全文获取类型
收费全文 | 185篇 |
免费 | 12篇 |
学科分类
工业技术 | 197篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 15篇 |
2011年 | 14篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2008年 | 12篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 4篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1978年 | 2篇 |
排序方式: 共有197条查询结果,搜索用时 31 毫秒
101.
Yasuhiro Matsumoto Takashi Aoki Yukihiko Tamura Shinji Ibuka Koichi Yasuoka Shozo Ishii Masashi Yura Naohiro Shimizu 《Electrical Engineering in Japan》2004,147(1):10-16
Turn‐on characteristics of semiconductor power devices are evaluated under external magnetic field to study the effects of external magnetic field generated in a pulsed power circuit. Two pin diodes that have a basic structure of power devices are connected in parallel and driven by a pulsed voltage source. It was found the magnetic field applied to one diode in the perpendicular direction of current‐flow changed the current balance between the diodes. Besides the on‐resistance of a diode was increased under external magnetic field. The carrier‐density distribution inside of the diodes was measured by using a free carrier absorption method. The data show that the carrier‐density distribution changes from nearly the uniform one to the one‐sided one. It can be concluded that the effects of magnetic‐field have to be considered for the evaluation of switching characteristic in pulsed power operations. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 10–16, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10271 相似文献
102.
Akinori Kuzuya Dr. Mayumi Kimura Kentaro Numajiri Naohiro Koshi Toshiyuki Ohnishi Fuminori Okada Makoto Komiyama Prof. Dr. 《Chembiochem : a European journal of chemical biology》2009,10(11):1811-1815
A new punched DNA origami assembly with periodic nanometer‐scale wells has been successfully designed and constructed. Through the attachment of two biotins at the two edges of each well, just one streptavidin (SA) tetramer (d=5 nm) was size‐selectively captured in each 6.8×12×2.0 nm well; this allowed formation of a 28 nm‐period SA nanoarray of individual molecules. The position of SA capture can be fully controlled by placement of biotins in the nanoarray well. Moreover, construction of a 2D nanoarray of individual SA tetramers through selective positioning of SA tetramers in any desired wells in a complex of such punched origami motifs is also possible. The stability of the SA captured by this fixation strategy (DNA wells and two biotin linkers) was directly compared on the same molecule with the stability of SA captured with other possible strategies that do not employ wells or two linkers. In this way, the robustness of this means of fixation was clearly established. 相似文献
103.
Ryoji Takahashi Satoshi Sato Toshiaki Sodesawa Kei Suzuki Masamoto Tafu Kazuki Nakanishi Naohiro Soga 《Journal of the American Ceramic Society》2001,84(9):1968-1976
Phase separation in a sol–gel process of SiO2 –ZrO2 in the presence of polyethylene oxide is investigated. An amorphous gel with interconnected macroporous morphology is obtained when phase separation and sol–gel transition concur to fix a transitional structure of spinodal decomposition. Macropore size, together with connectivity of the pores and gel skeleton, can be controlled precisely by selecting an appropriate starting composition for preparation at a zirconium content ≤11.7 mol%. The macroporous gel retains additional mesopores <4 nm and exhibits typical bimodal pore size distribution. The addition of ZrO2 in SiO2 improves the thermal stability of both macroporous and mesoporous structures. 相似文献
104.
Shin'ichi Mitsumoto Masayuki Nagao Masumi Fukuma Naohiro Hozumi 《Electrical Engineering in Japan》2003,142(3):1-7
This paper deals with the effects of acetophenone coating on dielectric properties such as tan δ and capacitance and on space charge formation up to electrical breakdown under AC voltage application in low‐density polyethylene (LDPE) film. The existence of acetophenone at the electrical interface enhances tan δ. tan δ in acetophenone‐coated specimens increased with electric field and decreased with the frequency in the high‐field and high‐temperature region. AC breakdown test revealed that the electric strength in noncoated specimens was higher than in acetophenone‐coated specimens, and that the electric strength also decreased with temperature. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 1–7, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.10086 相似文献
105.
为提高磁力研磨法光整异形波导管内凹槽底面的研磨效率和研磨效果,解决其难光整问题,采用正交试验法研究钢珠直径、加工间隙、磁极盘转速3个主要工艺参数对表面粗糙度降低率ΔRa的影响,并采用极差分析和方差分析法对工艺参数进行分析和优化。试验确定的最佳工艺参数组合是钢珠直径为1.0 mm,加工间隙为1 mm,磁极盘转速为800 r/min。采用最佳工艺参数对试样进行研磨抛光,加工30 min后试样表面的大量突起被去除,表面粗糙度值Ra从初始的11.059 μm降至1.513 μm,粗糙度降低率ΔRa达到最大值86.3%,试样的表面质量得到有效改善。 相似文献
106.
Synthetic small molecules for epigenetic activation of pluripotency genes in mouse embryonic fibroblasts 总被引:1,自引:0,他引:1
107.
Itoh M Takemon Y Makabe A Yoshimizu C Kohzu A Ohte N Tumurskh D Tayasu I Yoshida N Nagata T 《The Science of the total environment》2011,409(8):1530-1538
The Tuul River, which provides water for the daily needs of many residents of Ulaanbaatar, Mongolia, has been increasingly polluted by wastewater from the city's sewage treatment plant. Information on water movement and the transformation of water-borne materials is required to alleviate the deterioration of water quality. We conducted a synoptic survey of general water movement, water quality including inorganic nitrogen concentrations, and isotopic composition of nitrogen (δ15N-NO3−, δ18O-NO3−, and δ15N-NH4+) and water (δ18O-H2O) in a wetland area that receives wastewater before it enters the Tuul River. We sampled surface water, groundwater, and spring water along the two major water routes in the wetland that flow from the drain of the sewage treatment plant to the Tuul River: a continuous tributary and a discontinuous tributary. The continuous tributary had high ammonium (NH4+) concentrations and nearly stable δ15N-NH4+, δ15N-NO3−, and δ18O-NO3− concentrations throughout its length, indicating that nitrogen transformation (i.e., nitrification and denitrification) during transit was small. In contrast, NH4+ concentrations decreased along the discontinuous tributary and nitrate (NO3−) concentrations were low at many points. Values of δ15N-NH4+, δ15N-NO3−, and δ18O-NO3− increased with flow along the discontinuous route. Our results indicate that nitrification and denitrification contribute to nitrogen removal in the wetland area along the discontinuous tributary with slow water transport. Differences in hydrological pathways and the velocity of wastewater transport through the wetland area greatly affect the extent of nitrogen removal. 相似文献
108.
Naohiro Nishimura Zesen Lin Kazuya Jinnai Ryota Kabe Chihaya Adachi 《Advanced functional materials》2020,30(22)
Organic long‐persistent luminescence (OLPL) is a long‐lasting luminescence from a photogenerated intermediated state, such as a charge separated state. Here, it is shown that many exciplex systems exhibit OLPL and that emission pathways of OLPL can be controlled by the relationship among local excited states and charge‐transfer excited states of materials. 相似文献
109.
Abstract This paper investigates the thermal behavior of woody biomass waste—demolition wood of Japanese cedar (Cryptomeria japonica) and insect-attacked forest residue of Japanese red pine (Pinus densiflora)—using proximate analyses, thermogravimetry (TG), and differential thermal analysis (DTA), with comparison to virgin wood. For the pine samples, there was no significant difference in thermal behavior or elemental composition between the virgin pine and pine that had been damaged by insects, indicating that insect-damaged pine received here can be treated as virgin pine in terms of energy utilization. The cedar demolition wood used here was partly degraded by termites or fungi. Its degraded part had a lower weight loss rate under nitrogen and a broader exothermic peak in the char combustion stage under air than cedar virgin wood. The changes in the relative levels of the chemical components and the resultant chemical changes that occur upon fungal degradation might complicate char formation. 相似文献
110.
Prayoga SURYADARMA Yoshihiro OJIMA Yuto FUKUDA Naohiro AKAMATSU Masahito TAYA 《Frontiers of Chemical Science and Engineering》2012,6(2):152
The role of Escherichia coli rpoS on the central carbon metabolism was investigated through analyzing the deficiency of this regulon gene under aerobic and glucose-enriched culture conditions. The experimental results showed that while the wild type cells exhibited an overflow metabolism effect, the rpoS -deleting mutation alleviated this effect with the significant suppression of acetate accumulation under a high glucose condition. This gene deletion also induced the twofold upregulation of gltA and one-tenth downregulation of poxB , respectively. The overflow metabolism effect was confirmed to be recovered by re-introducing rpoS gene into the mutant. These results demonstrated rpoS changed the central carbon metabolism toward acetate overflow through dehydrogenation of pyruvate and reduction of TCA cycle activity. 相似文献