全文获取类型
收费全文 | 308篇 |
免费 | 7篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 130篇 |
金属工艺 | 1篇 |
机械仪表 | 7篇 |
建筑科学 | 4篇 |
能源动力 | 9篇 |
轻工业 | 72篇 |
石油天然气 | 2篇 |
无线电 | 15篇 |
一般工业技术 | 32篇 |
冶金工业 | 13篇 |
原子能技术 | 11篇 |
自动化技术 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 19篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 10篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 21篇 |
2012年 | 17篇 |
2011年 | 25篇 |
2010年 | 18篇 |
2009年 | 20篇 |
2008年 | 17篇 |
2007年 | 20篇 |
2006年 | 10篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 4篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有315条查询结果,搜索用时 0 毫秒
61.
Methylcis, cis-, cis, trans- andtrans,trans-9,12-octadecadienoates protect alkaline phosphatase from inactivation by γ-rays. The three isomers are equally efficient. 相似文献
62.
p-Styrenesulfonate derivatives having cycloaliphatic epoxide in a molecule, were synthesized. Oligomerization of the monomers and co-polymerization of the novel monomers with tert-butyl methacrylate were carried out. When the polymer films containing a photoacid generator (PAG) were irradiated, they became insoluble in solvents. The insoluble films became soluble in water on baking at 120-200 °C. The insolubilization and redissolution profiles were strongly affected by the structure of the monomer, irradiation and baking conditions, and a type of PAG used. The reaction mechanism was studied by TGA analysis and FT-IR spectroscopy. 相似文献
63.
Tamura Y Nagayama T Takano I Kobayashi M Tomizawa S Tateishi Y Kimura N Kitayama K Saito K 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2002,43(6):362-365
An unknown peak was detected in a GC chromatogram of many kiwi fruit extracts during analysis for pesticide residues. It was identified by GC/MS as diphenyl 2-ethylhexyl phosphate (DPEHP), used as a plasticizer and flame retardant. The concentration of DPEHP was investigated in 15 samples of kiwi fruit, and it was detected at between 0.02 and 0.14 microgram/g in 10 of the samples. It might be due to migration of DPEHP into the fruit from the printed portion of the polyethylene terephthalate (PET) package. 相似文献
64.
Kazama Haruna Ohata Yuto Ishiguri Yoichi Ono Hajime Mori Naoki Yoshinaga Naoko 《Journal of chemical ecology》2022,48(5-6):583-587
Journal of Chemical Ecology - TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate), a common plasticizer, inhibits the peach fruit moth, Carposina sasakii from ovipositing on young apple fruits.... 相似文献
65.
A series of bio-based self-healing polymers was prepared by cross-linking a furan polymer, poly(2,5-furandimethylene succinate), with bis-maleimide compounds by means of Diels–Alder reactions. In addition to the amount of the bis-maleimide linker, the molecular structure of the bis-maleimide played a key role in determining the extent of the Diels–Alder reaction and the mechanical and healing properties of the polymers. Bis-maleimides with phenylene rings markedly enhanced the tensile strength of the network polymers but hindered healing. In contrast, bis-maleimides with a flexible molecular structure tended to improve the polymer elongation, affording polymers with excellent healing ability. The efficiencies of self-healing (=healing without any external stimulus) and healing with an assistance of solvent (CHCl3) were over 70% and 80%, respectively, for the network polymer crosslinked by bis-maleimide with flexible long-alkyl segment. Thus, our results indicate that the choice of bis-maleimide linker is an important factor for designing furan-maleimide–based self-healing polymers. 相似文献
66.
Naoko Fujiwara Kazuaki YasudaTsutomu Ioroi Zyun SiromaYoshinori Miyazaki 《Electrochimica acta》2002,47(25):4079-4084
The ‘impregnation-reduction method’ has been investigated as a tool for the preparation of a direct methanol fuel cell (DMFC) anode. In this method, PtRu electrocatalysts were directly bonded onto a polymer electrolyte membrane by the chemical reduction of a mixture of Pt and Ru complexes impregnated in the membrane. The deposited PtRu particles were embedded in the 3-4 μm region of the membrane surface to form a porous and hydrophilic layer. The PtRu layers turned out to be applicable to the DMFC anode, despite their small active surface areas compared to PtRu nanoparticles used in the conventional method. Approximately, 3 mg cm−2 of the PtRu layer exhibited better catalyst utilization and facilitated the release of evolving CO2. This preparation technique is attractive for the application of various solid polymer electrolyte materials with low heat-resistance or various shapes, etc. 相似文献
67.
Hoyo Mizobe Tomoyuki Tanaka Naoko Hatakeyama Toshiharu Nagai Kenji Ichioka Hironori Hondoh Satoru Ueno Kiyotaka Sato 《Journal of the American Oil Chemists' Society》2013,90(12):1809-1817
We performed differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (SR-XRD) experiments of polymorphic structures and binary mixing characteristics of the enantiomers of 1-oleoyl-2,3-dipalmitoyl-sn-glycerol (S-OPP) and 1,2-dipalmitoyl-3-oleoyl-sn-glycerol (R-PPO). In the two enantiomers, oleic and palmitic acid moieties are asymmetrically connected at the sn-1 and sn-3 positions of the glycerol groups, with palmitic acid moiety at the sn-2 position. Pure enantiomer samples (>99 %) were synthesized and employed throughout this study. The following results were obtained. (1) A basic feature of the mixture systems of S-OPP and R-PPO is of a eutectic nature due to different polymorphic structures of two enantiomers and the racemic compound of PPO (rac-PPO). (2) Polymorphic behavior of S-OPP and R-PPO was quite similar, both having α-2 and β′-3, whereas rac-PPO contained α rac-3, β′rac-2, and β′rac-3. The DSC measurements showed that the melting points of β′-3 (S-OPP = 35.3 °C and R-PPO = 34.9 °C) were higher than that of β′rac-3 (31.0 °C). β was not crystallized in the pure enantiomers, and rac-PPO. (3) αrac-3 was crystallized at low cooling rates (~2 °C/min), whereas α-2 of the two enantiomers was crystallized only with very rapid cooling (~10 °C/min). (4) Triple-chain-length structures were formed in αrac-3, β′S-3 (=β′R-3), and β′rac-3; α-2 with a double-chain-length structure was formed in both enantiomers. These results indicate the importance of the relationship between subcell packing and glycerol conformation in the polymorphism and mixing characteristics of asymmetric unsaturated–saturated-saturated mixed-acid triacylglycerols. 相似文献
68.
Tomomi Kobayashi Sanae Tanaka Chihiro Toji Hideko Shinohara Miharu Kamimura Naoko Okamoto Shino Imai Mitsuru Fukui Chigusa Date 《Nutrition journal》2010,9(1):17
Background
Food frequency questionnaires (FFQ) are used for epidemiological studies. Because of the wide variations in dietary habits within different populations, a FFQ must be developed to suit the specific group. To date, no FFQ has been developed for Japanese children. In this study, we developed a FFQ to assess the regular dietary intake of Japanese children. The FFQ included questions regarding both individual food items and mixed dishes. 相似文献69.
Psoriasis is a chronic inflammatory skin disease characterized by IL-17-dominant abnormal innate and acquired immunity, and the hyperproliferation and aberrant differentiation of epidermal keratinocytes, and comorbid arthritis or cardiometabolic diseases. This Special Issue presented updated information on pathogenesis, comorbidities, and therapy of psoriasis. The pathogenesis of psoriasis may involve the dysfunction of indoleamine 2,3-dioxygenase 2 or of UBA domain containing 1-mediated regulation of CARD14/CARMA2sh. The blood cells of psoriasis patients showed the enhanced oxidative stress/autophagy flux and decreased 20S proteasome activity. Elafin, clusterin, or selenoprotein P may act as biomarkers for psoriasis and comorbid metabolic diseases. The proteomic profile of psoriasis lesions showed the dysfunction of dermal fibroblasts; up-regulation of proinflammatory factors and signal transduction or down-regulation of structural molecules. The skin inflammation in psoriasis may populate certain gut bacteria, such as Staphylococcus aureus and Streptococcus danieliae, which worsen the skin inflammation in turn. The psoriasis-associated pruritus may be caused by immune, nervous, or vascular mechanisms. In addition to current oral treatments and biologics, a new treatment option for psoriasis is now being developed, such as retinoic-acid-receptor-related orphan nuclear receptor γt inhibitors, IL-36 receptor antagonist, or aryl hydrocarbon receptor agonist. Antimicrobial peptides and innate immune cells, involved in the pathogenesis of psoriasis, may be novel therapeutic targets. The pathomechanisms and responses to drugs in collagen diseases are partially shared with and partially different from those in psoriasis. Certain nutrients can exacerbate or regulate the progress of psoriasis. The articles in this Special Issue will encourage attractive approaches to psoriasis by future researchers. 相似文献
70.
Kazuki Yamaoka Ryota Oikawa Dr. Naoko Abe Dr. Kosuke Nakamoto Dr. Fumiaki Tomoike Dr. Fumitaka Hashiya Dr. Yasuaki Kimura Prof. Dr. Hiroshi Abe 《Chembiochem : a European journal of chemical biology》2021,22(23):3273-3276
Chemical ligation reaction of DNA is useful for the construction of long functional DNA using oligonucleotide fragments that are prepared by solid phase chemical synthesis. However, the unnatural linkage structure formed by the ligation reaction generally impairs the biological function of the resulting ligated DNA. We achieved the complete chemical synthesis of 78 and 258 bp synthetic DNAs via multiple chemical ligation reactions with phosphorothioate and haloacyl-modified DNA fragments. The latter synthetic DNA, coding shRNA for luciferase genes with a designed truncated SV promoter sequence, successfully induced the expected gene silencing effect in HeLa cells. 相似文献