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排序方式: 共有309条查询结果,搜索用时 15 毫秒
41.
Lin Yang Leyi Loh Dilip Krishna Nandakumar Wanheng Lu Mengqi Gao Xue Le Charlotte Wee Kaiyang Zeng Michel Bosman Swee Ching Tan 《Advanced materials (Deerfield Beach, Fla.)》2020,32(25):2000971
Unlike traditional water splitting in an aqueous medium, direct decomposition of atmospheric water is a promising way to simultaneously dehumidify the living space and generate power. Here, a tailored superhygroscopic hydrogel, a catalyst, and a solar cell are integrated into a humidity digester that can break down ambient moisture into hydrogen and oxygen, creating an efficient electrochemical cell. The function of the hydrogel is to harvest moisture from ambient humidity and transfer the collected water to the catalyst. Barium titanate and vertical 2D MoS2 nanosheets are integrated as the catalyst: the negatively polarized cathode can enhance the electron transport and attract H+ to the MoS2 surface for water reduction, while water oxidation takes place at the positively polarized anode. By employing this mechanism, it is possible to maintain the relative humidity in a medium-sized room at <60% without any additional energy input, and a stable current of 12.5 mA cm−2 is generated by the humidity digester when exposed to ambient light. 相似文献
42.
X.P. Nie X.H. Yang L.Y. Chen K.B. Yeap K.Y. Zeng D. Li J.S. Pan X.D. Wang Q.P. Cao S.Q. Ding J.Z. Jiang 《Corrosion Science》2011,53(11):3557-3565
The oxidation kinetics of the Zr64Cu16Ni10Al10 bulk metallic glass (BMG) roughly follows a two-stage rate law at both 433 and 593 K in air. An oxide film of 940 nm can be formed by oxidation at 593 K, which is ZrO2-enriched but Cu-depleted on the outer surface. The oxide film leads to a superior passivity in 0.5 M NaCl and great corrosion resistance improvements in other solutions. The oxidation effect on mechanical properties were characterized by nanoindentation, wedge indentation and compression tests. The Zr-based BMG still keeps the amorphous nature and its good mechanical properties are retained after oxidation. 相似文献
43.
Reports an error in "The contributions of working memory and executive functioning to problem representation and solution generation in algebraic word problems" by Kerry Lee, Ee Lynn Ng and Swee Fong Ng (Journal of Educational Psychology, 2009[May], Vol 101[2], 373-387). In this article, the URL published for the supplemental material was incorrect. The correct URL is http://dx.doi.org/10.1037/a0013843.supp. (The following abstract of the original article appeared in record 2009-04640-010.) Solving algebraic word problems involves multiple cognitive phases. The authors used a multitask approach to examine the extent to which working memory and executive functioning are associated with generating problem models and producing solutions. They tested 255 11-year-olds on working memory (Counting Recall, Letter Memory, and Keep Track), ability to inhibit inappropriate responses (inhibition: numeric Stroop, Stop Signal), mental flexibility (switching: Number–Letter and Plus–Minus), English literacy, and algebraic problem-solving skills (problem representation, solution generation, and other subcomponents). Working memory explained about a quarter of the variance in both representation and solution formation. Literacy explained an additional 20% of the variance in representation formation. Ability to discern quantitative relationships explained an additional 10%. The findings go beyond a demonstration of an association between working memory and problem-solving accuracy. They show that success in word problems is particularly reliant on ability to decode and assign mathematical operators to quantitative relationships, 2 phases of problem solving that also draw heavily on working memory resources. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
44.
Superabsorbent polymer prepared using carboxymethyl cellulose derived from Ceiba pentandra (L.) Gaertn. (kapok) cotton 下载免费PDF全文
Superabsorbent polymers (SAPs) were synthesized by grafting acrylic acid and butyl acrylate onto carboxymethyl cellulose (CMC) modified from Ceiba pentandra (L.) Gaertn. (kapok) cotton, with N,N′‐methylenebisacrylamide as a crosslinker and ammonium persulphate as initiator. The effect of distilled water, saline solution, and applied pressure on superabsorbent was investigated. The product exhibited the maximum water absorbency of 554 g/g in distilled water and 96 g/g in saline solution. The SAP achieved the highest water absorbency under load of 83 g/g under applied pressure of 7.6 g/cm2. The kapok cotton modified cellulose‐based SAP exhibited stronger gel strength than the SAP based on commercial CMC. This is probably due to the higher grafting efficiency (78.3%) of the former. The SAP was characterized by FTIR analysis, thermogravimetric analysis, and scanning electron microscopy. Thermogravimetric analysis results showed that the SAP, with AA and BA grafted onto CMC, had better thermal stability than CMC alone. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40808. 相似文献
45.
SYNAPT~(TM) G2 HDMS质谱分析系统是沃特世公司第二代基于高效离子淌度(ion mobility spectrometry,IMS,也称离子迁移)技术的高性能四极杆-飞行时间质谱仪。通过两种技术的结合与升级,SYNAPT G2 HDMS不仅能按离子的质荷比分离检测,还可根据离子的大小、形状等将其分离。因此,此质谱系统不但可以提高传统质谱数据的准确性,更可以提供样品形态信息,从而得到样品活性、结构状态等信息。其在蛋白组学、代谢组学、糖及脂类分析、医学标志物发掘、药物开发与质控、食品安全检测、环境安全检测等方面有着广泛的应用空间,并已经表现出良好的性能优势,成为各领域工作者的有力的分析工具。本文简要介绍该系统的性能特点及应用。 相似文献
46.
In an irregular prism tensegrity, the number of force equilibrium equations is less than the number of unknown parameters of nodal coordinates and member force ratios. As a result, the form-finding process normally becomes nonlinear with additional conditions or needs to be carried out with the use of iterative procedures. For cases of irregular prism tensegrity which involves large number of members, it was found that previously proposed methods of form-finding are not practical. Moreover, there is a need for a form-finding approach which is able to cater to different requirements on final configuration. In this paper, the length relation condition is introduced to be used in combination with the force equilibrium equation. With the combined use of length relation and equilibrium conditions, a linear form-finding approach for irregular prism tensegrity was successfully formulated and developed. An easy-to-use interactive form-finding tool has been developed which can be used for form-finding of irregular prism tensegrities with large number of elements as well as under diverse specific requirements on their configurations. 相似文献
47.
A New In Situ Microscopy Approach to Study the Degradation and Failure Mechanisms of Time‐Dependent Dielectric Breakdown: Set‐Up and Opportunities 下载免费PDF全文
Zhongquan Liao Martin Gall Kong Boon Yeap Christoph Sander Oliver Aubel Uwe Mühle Jürgen Gluch Sven Niese Yvonne Standke Rüdiger Rosenkranz Markus Löffler Norman Vogel Armand Beyer Hans‐Jürgen Engelmann Peter Guttmann Gerd Schneider Ehrenfried Zschech 《Advanced Engineering Materials》2014,16(5):486-493
48.
49.
Decoupling Charge Transport and Electroluminescence in a High Mobility Polymer Semiconductor 下载免费PDF全文
50.
Noraini Nordin Samikannu Kanagesan Nur Rizi Zamberi Swee Keong Yeap Nadiah Abu Subramani Tamilselvan Mansor Hashim Noorjahan Banu Alitheen 《IET nanobiotechnology / IET》2017,11(3):343
In this study, nanocrystalline magnesium zinc ferrite nanoparticles were successfully prepared by a simple sol–gel method using copper nitrate and ferric nitrate as raw materials. The calcined samples were characterised by differential thermal analysis/thermogravimetric analysis, Fourier transform infrared spectroscopy and X‐ray diffraction. Transmission electron microscopy revealed that the average particle size of the calcined sample was in a range of 17–41 nm with an average of 29 nm and has spherical size. A cytotoxicity test was performed on human breast cancer cells (MDA MB‐231) and (MCF‐7) at various concentrations starting from (0 µg/ml) to (800 µg/ml). The sample possessed a mild toxic effect toward MDA MB‐231 and MCF‐7 after being examined with MTT (3‐[4, 5‐dimethylthiazol‐2‐yl]‐2, 5 diphenyltetrazolium bromide) assay for up to 72 h of incubation. Higher reduction of cells viability was observed as the concentration of sample was increased in MDA MB‐231 cell line than in MCF‐7. Therefore, further cytotoxicity tests were performed on MDA MB‐231 cell line.Inspec keywords: sol‐gel processing, nanoparticles, nanofabrication, magnesium compounds, zinc compounds, toxicology, biological organs, cancer, cellular biophysics, nanomedicine, calcination, differential thermal analysis, Fourier transform infrared spectra, X‐ray diffraction, transmission electron microscopy, particle size, organic compoundsOther keywords: sol‐gel method, cytotoxic effects, breast cancer cell line, MDA MB‐231 in vitro, nanocrystalline magnesium zinc ferrite nanoparticles, copper nitrate, ferric nitrate, raw materials, calcined samples, differential thermal analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, average particle size, cytotoxicity testing, human breast cancer cells, mild toxic effect, 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5 diphenyltetrazolium bromide) assay, cell viability, MCF‐7, MDA MB‐231 cell line, size 17 nm to 41 nm 相似文献