全文获取类型
收费全文 | 130篇 |
免费 | 4篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 54篇 |
金属工艺 | 2篇 |
建筑科学 | 4篇 |
能源动力 | 2篇 |
轻工业 | 6篇 |
水利工程 | 1篇 |
无线电 | 6篇 |
一般工业技术 | 32篇 |
冶金工业 | 11篇 |
原子能技术 | 3篇 |
自动化技术 | 6篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 11篇 |
2010年 | 12篇 |
2009年 | 4篇 |
2008年 | 8篇 |
2007年 | 10篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有134条查询结果,搜索用时 31 毫秒
21.
Rei Sonobe Yuta Miura Tomohito Sano Hideki Horie 《International journal of remote sensing》2018,39(5):1306-1320
Quantifying carotenoid contents has many applications in agriculture, ecology, and health science. Hyperspectral reflectance has been one of the promising tools for this purpose. However, previous studies were based on measurements under relatively low light–stress conditions. Therefore, assessing its robustness by using measurements under various levels of stress is required. In this study, the measurements of reflectance and carotenoid contents were carried out with four shading treatments including open–0%, 35%, 75%, and 90% shading to generate various chlorophyll/carotenoid ratios. Then the performances of 15 published hyperspectral indices and PROSPECT–D inversion were evaluated based on our data set for estimating leaf carotenoid contents. According to the ratio of performance to deviation, RNIR/R510, R720/R521–1, and PROSPECT–D inversion were applicable for this purpose, although calibration of the absorption coefficients was required for PROSPECT–D. Using them, root mean square percentage errors of 4.53–5.46% were achieved. Given that total chlorophyll/carotenoid ratios could be a good indicator for evaluating environmental stress in plants, PROSPECT–D, which also estimates total chlorophyll and anthocyanin contents, could be a strong tool for controlling the qualities of shade-grown tea. 相似文献
22.
Tomohito Hamazaki Eisuke Takazakura Kenzo Osawa Masaharu Urakaze Saburo Yano 《Lipids》1990,25(9):541-545
Eicosapentaenoic acid (EPA) ethyl ester (1.8 g/d) was administered to 16 diabetic patients (5 insulin-dependent and 11 noninsulin-dependent
diabetics) for 6 mon. EPA in total plasma fatty acids increased from 4.0±2.4 mol% (mean±SD) to 7.5±3.1 mol% (p<0.001). Albumin
excretion, measured with spot urine, was significantly reduced from 65 to 36 mg/g creatinine (geometric means, p<0.001). Fasting
blood sugar levels, glycohemoglobin, body weight and blood pressure did not change significantly during the study. There were
also no significant changes in serum levels of creatinine, urea nitrogen, total cholesterol and triglycerides. Although no
overt hemorrhage was observed in the patients, hematocrit was reduced from 42.6±2.8% to 41.0±3.9% (p<0.02). Ten other similar
diabetic patients (4 insulin-dependent and 6 non-insulin-dependent diabetics) were followed as a reference group, not concomitantly,
for 6 mon with neither EPA ethyl ester nor placebo. The parameters mentioned above were not changed significantly in this
group during 6 mon. EPA administration might retard the appearance of overt diabetic nephropathy. 相似文献
23.
The performance of a commercially available enzyme-linked immunosorbent assay (ELISA) kit containing highly sensitive monoclonal antibodies against fenitrothion was assessed. The experimentally estimated dynamic range (0.087 to 2 ng/g) agreed with that established by the kit manufacturer (0.075 to 1 ng/g). The linearity of the standard curve produced for the kit-assembled standard solutions (slope = -0.3829) agreed with that of the curve produced for the self-made standard solutions (slope = -0.3619). The sensitivity (I50 value) and the limit of detection for the kit were 0.23 and 0.033 ng/g, respectively. Selectivity of the ELISA indicates that the monoclonal antibody can readily distinguish the target pesticide from other structurally related analogs and some metabolites (oxon forms), with the exception of ethyl O-(p-nitrophenyl) phenyl phosphonothionate (EPN), parathion-methyl, and parathion. Methanol was the best organic solvent for the kit, with optimal sensitivity observed at a final concentration in the well of 10% (vol/vol) or less. Matrix interferences were minimized by direct dilution with water (60-fold) of the methanolic extracts fromapple and peach samples. To extract fenitrothion from these two agricultural products as simply and rapidly as possible, three extraction methods were used. The extraction method that involved shaking by hand for 3 min was the best among the three methods. High recovery percentages (116.6% for apple and 110.8% for peach) were obtained. Validation of the ELISA method was carried out using the gas chromatography-mass spectrometry method, resulting in high recovery and close correlation of results (r > 0.95). These findings strongly suggest that the ELISA kit may be routinely employed for on-site fenitrothion screening of fruit samples. 相似文献
24.
In this study, we utilized Mg-Al layered double hydroxide (Mg-Al LDH) modified by intercalation with three aromatic sulfonates—2,7-naphthalene disulfonate (2,7-NDS2−), benzenesulfonate (BS−), and benzenedisulfonate (BDS2−)—for the uptake of two aromatics—1,3-dinitrobenzene (DNB) and anisole (AS)—from aqueous solution and determined the effect of the aromatic sulfonates on the uptake of these aromatics. We found that the electron-rich aromatic ring of the intercalated aromatic sulfonates such as 2,7-NDS2− undergoes strong π-π stacking interactions with the electron-poorer benzene ring of DNB in aqueous solution, and these interactions result in a higher uptake of DNB by the modified Mg-Al LDHs. In contrast, the electron-poor aromatic ring of the aromatic sulfonates such as BDS2− undergoes weak π-π stacking interactions with the electron-poorer benzene ring of DNB, and these interactions result in a lower uptake of DNB by the modified Mg-Al LDHs. 相似文献
25.
Y. Arimoto T. Oki Y. Takubo T. Itahashi N. Miyamoto M. Yoshida 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(2):200-208
The PRISM-FFAG ring, which consists of 10 scaling-radial-sector magnets, has been designed to store muons with large emittance and momentum spread. The FFAG magnets differ from conventional dipole magnets in that they have a magnetic field that varies strongly with radius and the vertical direction of the magnetic field alternates. Each magnet is composed of three sets of coils to produce a defocussing (outward bending)-focussing-defocussing triplet. After careful design, the PRISM-FFAG magnets were constructed and magnetic field measurements were made. The field maps in the fiducial volume show satisfactory agreement with the design fields based on OPERA 3D/TOSCA calculations. 相似文献
26.
Abe K Nakamura K Arao T Sakurai Y Nakano A Suginuma C Tawarada K Sasaki K 《Journal of the science of food and agriculture》2011,91(8):1392-1397
BACKGROUND: A simple and quick on‐site test for trace levels of cadmium (Cd) in food is needed because of the human toxicity of this heavy metal. We developed an immunochromatography kit which uses the antigen‐antibody complex reaction between the Cd–ethylenediaminetetraacetic acid (Cd–EDTA) complex and an anti‐Cd–EDTA antibody. We previously reported the successful use of this kit to determine Cd concentrations in brown rice with respect to the international standard: 0.4 mg kg?1. Here, we measured, using this immunochromatography kit, Cd concentrations in crops with lower international standards than rice. RESULTS: Cadmium extracted with 0.1 mol L?1 HCl from wheat grain and fresh eggplant was purified sufficiently using an ion‐exchange column treatment. Appropriate HCl extraction rates and dilution rates for the column eluate were selected; Cd concentrations in wheat grain and fresh eggplant were determined successfully by immunochromatography with respect to the international standards of 0.2 mg kg?1 and 0.05 mg kg?1 fresh weight, respectively. CONCLUSION: Approximate Cd concentrations in wheat grain and fresh eggplant can be monitored easily and quickly by this method at locations where facilities for acid digestion and precision analysis are not available. Copyright © 2011 Society of Chemical Industry 相似文献
27.
Katsuya Akiyama Haeyang PakYoji Takubo Toshiya TadaYasuaki Ueki Ryo YoshiieIchiro Naruse 《Fuel Processing Technology》2011,92(7):1355-1361
Ash with a low melting point causes slagging and fouling problems in pulverized coal combustion boilers. Ash deposition on heat exchanger tubes reduces the overall heat transfer coefficient due to its low thermal conductivity. The purpose of this study is to evaluate the ash deposition for Upgraded Brown Coal (UBC) and bituminous coal in a 145 MW practical coal combustion boiler. The UBC stands for Upgraded Brown Coal. The melting temperature of UBC ash is relatively lower than that of bituminous coal ashes. Combustion tests were conducted on blended coal consisting 20 wt.% of UBC and 80 wt.% of bituminous coal. Before actual ash deposition tests, the molten slag fractions in those coal ashes were estimated by means of chemical equilibrium calculations. The calculation results showed the molten slag fraction for UBC ash reached approximately 90% at 1523 K. However, that for blended coal ash decreased to 50%. These calculation results mean that blending UBC with bituminous coal played a role in decreasing the molten slag fraction. This phenomenon occurred because the coal blending led to the formation of alumino-silicates compounds as a solid phase. Next, ash deposition tests were conducted using a practical pulverized coal combustion boiler. A water-cooled stainless-steel tube was inserted in locations at both 1523 K and 1273 K in the boiler to measure the amount of ash deposits. The results showed that the mass of ash deposition for blended coal did not greatly increase, compared with that for bituminous coal alone. Therefore, appropriately blending UBC with bituminous coal enabled the use of UBC without any ash deposition problems in practical boilers. 相似文献
28.
Tomohito Kameda Masahiko Ono Guido Grause Tadaaki Mizoguchi Toshiaki Yoshioka 《Journal of Polymer Research》2011,18(5):945-947
Poly(vinyl chloride) (PVC) modified in different solvents by nucleophilic substitution with thiocyanate was exposed to Gram-negative
bacteria of the strain Staphylococcus capitis. All modified pieces reduced the adhesion of bacteria by between 67 and 79%. More important for the bacteria suppression
than the substitution rate was the ratio between thiocyanate and isothiocyanate groups. The best result was obtained with
PVC modified in tetrahydrofuran/dimethylsulfoxide, containing only antibacterial active isothiocyanate groups, while inactive
thiocyanate groups were absent. 相似文献
29.
Thermal and electrical conduction properties of vertically aligned carbon nanotubes produced by water-assisted chemical vapor deposition 总被引:1,自引:0,他引:1
Atsuto Okamoto Itaru Gunjishima Takashi Inoue Megumi Akoshima Hidenori Miyagawa Tomohito Nakano Tetsuya Baba Masaki Tanemura Gendo Oomi 《Carbon》2011,(1):294-298
We present both thermal and electrical conduction properties of vertically aligned carbon nanotubes (VACNTs), synthesized by the water-assisted chemical vapor deposition method using Fe–Ti–O nanoparticles as catalyst. Thermal diffusivity and electrical resistance of VACNTs have been measured by the laser flash method and direct-current four-terminal method, respectively. The VACNTs are found to have thermal diffusivities of the same order as isotropic graphite and the electrical characteristics of semiconductors. The electrical resistance shows a T−1/4 temperature dependence, which implies that the conduction of electrons is dominated by 3D Mott variable range hopping. 相似文献
30.
Alumina (sapphire) is considered as a candidate material for bio-ceramics, because of its superior strength characteristics, corrosion resistance and bio-inert properties. These biomaterials are used in aggressive corrosive environments such as the human body under severe mechanical conditions superposing cyclic loading on constant load. Therefore, it is necessary to evaluate the static and cyclic fatigue characteristics in an environment as severe as the human body. In this paper, the effects of human body environment corrosion upon cyclic fatigue characteristics of single crystal sapphire and polycrystalline alumina have been investigated using in vitro testing in isotonic sodium chloride solution, whose composition is closely similar to body fluid. Also, degraded corrosion morphologies and fracture surfaces of single crystal sapphire specimens were examined in detail by SEM and AFM. The fatigue limit of single crystal sapphire was found to be extremely degraded in the isotonic sodium chloride solution compared with that in air. The importance of environment assisted slip deformation is indicated. 相似文献