全文获取类型
收费全文 | 713篇 |
免费 | 22篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 30篇 |
化学工业 | 176篇 |
金属工艺 | 35篇 |
机械仪表 | 17篇 |
建筑科学 | 9篇 |
能源动力 | 15篇 |
轻工业 | 47篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 39篇 |
一般工业技术 | 166篇 |
冶金工业 | 132篇 |
原子能技术 | 18篇 |
自动化技术 | 51篇 |
出版年
2022年 | 6篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 15篇 |
2017年 | 17篇 |
2016年 | 17篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 58篇 |
2012年 | 25篇 |
2011年 | 43篇 |
2010年 | 29篇 |
2009年 | 39篇 |
2008年 | 31篇 |
2007年 | 32篇 |
2006年 | 23篇 |
2005年 | 17篇 |
2004年 | 18篇 |
2003年 | 25篇 |
2002年 | 26篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 18篇 |
1998年 | 44篇 |
1997年 | 33篇 |
1996年 | 15篇 |
1995年 | 23篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有738条查询结果,搜索用时 15 毫秒
31.
D Ili? EA Almeida DD Schlaepfer P Dazin S Aizawa CH Damsky 《Canadian Metallurgical Quarterly》1998,143(2):547-560
In many malignant cells, both the anchorage requirement for survival and the function of the p53 tumor suppressor gene are subverted. These effects are consistent with the hypothesis that survival signals from extracellular matrix (ECM) suppress a p53-regulated cell death pathway. We report that survival signals from fibronectin are transduced by the focal adhesion kinase (FAK). If FAK or the correct ECM is absent, cells enter apoptosis through a p53-dependent pathway activated by protein kinase C lambda/iota and cytosolic phospholipase A2. This pathway is suppressible by dominant-negative p53 and Bcl2 but not CrmA. Upon inactivation of p53, cells survive even if they lack matrix signals or FAK. This is the first report that p53 monitors survival signals from ECM/FAK in anchorage- dependent cells. 相似文献
32.
S Suehara K Yamamoto S Hishita T Aizawa S Inoue A Nukui 《Canadian Metallurgical Quarterly》1995,51(21):14919-14922
33.
Kawata M Uchida H Itatani K Okada I Koda S Aizawa M 《Journal of materials science. Materials in medicine》2004,15(7):817-823
Porous hydroxyapatite (HAp) ceramics possessing well-controlled porosities and pore sizes were developed by firing apatite-fiber compacts mixed with carbon beads and agar. The total porosities could be controlled in the range from 40 to 85% by varying compaction pressure (20-40 MPa), firing temperature (1000-1300 degrees C) and carbon/HAp ratio (0/10-10/10 (w/w)). Most of the pores were regarded as open pores. The pore sizes were mainly affected by the carbon-bead diameter (5, 20 or 150 microm) and partly by the compaction pressure and the firing temperature. The pore sizes of the porous HAp ceramics derived from the carbon beads of 150 microm in diameter were distributed in the two separate ranges of several micrometers and more than 100 microm. 相似文献
34.
Awane T Kimura T Nishida K Ishikawa N Tanuma S Nakamura M 《Analytical chemistry》2003,75(15):3831-3836
Grazing exit electron probe microanalysis (GE-EPMA) is a new method of EPMA in which characteristic X-rays emitted from only near-surface regions of a specimen are detected at extremely low exit angles near 0 degrees (the grazing exit condition). This technique requires the analytical objects exist on a flat surface. Therefore, the GE-EPMA analysis has been used only for the analysis of particles or a thin film on a flat substrate so that there were only few applications for practical analysis. As a new application, we have carried out GE-EPMA analysis of approximately 0.2-microm inclusions on stainless steel, which appeared to be a projection on the specimen surface with chemical etching. The GE-EPMA quantitative results were in excellent agreement with those of inclusions that were extracted from the stainless steel and analyzed by EPMA with conventional exit condition (30 degrees). This method could be, therefore, applied to the analysis of the submicrometer inclusion in a wide variety of metallic materials if the inclusion appears to be a projection with chemical etching treatment. 相似文献
35.
Park JW Kurosawa S Aizawa H Han DS Yoshimoto M Nakamura C Miyake J Chang SM 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2003,50(2):193-195
We present conventional detection of 2,4-dinitrophenol (DNP) for using the competitive reaction between DNP and DNP-conjugated albumin onto DNP antibody immobilized quartz crystal microbalance (QCM). This QCM method allows detection of DNP concentration in the range of 0.01 to 100 ng/ml; linear correlation obtains DNP concentration from 1 to 100 ng/ml. 相似文献
36.
Aizawa T 《Applied optics》2001,40(27):4894-4903
The in situ quantitative profiles of temperature and OH radical concentration in a postflame region of methane-air premixed counterflow flames were measured by wavelength modulation spectroscopy with a 1.5-mum external cavity diode laser. The second harmonic (2f) signal was generated from absorption by overtone vibrational-rotational transitions of OH: the ?(3/2) (v?, v?) = (2, 0) P11.5e (nu(0) = 6421.35 cm(-1)) or the ?(3/2) (v?, v?) = (3, 1) P5.5f (nu(0) = 6434.61 cm(-1)) transitions. The absorption occurred in the postflame region between methane-air premixed twin flames stabilized in a two-dimensional laminar counterflow burner (Tsuji burner) with a 60-mm line-of-sight path length. The temperature and OH concentration profiles at an equivalence ratio of phi = 0.85 were determined by least-squares fitting of theoretical 2f line shapes to the experimental counterparts and by calculation of the ratio of the line intensities of the two different OH transitions (two-line thermometry). The measured temperature and OH concentration profiles were cross checked by Rayleigh scattering thermometry, thermocouple measurements, and two-dimensional numerical prediction of premixed combustion by use of a detailed chemical kinetic mechanism. The measurements and the prediction showed reasonable agreement. 相似文献
37.
Xiujun Gong Kensuke Nakamura Hua Yu Kei Yura Nobuhiro Go 《IEEE transactions on information technology in biomedicine》2007,11(4):428-434
The emerging grid computing technologies enable bioinformatics scientists to conduct their researches in a virtual laboratory, in which they share public databases, computational tools as well as their analysis workflows. However, the development of grid applications is still a nightmare for general bioinformatics scientists, due to the lack of grid programming environments, standards and high-level services. Here, we present a system, which we named Bioinformatics: Ask Any Questions (BAAQ), to automate this development procedure as much as possible. BAAQ allows scientists to store and manage remote biological data and programs, to build analysis workflows that integrate these resources seamlessly, and to discover knowledge from available resources. This paper addresses two issues in building grid applications in bioinformatics: how to smoothly compose an analysis workflow using heterogeneous resources and how to efficiently discover and re-use available resources in the grid community. Correspondingly an intelligent grid programming environment and an active solution recommendation service are proposed. Finally, we present a case study applying BAAQ to a bioinformatics problem. 相似文献
38.
Toru Katsumata Hiromi Kubo Shuji Komuro Hiroaki Aizawa 《Journal of the American Ceramic Society》2014,97(6):1704-1707
Photoluminescence spectrum, trap depths, and densities of trapped carriers of CaAl2O4:Eu phosphor crystals doped with rare‐earth elements were studied using the thermally stimulated luminescence technique. Trap depths and densities of the specimens vary with rare‐earth elements doped as the auxiliary activators. Tm and Nd are found to be effective for the strong afterglow phosphorescence peaking at λ = 442 nm for several hours after the excitation. CaAl2O4:Eu phosphor crystals doped with Nd and Tm include high density of carriers trapped at E = 0.59 and 0.52 eV, respectively. 相似文献
39.
Nobuhiro Kuramoto 《Coloration Technology》1987,103(9):318-321
The effect of some added antioxidants on the photodegradation of C.I. Solvent Yellow 33 (quinophthalone) and C.I. Direct Red 39 in cellulose acetate films have been investigated. The effects varied according to antioxidant type. For example, the addition of 2, 6-di-t-butyl-4-methylphenol, an effective radical scavenger, afforded little protection against photodegradation, while singlet oxygen quenching of antioxidants such as nickel bis(dithiobenzil), nickel dialkyldithiocarbamate, nickel bis(mesitylenesulphonate) conferred improved resistance of the dyes towards photodegradation. 相似文献
40.
Nobuhiro Iwasa Tomoyuki Mayanagi Noriaki Ogawa Kentaro Sakata Nobutsune Takezawa 《Catalysis Letters》1998,54(3):119-123
Pd and Pt supported on ZnO, Ga2O3 and In2O3 exhibit high catalytic performance for the steam reforming of methanol, CH3OH+H2OCO2+3HH2, and the dehydrogenation of methanol to HCOOCH3, 2CH3OHHCOOCH3+2HH2. Combined results with temperature-programmed reduction (TPR) and XRD method revealed that Pd–Zn, Pd–Ga, Pd–In, Pt–Zn, Pt–Ga and Pt–In alloys were produced upon reduction. Over the catalysts having the alloy phase, the reactions proceeded selectively, whereas the catalysts having metallic phase exhibited poor selectivities. 相似文献