首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   176篇
  免费   12篇
电工技术   1篇
化学工业   45篇
金属工艺   1篇
机械仪表   5篇
建筑科学   6篇
能源动力   6篇
轻工业   6篇
水利工程   1篇
无线电   11篇
一般工业技术   50篇
冶金工业   42篇
自动化技术   14篇
  2023年   4篇
  2022年   8篇
  2021年   13篇
  2020年   5篇
  2019年   3篇
  2018年   6篇
  2017年   5篇
  2016年   7篇
  2015年   5篇
  2014年   8篇
  2013年   11篇
  2012年   12篇
  2011年   5篇
  2010年   4篇
  2009年   1篇
  2008年   3篇
  2007年   4篇
  2006年   4篇
  2005年   5篇
  2004年   3篇
  2003年   1篇
  2002年   3篇
  2001年   5篇
  2000年   4篇
  1999年   7篇
  1998年   11篇
  1997年   9篇
  1996年   5篇
  1995年   6篇
  1994年   2篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1988年   2篇
  1987年   2篇
  1985年   3篇
  1982年   1篇
  1981年   3篇
  1980年   2篇
  1976年   1篇
  1972年   1篇
排序方式: 共有188条查询结果,搜索用时 15 毫秒
1.
The release rate of a drug dissolved in the liquid phase of lipogels may be greatly affected by the type and concentration of gelling agent and by processing conditions and mechanical treatment of the ointment. These differences in release rate are reduced after application of mechanical stress comparable with the strain exerted on the ointment during application to the skin. Therefore, changes in the concentration of gelling agents used to achieve suitable consistency and manufacturing and packing processes that meet industrial and marketing requirements do not appear to exert a practical influence on drug availability after application to the skin.  相似文献   
2.
3.
Notch pathway is a highly conserved intracellular signaling route that modulates a vast variety of cellular processes including proliferation, differentiation, migration, cell fate and death. Recently, the presence of a strict crosstalk between Notch signaling and inflammation has been described, although the precise molecular mechanisms underlying this interplay have not yet been fully unravelled. Disruptions in Notch cascade, due both to direct mutations and/or to an altered regulation in the core components of Notch signaling, might lead to hypo- or hyperactivation of Notch target genes and signaling molecules, ultimately contributing to the onset of autoinflammatory diseases. To date, alterations in Notch signaling have been reported as associated with three autoinflammatory disorders, therefore, suggesting a possible role of Notch in the pathogenesis of the following diseases: hidradenitis suppurativa (HS), Behçet disease (BD), and giant cell arteritis (GCA). In this review, we aim at better characterizing the interplay between Notch and autoinflammatory diseases, trying to identify the role of this signaling route in the context of these disorders.  相似文献   
4.
Systematic characterisation of the reactivity of the lysine moieties in CRM197 towards N‐hydroxysuccinimide linkers bearing alkynes or azides is described. This involves two‐step conjugation of various glycans to CRM197 by click chemistry in a well‐defined manner. By semiquantitative LC‐MS/MS analysis of proteolytic digests of the conjugates formed, the reactivity of lysine residues in the protein was mapped and ranked. Computational analysis of the solvent accessibility of each lysine residue (based on the CRM197 crystal structure) established a correlation between reactivity and surface exposure. By this approach, conjugation involving lysine residues (normally a random process) can be controlled. It enables the preparation of lysine‐mediated glycoconjugates with improved batch‐to‐batch reproducibility, thereby producing neo‐glycoconjugates with more‐consistent biological activity.  相似文献   
5.
6.
The system Na-feldspar (F) and kaolinite (K) was investigated at temperatures of interest in ceramic applications (1200–1280 °C) to study the effects of F/K ratios by weight and crystallinity degree of kaolinite on the final product, micro-structural features and mullite-glass Gibbs energy of formation (ΔGeff). Mullite and glass are the dominant phases; in general, the higher the temperature, the larger the former. An F/K increase promotes the formation of glass and secondary mullite, appearing along with the primary one. ΔGeff was modelled by α(T) × (F/K)2 + β(T) × F/K + γ(T), α, β and γ being linear functions of temperature whose coefficients were determined by fitting the ΔGeff-theoretical to the ΔGeff-obtained from the measured phase compositions. ΔGeff is less affected by temperature than by F/K, whose increase shifts equilibrium towards glass phases. The ΔGeff-curves for ordered and disordered kaolinite intersect one another at F/K ~0.5, a ratio close to that used in industrial practice.  相似文献   
7.
Notch signaling has been identified as a critical regulator of cartilage development and homeostasis. Its pivotal role was established by both several joint specific Notch signaling loss of function mouse models and transient or sustained overexpression. NOTCH1 is the most abundantly expressed NOTCH receptors in normal cartilage and its expression increases in osteoarthritis (OA), when chondrocytes exit from their healthy “maturation arrested state” and resume their natural route of proliferation, hypertrophy, and terminal differentiation. The latter are hallmarks of OA that are easily evaluated in vitro in 2-D or 3-D culture models. The aim of our study was to investigate the effect of NOTCH1 knockdown on proliferation (cell count and Picogreen mediated DNA quantification), cell cycle (flow cytometry), hypertrophy (gene and protein expression of key markers such as RUNX2 and MMP-13), and terminal differentiation (viability measured in 3-D cultures by luminescence assay) of human OA chondrocytes. NOTCH1 silencing of OA chondrocytes yielded a healthier phenotype in both 2-D (reduced proliferation) and 3-D with evidence of decreased hypertrophy (reduced expression of RUNX2 and MMP-13) and terminal differentiation (increased viability). This demonstrates that NOTCH1 is a convenient therapeutic target to attenuate OA progression.  相似文献   
8.
Carotenoids and phenylpropanoids play a dual role of limiting and countering photooxidative stress. We hypothesize that their “antioxidant” function is prominent in plants exposed to summer drought, when climatic conditions exacerbate the light stress. To test this, we conducted a field study on Phillyrea latifolia, a Mediterranean evergreen shrub, carrying out daily physiological and biochemical analyses in spring and summer. We also investigated the functional role of the major phenylpropanoids in different leaf tissues. Summer leaves underwent the most severe drought stress concomitantly with a reduction in radiation use efficiency upon being exposed to intense photooxidative stress, particularly during the central hours of the day. In parallel, a significant daily variation in both carotenoids and phenylpropanoids was observed. Our data suggest that the morning-to-midday increase in zeaxanthin derived from the hydroxylation of ß-carotene to sustain non-photochemical quenching and limit lipid peroxidation in thylakoid membranes. We observed substantial spring-to-summer and morning-to-midday increases in quercetin and luteolin derivatives, mostly in the leaf mesophyll. These findings highlight their importance as antioxidants, countering the drought-induced photooxidative stress. We concluded that seasonal and daily changes in photosynthetic and non-photosynthetic pigments may allow P. latifolia leaves to avoid irreversible photodamage and to cope successfully with the Mediterranean harsh climate.  相似文献   
9.
In this paper, the ability of chitosan film to remove dyestuff from wastewater was evaluated for environmental applications, using three commercial direct azo dyes. Two chitosan films were adopted: the standard one prepared following a well‐known procedure to form it, and a novel one, with a weakly acidic character. Moreover, to improve the adsorption process, the hydrophobic character of the films was investigated. The pH of the dye solutions was also changed, showing an excellent ability in dye removal at pH 12. The films were characterized by means of spectroscopic and morphologic methods to better understand the nature of interactions between dyes and chitosan chains. Swelling ratio measurements were also performed. All analyses suggest that all dyes showed a strong affinity to chitosan polymer chains, with the presence of extended hydrogen bonds and Van der Waals forces perturbing the chitosan network. Interestingly, very good results were obtained in recycling experiments related to the dyeing capacities of chitosan blended films in the presence of textiles. An ecofriendly application is thus presented in this paper. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45945.  相似文献   
10.
A growing interest in designing high-alumina MgO-bonded refractory castables has been identified in recent years due to the magnesia ability to react: (i) with water at the initial processing stages of these materials (inducing the precipitation of brucite phase) or (ii) with alumina, giving rise to in situ MgAl2O4 generation at high temperatures. Nevertheless, despite the great potential of caustic magnesia to be used as a binder in such systems due to its high reactivity, it is still a challenge to control the hydration reaction rate of this oxide and the negative effects derived from the expansive feature of Mg(OH)2 formation. Thus, this work evaluated the incorporation of different contents of aluminum hydroxyl lactate (AHL) into caustic magnesia-bonded castables, aiming to control the brucite precipitation during the curing and drying steps of the prepared samples, resulting in crack-free refractories. The designed compositions were characterized via flowability, setting behavior, X-ray diffraction, cold flexural strength, porosity, permeability and thermogravimetric measurements. According to the results, instead of Mg(OH)2, hydrotalcite-like phases [Mg6Al2(OH)16(OH)2.4.5H2O and Mg6Al2(OH)16(CO3)·4H2O] were the main hydrated phases identified in the AHL-containing compositions. The addition of 1.0 wt% of aluminum hydroxyl lactate to the designed castable proved to be, so far, the best option for this magnesia source, resulting in the development of a crack-free refractory with enhanced properties and greater spalling resistance under heating.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号