to dialkyl chains. Therefore, the differences in water accessibility to the films may cause the difference of the phase transition behaviors of the oligopeptide-carrying lipids between the Langmuir monolayers and the aqueous bilayer vesicles. Although the proposed mechanism is not fully supported by experimental evidences, the data presented here clearly demonstrated the presence of significant difference of the phase transition properties between the Langmuir monolayers at the air-water interface and aqueous bilayer vesicles of the oligopeptide-carrying lipids. 相似文献
99.
Conventional multi-zonal ventilation measurement methods by multiple types of perfluorocarbon tracers use a number of different gases equal to the number of zones (n). The possible n×n+n airflows are estimated from the mass balance of the gases and the airflow balance. However, some airflows may not occur because of inter-zonal geometry, and the introduction of unnecessary, unknown parameters can impair the accuracy of the estimation. Also, various error factors often yield an irrational negative airflow rate. Conventional methods are insufficient for the evaluation of error. This study describes a way of using the least-squares technique to improve the precision of estimation and to evaluate reliability. From the equations’ residual, the error variance–covariance matrix Λq of the estimated airflow rate error is deduced. In addition, the coefficient of determinant using the residual sum of squares and total variation is introduced. Furthermore, the error matrix mΛq from the measurement errors in the gas concentration and gas emission rate is deduced. The discrepancy ratio of the model premises is defined by dividing the diagonal elements of the former by those of the latter. Moreover, the index of irrationality of the estimated negative airflow rate is defined, based on the different results of the three estimation methods. Some numerical experiments are also carried out to verify the flow rate estimation and the reliability evaluation theory. 相似文献
100.
Yoshihiko Arao Okudoi Yukie Jun Koyanagi Shin-ichi Takeda Hiroyuki Kawada 《Mechanics of Time-Dependent Materials》2012,16(2):169-180
A simple method for obtaining viscoelastic parameters from the results of static tensile tests is presented herein. Viscoelastic
parameters were obtained by fitting experimental results and calculated results based on the power law model and linear viscoelasticity.
The static tensile tests were carried out at various pre-aging times and the effect of physical aging was determined. The
data confirmed that the physical aging process has a significant effect on the viscoelastic behavior. A creep test was conducted
in order to discuss the validity of the prediction using the results of the static tensile test. It was confirmed that the
predictions based on the viscoelastic parameters obtained from static tensile tests cannot adequately model actual viscoelastic
behavior. The effective time theory was incorporated into the prediction in order to account for the progress of physical
aging. It was verified that incorporating effective time theory into the prediction allows for the precise prediction of the
long-term viscoelastic behavior. 相似文献