全文获取类型
收费全文 | 1475篇 |
免费 | 51篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 1527篇 |
出版年
2023年 | 7篇 |
2022年 | 33篇 |
2021年 | 56篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 42篇 |
2017年 | 19篇 |
2016年 | 38篇 |
2015年 | 34篇 |
2014年 | 56篇 |
2013年 | 108篇 |
2012年 | 59篇 |
2011年 | 93篇 |
2010年 | 73篇 |
2009年 | 97篇 |
2008年 | 68篇 |
2007年 | 72篇 |
2006年 | 59篇 |
2005年 | 47篇 |
2004年 | 40篇 |
2003年 | 40篇 |
2002年 | 34篇 |
2001年 | 25篇 |
2000年 | 27篇 |
1999年 | 30篇 |
1998年 | 35篇 |
1997年 | 26篇 |
1996年 | 18篇 |
1995年 | 22篇 |
1994年 | 23篇 |
1993年 | 19篇 |
1992年 | 13篇 |
1991年 | 16篇 |
1990年 | 9篇 |
1989年 | 21篇 |
1988年 | 10篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1969年 | 3篇 |
排序方式: 共有1527条查询结果,搜索用时 0 毫秒
61.
Magdalena
miech Pawe Leszczyski Christopher Wardell Piotr Poznaski Mariusz Pierzchaa Hiroaki Taniguchi 《International journal of molecular sciences》2022,23(3)
The accumulation of mutations in cancer driver genes, such as tumor suppressors or proto-oncogenes, affects cellular homeostasis. Disturbances in the mechanism controlling proliferation cause significant augmentation of cell growth and division due to the loss of sensitivity to the regulatory signals. Nowadays, an increasing number of cases of liver cancer are observed worldwide. Data provided by the International Cancer Genome Consortium (ICGC) have indicated many alterations within gene sequences, whose roles in tumor development are not well understood. A comprehensive analysis of liver cancer (virus-associated hepatocellular carcinoma) samples has identified new and rare mutations in B-Raf proto-oncogene (BRAF) in Japanese HCC patients, as well as BRAF V600E mutations in French HCC patients. However, their function in liver cancer has never been investigated. Here, using functional analysis and next generation sequencing, we demonstrate the tumorigenic effect of BRAF V600E on hepatocytes (THLE-2 cell line). Moreover, we identified genes such as BMP6, CXCL11, IL1B, TBX21, RSAD2, MMP10, and SERPIND1, which are possibly regulated by the BRAF V600E-mediated, mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK) signaling pathway. Through several functional assays, we demonstrate that BRAF L537M, D594A, and E648G mutations alone are not pathogenic in liver cancer. The investigation of genome mutations and the determination of their impact on cellular processes and functions is crucial to unraveling the molecular mechanisms of liver cancer development. 相似文献
62.
Hiroaki Takeda Masataka Ohgaki Takashi Kizuki Kazuaki Hashimoto Yoshitomo Toda Shigekazu Udagawa Kimihiro Yamashita 《Journal of the American Ceramic Society》2000,83(11):2884-2886
The formation process of Ba2 La8 (SiO4 )6 O2 was clarified using thermogravimetry–differential thermal analysis (TG-DTA) and a high-temperature powder X-ray diffraction (HT-XRD) method. Phase changes identified from the HT-XRD data surprisingly corresponded to the weight loss and/or endothermic peaks observed in the TG-DTA curves. Raw material with the composition Ba2 La8 (SiO4 )6 O2 was completely reacted at 1400°C and produced only an apatite-type compound without a secondary phase. Moreover, the synthesis of Ba2+ x La8− x (SiO4 )6 O2−δ crystals with x = 0–2 was attempted using a solid-state reaction. 相似文献
63.
Hiromichi Gima Jun Adachi Masahito Katayama Hiroaki Muta Masayoshi Uno Shinsuke Yamanaka 《Journal of Nuclear Materials》2009,389(1):155-159
We prepared polycrystalline pellets of (U,Y)O2, containing YO1.5 up to 11 mol.%. We performed indentation tests on the pellets, and evaluated the Young’s modulus and hardness. We measured the heat capacity and the thermal diffusivity, and evaluated the thermal conductivity. We succeeded in evaluating the effect of Y content on the thermophysical properties of (U,Y)O2. We revealed that the Young’s modulus, hardness, and thermal conductivity of (U,Y)O2 decreased with increasing the Y content. 相似文献
64.
Sho Kano Huilong Yang John McGrady Tomonori Ihara Hazuku Tatsuya Hiroaki Abe 《Journal of Nuclear Science and Technology》2019,56(3):300-309
The radiation-induced surface activation (RISA) effect will be applied to the core design in supercritical light water reactor (SCWR) in order to achieve a high performance with excellent economy and safety. The purpose of the present study is to investigate the RISA effect in the candidate fuel cladding materials in SCWR such as PNC1520. The change of weldability due to RISA effect and the related microstructure analysis were performed in oxidized PNC1520 and 304 stainless steel with various oxidization periods. The phases contained in the surface oxide layer of the present specimen were identified as Fe2CrO4, γ-Fe2O3, and Fe2O3. The lifetime of 13.8 days for wettability improving factor was confirmed in the ultraviolet (UV) irradiation. Meanwhile, the long life of 13.8 days and short life of 0.8 days for wettability improving factors were identified in the γ-ray irradiation. Based on the fact that the band gap energies of Fe2CrO4, γ-Fe2O3, and Fe2O3 were, respectively, 2.1, 2.0, and 2.2 eV, and the photo energies of UV and γ-ray irradiation were 4.48 eV and 13.3 MeV, it is therefore clarified that the hydrophilization on the oxide layer is ascribed to the RISA effect. 相似文献
65.
Processability at extrusion coating and mechanical properties of the films obtained are investigated by means of linear and nonlinear rheological measurements and tensile tests for blends of polypropylene (PP) and linear low‐density polyethylene (LLDPE). Both materials are produced by metallocene catalyst. The processability of PP is found to be improved by the addition of LLDPE; the blend shows low level of motor torque and head pressure in an extruder and small level of neck‐in as compared with pure PP. Further, the anisotropy of ultimate tensile strength, which is prominent for PP, is reduced by blending with LLDPE. As a result, the blend having 20 wt % of LLDPE shows appropriate properties in the molten state for extrusion coating and in the solid state as a film. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
66.
67.
Creation of Superhydrophobic Electrospun Nonwovens Fabricated from Naturally Occurring Poly(Amino Acid) Derivatives 下载免费PDF全文
Hiroaki Yoshida Doris Klee Martin Möller Mitsuru Akashi 《Advanced functional materials》2014,24(40):6359-6364
Creation of superhydrophobic materials bio‐inspired by nature fascinates many scientists. One of the most intriguing challenges in this field is the fabrication of these materials using biopolymers from the viewpoint of green chemistry and environmental chemistry. Here, superhydrophobic and biodegradable nonwovens are constructed by electrospinning from a naturally occurring poly(amino acid), poly(γ‐glutamic acid) (γ‐PGA), modified with a hydrophobic α‐amino acid, l ‐phenylalanine. The contact angle of a water droplet on the materials is 154°, and the droplet remains stuck to the material surface even if it is inverted, clearly indicating a petal‐type superhydrophobic property. Biodegradability and post‐functionalization of the nonwovens as well as cell adhesion on the superhydrophobic materials are also evaluated. As far as we know, this is the first report on biodegradable materials exhibiting a petal‐type superhydrophobicity. The material design and processing shown here can be applied to various bioresources and such functional materials will become a new class of functional materials satisfying some of the requirements in green science. 相似文献
68.
Rintaro Aoyagi Hiroaki TakedaSoichiro Okamura Tadashi Shiosaki 《Materials Research Bulletin》2003,38(1):25-32
The crystal structure of Na0.5Bi2.5Nb2O9 was refined from its powder X-ray diffraction (XRD) data. Sodium bismuth niobate at 23 °C is orthorhombic, A21am, with a=5.4998(3) Å, b=5.4602(2) Å, c=24.952(1) Å, and Z=4. The piezoelectric properties were investigated using the dense bulk ceramics. The electromechanical coupling coefficients (kij) and electrical quality factors (Qm) are k31=3.2%, kt=10.0%, and Qm=3800. Single crystals were also grown from stoichiometric melts using a slow cooling technique. The dielectric and ferroelectric properties of the crystal indicates that a spontaneous polarization clearly occurs in the crystallographic a-b plane. 相似文献
69.
Garrett C. Lau Nicholas A. Sather Hiroaki Sai Elizabeth M. Waring Elad Deiss‐Yehiely Leonel Barreda Emily A. Beeman Liam C. Palmer Samuel I. Stupp 《Advanced functional materials》2018,28(3)
In energy storage materials, large surface areas and oriented structures are key architecture design features for improving performance through enhanced electrolyte access and efficient electron conduction pathways. Layered hydroxides provide a tunable materials platform with opportunities for achieving such nanostructures via bottom‐up syntheses. These nanostructures, however, can degrade in the presence of the alkaline electrolytes required for their redox‐based energy storage. A layered Co(OH)2–organic hybrid material that forms a hierarchical structure consisting of micrometer‐long, 30 nm diameter tubes with concentric curved layers of Co(OH)2 and 1‐pyrenebutyric acid is reported. The nanotubular structure offers high surface area as well as macroscopic orientation perpendicular to the substrate for efficient electron transfer. Using a comparison with flat films of the same composition, it is demonstrated that the superior performance of the nanotubular films is the result of a large accessible surface area for redox activity. It is found that the organic molecules used to template nanotubular growth also impart stability to the hybrid when present in the alkaline environments necessary for redox function. 相似文献
70.
Tadashi Inoue Takeo Onchi Hiroaki Kôyama Hiroshige Suzuki 《Journal of Nuclear Materials》1978,74(1):114-122
The paper describes radiation effects on 84C pellets used as control rod elements in the Enrico Fermi Fast Breeder Reactor. Pellet swelling (Δ) caused by irradiation was less than 1% in which crystal lattice swelling was less than 20%. Many microcracks, a main cause of pellet swelling, appeared in the irradiated pellets. The production of microcracks was related to graphite precipitation in the pellets before irradiation. Open pores which did not exist in the unirradiated pellets were formed in the irradiated ones. In a unit cell of B4C, the α-axis elongated by 0.025 Å and the shrank by 0.07 Å by irradiation. Moreover, we found three recovery stages which were from room temperature to 400°C, from 400 to 750°C and from 850 to 1100°C. The recovery mechanisms in the irradiated pellets are discussed in terms of the helium behavior. 相似文献