全文获取类型
收费全文 | 38篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 5篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
能源动力 | 1篇 |
轻工业 | 15篇 |
一般工业技术 | 6篇 |
冶金工业 | 1篇 |
自动化技术 | 4篇 |
出版年
2022年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2013年 | 6篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2006年 | 2篇 |
2004年 | 2篇 |
2002年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有46条查询结果,搜索用时 93 毫秒
1.
2.
Basic Study on Islanding Detection Method for PV Systems by Harmonic Impedance Detection in Case of Including Induction Motor in Load System 下载免费PDF全文
YOSHIAKI YOSHIDA HIROKAZU SUZUKI KOJI FUJIWARA YOSHIYUKI ISHIHARA 《Electrical Engineering in Japan》2016,194(3):20-34
It is important that photovoltaic (PV) systems detect islanding caused by power system faults to ensure electrical safety. Thus we propose a novel islanding detection method which detects the harmonic impedance by injecting harmonic currents synchronized with the exciting current harmonics of the pole transformer. For the case in which an induction motor load is included in the load system, basic experiments on islanding detection and simulation analysis are conducted to verify the effectiveness of the proposed method. 相似文献
3.
TAKASHI KURIHARA EIJI TSUTSUI EIJI NAKANISHI KIYOSHI MAKI KENICHI MURAKAWA KOJI MORIMOTO TOSHIHIRO TAKAHASHI TATSUKI OKAMOTO 《Electrical Engineering in Japan》2017,198(4):37-50
Dry‐cured and extruded three‐layer (E‐E type) 6.6‐kV cross‐linked polyethylene (XLPE) cables were introduced into electric power systems more than 30 years ago, but they do not experience failures because of water tree degradation. Also, the degradation index of water treeing for these cables has not been established. Therefore, investigating results of residual breakdown voltage and water tree degradation of these cables will help us plan for cable replacement and determine water tree degradation diagnosis scheduling, and will be fundamental data for cable lifetime evaluation. In this study, the authors measured the ac breakdown voltages of dry‐cured and E‐E type 6.6‐kV XLPE cables removed after 18 to 25 years of operation and observed the water trees in their XLPE insulation. As a result, it was observed that breakdown voltages were larger than the maximum operating voltage (6.9 kV) and the ac voltage for the dielectric withstanding test (10.3 kV). Water trees were mainly bow‐tie water trees and their maximum length was approximately 1 mm. Although the number of measured cables was limited, the lifetime of this type of cable was estimated to be approximately 40 years, even experiencing water immersion. 相似文献
4.
To improve the efficiency and fidelity of the numerical analysis for cascade flutter, we propose an efficient scale-resolving simulation method dedicated to time-periodic flows by incorporating the harmonic balance approach into the large-eddy simulation. This method combined convergence calculations of the steady-state problem based on the harmonic balance method for periodic components, and the nonlinear time-marching method for turbulent fluctuations. Using the proposed method, deterministic periodic components and stochastic turbulent fluctuations were calculated simultaneously, and the effect of turbulent fluctuations on deterministic periodic components was directly calculated without using turbulence models. In this paper, we explain the algorithm and feature of this simulation technique and present the results of the computation for channel flow excited in the streamwise direction as an analysis example using the proposed method. In order to validate the proposed method, an analysis of sinusoidally pulsating channel flow at the central friction-velocity Reynolds numbers Rer = 180 was conducted, confirming that the amplitude and phase of the mean velocity oscillation computed by the proposed method were in good agreement with those of the conventional LES. The present calculation achieved an order of magnitude improvement in computational efficiency compared to conventional LES. 相似文献
5.
The reersible association and dissociation of starch chain populations obtained from acid-treated starches (ATSs) was investigated. Potato starch, both nonglutinous and glutinous rice starches and sago starch were suspended in 15% sulfuric acid until 1% hydroysis occured. These ATSs had relative molecular weight ranges of 25,00–29,000 daltons. In water, about half the molecules were reconstituted into large aggregates of a few million daltons. This change in molecular size depended on presence of potassium chloride. It was not observed in debranched samples. The aggregates showed a clear endothermic peak on a DSC curve. Thus, the reversibly rearranging starch chain populations were not linear, but were branched and had some type of ordered structure. 相似文献
6.
春的樱花,夏的萤火,秋的落叶,冬的飘雪。四季的景致在平凡琐碎的生活中悄然划过。时间流转之中的细微美感也在快速厚重的现代化包裹之中渐渐磨失不见。或许大多数的我们选择接受这种方式、调整自己适合如此的生活,但也有人最终还是逆势去找寻内心最渴望的回归。 相似文献
7.
KAZUMARU IIJIMA KOJI SUZUKI KAZUTAKA OZAKI HIDETOSHI KURIYAMA YASUSHI KITAGAWA HIROSHI YAMASHITA 《Journal of food quality》2006,29(5):531-542
To identify food‐associated foreign substances, a DNA analysis consisting of 18S rDNA sequencing and homology search analysis has been developed. In this method, we designed universal primer pairs for specific amplification of animal and plant 18S rDNA and constructed an original DNA database storing partial 18S rDNA sequences of 222 organisms commonly used for culinary purposes. In the model experiments, food materials were successfully identified, indicating that our DNA analysis method can be practically applied to the identification of food‐associated foreign substances. It is also expected that this method complements conventional morphological and compositional analysis, leading to more accurate and reliable identification of food‐associated foreign substances. 相似文献
8.
TAKAHIRO WATANABE HIROSHI AKIYAMA SOHEILA MALEKI HIROHITO YAMAKAWA KEN IIJIMA FUMINORI YAMAZAKI TAKASHI MATSUMOTO SATOSHI FUTO FUMIHIRO ARAKAWA MASATOSHI WATAI TAMIO MAITANI 《Journal of Food Biochemistry》2006,30(2):215-233
A qualitative method for detection of peanuts in foods using polymerase chain reaction was developed. A universal primer pair CP 03‐5′/CP 03‐3′ was designed to confirm the validity of the DNAs for PCR. The plant‐specific amplified fragments were detected from 13 kinds of plants using the universal primer pair. In addition, for the specific detection of peanuts with high sensitivity, the primer pair agg 04‐5′/agg 05‐3′ was designed to detect the gene encoding the peanut agglutinin precursor. The primer pair specifically generates a 95‐bp amplified fragment from peanut genomic DNA. Five hundred femto grams of peanut genomic DNA can be detected using the established method. The same qualitative results were obtained from both model processed and nonprocessed food samples containing 0.001, 0.01 and 0.1% of peanut. Moreover, it was shown that the trace amount of peanut in the commercial food products could be qualitatively detected using this method. The reproducibility and applicability of the proposed methods were verified in a six‐laboratory collaborative study. 相似文献
9.
KOJI AIZAWA SOTA KOBAYASHI HIROSHI ISHIWARA KAZUYUKI SUZUKI KAZUMI KATO 《Integrated ferroelectrics》2013,141(1):169-174
Fabrication and characterization of metal-ferroelectric-insulator-semiconductor field-effect-transistors (MFIS FETs) using (Y,Yb)MnO3/Y2O3/Si structures were introduced for the first time. P-channel MFIS FETs were fabricated on n-type Si(111) substrates, in which an Y0.5Yb0.5MnO3(200 nm)/Y2O3(25 nm) structure was used as gate insulator. The Y0.5Yb0.5MnO3 and Y2O3 films were prepared by chemical solution deposition. A fabricated MFIS FETs showed the hysteresis loop due to spontaneous polarization in the ID-VGS characteristic, in which the memory window was about 0.9V when the applied gate voltage was swept between 8 V and ?8 V. Especially, the alternative drain current was retained after applying a single voltage pulse with a magnitude of +9 V or ?9 V. 相似文献
10.
在基本查明铝合金与不锈钢焊接困难原因的基础上,参考钎料对纯铝等温凝固过程的数值解析以及熔融钎料层消失时间的推定及试验结果,探讨了解决对策.采用电阻炉、TCM10000万能试验机进行了钎焊接头改善及评价试验,以此为依据提出了改善铝合金与不锈钢钎焊性的新焊接方法,即增大钎焊间隙实施钎焊的方法;预先使钎料对不锈钢产生润湿,然后再与铝合金实施钎焊的方法.又采用上述方法进行了其它形状部件的制作,从理论到实践验证了新焊接方法的可行性. 相似文献