全文获取类型
收费全文 | 232篇 |
免费 | 5篇 |
专业分类
电工技术 | 13篇 |
综合类 | 1篇 |
化学工业 | 34篇 |
金属工艺 | 4篇 |
机械仪表 | 3篇 |
建筑科学 | 1篇 |
能源动力 | 7篇 |
轻工业 | 18篇 |
无线电 | 30篇 |
一般工业技术 | 30篇 |
冶金工业 | 78篇 |
原子能技术 | 3篇 |
自动化技术 | 15篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1998年 | 27篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1973年 | 4篇 |
1971年 | 1篇 |
排序方式: 共有237条查询结果,搜索用时 0 毫秒
61.
Mohammed A. Khuddus Yutaka Usui Daniel Swern 《Journal of the American Oil Chemists' Society》1973,50(12):524-528
A mixture of isomeric 9,10,12,13-tetrahydroxystearic acids (threo, threo, threo andthreo, erythro, threo) can be prepared fromanti-cis, cis-9,10,12,13-diepoxystearic acid in over 80% yield by way of the intermediate di(hydroxy-alkoxysulfonium) salts and in ca.
68% yield by way of the intermediate di(hydroxy-formate) esters obtained by acid-catalyzed epoxide ring opening with dimethyl
sulfoxide and formic acid, respectively. Mechanisms and stereochemistry of formation of the two isomers are discussed. Factors
that influence the formation of cyclic products in competition with tetrahydroxystearic acids also are described. The key
to the greatly improved yield of tetrahydroxystearic acids over prior literature procedures is avoiding water during ring
opening of the protonated epoxide, as even small quantities of water cause marked reduction in yields of tetrahydroxystearic
acids.
Presented in part at the AOCS Meeting, Ottawa, September 1972. 相似文献
62.
63.
64.
The authors have proposed that a counter-rotating type tidal stream power unit mounted rigidly on a pile, and outputs of the power unit and forces acting on the pile were investigated experimentally at a previous paper, A single propeller makes the pile undertake a reaction force orthogonal to the stream direction. On the contrary, proposed counter-rotating propellers do not require undertaking the reaction force of the pile, because the rotational torque is counter-balanced in the unit. This advantage means that the unit can be moored by only one cable. Continuously, this paper proposes such a power unit with tandem propellers, and experimentally investigates a behavior of the unit floating in a water channel. The vibrations of the power unit are induced from not only the individual but also the interacting rotations of the front and the rear propellers. 相似文献
65.
A 41-year-old male with myelomenigocele underwent a bladder auto-augmentation and endoscopic collagen injections. He has been performing self intermittent catheterization for 10 years but urinary incontinence remained unchanged. Furthermore, he suffered from recurrent pyelonephritis due to the left vesicoureteral reflux. A preoperative fluoroscopic urodynamic study showed a poorly compliant bladder with the maximal bladder capacity of 200 ml at 60 cmH2O. The left vesicoureteral reflux was observed at 10 cmH2O. The low compliant bladder was treated with the bladder autoaugmentation and the left vesicoureteral reflux was treated with the endoscopic subureteral injection of collagen 5 months after the previous operation. A fluoroscopic urodynamic study 6 months postoperatively showed the increase of the maximal bladder capacity of 300 ml at 18 cmH2O and the reflux disappeared completely. The endoscopic periurethral injections of collagen improved his persisting urinary incontinence. In patient with neurogenic bladder having a lot of clinical problems, bladder auto-augmentation is less invasive and offers many advantages over enterocystoplasy. 相似文献
66.
G Tanaka M Shigeta H Komatsuzawa M Sugai H Suginaka T Usui 《Canadian Metallurgical Quarterly》1999,45(1):28-36
The combined effects of meal cost and food flavor on meal size were studied with a method that avoided the covariation of nutrient composition and caloric density with palatability. As rats (Rattus norvegicus) drank flavored fluids (unpalatable 0.05% sucrose octaacetate [SOA], neutral 0.05% saccharin, and palatable 2% Polycose + 0.2% saccharin [P + S]), liquid diet was infused intragastrically. Relative to saccharin, rats with free access ate 10% more calories in larger meals while consuming P + S and initially ate fewer calories in smaller but more frequent meals while drinking SOA. Other rats lever-pressed to begin meals, which halved meal number and doubled meal size relative to the free-access group. Although foraging rats also ate larger P + S meals and smaller SOA meals, the changes did not affect total intake. Without the usual differential postingestive effects of foods that differ in palatability, making food more costly blunts rats' response to its flavor. 相似文献
67.
This paper presents a position sensorless drive of salient‐pole PM synchronous motors in all speed ranges including zero speed. Two position and speed estimation algorithms using the current differences between the actual and the estimated currents are proposed. One is based on the back emf estimation in the medium‐ and high‐speed ranges. Another is based on the position dependency of the winding inductances in the low‐speed ranges including zero speed. The effectiveness of the proposed algorithm has been verified with a six‐pole, 1.5‐kW, 1500‐rpm test motor. Stable sensorless speed control from zero to 3000 rpm within ±100% load torque range was achieved. © 2001 Scripta Technica, Electr Eng Jpn, 135(3): 64–73, 2001 相似文献
68.
69.
Mohamed Elbadawy Yuki Kato Nagisa Saito Kimika Hayashi Amira Abugomaa Mio Kobayashi Toshinori Yoshida Makoto Shibutani Masahiro Kaneda Hideyuki Yamawaki Tetsuya Mizutani Chang-Kweng Lim Masayuki Saijo Kazuaki Sasaki Tatsuya Usui Tsutomu Omatsu 《International journal of molecular sciences》2021,22(19)
Various pathogens, such as Ebola virus, Marburg virus, Nipah virus, Hendra virus, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2, are threatening human health worldwide. The natural hosts of these pathogens are thought to be bats. The rousette bat, a megabat, is thought to be a natural reservoir of filoviruses, including Ebola and Marburg viruses. Additionally, the rousette bat showed a transient infection in the experimental inoculation of SARS-CoV-2. In the current study, we established and characterized intestinal organoids from Leschenault’s rousette, Rousettus leschenaultii. The established organoids successfully recapitulated the characteristics of intestinal epithelial structure and morphology, and the appropriate supplements necessary for long-term stable culture were identified. The organoid showed susceptibility to Pteropine orthoreovirus (PRV) but not to SARS-CoV-2 in experimental inoculation. This is the first report of the establishment of an expandable organoid culture system of the rousette bat intestinal organoid and its sensitivity to bat-associated viruses, PRV and SARS-CoV-2. This organoid is a useful tool for the elucidation of tolerance mechanisms of the emerging rousette bat-associated viruses such as Ebola and Marburg virus. 相似文献
70.
In this study, we perform experiments and analyses to examine the warpage of Al/AlN layered structures connected by direct brazing. Al/AlN layered structures are considered under the high temperature fluctuations that occur in the brazing and baking processes. Three Al thicknesses are considered, using A3003 (JIS code) Al to clarify the variations in warpage. For the inelastic analysis, two types of constitutive model are used for Al: a non-linear kinematic hardening model considering cyclic hardening, viscoplasticity, and creep, and a conventional isotropic hardening model. Then, it is shown that the warpage in both brazing and baking processes can be simulated well using the kinematic hardening model. 相似文献