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Preparation and characterization of (CeO2)x-(Fe2O3)1-x nanocomposites:reduction kinetics and hydrogen storage
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作者 Shimaa G.Sayed Waleed M.A.El Rouby Ahmed A.Farghali 《稀有金属:英文版》 SCIE EI CAS CSCD 2020年第3期218-229,共12页
A series of nanosized CeO2-Fe2O3 mixed-oxide nanocomposites with different Ce4+/Fe3+molar ratios were successfully prepared by a co-precipitation technique.The surface area increased with Fe2O3 content increasing up t... A series of nanosized CeO2-Fe2O3 mixed-oxide nanocomposites with different Ce4+/Fe3+molar ratios were successfully prepared by a co-precipitation technique.The surface area increased with Fe2O3 content increasing up to 60 wt%in the composite.However,with further increase in Fe2O3 content,the surface area began to decrease.The reduction processes of the CeO2-Fe2O3 nanocomposites were studied in a hydrogen atmosphere at 300-600℃.The reduction rates increased by increasing both the temperature and Fe2O3 content in the nanocomposites.The microstructure of the reduced composites at 500℃illustrated the presence of a considerable number of macro-and micro-pores.The activation energy values were calculated which were in the range of 3.56-5.37 kJ mol-1 at the initial stages(up to 35%reduction)and 5.21-10.2 kJ·mol-1 at the final stages(up to 80%reduction)of reduction.The rate-controlling mechanisms in both the initial and final reduction stages were determined,and the initial reaction stage was controlled by combined gaseous diffusion and interfacial chemical reaction mechanisms for all the composites except for pure CeO2,which was controlled by a chemical reaction mechanism.The final reaction stage was controlled by a gaseous diffusion mechanism for some composites,while for the others it was controlled by combined gaseous diffusion and interfacial chemical reaction mechanisms.The hydrogen sorption properties of the nanocomposites were studied by pressure composition isotherms using a volumetric method.Hydrogen storage in the nanocomposites increased by increasing the temperature because of the formation of oxygen vacancies which enhance atomic H adsorption and function as strong adsorption sites forming more metal hydride covalent bonds. 展开更多
关键词 CeO2-Fe2O3 nanocomposite REDUCTION kinetics REDUCTION mechanism Hydrogen storage Oxygen VACANCIES
Poverty Reduction Effects of China’s Aid and Investment to Developing Countries 预览
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作者 张原 《中国经济学人:英文版》 2020年第2期2-18,共17页
The Chinese approach to poverty reduction is a government-led and marketbased approach that gives priority to infrastructure and combines fiscal subsidy with development as an antidote to poverty.These characteristics... The Chinese approach to poverty reduction is a government-led and marketbased approach that gives priority to infrastructure and combines fiscal subsidy with development as an antidote to poverty.These characteristics are also evident in China’s cooperation with other developing countries on poverty reduction.China supports other developing countries to reduce poverty via aid and investment mainly in the field of infrastructure.While the government and SOEs take the lead in foreign aid and investment,China also invites other sources of capital to participate in market-based development in partnership with recipient countries.Our empirical research finds that aid and investment from China are generally conducive to reducing poverty incidence in recipient developing countries,but their poverty reduction effects vary across different types of aid and investment.The elements characteristic of the Chinese approach to poverty reduction proved to be effective in helping other developing countries reduce poverty as well.Nevertheless,the effectiveness of aid and investment in reducing poverty is subject to the governance and market efficiency of recipient countries.In order for the Chinese experience to work in less developed countries,future cooperation on poverty reduction must put a premium on governance and market systems. 展开更多
关键词 poverty reduction effects foreign aid cross-border investment cooperation on poverty reduction threshold regression.
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棉田棉蚜飞防药剂筛选及农药减量增效药效分析 预览
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作者 吴金龙 冯宏祖 +3 位作者 马小艳 王兰 张亚林 武刚 《新疆农业科学》 CAS CSCD 北大核心 2020年第1期167-172,共6页
【目的】筛选高效安全适用于无人机防治棉蚜的药剂和助剂,实现农药减量增效。【方法】采用田间喷雾法测定大疆MG-1P型植保无人机喷洒5种药剂及添加助剂后对棉蚜防效。【结果】药后1 d,200 g/L丁硫克百威EC对棉蚜的防效最高,达85.9%,80%... 【目的】筛选高效安全适用于无人机防治棉蚜的药剂和助剂,实现农药减量增效。【方法】采用田间喷雾法测定大疆MG-1P型植保无人机喷洒5种药剂及添加助剂后对棉蚜防效。【结果】药后1 d,200 g/L丁硫克百威EC对棉蚜的防效最高,达85.9%,80%烯啶·吡蚜酮WG防效次之,达75.1%;药后7 d,22%氟啶虫胺腈SC防效最高,防效为96.2%,70%吡虫啉WG防效次之,为92.4%。施药后1~7 d,药剂减量20%与对照无显著差异,施药后15 d,减量20%与对照存在显著差异,减量10%与对照无显著差异。【结论】供试药剂中22%氟啶虫胺腈悬浮剂和70%吡虫啉水分散颗粒剂对棉蚜防效最佳,且添加助剂后减量10%~20%对棉蚜的防效与常规药量相比二者防效无显著性差异。 展开更多
关键词 棉花 棉蚜 无人机 药剂筛选 减量 增效
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芽孢杆菌Bacillus sp.dwc-2对模拟地下水中U(Ⅵ)的还原行为研究 预览
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作者 王静 刘军 +6 位作者 赵长菘 涂鸿 贺含毅 杨吉军 廖家莉 杨远友 刘宁 《原子能科学技术》 EI CAS CSCD 北大核心 2020年第1期6-13,共8页
在厌氧条件下研究了西南地区一种典型土壤微生物芽孢杆菌Bacillus sp.dwc-2对模拟地下水中U(Ⅵ)的还原行为,重点考察了时间、无机阴离子、腐殖酸(HA)及富里酸(FA)对还原的影响,并利用TEM、EDS、SAED和XPS对还原后的样品进行了表征。结... 在厌氧条件下研究了西南地区一种典型土壤微生物芽孢杆菌Bacillus sp.dwc-2对模拟地下水中U(Ⅵ)的还原行为,重点考察了时间、无机阴离子、腐殖酸(HA)及富里酸(FA)对还原的影响,并利用TEM、EDS、SAED和XPS对还原后的样品进行了表征。结果表明:在pH=7.0、cNaHCO3=5 mmol/L和T=303 K条件下,Bacillus sp.dwc-2对U(Ⅵ)的还原率随时间的增加而增加,24 h内最大还原率为12.2%,此后则随时间的增加逐渐降低;HA和FA对U(Ⅵ)的微生物还原行为有一定影响,其中HA和FA浓度为25 mg/L时,U(Ⅵ)的还原在24 h最明显,其还原率分别为14.2%和16.2%,但随着HA和FA浓度的继续增加,因在U(Ⅵ)离子与HA、FA形成的配合物表面形成致密的腐殖层,抑制了电子的转移,阻止了U(Ⅵ)的还原。此外,研究表明HCO3-也会抑制U(Ⅵ)的还原。TEM-SAED和XPS分析证实了还原过程中U(Ⅳ)的存在。上述结果可为真实环境中微生物还原U(Ⅵ)提供基础数据和参考。 展开更多
关键词 芽孢杆菌 HA FA U(Ⅵ) 还原
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Technology of Eliminating White Smoke from Flue Gas 预览
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作者 Ping ZHAO Jinghai TAN +1 位作者 Minghao WANG Hongliang BAO 《气象与环境研究:英文版》 CAS 2020年第1期66-69,共4页
Based on the corresponding relationship chart of saturation humidity and temperature of wet flue gas,the formation mechanism of"white smoke plume"and the technology of eliminating white smoke from flue gas w... Based on the corresponding relationship chart of saturation humidity and temperature of wet flue gas,the formation mechanism of"white smoke plume"and the technology of eliminating white smoke from flue gas were analyzed.Besides,the energy balance of each elimination technology was calculated according to the theoretical formulas,and"energy saving"was compared.The technology of eliminating white smoke from flue gas needs to solve the problems of"emission reduction"and"energy conservation"in industrial enterprises.It brings new ideas and directions to enterprises for"energy conservation and emission reduction",eases the pressure on enterprises to protect the environment,improves enterprises'use efficiency of primary energy,and provides a reliable choice for enterprises to survive and enhance their competitiveness.In addition,it can effectively solve the dehumidification and elimination of wet flue gas,not only eliminate the pollution from white smoke plume,but also achieve environmental protection up-to-standard and ultra-low near zero emission at low cost,enhance the efficiency of coal combustion,in particular recover the moisture and residual heat in flue gas,and solve the contradiction between the environment and development. 展开更多
关键词 ELIMINATION of WHITE SMOKE Emission reduction ENERGY conservation WHITE wet SMOKE PLUME ENERGY Environment
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Detection of Pesticide Metsulfuron-methyl in Drinking Water by Differential Pulse Cathodic Stripping Voltammetry 预览
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作者 Chuan JIANG Xuwei TANG +2 位作者 Xiaolong ZOU Xiayi ZHANG Weibo ZHANG 《气象与环境研究:英文版》 CAS 2020年第1期70-72,77共4页
Differential pulse cathodic stripping voltammetry was used to determine pesticide metsulfuron-methyl on a suspended mercury electrode.Specific experimental parameters,such as the pH of Britton-Robinson buffer,accumula... Differential pulse cathodic stripping voltammetry was used to determine pesticide metsulfuron-methyl on a suspended mercury electrode.Specific experimental parameters,such as the pH of Britton-Robinson buffer,accumulation time,accumulation potential,and initial potential were optimized.The results show that a typical reduction peak appeared when pH was 2.0-4.0 and initial potential ranged from-0.75 to-1.0 V.To obtain the stripping signal of the best reduction peak,it is determined that the best pH was 2.0.The detection limit of the method was only 0.04 mg/L,and it had good selectivity and high accuracy,so the method has high sensitivity.In the analysis of actual drinking water,the recovery rate of metsulfuron-methyl could reach 93%-101%. 展开更多
关键词 Differential pulse cathodic STRIPPING VOLTAMMETRY Suspended mercury electrode Metsulfuron-methyl PESTICIDE Reduction PEAK
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前后联合直视下复位治疗新鲜下胫腓联合损伤
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作者 郑建平 秦悦 杨海波 《中国矫形外科杂志》 CAS CSCD 北大核心 2020年第6期490-495,共6页
[目的]探讨前、后联合直视下复位治疗Dannis-Weber C型踝关节骨折中新鲜的下胫腓联合损伤的临床疗效。[方法]回顾性分析本科收治的85例Dannis-Weber C型踝关节骨折,所有下胫腓联合损伤均为新鲜损伤。依据下胫腓前间隙是否被切开直视下... [目的]探讨前、后联合直视下复位治疗Dannis-Weber C型踝关节骨折中新鲜的下胫腓联合损伤的临床疗效。[方法]回顾性分析本科收治的85例Dannis-Weber C型踝关节骨折,所有下胫腓联合损伤均为新鲜损伤。依据下胫腓前间隙是否被切开直视下复位将患者分为两组,其中直视复位组42例,常规复位组43例。对比两组患者围手术期资料、美国足踝外科协会(AOFAS)踝-后足评分,疼痛视觉模拟评分(VAS)和影像评估下胫腓复位情况。[结果]两组患者均顺利手术,直视复位组3例患者出现后踝骨折复位不满意致使下胫腓不能精准复位,术中通过切开下胫腓前间隙辅助复位直到满意;常规组有3例患者术中出现固定后踝骨块的钉板放置不满意,术中予以纠正。两组患者随访24~31个月,平均(26.14±1.48)个月。直视复位组开始负重时间近似于常规复位组,差异无统计学意义(P>0.05);直视复位组完全负重时间明显早于常规复位组,差异有统计学意义(P<0.05)。末次随访时,两组患者AOFAS评分均较术前显著增加(P<0.05);而两组的VAS评分均显著降低(P<0.05)。术前两组间ASFAS和VAS评分的差异均无统计学意义(P>0.05),但末次随访时直视复位组的AOFAS和VAS评分均显著优于常规复位组(P<0.05)。影像评估方面:直观组复位不良率为7.14%(3/42),而常规复位组为33.33%(15/45),差异有统计学意义(P<0.05)。至末次随访时,直视复位组发生踝关节炎1例,而常规复位组6例,但差异无统计学意义(P>0.05)。Spearman秩相关分析表明:复位不良累及的平面数与AOFAS评分呈负相关(R=-0.878,P<0.001)。[结论]下胫腓复位质量与功能恢复密切相关,直视下复位手术治疗Dannis-Weber C型踝关节骨折的下胫腓联合损伤可明显提升复位质量。 展开更多
关键词 下胫腓联合损伤 直视 前后入路 复位
国内外垃圾无害化减量化资源化经验比较研究 预览
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作者 朱中宏 王伟伟 +2 位作者 姜宇龙 于清月 吴昱筱 《价值工程》 2020年第5期113-114,共2页
城市化进程的加快导致城市人口较为集中且产生的生活垃圾占比较高。考虑到绿色发展和可持续发展的目标,本文剖析了日本、台湾、美国和德国对生活垃圾处理的方式与经验,并将其划分为以政府为主导和以市场为主导的两类资源化体系;通过经... 城市化进程的加快导致城市人口较为集中且产生的生活垃圾占比较高。考虑到绿色发展和可持续发展的目标,本文剖析了日本、台湾、美国和德国对生活垃圾处理的方式与经验,并将其划分为以政府为主导和以市场为主导的两类资源化体系;通过经验借鉴,提出了完善镇江市资源化体系的对策建议。 展开更多
关键词 生活垃圾 无害化 减量化 资源化
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Three matrix conditions for the reduction of finite automata based on the theory of semi-tensor product of matrices
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作者 Jumei YUE Yongyi YAN Zengqiang CHEN 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2020年第2期227-229,共3页
Dear editor,Reduction of finite automata(FA)is of great importance because of its practical applications in engineering;for example the memory space of hardware realization grows exponentially with the number of state... Dear editor,Reduction of finite automata(FA)is of great importance because of its practical applications in engineering;for example the memory space of hardware realization grows exponentially with the number of states of FSMs.Existing results for reducing FA can roughly be classified into four categories:merging of states[1]. 展开更多
关键词 STP Sr THREE MATRIX CONDITIONS for the REDUCTION of finite AUTOMATA based on the theory of semi-tensor product of matrices
Controlled synthesis of nanosized Si by magnesiothermic reduction from diatomite as anode material for Li-ion batteries 预览
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作者 Li-fen Guo Shi-yun Zhang +6 位作者 Jian Xie Dong Zheng Yuan Jin Kang-yan Wang Da-gao Zhuang Wen-quan Zheng Xin-bing Zhao 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2020年第4期515-525,共11页
Li-ion batteries(LIBs)have demonstrated great promise in electric vehicles and hybrid electric vehicles.However,commercial graphite materials,the current predominant anodes in LIBs,have a low theoretical capacity of o... Li-ion batteries(LIBs)have demonstrated great promise in electric vehicles and hybrid electric vehicles.However,commercial graphite materials,the current predominant anodes in LIBs,have a low theoretical capacity of only 372 mAh·g−1,which cannot meet the everincreasing demand of LIBs for high energy density.Nanoscale Si is considered an ideal form of Si for the fabrication of LIB anodes as Si–C composites.Synthesis of nanoscale Si in a facile,cost-effective way,however,still poses a great challenge.In this work,nanoscale Si was prepared by a controlled magnesiothermic reaction using diatomite as the Si source.It was found that the nanoscale Si prepared under optimized conditions(800°C,10 h)can deliver a high initial specific capacity(3053 mAh·g−1 on discharge,2519 mAh·g−1 on charge)with a high first coulombic efficiency(82.5%).When using sand-milled diatomite as a precursor,the obtained nanoscale Si exhibited a well-dispersed morphology and had a higher first coulombic efficiency(85.6%).The Si–C(Si:graphite=1:7 in weight)composite using Si from the sand-milled diatomite demonstrated a high specific capacity(over 700 mAh·g−1 at 100 mA·g−1),good rate capability(587 mAh·g−1 at 500 mA·g−1),and a long cycle life(480 mAh·g−1 after 200 cycles at 500 mA·g−1).This work gives a facile method to synthesize nanoscale Si with both high capacity and high first coulombic efficiency. 展开更多
关键词 silicon anode magnesiothermic reduction DIATOMITE Li-ion batteries
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PDCA循环管理在降低住院患者用药错误的临床应用 预览
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作者 陈腊梅 《中国社区医师》 2020年第10期187-187,189,共2页
目的:探究PDCA循环管理在降低住院患者用药错误的应用效果。方法:2017年7月-2018年6月共发生用药错误23例,应用PDCA循环管理进行回顾性分析,找出主因、制定计划、实施措施、检查落实、处理结果。对比运用PDCA循环管理前后,病区药品管理... 目的:探究PDCA循环管理在降低住院患者用药错误的应用效果。方法:2017年7月-2018年6月共发生用药错误23例,应用PDCA循环管理进行回顾性分析,找出主因、制定计划、实施措施、检查落实、处理结果。对比运用PDCA循环管理前后,病区药品管理达标率及住院患者用药错误发生例数。结果:运用PDCA循环管理后,病区药品管理达标率由整改前的85%升至98%;管理后用药错误发生例数降至15例。结论:运用PDCA循环管理能够显著降低临床用药错误发生情况,保证患者用药安全。 展开更多
关键词 PDCA循环管理 降低 用药错误
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Hybrid Channel Access Mechanism Based on Coexistence Scenario of NR-Unlicensed 预览
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作者 Zhening Zhang Jingyi Chen +2 位作者 Mingyang Dong Yuehong Gao Jingjing Wang 《中国通信:英文版》 SCIE CSCD 2020年第1期49-62,共14页
With the rapid development of 5G NR(New Radio),the explosive increment of traffic amount is calling the utilization of unlicensed band.3GPP has proposed LAA(Licensed Assisted Access)to use LTE in unlicensed band and p... With the rapid development of 5G NR(New Radio),the explosive increment of traffic amount is calling the utilization of unlicensed band.3GPP has proposed LAA(Licensed Assisted Access)to use LTE in unlicensed band and pointed out that NR-U(NR-Unlicensed)can reuse most designs of it.However,the existing channel access mechanism of LAA is conservative under the coexistence scenario of NR-U,which leads to the waste of time resource.To address the problem this paper proposes a hybrid channel access mechanism to take advantage of the LBT(Listen-Before-Talk)mechanism of LAA when channel is quite busy and transmit directly with reduced power when it is relatively idle.The channel busy degree is judged by a series of periodically updated adaptive thresholds.System-level simulation verifies that under the coexistence scenario of NR-U the proposed mechanism can achieve higher UPT(User Perceived Throughput)and lower delay than other channel access mechanisms. 展开更多
关键词 NR-U CHANNEL access mechanism LBT power REDUCTION
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三种降低硝酸盐含量水培技术对菜心品质的影响研究 预览
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作者 冯慧珊 余知远 《广东农工商职业技术学院学报》 2020年第1期83-86,共4页
以广州乾农农业科技发展有限公司"特青迟心4号菜心"为试验材料,先采用日本园试营养液配方以水培方式来进行种植,当达到采收标准前两周时,各取五十株菜心,分别采用酰胺态氮来全部代替营养液配方中的硝态氮的方法、收获前直接... 以广州乾农农业科技发展有限公司"特青迟心4号菜心"为试验材料,先采用日本园试营养液配方以水培方式来进行种植,当达到采收标准前两周时,各取五十株菜心,分别采用酰胺态氮来全部代替营养液配方中的硝态氮的方法、收获前直接在营养液中中断硝态氮供给的方法和将种植方式转为基质培的方法种植两周,并测定相应指标,研究不同培养技术对降低菜心硝酸盐含量的变化规律和对菜心品质的影响。实验结果表明,三种技术均能有效降低水培蔬菜硝酸盐含量,然而替代法和中断法均会对蔬菜的品质带来较严重的影响,而基质培方法则不会。 展开更多
关键词 降低 水培蔬菜 硝酸盐含量 品质
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Characteristics of the reduction behavior of zinc ferrite and ammonia leaching after roasting 预览
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作者 Chao Wang Yu-feng Guo +4 位作者 Shuai Wang Feng Chen Yu-jia Tan Fu-qiang Zheng Ling-zhi Yang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2020年第1期26-36,共11页
A novel method for recovering zinc from zinc ferrite by reduction roasting–ammonia leaching was studied in this paper. The reduction thermodynamic of zinc ferrite by CO was analyzed. The effects of roasting parameter... A novel method for recovering zinc from zinc ferrite by reduction roasting–ammonia leaching was studied in this paper. The reduction thermodynamic of zinc ferrite by CO was analyzed. The effects of roasting parameters on the phase transformation and conversion rate of zinc ferrite, and the leaching behavior of zinc from the reductive roasted samples by ammonia leaching, were experimentally investigated. The mineralogical phase compositions and chemical compositions of the samples were characterized by X-ray diffraction and chemical titration methods, respectively. The results showed that most of the zinc ferrite was transformed to zinc oxide and magnetite after weak reduction roasting. 86.43% of the zinc ferrite was transformed to zinc oxide under the optimum conditions: CO partial pressure of 25%, roasting temperature of 750°C, and roasting duration of 45 min. Finally, under the optimal leaching conditions, 78.12% of zinc was leached into the solution from the roasted zinc ferrite while all iron-bearing materials were kept in the leaching residue. The leaching conditions are listed as follows: leaching duration of 90 min,ammonia solution with 6 mol/L concentration, leaching temperature of 50°C, solid-to-liquid ratio of 40 g/L, and stirring speed of 200 r/min. 展开更多
关键词 ZINC FERRITE reduction ROASTING AMMONIA LEACHING ZINC extraction zinc-bearing waste
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Integrating photocatalytic reduction of CO2 with selective oxidation of tetrahydroisoquinoline over InP-In2O3 Z-scheme p-n junction
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作者 Bohang Zhao Yi Huang +2 位作者 Dali Liu Yifu Yu Bin Zhang 《中国科学:化学英文版》 SCIE EI CAS CSCD 2020年第1期28-34,共7页
The development of a facile strategy to construct stable hierarchal porous heterogeneous photocatalysts remains a great challenge for efficient CO2 reduction.Additionally,hole-trapping sacrificial agents(e.g.,triethan... The development of a facile strategy to construct stable hierarchal porous heterogeneous photocatalysts remains a great challenge for efficient CO2 reduction.Additionally,hole-trapping sacrificial agents(e.g.,triethanolamine,triethylamine,and methanol)are mostly necessary,which produce useless chemicals,and thus cause costs/environmental concerns.Therefore,utilizing oxidation ability of holes to develop an alternative photooxidation reaction to produce value-added chemicals,especially coupled with CO2 photoreduction,is highly desirable.Here,an in situ partial phosphating method of In2O3 is reported for synthesizing In P–In2O3 p-n junction.A highly selective photooxidation of tetrahydroisoquinoline(THIQ)into value-added dihydroisoquinoline(DHIQ)is to replace the hole driven oxidation of typical sacrificial agents.Meanwhile,the photoelectrons of In P–In2O3 p-n junction can induce the efficient photoreduction of CO2 to CO with high selectivity and stability.The evolution rates of DHIQ and CO are 2 and 3.8 times higher than those of the corresponding In2O3 n-type precursor,respectively.In situ irradiated X-ray photoelectron spectroscopy and electron spin resonance are utilized to confirm that the direct Z-scheme mechanism of In P–In2O3 p-n junction accelerate the efficient separation of photocarriers. 展开更多
关键词 CO2 reduction DEHYDROGENATION photocatalysis Z-scheme TETRAHYDROISOQUINOLINE
吡唑醚菌酯合成工艺的原子经济性评价
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作者 白玉兰 许洁 +5 位作者 吴现力 王菊 陈怀春 梁晨 徐啸 杜春华 《农药》 CAS CSCD 北大核心 2020年第3期175-179,183,共6页
[目的]比较吡唑醚菌酯2种主流合成工艺的原子经济性,分析合成过程的主要杂质。[方法]通过2种工艺涉及的24个单反应、3个总反应的完整反应式,计算这些反应的原子经济性,给出主要过程的副反应产物。[结果]先缩合路线与后缩合路线的原子经... [目的]比较吡唑醚菌酯2种主流合成工艺的原子经济性,分析合成过程的主要杂质。[方法]通过2种工艺涉及的24个单反应、3个总反应的完整反应式,计算这些反应的原子经济性,给出主要过程的副反应产物。[结果]先缩合路线与后缩合路线的原子经济性相近。选择性加氢还原、H2O2-HBr体系选择性溴化是目前原子利用率较高的单元过程。重氮化制备对氯苯肼盐酸盐,而后环合制备1-(4-氯苯基)-3-吡唑醇是三废的主要来源。副反应产生的杂质主要有过度还原产生的胺化物、深度溴化产生的二溴化物、-NHOH的O-酰化副产物等。[结论]提供了一个计算多过程总反应原子经济性及利用原子经济性工具寻找农药工艺开发思路的典型案例。应开发吡唑醚菌酯中间体对氯苯肼盐酸盐、1-(4-氯苯基)-3-吡唑醇的新合成工艺。 展开更多
关键词 吡唑醚菌酯 原子经济性 还原 溴化 重氮化 杂质
Speckle reduction using phase plate array and lens array 预览
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作者 Xiaohui Ma Anting Wang +2 位作者 Fenghua Ma Shuimei Wu Hai Ming 《光电进展(英文)》 2020年第1期16-21,共6页
In this paper,a solution for speckle reduction using phase plate array(PPA)and lens array(LA)in a motionless way is proposed.The specially designed PPA is composed of sub-phase plates,which are constituted by phase pa... In this paper,a solution for speckle reduction using phase plate array(PPA)and lens array(LA)in a motionless way is proposed.The specially designed PPA is composed of sub-phase plates,which are constituted by phase patterns formed by Hadamard sub-matrices.Each component of the proposed optical system should satisfy the stated relationships.The incident laser beam will be incoherent after passing through PPA,and superpose on the screen under the action of LA and main lens.Speckle reduction can be achieved by the averaging of the incoherent speckle patterns.Because of abandoning the mechanical movement,it will be suitable for laser displays and images. 展开更多
关键词 laser DISPLAY SPECKLE REDUCTION LENS ARRAY HADAMARD
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中西医结合侧方入针复位技术在老年难复型股骨转子间骨折中的应用
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作者 周奉皋 邱斌 何涛 《四川中医》 2020年第3期138-141,共4页
目的:观察股骨近端侧方入针复位技术在PFNA治疗老年难复型股骨转子间骨折中的应用效果。方法:选取2013年1月至2014年12月采用PFNA治疗的老年股骨转子间骨折35例:男14例,女21例;年龄70~94岁,平均76.6岁。根据复位方式不同分为观察组(股... 目的:观察股骨近端侧方入针复位技术在PFNA治疗老年难复型股骨转子间骨折中的应用效果。方法:选取2013年1月至2014年12月采用PFNA治疗的老年股骨转子间骨折35例:男14例,女21例;年龄70~94岁,平均76.6岁。根据复位方式不同分为观察组(股骨近端侧方入针复位技术闭合微创复位)14例、对照组(有限切开钳夹复位)21例。回顾性比较两组患者手术时间、术中出血量和术后并发症发生情况,末次随访时根据髋关节Harris评分标准评定疗效。结果:观察组与对照组患者手术时间平均分别为(55.8±18.5)分钟、(71.3±21.9)分钟,术中出血量平均分别为(151.3±55.1)ml、(232.5±71.5)ml。以上项目两组之间比较有统计学意义差异(P<0.05)。两组患者术后获平均12个月(6~23个月)随访。骨折均获骨性愈合,愈合时间分别为(12.2±4.0)周,(12.1±3.5)周,术后并发症发生率分别为7.1%(1/14)及9.5%(2/21),末次随访时据髋关节Harris评分标准评定疗效观察组优11例,良1例,可2例,对照组优15例,良4例,可2例。以上项目两组之间比较无统计学意义差异(P>0.05)。结论:PFNA治疗老年难复型股骨转子间骨折时,股骨近端侧方入针复位技术有助于缩短手术时间、减少术中出血量,从而降低手术创伤,值得临床推广。 展开更多
关键词 股骨转子间骨折 骨折固定术 复位 治疗结果
Towards the diffusion source cost reduction for NdFeB grain boundary diffusion process
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作者 H.X.Zeng Z.W.Liu +2 位作者 J.S.Zhang X.F.Liao H.Y.Yu 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第1期50-54,共5页
Aiming at improving the performance/cost ratio in grain boundary diffusion process(GBDP),the critical RE containing Pr-Al-Cu alloy,less expensive RE containing La-Al-Cu alloy and non-RE Al-Cu alloy were employed as th... Aiming at improving the performance/cost ratio in grain boundary diffusion process(GBDP),the critical RE containing Pr-Al-Cu alloy,less expensive RE containing La-Al-Cu alloy and non-RE Al-Cu alloy were employed as the diffusion sources.The preliminary results show that the coercivity was successfully enhanced from 1000 kA/m to 1695,1156 and 1125 kA/m by Pr70Al20Cu10,La70Al20Cu10 and Al75Cu25(at.%) alloys diffusion,respectively,due to the formation of(Nd,Pr)-Fe-B,La2 O3 and c-Nd2 O3 phases respectively,after diffusion.It is also found that the corrosion resistance can be improved by Al-Cu diffusion due to the positive effects of Al and Cu elements in grain boundary.The present results demonstrated the various coercivity enhancement mechanisms for the GBDP based on different diffusion sources,and provided feasible solutions for cost reduction of GBDP and NdFeB production by saving RE resource. 展开更多
关键词 Grain boundary diffusion Cost reduction COERCIVITY Microstructure Corrosion resistance
Effect of reduction in area per pass on strain distribution and microstructure during caliber rolling in twinning-induced plasticity steel
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作者 Joong-ki Hwang Sung Jin Kim 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2020年第1期62-74,共13页
The effects of reduction in area(RA)per pass during caliber rolling on microstructure and strain distribution of twinninginduced plasticity steel have been investigated to find solutions to make a more homogeneous mat... The effects of reduction in area(RA)per pass during caliber rolling on microstructure and strain distribution of twinninginduced plasticity steel have been investigated to find solutions to make a more homogeneous material along the radial direction for wire rod applications.The steel wires subjected to an average RA per pass of 2.5%(skin pass caliber rolling)and 10.0%(conventional caliber rolling)were analyzed.The skin pass caliber-rolled wire was characterized as a duplex fiber texture of major<111>and minor<100>.and the textures were almost same at/between center and surface area,which is totally different from those of conventional caliber rolling and wire drawing.The skin pass caliber rolling led to more homogeneous microstructure and mechanical properties along the radial direction in comparison with the conventional caliber rolling and wire drawing due to the more homogeneous Hall-Petch hardening,dislocation hardening,and texture behavior with area,resulting in higher formability. 展开更多
关键词 Twinning-induced plasticity steel Caliber rolling Deformation twin Reduction in area Skin pass
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