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In situ generation and detection of methyl radical by voltammetry

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Chinese Science Bulletin 2003年第11期48卷 1093-1096页

作者： song Junfeng CHEN Zhaopeng GUO wei WANG Fumin Institute of Analytical Science Northwest UniversityInstitute of Analytical Science Northwest UniversityDepartment of Chemistry Northwest UniversityDepartment of Chemistry Weinan Normal College Xi'an 710069 ChinaXi'an 710069 ChinaXi'an 710069 ChinaWeinan 714000 China

In persulfate-acetate, dimethyl sulfoxide or tert-butyl alcohol systems, in situ generation and detection of methyl free radical are realized with voltammetry. It includes the following successive processes. The persulfate S2O82 is polarographically reduced via one-electron addition to sulfate radical SO4, the SO4 initiates chain reaction with acetate, dimethyl sulfoxide, or tert-butyl alcohol on the electrode surface to produce a methyl radical, and one-electron reduction of the methyl radical yields its polarographic reduction wave. In comparison with the known techniques such as ultraviolet radiolysis coupling with electron spin resonance, etc., the proposed method is simple, sensitive and selective.

关键词：伏安法二甲基亚砜醋酸盐甲基自由基辐射分解 SO4^ˉ 硫酸根离子

Experimental study on the bank erosion and interaction with near-bank bed evolution due to fluvial hydraulic force

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International Journal of Sediment Research 2015年第1期30卷 81-89页

作者： Ming-hui YU Hong-yan wei song-bai WU State Key Laboratory of Water Resources and Hydropower Engineering Sciences Wuhan University

Bank erosion is a typical process of lateral channel migration,which is accompanied by vertical bed *** a main sediment source,the failed bank soil may directly cause the increase of sediment concentration and considerable channel evolution in a short *** paper presents an experimental study on non-cohesive and cohesive homogenous bank failure processes,influence of the failed bank soil on bank re-collapse,as well as the interaction between bank failure and near-bank bed evolution due to fluvial hydraulic force.A series of experiments were carried out in a 180° bend rectangular *** results reveal the iteration cycle between bank erosion and bed deformation:undercutting of the riverbank,slip failure of the submerged zone of the bank,as well as cantilever failure of the overhang,failed bank soil staying at bank toe temporarily or hydraulic transportation,exchange between the failed bank soil and bed material,bed material load being re-transported either as bed load or as suspended load,and bed *** as bank failure,the mixing of failed bank soil and bed material is more severe near the curved flow ***,non-cohesive bank failure tends to occur near the water surface while cohesive bank failure near the bank *** non-cohesive dense(sandy) soil,the bank erosion amount and residual amount of failed bank soil on the bed increase with the near-bank velocity or bed *** for cohesive soil,only bank erosion amount follows the above *** results are expected to provide theoretical basis for river management and flood prevention.

关键词： Bank erosion Near-bank bed evolution Hydraulic transport Interaction Flume experiment

Electrochemical performance of LiNi_(0.5)Mn_(0.5)O_2 with different synthesis methods

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Rare Metals 2015年第8期34卷 580-585页

作者： Hong Li Qiang Xu Xi-Xi Shi Da-wei song Lian-Qi Zhang Department of Applied Chemistry School of Chemical and Engineering Tianjin University School of Materials Science and Engineering Tianjin University of Technology

Li Ni0.5Mn0.5O2 as a cathode material for Li-ion battery was prepared by the metal acetate decomposition method, sol–gel method, and carbonate co-precipitation method, respectively. The influences of synthesis methods on the physical and electrochemical behaviors of Li Ni0.5Mn0.5O2 were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and electrochemical tests. XRD patterns show that both the sol–gel and carbonate co-precipitation methods can form single phase of layered structure, while a trace of Ni O impurity is observed via the metal acetate decomposition method. SEM results show the as-prepared carbonate particle has a spherical morphology with an average diameter of 10 lm, consisted of primary nano-sized particles with particle diameter of200 nm. The sample prepared by the carbonate co-precipitation method exhibits the highest discharge specific capacity and the best cycling stability, which results from the steady homogeneity of precursor constant by the fixation of CO2-3group. It can deliver an initial discharge specific capacity of 186.3 m Ahág-1, and retain 170 m Ahág-1after100 cycles at a current rate of 20 m Aág-1in the voltage range of 2.5–4.7 V at 25 °C. Moreover, even at the high temperature of 55 °C, it still delivers a reversible specific capacity of 222.6 m Ahág-1with little capacity loss after 30 cycles.

关键词： Sol–gel Carbonate co-precipitation LiNi0.5Mn0.5O2

Effect of high-molecular-weight glutenin subunit deletion on soft wheat quality properties and sugar-snap cookie quality estimated through near-isogenic lines

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Journal of Integrative Agriculture 2018年第5期17卷 1066-1073页

作者： ZHANG Xiao ZHANG Bo-qiao WU Hong-ya LU Cheng-bin Lü Guo-feng LIU Da-tong LI Man JIANG wei song Gui-hua GAO De-rong Key Laboratory of Wheat Biology and Genetic Improvement for Low and Middle Yangtze River Valley Wheat Region Ministry of Agriculture/Yangzhou Academy of Agricultural Sciences

High-molecular-weight glutenin subunits（HMW-GSs） play a critical role in determining the viscoelastic properties of wheat dough. The HMW-GSs are encoded by Glu-A1, Glu-B1, and Glu-D1 loci on the long arms of chromosomes 1A, 1B, and 1D, respectively. In the present study, four near-isogenic lines with different HMW-GS deletions and compositions at the Glu-A1 and Glu-D1 loci in Yangmai 18 background were used for quality analysis. Deletion in Glu-D1 showed much weaker gluten quality and dough strength than null Glu-A1 genotype and wild genotype（WT）, based on the measurements of sodium dodecyl sulfate（SDS）-sedimentation, lactic acid solvent retention capacity（SRC）, gluten index, development time, stability time, and alveograph P and L values. The deletion of Glu-D1 did not significantly affect grain hardness, grain protein content, water SRC, sodium carbonate SRC, and sucrose SRC. Double null genotype in Glu-A1 and Glu-D1 and single null genotype in Glu-D1 showed significantly higher cookie diameter, crispness, and lower cookie height compared with single null genotype in Glu-A1 and WT. These indicate that the null Glu-D1 genotype is useful for improvement of biscuit quality, and use of this germplasm would be a viable strategy to develop new wheat varieties for biscuit processing.

关键词： wheat HMW-GS deletion near-isogenic lines cookie quality

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输水渠系着生藻类多目标水力优化调控研究

节水灌溉 2024年第8期 117-123,130页

作者：胡靖宇管光华杨梦薇吴婷婷吴永妍中国南水北调集团中线有限公司河南分公司郑州450018 武汉大学水资源工程与调度全国重点实验室武汉430072 长江勘测规划设计研究有限责任公司武汉430010

输水渠系正面临着生藻类肆虐的危害,亟需通过水力调控方法剥离边壁的着生藻类,然而大范围的着生藻类脱落将进一步造成渠道水质破坏。为了探究同时满足除藻和水质管理双重目标的最优水力调控模式,研究基于着生藻类水力调控模型,以南方某... 详细信息

输水渠系正面临着生藻类肆虐的危害,亟需通过水力调控方法剥离边壁的着生藻类,然而大范围的着生藻类脱落将进一步造成渠道水质破坏。为了探究同时满足除藻和水质管理双重目标的最优水力调控模式,研究基于着生藻类水力调控模型,以南方某灌区四干渠为仿真实例,运用正交试验和极差分析方法设计不同类型的水力调控方案,对比分析水力调控对边壁着生藻类生物量的剥离效果以及对渠道水质的干扰。研究结果表明,在着生藻类爆发后期用高冲刷流量持续冲刷中等时长的调控模式可极大程度地兼顾藻类调控与水质管理两大需求。实际运用中应结合渠道的着生藻类爆发时段以及流量调度能力,在区间内选择适宜的水力调控组合。

关键词：输水渠系着生藻类水力除藻多目标优化

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Chinese patent medicine for chronic obstructive pulmonary disease based on principles of tonifying Qi, promoting blood circulation by removing blood stasis, and resolving phlegm: a systematic review of randomized controlled trials

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Journal of Traditional Chinese Medicine 2015年第1期35卷 1-10页

作者： Liu wei Yang Shuang Fu Min Li Jian song Yaling wei Baolin Liu Enshun Sun Zengtao Department of Integrated Traditional Chinese and Western Medicine West China Hospital of Sichuan University Department of Respiratory Medicine the Secondary Affiliated Hospital of Tianjin Traditional Chinese Medicine University

OBJECTIVE: To assess the efficacy and safety of Chinese patent medicine(CPM) with the principle of tonifying Qi, promoting blood circulation by removing blood stasis, and resolving phlegm(TQ-PBC-RP)in the management of stable chronic obstructive pulmonary disease(COPD).METHODS: A systematic review of randomized controlled trials(RCTs) identified from electronic databases and print was conducted. RCTs testing CPMs with TQ-PBC-RP against any type of controlled intervention in patients with stable COPD and assessing clinically relevant outcomes were included. Methodological quality was evaluated with the risk of bias tool according to systematic review handbook 5.0.2. Quality of evidence was estimatedby the rating approach developed by the Grading of Recommendations, Assessment, Development,and Evaluation Working ***: Thirteen eligible RCTs with 12 oral CPMs were tested. Significant differences between groups in favor of CPMs were not reported in all trials. Most trials included were deemed to be of low methodological quality with poor evidence *** of large data heterogeneity, statistical pooling was not performed for all ***: The effectiveness of CPM in the treatment of stable COPD is not supported by evidence. Currently, evidence from RCTs is scarce and methodologically weak. Considering the popularity of CPMs among patients undergoing COPD, rigorously designed trials are warranted.

关键词： Medicine, Chinese traditional Pulmo-nary disease, chronic obstructive Randomized con-trolled trial Review Reinforcing Qi-activatingblood Blood-activating stasis-removing

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星间通信系统高精度分光镜的研制

中国光学（中英文） 2024年第2期17卷 334-341页

作者：王振宇付秀华林兆文黄健山魏雨君吴桂青潘永刚董所涛王奔长春理工大学光电工程学院吉林长春130022 长春理工大学中山研究院广东中山528437 中山吉联光电科技有限公司广东中山528437

随着星间通信系统的迅速发展,数据传输的精度要求不断提高。分光镜作为系统的核心元件,其光谱特性和面形精度直接影响整个系统的传输精度。本文基于薄膜干涉理论,选取Ta_(2)O_(5)与SiO_(2)作为高低折射率膜层材料进行膜系设计,采用电子... 详细信息

随着星间通信系统的迅速发展,数据传输的精度要求不断提高。分光镜作为系统的核心元件,其光谱特性和面形精度直接影响整个系统的传输精度。本文基于薄膜干涉理论,选取Ta_(2)O_(5)与SiO_(2)作为高低折射率膜层材料进行膜系设计,采用电子束蒸发的方式在石英基板上制备高精度分光镜。同时根据膜层应力补偿原理建立面形修正模型,修正分光镜面形。光谱分析仪检测结果显示,分光镜在入射角度为21.5°~23.5°内,1563 nm透过率大于98%,1540 nm反射率大于99%。激光干涉仪检测结果显示,分光镜反射面形精度RMS由λ/10修正至λ/90(λ=632.8 nm),透过面形精度RMS为λ/90。

关键词：星间通信分光镜应力补偿面形精度

Resonance and Antiresonance in Electronic Transport Process Through a T-Shaped Quantum Waveguide

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Communications in Theoretical Physics 2008年第4期49卷 1039-1044页

作者： GAO Wen-Zhu ZHENG Yi-song GONG wei-Jiang SUN Lang Department of Physics Jilin University Changchun 130023 China

By means of the transfer matrix approach, the linear conductance spectrum for electronic transport through a T-shaped quantum waveguide is calculated. The resonant peaks and the antiresonant dips in the conductance spectrum are mainly focused. The previous prediction about their positions by other theoretical approaches is checked. In addition, a function of spin filtering is suggested based on the interplay of the resonance and antiresonance in this T-shaped quantum waveguide.

关键词： transfer matrix method linear conductance spectrum electronic transport quantum waveguide

Development and evaluation of an electropositive wellbore stabilizer with flexible adaptability for drilling strongly hydratable shales

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Petroleum Science 2015年第3期12卷 458-469页

作者： wei-An huang Zheng-song Qiu Ming-Lei Cui Xin Zhao Jun-Yi Liu wei-Ji Wang School of Petroleum Engineering China University of Petroleum School of Mechanical and Chemical Engineering The University of Western Australia Shandong Shengli Vocational College

In order to overcome serious instability prob- lems in hydratable shale formations, a novel electropositive wellbore stabilizer （EPWS） was prepared by a new approach. It has good colloidal stability, particle size dis- tribution, compatibility, sealing property, and flexible adaptability. A variety of methods including measurements of particle size, Zeta potential, colloidal stability, contact angle, shale stability index, shale dispersion, shale swelling, and plugging experiments were adopted to characterize the EPWS and evaluate its anti-sloughing capacity and flexible adaptability. Results show that the EPWS has advantages over the conventional wellbore stabilizer （ZX-3） in particle size distribution, colloidal stability, inhibition, compatibil- ity, and flexible adaptability. The EPWS with an average particle size of 507 nm and an average Zeta potential of 54 mV could be stable for 147 days and be compatible with salt tolerant or positive charged additives, and it also exhibited preferable anti-sloughing performance to hydrat- able shales at 77, 100, and 120 ~C, and better compatibility with sodium bentonite than ZX-3 and KC1. The EPWS can plug micro-fractures and pores by forming a tight external mud cake and an internal sealing belt to retard pressure transmission and prevent filtrate invasion, enhancing hydrophobicity of shale surfaces by adsorption to inhibithydration. The EPWS with flexible adaptability to tem- perature for inhibition and sealing capacity is available for long open-hole sections during drilling.

关键词： Shale Wellbore stabilizer Colloidalstability Plugging Hydrophobic modification