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Hao-Ming Jeng Chung-Zen Tsai Tsu-Yen Chang 《Fresenius' Journal of Analytical Chemistry》1990,338(8):902-904
Summary The composition and stability of copper(I) complexes with thioacetamide (TAA) have been evaluated with the help of square-wave voltammetry using the fast pulse technique. Two species, namely Cu(I) (TAA) and Cu(I) (TAA)2, have been identified having the formation constants log 1=16.85; log 2=18.03. The complex is stable in highly acidic medium (pH1). The application for the determination of copper is pointed out. 相似文献
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失效原子力显微镜硅针尖再生 总被引:2,自引:0,他引:2
原子力显微镜的传统商品硅针尖在使用过程中极易因磨损而失效,本文研究了一种在实验室条件下简易可行的回收利用失效硅针尖的方法。在原子力显微镜的敲击模式下使用曲率半径大于100 nm的失效硅针尖对生长单壁碳纳米管的样品表面进行扫描,把样品表面的单壁碳纳米管管束粘接到硅针尖上,可制得直径在5~20 nm的碳纳米管针尖。实验对碳纳米管针尖和新的商品硅针尖进行了成像对比,所制备的碳纳米管针尖不仅在成像分辨率而且在成像稳定性上都优于新的商品硅针尖。 相似文献
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Chih-Wei HuangMuthian Shanmugasundaram Hao-Ming ChangChien-Hong Cheng 《Tetrahedron》2003,59(20):3635-3641
An efficient method for the preparation of various monosubstituted arylallenes, disubstituted allenes and alkenylallenes via palladium-catalyzed coupling of allenylstannanes with aryl iodides or alkenyl iodides is described. The coupling reaction was carried out in the presence of Pd(PPh3)4 and LiCl using DMF as solvent. The possible role of LiCl in this coupling process is discussed based on the 119Sn NMR studies. 相似文献
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A strategy for Pd-catalyzed ortho-C–H silylation of biaryl aldehydes enabled by a transient auxiliary is presented. This protocol provides a broad range of ortho-silylated biaryl aldehydes in good yields. The silyl moiety can be further functionalized under mild conditions, rendering the silylated products useful building blocks. Notably, this protocol also offers an opportunity to establish a platform for expeditious synthesis of structurally diverse axially chiral biaryl aldehydes via sequential atroposelective interannular C–H functionalization/intraanular C–H silylation. 相似文献
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力调制显微术被用于观测铜基碳化硅样品,实验中发现在样品表面台阶边缘处出现一些异常信息。为此,文章作者通过测试一种表面同样有台阶但却是由同一种材料组成的样品来通信验证这些异常主要是由台阶的边界引起的,并对引起的异常作了半定量的估算。 相似文献
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用简单有效的静电纺丝法制备了Ce掺杂的In2O3纳米纤维材料.采用X射线衍射(XRD)、透射电子显微镜(TEM)、高分辨率透射电子显微镜(HRTEM)和扫描电子显微镜(SEM)对合成样品的晶体结构和形貌进行了表征.结果显示,此纤维材料的平均直径约为90nm,长度达到几十个微米.气敏性能测试结果表明,4%(w)Ce掺杂的In2O3纳米纤维对三乙胺的灵敏度最高,该气敏元件对3μL·L-1三乙胺的灵敏度达到2.6,响应时间为5s,恢复时间约为6s,且具有较好的选择性. 相似文献
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Ke Liu Duan-Wei He Xiao-Lin Zhou Hao-Ming Wang Tie-Cheng Lu Jing Chang 《Journal of Thermal Analysis and Calorimetry》2013,111(1):289-294
We first introduce the latest experimental results, i.e., production of the fine nanostructured and near fully dense transparent Y3Al5O12 (YAG) bulks at high pressure and modest temperature (2.0–5.0 GPa and 300–500 °C). And then, we employ the first-principles plane wave pseudopotential density functional theory method to calculate the equilibrium lattice parameters and the thermodynamic properties of YAG. The obtained lattice parameters are consistent with the experimental data and the available theoretical data of others. Through the quasi-harmonic Debye model, the dependences of the normalized primitive volume V/V 0 on pressure P, the Debye temperature $ \Uptheta_{\rm{D}} $ , and the heat capacity C V on pressure P and temperature T, as well as the variation of the thermal expansion α with temperature and pressure are obtained successfully. 相似文献
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Hao-Ming Liang Ce-Kuen Shieh Tzu-Chi Huang Wen-Shyang Hwang Chih-Heng Ke 《Mathematical and Computer Modelling》2011,53(3-4):443-457
According to previous work, the performance of the Distributed Coordination Function (DCF) (i.e., the basic access method of the IEEE 802.11 protocol) is far from optimum due to use of the binary exponential backoff (BEB) scheme as its collision avoidance mechanism. There has been considerable discussion of DCF issues and its performance analysis. However, most schemes assume an ideal channel, which is contrary to realistic wireless environments. In this paper, we present a simple yet pragmatic distributed algorithm, designated the density based access method (DBM), which allows stations to dynamically optimize the network throughput based on run-time measurements of the channel status. Our simulation results demonstrate that the DBM is highly accurate. The performance in terms of throughput and fairness is nearly optimal by use of the proposed scheme. 相似文献
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