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   74篇
  免费   5篇
化学   59篇
晶体学   1篇
数学   5篇
物理学   14篇
  2023年   1篇
  2021年   1篇
  2020年   1篇
  2019年   2篇
  2018年   2篇
  2017年   2篇
  2016年   2篇
  2015年   5篇
  2014年   2篇
  2013年   3篇
  2012年   8篇
  2011年   4篇
  2010年   2篇
  2009年   8篇
  2008年   3篇
  2007年   5篇
  2006年   7篇
  2005年   5篇
  2004年   3篇
  2003年   5篇
  2002年   2篇
  2001年   2篇
  2000年   1篇
  1997年   1篇
  1996年   1篇
  1984年   1篇
排序方式: 共有79条查询结果,搜索用时 19 毫秒
41.
InMnP:Zn epilayers doped with Mn (0.290 at.%) were annealed at 723-873 K for 60 s and 473-573 K for 30 min. Using Auger electron spectroscopy, the changes in concentration profiles of the epilayers correlated to the ferromagnetic origin as a function of the annealing conditions. The epilayers annealed at 723-873 K for 60 s exhibited InMn3 persisting up to 583 K. For InMnP:Zn epilayers annealed at 523-573 K for 30 min, the concentration depth profiles remained flat so that the stoichiometry was well maintained without precipitates such as InMn3 and MnP comparable to the as-grown InP:Zn before doping Mn. These samples showed clear ferromagnetic hysteresis loops. Curie temperature was about 150 K. A ferromagnetic hysteresis loop was obtained even at very lower annealing temperature of 473 K.  相似文献   
42.
In Korea, commercialized sauce for ready-to-eat (RTE) Bulgogi is usually manufactured using heat treatment to ensure that it has a long shelf-life. However, heat treatment may adversely affect the taste and flavor of the sauce, thus, the development of suitable sterilizing methods for RTE sauces is necessary to preserve the quality of the sauce during long storage periods. In this study, total bacterial growth, the viscosity, and the sensory properties of Bulgogi sauce were compared between sterilization with gamma irradiation (0–40 kGy) and autoclave treatment during storage at 35 °C for 90 days. No bacterial growth was observed following irradiation at more than 10 kGy or after autoclave treatment. However, the viscosity and sensory properties of samples gamma-irradiated at above 10 kGy or autoclave-treated were significantly changed, even though autoclave treatment induced a burnt taste and flavor. Therefore, a gamma irradiation of 10 kGy was effective to prepare ready-to-eat Bulgogi sauce with microbial safety and original sensory qualities.  相似文献   
43.
In the present study, initial microbial load of instant cup noodle (ICN) was investigated and gamma irradiation applied to develop immuno-compromised patients food for their safe consumption. The initial microbial population of dried vegetable and meat, and noodle was below the detection limit (1 log CFU/g); however, that of seasoning powder was just above 4 log CFU/g. Moreover, rehydrated-ICN with water at 100 °C still show above 3 log CFU/g of microbial load, which indicates the need for an additional process to control microbial safety of the seasoning powder. The total aerobic bacteria in seasoning powder and rehydrated-ICN could be controlled with 17 kGy gamma irradiation. This result referred 17 kGy gamma irradiation could reach ‘practical sterility’ of ICN. The overall difference in sensory properties between the non-irradiated and irradiated ICN was insignificant. Thus, gamma irradiation could improve the microbial quality of ICN, and reduce the risk of infection posed by the seasoning powder, without any adverse effects on their sensory quality. These results suggest that gamma-irradiated ICN can be used as a snack food for immuno-compromised patients.  相似文献   
44.
Bibimbap, Korean traditional cooked rice mixed with various kinds of vegetables, together with mushrooms and a ground meat, and seasoned with red pepper paste, was developed as a ready-to-cook food by combined treatment with irradiation for the use in space. By gamma irradiation of 25 kGy, the total aerobic bacteria of Bibimbap that was initial by 6.3 log CFU/g decreased to below detection limit, but its sensory qualities were drastically decreased. To enhance the sensory quality, the effects of antioxidant in Bibimbap were evaluated. A treatment with 0.1% of vitamin C, vacuum packaging and gamma-irradiated at 25 kGy and ?70 °C showed higher sensory scores than only the irradiation process. This result indicates that the radiation technology may be useful to produce a variety of space foods with high quality of taste and flavor, when combined with other methods.  相似文献   
45.
Oxidized LDL (OxLDL), a causal factor in atherosclerosis, induces the expression of heat shock proteins (Hsp) in a variety of cells. In this study, we investigated the role of CD36, an OxLDL receptor, and peroxisome proliferator-activated receptor γ (PPARγ) in OxLDL-induced Hsp70 expression. Overexpression of dominant-negative forms of CD36 or knockdown of CD36 by siRNA transfection increased OxLDL-induced Hsp70 protein expression in human monocytic U937 cells, suggesting that CD36 signaling inhibits Hsp70 expression. Similar results were obtained by the inhibition of PPARγ activity or knockdown of PPARγ expression. In contrast, overexpression of CD36, which is induced by treatment of MCF-7 cells with troglitazone, decreased Hsp70 protein expression induced by OxLDL. Interestingly, activation of PPARγ through a synthetic ligand, ciglitazone or troglitazone, decreased the expression levels of Hsp70 protein in OxLDL-treated U937 cells. However, major changes in Hsp70 mRNA levels were not observed. Cycloheximide studies demonstrate that troglitazone attenuates Hsp70 translation but not Hsp70 protein stability. PPARγ siRNA transfection reversed the inhibitory effects of troglitazone on Hsp70 translation. These results suggest that CD36 signaling may inhibit stress-induced gene expression by suppressing translation via activation of PPARγ in monocytes. These findings reveal a new molecular basis for the anti-inflammatory effects of PPARγ.  相似文献   
46.
This paper presents a fuzzy model-based adaptive approach for synchronization of chaotic systems which consist of the drive and response systems. Takagi–Sugeno (T–S) fuzzy model is employed to represent the chaotic drive and response systems. Since the parameters of the drive system are assumed unknown, we design the response system that estimates the parameters of the drive system by adaptive strategy. The adaptive law is derived to estimate the unknown parameters and its stability is guaranteed by Lyapunov stability theory. In addition, the controller in the response system contains two parts: one part that can stabilize the synchronization error dynamics and the other part that estimates the unknown parameters. Numerical examples, including Duffing oscillator and Lorenz attractor, are given to demonstrate the validity of the proposed adaptive synchronization approach.  相似文献   
47.
With small molecules, it is not easy to create large void spaces. Flat aromatics stack tightly, while flexible chains fold to fill the cavities. As an intuitive design to make open channels inside molecularly constructed solids, we employed propeller-shaped bicyclic triazoles to prepare a series of aromatic-rich three-dimensional (3D) building blocks. This modular approach has no previous example, but is readily applicable to build linear, bent, and branched arrays of non-stackable architectural motifs from existing flat aromatics by single-pot reactions. A letter H-shaped molecule thus prepared self-assembles into porous crystals, the highly unusual stepwise gas sorption behaviour of which prompted in-depth studies. A combination of single-crystal and powder X-ray diffraction analysis revealed multiple polymorphs, and sterically allowed pathways for their reversible interconversions that open and close the pores in response to external stimuli.

Like non-collapsible open voids within stacks of steel H-beams, a non-covalent assembly of three-dimensional aromatics produces porous crystals. Concerted motions of the molecular H-beams open and close the cavities in response to external stimuli.  相似文献   
48.
49.
50.
A quantitative analysis of mineral contents in several kinds of foods is needed to obtain information on a comprehensive elemental composition as well as an investigation on the effects of human health and nutrition based on the dietary intake of mineral elements. In 2012, six kinds of new Korean space foods (KSF) such as sweet pumpkin porridge, dakgalbi (spicy grilled chicken), Manila clam porridge, ox leg bone-cabbage soup, ginseng-chicken porridge, and chicken curry rice were developed by KAERI, and the contents of more than 15 elements in the samples were determined using an instrumental neutron activation analysis. A certified reference material associated with a biological food sample was used for analytical quality control. The analytical results were evaluated according to the elemental concentrations with KSF samples and compared with the reported values. These results will be applied toward the identification of gamma-irradiated foods.  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