全文获取类型
收费全文 | 1233篇 |
免费 | 63篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 38篇 |
综合类 | 2篇 |
化学工业 | 349篇 |
金属工艺 | 33篇 |
机械仪表 | 35篇 |
建筑科学 | 25篇 |
矿业工程 | 1篇 |
能源动力 | 41篇 |
轻工业 | 86篇 |
石油天然气 | 2篇 |
无线电 | 76篇 |
一般工业技术 | 307篇 |
冶金工业 | 126篇 |
原子能技术 | 26篇 |
自动化技术 | 154篇 |
出版年
2024年 | 3篇 |
2023年 | 25篇 |
2022年 | 20篇 |
2021年 | 65篇 |
2020年 | 30篇 |
2019年 | 35篇 |
2018年 | 32篇 |
2017年 | 49篇 |
2016年 | 46篇 |
2015年 | 33篇 |
2014年 | 51篇 |
2013年 | 95篇 |
2012年 | 78篇 |
2011年 | 89篇 |
2010年 | 91篇 |
2009年 | 79篇 |
2008年 | 58篇 |
2007年 | 41篇 |
2006年 | 44篇 |
2005年 | 35篇 |
2004年 | 19篇 |
2003年 | 22篇 |
2002年 | 11篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 21篇 |
1998年 | 37篇 |
1997年 | 29篇 |
1996年 | 26篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 2篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1301条查询结果,搜索用时 15 毫秒
1.
Sawao Honda Shinobu Hashimoto Benoît Nait-Ali David S. Smith Yusuke Daiko Yuji Iwamoto 《Journal of the American Ceramic Society》2022,105(10):6335-6344
Porous alumina with a highly textured microstructure was fabricated by pulse electric current sintering (PECS) using alumina platelets. Highly oriented porous alumina with a porosity of 3%–50% was obtained by a pressure-controlled method of PECS. The properties of the highly textured porous alumina were measured in two directions. The nitrogen gas permeance and thermal conductivity at room temperature were higher in the direction along the platelet length due to the higher continuity of pores and the connectivity of alumina platelets, respectively. The anisotropy of the thermal conductivity at room temperature was investigated and explained by the effect of grain size of platelets as well as morphology and orientation of pores. The bending strength was higher with the loading direction along the platelet thickness. The thermal shock strength was clearly different in the two directions. The difference in the thermal shock strength was investigated by the measurement of properties and thermal stress analysis. 相似文献
2.
3.
4.
Keita Ikeue Shingo Ando Tomohiro Mitsuyama Yusuke Ohta Keishi Arayama Akiko Tsutsumi Masato Machida 《Topics in Catalysis》2008,47(3-4):175-180
Lanthanide-based oxysulfides and sulfide, LnTaO3.5S0.5, Ln10OS14 (Ln = La, Pr, Nd, Sm) and La4In5S13, were successively synthesized by sulfurization in a flowing H2S. The sulfurization decreased the band-gap energies from >4 eV to <3eV, because of the formation of occupied S3p orbitals
on the top of valence band. In accordance with the small band gap, the H2 evolution from a 0.01 M Na2S and 0.01 M Na2SO3 solution system was observed under irradiation of light up to >500 nm. The rate of H2 evolution under light irradiation of >500 nm increased in the order of Ni/LaTaO3.5S0.5 < Ru/La10OS14 < Pt/La4In5S13. 相似文献
5.
K Kamigiri T Tokunaga T Sugawara K Nagai M Shibazaki B Setiawan RM Rantiatmodjo M Morioka K Suzuki 《Canadian Metallurgical Quarterly》1997,50(7):556-561
Two new types of macrolide antibiotics, YM-32890 A and B, have been isolated from the fermentation broth of cytophaga sp. YL-02905S. In this paper, the taxonomy of the producing strain, fermentation, isolation, structure elucidation, and biological activity of the antibiotics are reported. YM-32890 A inhibits the growth of staphylococci including a macrolide-resistant strain, but shows no antimicrobial activity against other Gram-positive, Gram-negative bacteria and yeast. 相似文献
6.
J Arikawa M Tokunaga Y Tashiro S Tanaka E Sato K Haraguchi A Yamamoto O Toyohira A Tsuchimochi 《Canadian Metallurgical Quarterly》1997,47(10):730-734
Epstein-Barr virus (EBV) has been implicated as a causal virus of gastric cancer with episomal monoclonality, elevated antibodies and a unique morphologic expression in the early intramucosal stage, but the infection mechanisms have not been demonstrated. EBV has been shown only in the cancerous lesions by the highly sensitive EBV-encoded small RNA in situ hybridization (EBER-ISH) method, not in the dysplastic mucosa adjacent to the cancer. A case is presented of multiple EBV-positive gastric cancer and dysplastic epithelium observed in a 52-year-old man. Serial cut sections of the gastrectomy specimen showed four small cancerous lesions, three of which were EBER-positive, and three EBER-positive, minute, non-cancerous dysplastic lesions. The three cancerous lesions were intramucosal cancer, with one having minimal submucosal invasion forming a lymphoepithelioma-like histology. All of these EBER-positive cancerous and dysplastic lesions showed intense CD8 T-lymphocytic infiltration. There was no such findings in the EBV-negative cancerous lesion. It was concluded that EBV infection may occur in the epithelial cells of atrophic gastric mucosa, and progress to cancer with monoclonal expansion through the EBV-positive dysplastic change. Cytotoxic T-lymphocytic reactions can occur even in the dysplastic lesions. Multifocal EBV infection in the gastric mucosa may occur and, if necessary, total gastrectomy is recommended in such a case. 相似文献
7.
Y Asano Y Tokunaga Y Inoue H Gondo T Miyamoto Y Niho 《Canadian Metallurgical Quarterly》1998,39(6):460-462
We report on a case of adenovirus hemorrhagi cystitis that developed in a 49-year-old woman during intensive chemotherapy for adult T-cell leukemia. Although rapid etiologic diagnosis is essential for the effective management of viral hemorrhagic cystitis, the isolation of adenovirus from urine is often too time-cousuming. We detected the adenovirus antigen in the patient's urine using an Adenoclone direct sandwich ELISA kit (Cambridge Bio Science), which is commonly employed for the diagnosis of adenovirus conjunctivitis. Treatment consisted of intravenous vidarabine and bladder irrigation, which resulted in prompt clinical improvement. The Adenoclone kit was useful for the rapid etiologic diagnosis of adenovirus hemmorrhagic cystitis. 相似文献
8.
Y Shioda S Koizumi S Furuya S Akira N Kameyama N Hamano W Takahashi A Tokunaga N Tanaka M Onda 《Canadian Metallurgical Quarterly》1993,23(6):556-561
Respiratory infections are the most common infection in children. They differ remarkably according to age, bacteria and viruses. Therefore a careful history of outbreak, age, former infections, involvement of surroundings, symptoms, etc are essential. The present study included 50 children, aged between 0.3 and 12 yrs, all treated ambulatorily. 21 received brodimoprim (B) and 29 erythromycin (E). Indications were: tonsillitis, bronchitis, otitis media, sinusitis and scarlet fever. Dosages were: B was given 10 mg/kg body weight (b.w.) initially followed by 5 mg/kg b.w., once-a-day. The duration of treatment varied between 4 and 14 days (mean 8.3 days). E was given 30.50 mg/kg b.w. 3 times per day; duration 4 to 14 days (mean 8.6 days). Overall results were: in group B:12 cures, 5 improvements, 3 failures; 1 not assessable. In group E: 20 cures, 8 improvements, 1 failure. Side effects: in group B: vomiting (1), skin reaction (2), discontinuation (2); in group E: skin reaction (1), diarrhea (5), diarrhea+vomiting (1); discontinuation (2). The differences in efficacy and tolerability in the two groups are not statistically significant. The improved compliance with a single versus t.i.d. dosages has to be taken into account. 相似文献
9.
Matsuo N. Matsui H. Tokunaga Y. 《Selected Areas in Communications, IEEE Journal on》1991,9(4):548-554
People faced with an unfamiliar product or service tend to fall back on mental models based on analogical relationships with familiar products or services. Two experiments on the analogical relationships or metaphors that people might use when operating a communications terminal are described. In the first experiment, the role previously acquired operating knowledge has in determining the mental models people use when directory dialing with novel equipment is examined. In a second experiment, it is shown that an explicit appeal to an analogy between conventional mail and electronic mail can help users learn to use an electronic mail system, and make it easier for them to remember how to use the system as long as 90 days after initial exposure. It is concluded that the mental model is constructed only from the user's operating knowledge acquired as a result of past experiences, and the metaphor method is effective when the instructions are metaphorically taught 相似文献
10.
T Dumrese S Stevanovi? FH Seeger N Yamada Y Ishikawa K Tokunaga M Takiguchi H Rammensee 《Canadian Metallurgical Quarterly》1998,48(5):350-353
BACKGROUND: Fiberoptic flexible sigmoidoscopy (FFS) is routinely requested preoperatively as part of evaluation of pelvic masses to exclude colonic involvement by the tumor or concurrent colonic neoplasm. The aim of our study was to evaluate the utility of preoperative FFS in patients with suspected gynecologic malignancy. METHODS: FFS, performed using a 60 cm sigmoidoscope, evaluated (1) presence of bowel involvement by the tumor, (2) extrinsic compression by the tumor, and (3) presence of colonic neoplasms. FFS findings were correlated with surgical findings. RESULTS: A total of 107 women underwent preoperative FFS and subsequent surgery. Eleven patients (11%) had lower gastrointestinal symptoms. At surgery, 63% of pelvic tumors were malignant and 37% were benign. The most common abnormality at FFS was colonic polyps in 23 patients (21%). Colonic adenomas were found in 11 patients (10%). Extrinsic compression by the tumor without mucosal abnormalities was seen in 15 patients (14%). The most common intraoperative finding was tumor adhering to the bowel in 18 patients requiring dissection, but only 1 patient required bowel resection. Eight of these 18 patients had preoperative lower gastrointestinal symptoms. All 15 patients with extrinsic compression at FFS had tumor adhering to the bowel. CONCLUSIONS: Pelvic masses cause extrinsic compression at FFS in 14% of patients. This is suggestive of tumor adherent to the bowel at surgery. However, bowel resection is rarely required because of tumor involvement. Most patients with bowel adherence by tumor have lower gastrointestinal symptoms. Colonic adenomas are found in one tenth of patients, mostly in patients older than 50 years of age. Preoperative FFS does not change the surgical management of pelvic tumors. Screening FFS is indicated in all patients with pelvic tumors over age 50, as in persons with average risk, but is otherwise unnecessary in evaluation of pelvic masses. 相似文献