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   119篇
  免费   7篇
  国内免费   2篇
化学工业   24篇
金属工艺   2篇
建筑科学   2篇
能源动力   7篇
轻工业   12篇
水利工程   6篇
石油天然气   2篇
无线电   7篇
一般工业技术   43篇
冶金工业   15篇
自动化技术   8篇
  2023年   7篇
  2022年   4篇
  2021年   9篇
  2020年   6篇
  2019年   8篇
  2018年   8篇
  2017年   4篇
  2016年   5篇
  2015年   2篇
  2014年   10篇
  2013年   11篇
  2012年   4篇
  2011年   6篇
  2010年   2篇
  2009年   7篇
  2008年   6篇
  2007年   4篇
  2006年   4篇
  2005年   6篇
  2004年   7篇
  2003年   4篇
  2002年   2篇
  1999年   1篇
  1996年   1篇
排序方式: 共有128条查询结果,搜索用时 93 毫秒
71.

1 Scope

Several dietary fiber properties are suggested to be important for the profiling of the microbiota composition, but those characteristics are rather unclear. Whether different physico‐chemical properties of barley dietary fiber influence the gut microbiota composition is investigated.

2 Methods and results

Seven diets containing equal amounts of dietary fiber from barley malts, brewer's spent grain (BSG), and barley extracts, resulting in varying amounts of β‐glucan, soluble arabinoxylan, and insoluble arabinoxylan in the diets were given to conventional rats. Malts increased microbiota alpha diversity more than BSG and the extracts. The intake of soluble arabinoxylan was related to Akkermansia and propionic acid formation in the cecum of rats, whereas β‐glucan and/or insoluble arabinoxylan were attributed to some potentially butyrate‐producing bacteria (e.g., Lactobacillus, Blautia, and Allobaculum).

3 Conclusion

This study demonstrates that there is a potential to stimulate butyrate‐ and propionate‐producing bacteria in the cecum of rats with malt products of specific fiber properties. Moreover, BSG, a by product from beer production, added to malt can possibly be used to further modulate the microbiota composition, toward a higher butyric acid formation. A complex mixture of fiber as in the malts is of greater importance for microbiota diversity than purer fiber extracts.  相似文献   
72.
73.
Zinc oxide (ZnO) and its ternary alloy magnesium zinc oxide (Mg x Zn1−x O) are piezoelectric materials that can be used for high-quality-factor bulk acoustic wave (BAW) resonators operating at GHz frequencies. Thin-film bulk acoustic resonators (TFBARs) are attractive for applications in advanced communication and in various sensors as they offer the capability of monolithic integration of BAW resonators with radio-frequency integrated circuits (RF ICs). In this paper we report Mg x Zn1−x O-based TFBAR biosensors. The devices are built on Si substrates with an acoustic mirror consisting of alternating quarter-wavelength silicon dioxide (SiO2) and tungsten (W) layers to isolate the TFBAR from the Si substrate. High-quality ZnO and Mg x Zn1−x O thin films are achieved through a radio-frequency (RF) sputtering technique. Tuning of the device operating frequency is realized by varying the Mg composition in the piezoelectric Mg x Zn1−x O layer. Simulation results based on a transmission-line model of the TFBAR show close agreement with the experimental results. ZnO nanostructures are grown on the TFBAR’s top surface using metal- organic chemical vapor deposition (MOCVD) to form the nano-TFBAR sensor, which offers giant sensing area, faster response, and higher sensitivity over the planar sensor configuration. Mass sensitivity higher than 103 Hz cm2/ng is achieved. In order to study the feasibility of the nano-TFBAR for biosensing, the nanostructured ZnO surfaces were functionalized to selectively immobilize␣DNA, as verified by hybridization with its fluorescence-tagged DNA complement.  相似文献   
74.
The dissolution of Cr-rich carbides formed in the martensitic constituent of a 13 pct Cr stainless steel was studied by dilatometry and correlative electron channeling contrast examinations. The dissolution of carbides subsequent to the martensite reversion to austenite was associated with a net volume expansion which in turn increased the dilatometry-based apparent coefficient of thermal expansion (CTEa) during continuous heating. The effects of carbides fraction and size on the CTEa variations during carbides dissolution are discussed.  相似文献   
75.
Purpose: To evaluate the antifungal activity of amphotericin B (AmB) in a mouse model of systemic candidiasis following administration of a novel oral AmB formulation (iCo-010) that has been pre-exposed to tropical temperatures.

Methods: Amphotericin B (AmB) was prepared as a 5?mg/mL dispersion in a mixture of Peceol, Gelucire 44/14 and VitE-TPGS 2,3 (iCo-010). The formulation was protected from light and incubated in a sealed container at 43?°C for 60 days. Mice infected with Candida albicans were treated with either iCo-010 formulation pre-incubated at 43?°C for 60 days or freshly prepared iCo-010 formulation at doses of 5, 10 and 20?mg/kg once daily for five consecutive days. Single intravenous 5?mg/kg dose of AmBisome® was used as a positive control group. Seven days following the last dose, the kidney, liver, spleen, lung, heart and brain were removed and the number of colony forming units (CFUs) was determined as a measure of tissue fungal load. In addition, the concentration of AmB within each tissue was determined using high performance liquid chromatography (HPLC).

Results: There were no significant differences in the reduction of CFUs and the concentration of AmB recovered in all organs at all iCo-010 doses tested between the freshly prepared iCo-010 formulation compared to the formulation that was incubated at 43?°C for 60 days.

Conclusions: A novel oral AmB formulation, iCo-010, incubated at 43?°C for 60 days to simulate the exposure of the formulation to tropical temperatures remained highly effective against murine systemic candidiasis.  相似文献   
76.
ABSTRACT

Purpose: The purpose of this study was to assess the lipid lowering and plasma cholesteryl ester transfer protein (CETP) activity following administration of simvastatin to rabbits fed a high fat/cholesterol diet. Methods: Male New Zealand white rabbits were housed in individual cages and fed a standard diet for 7 days. After 7 days, animals were fed 10 g of a regular chow diet plus 100 g of the same diet supplemented with 0.5% (w/v) cholesterol and 14.0% (w/v) coconut oil for 28 days. Following 28 days on this diet, the animals were randomized based on plasma cholesterol and triglyceride levels, into a group of control animals and a group (n = 6) of animals fed 100 g of cholesterol/coconut diet plus 10 g regular chow diet containing simvastatin (3 mg/kg/day) for an additional 28 days. Blood samples were taken from the marginal ear vein prior to and 28 days after the initiation of drug treatment. Plasma was harvested and stored at 4°C prior to lipid analysis. Plasma total cholesterol and triglyceride levels were quantified using enzymatic kits. HDL (high-density lipoproteins) cholesterol levels were determined using the dextran sulfate-Mg2+ precipitation method. ApoB cholesterol levels were determined by subtracting total cholesterol from HDL cholesterol. Cholesteryl ester transfer protein (CETP) activity was determined by standard assay methods. Results: We observed that simvastatin significantly reduced total plasma cholesterol, triglyceride, and apoB cholesterol compared to non-treated controls. Simvastatin treatment did not alter serum CETP activity compared to non-treated controls. Conclusions: These findings suggest that decreasing plasma lipid levels by treatment with simvastatin is not due to changes in serum CETP activity in rabbits fed a high fat/cholesterol diet.  相似文献   
77.
Clean Technologies and Environmental Policy - According to the Porter hypothesis, regulations on environmental emissions under certain conditions can promote eco-innovation. This is why the...  相似文献   
78.
High content of heavy metals and presence of pathogens in the dewatered sewage sludge have been the main obstacles for land application of sewage sludge-made fertilizer. The aim of this study was to examine the effects of the innovative electrokinetic (EK) technology on removal of heavy metals from sewage sludge, on the reduction of pathogens, and on sludge chemical characteristics. The results showed that the removal efficiencies for Zn, Cu, Ni, Cr, As and Pb were 94.9%, 95.4%, 89.7%, 67.8%, 31.2% and 18.7%, respectively. Acidification pretreatment of the dewatered sludge for 29 h decreased the content of heterotrophic bacteria from 1.5 x 10(8) c.f.u./g of wet sludge to 1.1 x 10(4) c.f.u./g of wet sludge. Although the initial content of total coliforms and fecal coliforms in sewage sludge were 5.8 x 10(5) c.f.u./g of wet sludge and 4.0 x 10(5) c.f.u./g of wet sludge, respectively, no viable cells were detected. Minor losses of K and N were detected, but the loss of P was found to be significant in EK treated sewage sludge. The treated sludge was technically considered as very stable based on the carbon dioxide evolution rate.  相似文献   
79.
There often exist many secondary data that must be considered in geostatistical reservoir modeling. These include multiple seismic attributes, geological trends and structural controls. It is essential that all secondary data are accounted for when estimating a primary variable (e.g., porosity or water saturation) with the precision warranted by that secondary data type. Characterizing the distribution of primary and secondary variables requires multivariate geostatistical techniques. Collocated cokriging is a common technique in geostatistics to account for multiple data types. This technique, however, has a longstanding problem with variance inflation that leads to problems in histogram reproduction. This paper, analyses an alternative method to collocated cokriging. This method, referred to as intrinsic collocated cokriging (ICCK), is equally simple, but ensures histogram reproduction. To improve practical implementation of ICCK in the case of multiple secondary data a novel merged secondary variable approach is developed in this paper. This approach is aimed at merging all secondary data into a single variable, then implementing ICCK with that single variable. It is shown that the proposed technique yields the same results as would be obtained using all multiple secondary variables simultaneously.  相似文献   
80.
A universal technique is developed to coat uniform layer of catalyst on any targeted substrate. The technique is based on a novel concept of catalyst deposition by using polymer-metal complexes in the form of invertible polymeric nanostructures through molecular self-assembly. Growth of carbon nanofibres on carbon microfibres was demonstrated to show this technique.  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