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排序方式: 共有117条查询结果,搜索用时 15 毫秒
61.
T. Nabatame Y. Nunoshige H. Takaba S. Kimura H. Ota A. Toriumi 《Microelectronic Engineering》2008,85(7):1524-1528
Effective work function (?m,eff) values of Hfx Ru1−x alloy gate electrodes on SiO2 metal-oxide-semiconductor (MOS) capacitors were carefully examined to assess whether the ?m,eff was determined by the crystalline structure or the composition of the HfxRu1−x alloy. X-ray diffraction results indicated that the crystalline structures of HfxRu1−x alloy were divided into hexagonal-Ru, cubic-HfRu or hexagonal-Hf with the increase of Hf content. The ?m,eff values could be controlled continuously from 4.6 to 4.0 eV by changing the Hf content. The experimental ?m,eff value showed a good agreement with theoretical results considering the compositional ratio of pure Hf and Ru. These results suggest that the ?m,eff of HfxRu1−x alloy gates on SiO2 MOS capacitors is dominantly determined by the HfxRu1−x composition rather than the crystalline structure. 相似文献
62.
Jiang G Xu Y Fujiwara Y Tsukahara T Tsukahara R Gajewiak J Tigyi G Prestwich GD 《ChemMedChem》2007,2(5):679-690
Isoform-selective agonists and antagonists of the lysophosphatidic acid (LPA) G-protein-coupled receptors (GPCRs) have important potential applications in cell biology and therapy. LPA GPCRs regulate cancer cell proliferation, invasion, angiogenesis, and biochemical resistance to chemotherapy- and radiotherapy-induced apoptosis. LPA and its analogues are also feedback inhibitors of the enzyme lysophospholipase D (lysoPLD, also known as autotaxin), a central regulator of invasion and metastasis. For cancer therapy, the ideal therapeutic profile would be a metabolically stabilized pan-LPA receptor antagonist that also inhibits lysoPLD. Herein we describe the synthesis of a series of novel alpha-substituted methylene phosphonate analogues of LPA. Each of these analogues contains a hydrolysis-resistant phosphonate mimic of the labile monophosphate of natural LPA. The pharmacological properties of these phosphono-LPA analogues were characterized in terms of LPA receptor subtype-specific agonist and antagonist activity using Ca(2+) mobilization assays in RH7777 and CHO cells expressing the individual LPA GPCRs. In particular, the methylene phosphonate LPA analogue is a selective LPA(2) agonist, whereas the corresponding alpha-hydroxymethylene phosphonate is a selective LPA(3) agonist. Most importantly, the alpha-bromomethylene and alpha-chloromethylene phosphonates show pan-LPA receptor subtype antagonist activity. The alpha-bromomethylene phosphonates are the first reported antagonists for the LPA(4) GPCR. Each of the alpha-substituted methylene phosphonates inhibits lysoPLD, with the unsubstituted methylene phosphonate showing the most potent inhibition. Finally, unlike many LPA analogues, none of these compounds activate the intracellular LPA receptor PPARgamma. 相似文献
63.
64.
Vertical profiles of environmental radionuclides (40K, 226Ra, 210Pb and 137Cs) were investigated in several temperate forest soils in Germany to estimate heterogeneity of the soil horizon of interest. Absolute values of the activity concentrations of these nuclides varied to a large extent depending on the properties of individual forests as well as local geology. Several trends were generally observed independent of the location: (1) Activity concentrations of 40K increased with increasing soil density reflecting that most potassium is contained in mineral components of the soil. The variations in the 40K activity with depth may relate to biological activities in subsoil, such as root uptake of the nutrients. (2) Profiles of 226Ra with depth could be an indicator for evaluating soil heterogeneity within a horizon of interest. They are also useful to estimate anthropogenic 210Pb (210Pbexc) derived from the atmosphere via dry fallout or wet deposition. In several forests, there appeared surface enrichment of 210Pb down to a depth of approximately 10 cm, in which the 210Pb would have come from the atmosphere by combustion of fossil fuels. (3) Depth profiles of 137Cs were roughly divided into three types in which (a) the activity concentration decreased exponentially with soil depth, (b) small amounts of 137Cs existed only in the upper-most layer of the soil (0-5 cm) and (c) 137Cs disappeared at certain depths and appeared again at deeper portions of the soil. Consequences of bioturbation could be deduced from variability in vertical profiles of the environmental radionuclides. It is probable that a site showing an exponential decrease of the 137Cs activity with depth and also having a surface enrichment of 210Pb is not significantly influenced by bioturbation. 相似文献
65.
Ryoko Yahata 《Thin solid films》2009,517(6):1983-1988
The effects of the solvent on in-plane stress evolution were studied on sol-gel-derived silica gel coatings during heating. Si(OC2H5)4-H2O-HNO3-ROH (ROH = CH3OH, C2H5OH, n-C3H7OH, and n-C4H9OH) solutions were prepared where the mole ratio Si(OC2H5)4:H2O:HNO3 = 1:8:0.01 and the volume ratio Si(OC2H5)4:ROH = 1:1.1. Silica gel films were deposited by spin coating on Si (100) wafers 4 in. in diameter, and heated at 5 °C/min up to 500 °C, where in situ stress measurement was conducted by measuring the substrate curvature. The stress was tensile and increased with increasing temperature. The stress was found to be identical below 200 °C between the films prepared with different alcohols while the stress above 200 °C was larger in the order, n-C4H9OH < n-C3H7OH ≈ C2H5OH < CH3OH, namely in the order of the boiling points of the solvents. 相似文献
66.
Takumi Oti Ryota Ueda Ryoko Kumagai Junta Nagafuchi Takashi Ito Tatsuya Sakamoto Yasuhiko Kondo Hirotaka Sakamoto 《International journal of molecular sciences》2021,22(19)
Male sexual function in mammals is controlled by the brain neural circuits and the spinal cord centers located in the lamina X of the lumbar spinal cord (L3–L4). Recently, we reported that hypothalamic oxytocin neurons project to the lumbar spinal cord to activate the neurons located in the dorsal lamina X of the lumbar spinal cord (dXL) via oxytocin receptors, thereby facilitating male sexual activity. Sexual experiences can influence male sexual activity in rats. However, how this experience affects the brain–spinal cord neural circuits underlying male sexual activity remains unknown. Focusing on dXL neurons that are innervated by hypothalamic oxytocinergic neurons controlling male sexual function, we examined whether sexual experience affects such neural circuits. We found that >50% of dXL neurons were activated in the first ejaculation group and ~30% in the control and intromission groups in sexually naïve males. In contrast, in sexually experienced males, ~50% of dXL neurons were activated in both the intromission and ejaculation groups, compared to ~30% in the control group. Furthermore, sexual experience induced expressions of gastrin-releasing peptide and oxytocin receptors in the lumbar spinal cord. This is the first demonstration of the effects of sexual experience on molecular expressions in the neural circuits controlling male sexual activity in the spinal cord. 相似文献
67.
Nanami Nakamura Hisako Fujihara Koji Kawaguchi Hiroyuki Yamada Ryoko Nakayama Masaaki Yasukawa Yuta Kishi Yoshiki Hamada Mitsuko Masutani 《International journal of molecular sciences》2022,23(5)
Despite recent advances in treatment, the prognosis of oral cancer remains poor, and prevention of recurrence and metastasis is critical. Olaparib is a PARP1 inhibitor that blocks polyADP-ribosylation, which is involved in the epithelial–mesenchymal transition (EMT) characteristic of tumor recurrence. We explored the potential of olaparib in inhibiting cancer invasion in oral carcinoma using three oral cancer cell lines, HSC-2, Ca9-22, and SAS. Olaparib treatment markedly reduced their proliferation, migration, invasion, and adhesion. Furthermore, qRT-PCR revealed that olaparib inhibited the mRNA expression of markers associated with tumorigenesis and EMT, notably Ki67, Vimentin, β-catenin, MMP2, MMP9, p53, and integrin α2 and β1, while E-Cadherin was upregulated. In vivo analysis of tumor xenografts generated by injection of HSC-2 cells into the masseter muscles of mice demonstrated significant inhibition of tumorigenesis and bone invasion by olaparib compared with the control. This was associated with reduced expression of proteins involved in osteoclastogenesis, RANK and RANKL. Moreover, SNAIL and PARP1 were downregulated, while E-cadherin was increased, indicating the effect of olaparib on proteins associated with EMT in this model. Taken together, these findings confirm the effects of olaparib on EMT and bone invasion in oral carcinoma and suggest a new therapeutic strategy for this disease. 相似文献
68.
Yoshiko Hada Haruhito A. Uchida Ryoko Umebayashi Masashi Yoshida Jun Wada 《International journal of molecular sciences》2022,23(16)
Cardiac fibrosis is characterized by the net accumulation of extracellular matrix in the myocardium and is an integral component of most pathological cardiac conditions. Cilostazol, a selective inhibitor of phosphodiesterase type III with anti-platelet, anti-mitogenic, and vasodilating properties, is widely used to treat the ischemic symptoms of peripheral vascular disease. Here, we investigated whether cilostazol has a protective effect against Angiotensin II (AngII)-induced cardiac fibrosis. Male apolipoprotein E-deficient mice were fed either a normal diet or a diet containing cilostazol (0.1% wt/wt). After 1 week of diet consumption, the mice were infused with saline or AngII (1000 ng kg−1 min−1) for 28 days. AngII infusion increased heart/body weight ratio (p < 0.05), perivascular fibrosis (p < 0.05), and interstitial cardiac fibrosis (p < 0.0001), but were significantly attenuated by cilostazol treatment (p < 0.05, respectively). Cilostazol also reduced AngII-induced increases in fibrotic and inflammatory gene expression (p < 0.05, respectively). Furthermore, cilostazol attenuated both protein and mRNA abundance of osteopontin induced by AngII in vivo. In cultured human cardiac myocytes, cilostazol reduced mRNA expression of AngII-induced osteopontin in dose-dependent manner. This reduction was mimicked by forskolin treatment but was cancelled by co-treatment of H-89. Cilostazol attenuates AngII-induced cardiac fibrosis in mice through activation of the cAMP–PKA pathway. 相似文献
69.
Mana Yamano Ryoko Hirose Ping Ying Lye Keiko Takaki Rina Maruta Mervyn Wing On Liew Shinichi Sakurai Hajime Mori Eiji Kotani 《International journal of molecular sciences》2022,23(13)
Silk fibroin exhibits high biocompatibility and biodegradability, making it a versatile biomaterial for medical applications. However, contaminated silkworm-derived substances in remnant sericin from the filature and degumming process can result in undesired immune reactions and silk allergy, limiting the widespread use of fibroin. Here, we established transgenic silkworms with modified middle silk glands, in which sericin expression was repressed by the ectopic expression of cabbage butterfly-derived cytotoxin pierisin-1A, to produce cocoons composed solely of fibroin. Intact, nondegraded fibroin can be prepared from the transgenic cocoons without the need for sericin removal by the filature and degumming steps that cause fibroin degradation. A wide-angle X-ray diffraction analysis revealed low crystallinity in the transgenic cocoons. However, nondegraded fibroin obtained from transgenic cocoons enabled the formation of fibroin sponges with varying densities by using 1–5% (v/v) alcohol. The effective chondrogenic differentiation of ATDC5 cells was induced following their cultivation on substrates coated with intact fibroin. Our results showed that intact, allergen-free fibroin can be obtained from transgenic cocoons without the need for sericin removal, providing a method to produce fibroin-based materials with high biocompatibility for biomedical uses. 相似文献
70.
Ryoko Kawahara Ken‐ichi Fujita Ryohei Yamaguchi 《Advanced Synthesis \u0026amp; Catalysis》2011,353(7):1161-1168
An efficient and environmentally benign catalytic system for the synthesis of various organic amines catalyzed by the water‐soluble and air‐stable (pentamethylcyclopentadienyl)‐iridium‐ammine iod‐ ide complex, [Cp*Ir(NH3)3][I]2 (Cp*=pentamethylcyclopentadienyl), has been developed. A wide variety of secondary and tertiary amines were synthesized by the N‐alkylation reactions of theoretical equivalents of amines with alcohols in water under air without a base. The synthesis of cyclic amines was also achieved by the N‐alkylation of benzylamine with diols. Furthermore, the recycle use of the present water‐soluble Cp*Ir catalyst was accomplished. 相似文献