全文获取类型
收费全文 | 170篇 |
免费 | 15篇 |
专业分类
电工技术 | 24篇 |
综合类 | 1篇 |
化学工业 | 62篇 |
金属工艺 | 5篇 |
机械仪表 | 7篇 |
建筑科学 | 1篇 |
能源动力 | 9篇 |
轻工业 | 9篇 |
石油天然气 | 1篇 |
无线电 | 13篇 |
一般工业技术 | 30篇 |
冶金工业 | 3篇 |
原子能技术 | 3篇 |
自动化技术 | 17篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 14篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 26篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 16篇 |
2012年 | 10篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 2篇 |
1997年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
排序方式: 共有185条查询结果,搜索用时 15 毫秒
41.
Yuki Ito Takuya Araki Shota Shiga Hiroyuki Konno Koki Makabe 《International journal of molecular sciences》2022,23(2)
Top7 is a de novo designed protein whose amino acid sequence has no evolutional trace. Such a property makes Top7 a suitable scaffold for studying the pure nature of protein and protein engineering applications. To use Top7 as an engineering scaffold, we initially attempted structure determination and found that crystals of our construct, which lacked the terminal hexahistidine tag, showed weak diffraction in X-ray structure determination. Thus, we decided to introduce surface residue mutations to facilitate crystal structure determination. The resulting surface mutants, Top7sm1 and Top7sm2, crystallized easily and diffracted to the resolution around 1.7 Å. Despite the improved data, we could not finalize the structures due to high R values. Although we could not identify the origin of the high R values of the surface mutants, we found that all the structures shared common packing architecture with consecutive intermolecular β-sheet formation aligned in one direction. Thus, we mutated the intermolecular interface to disrupt the intermolecular β-sheet formation, expecting to form a new crystal packing. The resulting mutant, Top7sm2-I68R, formed new crystal packing interactions as intended and diffracted to the resolution of 1.4 Å. The surface mutations contributed to crystal packing and high resolution. We finalized the structure model with the R/Rfree values of 0.20/0.24. Top7sm2-I68R can be a useful model protein due to its convenient structure determination. 相似文献
42.
Shota Nemoto Shinsuke Ohnuki Fumiyoshi Abe Yoshikazu Ohya 《Yeast (Chichester, England)》2019,36(2):85-97
Reduction of gravity results in changes in gene expression and morphology in the budding yeast Saccharomyces cerevisiae. We studied the genes responsible for the morphological changes induced by simulated microgravity (SMG) using the yeast morphology data. We comprehensively captured the features of the morphological changes in yeast cells cultured in SMG with CalMorph, a high-throughput image-processing system. Statistical analysis revealed that 95 of 501 morphological traits were significantly affected, which included changes in bud direction, the ratio of daughter to mother cell size, the random daughter cell shape, the large mother cell size, bright nuclei in the M phase, and the decrease in angle between two nuclei. We identified downregulated genes that impacted the morphological changes in conditions of SMG by focusing on each of the morphological features individually. Gene Ontology (GO)-enrichment analysis indicated that morphological changes under conditions of SMG were caused by cooperative downregulation of 103 genes annotated to six GO terms, which included cytoplasmic ribonucleoprotein granule, RNA elongation, mitotic cell cycle phase transition, nucleocytoplasmic transport, protein–DNA complex subunit organization, and RNA localization. P-body formation was also promoted under conditions of SMG. These results suggest that cooperative downregulation of multiple genes occurs in conditions of SMG. 相似文献
43.
The effects of surface texturing on spherical silicon solar cells were investigated. Surface texturing for spherical Si solar cells was prepared by immersing p-type spherical Si crystals in KOH solution with stirring. Two kinds of texture feature sizes (1 and 5μm pyramids) were prepared by changing stirring speed. After fabrication through our baseline processes, these cells were evaluated by solar cell performance and external quantum efficiency. The cell with 1 and 5μm pyramids shows the short circuit current density ( Jsc ) value of 31.9 and 33.2 mA·cm-2 , which is 9% and 13% relative increase compared to the cell without texturing. Furthermore, the cell with 5 μm pyramids has a higher open-circuit voltage (0.589 V) than the cell with 1 μm pyramids (0.577 V). As a result, the conversion efficiency was improved from 11.4% for the cell without texturing to 12.1% for the cell with 5 μm pyramids. 相似文献
44.
A new microcellular foam injection‐molding technology using non‐supercritical fluid physical blowing agents
下载免费PDF全文
![点击此处可从《Polymer Engineering and Science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Atsushi Yusa Satoshi Yamamoto Hideto Goto Hiromasa Uezono Fumiya Asaoka Long Wang Megumi Ando Shota Ishihara Masahiro Ohshima 《Polymer Engineering and Science》2017,57(1):105-113
A new foam injection‐molding technology was developed to produce microcellular foams without using supercritical fluid (SCF) pump units. In this technology, physical blowing agents (PBA), such as nitrogen (N2) and carbon dioxide (CO2), do not need to be brought to their SCF state. PBAs are delivered directly from their gas cylinders into the molten polymer through an injector valve, which can be controlled by a specially designed screw configuration and operation sequence. The excess PBA is discharged from the molten polymer through a venting vessel. Alternatively, additional PBA is introduced through the venting vessel when the polymer is not saturated with PBA. The amount of gas delivered into the molten polymer is controlled by the gas dosing time of the injector valve, the secondary reducing pressure of the gas cylinder and the outlet (back) pressure of the venting vessel. Microcellular polypropylene foams were prepared using the developed foam injection‐molding technology with 2–6 MPa CO2 or 2–8 MPa N2. High expansion foams with an average cell size of less than 25 μm were prepared. The developed technology dispels arguments for the necessity to pressurize N2 or CO2 to the SCF to prepare microcellular foams. POLYM. ENG. SCI., 57:105–113, 2017. © 2016 Society of Plastics Engineers 相似文献
45.
Shota Shiga Prof. Masaru Yamanaka Wataru Fujiwara Prof. Shun Hirota Prof. Shuichiro Goda Prof. Koki Makabe 《Chembiochem : a European journal of chemical biology》2019,20(19):2454-2457
During domain swapping, proteins mutually interconvert structural elements to form a di-/oligomer. Engineering this process by design is important for creating a higher order protein assembly with minimal modification. Herein, a simple design strategy is shown for domain-swapping formation by loop deletion and insertion of a polyproline rod. Crystal structures revealed the formation of the domain-swapped dimers and polyproline portion formed a polyproline II (PPII) structure. Small-angle X-ray scattering demonstrated that an extended orientation of domain-swapped dimer was retained in solution. It is found that a multiple of three of inserting proline residue is favored for domain swapping because of the helical nature of PPII. The rigid nature of the polyproline rod enables precise control of the interdomain distance and orientation. 相似文献
46.
Mukaiyama Koki Arao Susumu Matsui Shota Nakagawa Masao Hirogaki Toshiki Aoyama Eiichi 《Forschung im Ingenieurwesen》2019,83(3):445-459
Forschung im Ingenieurwesen - Hypoid gears are widely used in automobile differentials. Furthermore, it is well known that the efficiency of hypoid gears is lower than that of other gears due to... 相似文献
47.
This paper provides a new concept based on the Damköhler number (Da) to describe the complete transition behavior found in a flame spread in a solid combustible tube. Through a series of experiments performed with various diameters of the tube, ambient pressure, and oxidizer velocity within a wide range, three combustion modes are observed for the flame spread in a solid fuel tube namely combustion dominated by heat transfer (mode 1), by chemical kinetics (mode 2), and slow combustion sustained under very high blowing conditions (so-called “stabilized combustion”: mode 3). Previous studies on the flame spread in tubes have shown that each transition, from mode 1 to mode 2 (transition 1–2) and from mode 2 to mode 3 (transition 2–3), is characterized by an equivalent velocity and by a friction velocity respectively. Meanwhile, for a flame spread on a fuel plate, it is widely known that both transitions are summarized by the Da. To achieve a comprehensive understanding of the transition characteristics of the combustion modes for the flame spread in the tube, the flame-spread rates under various conditions are experimentally investigated to elucidate the parameters that determine both transitions. First, the authors introduce a laminar friction velocity for the laminar flow region and revealed that transition 2–3 is determined by the laminar and turbulent friction velocity for laminar flow and turbulent flow regime respectively. The correlation between the Da and the friction velocity was experimentally obtained to show that transition 2–3 is consequently determined by the Da. This finding suggests that transition 2–3 corresponds to a blow-off limit that is observed for flame spread on a fuel plate. Second, the same correlation between the non-dimensional flame-spread rate and the Da is obtained, and it clearly showed that the transition 1–2 was determined by the Da. In conclusion, both transition phenomena are physically identical to those observed for on-plate flame spread, except the transition 2–3 occurs instead of the blow-off. 相似文献
48.
49.
A method of selecting the circuit parameters of a self-commutated rectifier circuit which aims at improving the power factor is proposed. 相似文献
50.
Kataoka Teruo Mizumachi Kazuhiro Miyairi Shota 《Industry Applications, IEEE Transactions on》1979,(6):670-675
As a method for improving power factor and waveform of ac line current drawn by an ac-to-dc converter a new pulsewidth controlled converter is proposed, its commutation mechanism is described, and experimental results are given which show a good power factor, a good waveform of the line current, and a wide adjustable range of dc output voltage. 相似文献