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基于科学思维视角探讨一道电磁感应高考试题
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作者 姚华鑫 闫俊卿 《河北理科教学研究》 2024年第1期54-59,共6页
本文探讨教学2023年高考浙江卷物理第19题,运用多视角解答问题时遇到答案不一致的矛盾.在科学思维理论的指引下通过“模型建构、提出问题、科学推理、科学论证、迁移创造、质疑创新”等解决问题的过程和经历分析、评价、创造等思维过程... 本文探讨教学2023年高考浙江卷物理第19题,运用多视角解答问题时遇到答案不一致的矛盾.在科学思维理论的指引下通过“模型建构、提出问题、科学推理、科学论证、迁移创造、质疑创新”等解决问题的过程和经历分析、评价、创造等思维过程,使得探讨层层递进、不断深入,明确了问题的关键所在,并为解决问题提供多种可行的办法,同时也探讨题目假设条件的严谨性、结论运用条件性和感应电动势产生机制,培养学生批判性思维和辩证性思维,达到发展学生科学思维的教学目标. 展开更多
关键词 科学思维 高阶思维 磁能 电磁感应强度 矛盾探讨
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Recent advances in paired electrolysis coupling CO_(2) reduction with alternative oxidation reactions 被引量:1
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作者 Deng Li Jiangfan yang +2 位作者 Juhong Lian junqing yan Shengzhong(Frank) Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期406-419,I0011,共15页
Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)holds great promise in green energy conversion and storage.However,for current CO_(2) electrolyzers that rely on the oxygen evolution reaction,a large portion of the... Electrocatalytic CO_(2) reduction reaction(CO_(2)RR)holds great promise in green energy conversion and storage.However,for current CO_(2) electrolyzers that rely on the oxygen evolution reaction,a large portion of the input energy is"wasted"at the anode due to the high overpotential requirement and the recovery of low-value oxygen.To make efficient use of the electricity during electrolysis,coupling CO_(2)RR with anodic alternatives that have low energy demands and/or profitable returns with high-value products is then promising.Herein,we review the latest advances in paired systems for simultaneous CO_(2) reduction and anode valorization.We start with the cases integrating CO_(2)RR with concurrent alternative oxidation,such as inorganic oxidation using chloride,sulfide,ammonia and urea,and organic oxidation using alcohols,aldehydes and primary amines.The paired systems that couple CO_(2)RR with on-site oxidative upgrading of CO_(2)-reduced chemicals are also introduced.The coupling mechanism,electrochemical performance and economic viability of these co-electrolysis systems are discussed.Thereby,we then point out the mismatch issues between the cathodic and anodic reactions regrading catalyst ability,electrolyte solution and reactant supply that will challenge the applications of these paired electrolysis systems.Opportunities to address these issues are further proposed,providing some guidance for future research. 展开更多
关键词 ELECTROLYSIS Coupling Reaction CO_(2)Utilization Co-Valorization
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金属(Fe,Co,Ni,Cu)掺杂的Mo2C催化剂在TiO2表面用于中性条件光催化分解水产氢 被引量:9
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作者 刘晶 盖瑞侯得 +1 位作者 闫俊青 刘生忠 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第1期205-216,共12页
中性条件下的分解水产氢(HER)是化工领域的重要反应之一,其效率取决于催化剂的内在特性.在本工作中,我们利用3d金属(Fe,Co,Ni,Cu)对Mo2C进行掺杂来调节其费米能级,从而达到催化剂可在中性条件下吸附水并提高最终活性的目的.首先,利用简... 中性条件下的分解水产氢(HER)是化工领域的重要反应之一,其效率取决于催化剂的内在特性.在本工作中,我们利用3d金属(Fe,Co,Ni,Cu)对Mo2C进行掺杂来调节其费米能级,从而达到催化剂可在中性条件下吸附水并提高最终活性的目的.首先,利用简单浸渍法将四种金属的前驱体吸附到MoO3表面,然后通过煅烧一步合成金属掺杂的Mo2C.产物Mo2C的XRD峰位移以及XPS表征结果表明,四种金属通过掺杂进入到了Mo2C晶格.利用HRTEM以及相应的元素面扫分析,也证明金属确实掺杂进入了Mo2C体相.考察了Mo2C基催化剂在中性条件下电解水产氢的性能,结果表明,在10 mA/cm2条件下,Cu-Mo2C催化剂表现出最优的HER性能,其次,是Ni-Mo2C,Co-Mo2C,Fe-Mo2C和纯Mo2C,它们的过电位分别为78,90,95,100和173 mV,Tafel斜率分别是40,43,42,56和102 mV/dec.利用阻抗测试详细分析了催化剂-反应液界面电阻Rct的变化情况,样品Mo2C,Fe-Mo2C,Co-Mo2C,Ni-Mo2C和Cu-Mo2C拟合后的Rct值分别为119,89.6,46.5,33.8和23.2 ohm/cm^2,表明金属掺杂能明显降低催化剂的反应界面电阻.由于电催化过程的主要研究对象是表面双电层,所以我们利用循环伏安法计算了催化剂表面双电层的数值,得到上述五个样品的Cdl数值分别为0.047,0.06,0.1,0.16和0.24 F/cm^2,双电层的提高为催化剂表面提供了更多的反应位点.考虑了到光解水的界面反应实质也是电催化过程,我们通过浸渍方法将催化剂负载到锐钛矿TiO2表面,考察调控的功函数对光催化效率的影响.XPS表征验证了M-Mo2C负载于TiO2表面.负载助催化剂的TiO2-M-Mo2C样品均表现出了优于纯TiO2的光解水产氢性能.样品TiO2-Cu-Mo2C,TiO2-Ni-Mo2C,TiO2-Co-Mo2C,TiO2-Fe-Mo2C,TiO2-Mo2C和纯TiO2的产氢速率分别为21,404,275,224,147和112μmol/h.利用瞬态荧光研究了载流子在助催化剂和TiO2两相的界面迁移,通过单指数拟合得到样品TiO2,TiO2-Mo2C,TiO2-Fe-Mo2C,TiO2-Co-Mo2C,TiO2-Ni-Mo2C,TiO2-Cu-Mo2C和TiO2-Pt的荧光寿命分别是22.6,20.5,10.1,4.7,4.0,2.5和1.9 ns,说明不同金属掺杂的Mo2C对提取光生电子的效果不同,元素Cu最有效.进一步利用瞬态吸收光谱研究了TiO2-Mo2C,TiO2-Cu-Mo2C和TiO2-Pt三个样品的载流子迁移,同样采用单指数拟合得到的荧光寿命分别为105,73和31 ps,进一步说明掺杂Cu后助催化剂Mo2C对于提取TiO2的光生电子寿命具有很好的促进作用.利用UPS技术探究了金属掺杂后Mo2C的缺陷能级位置,从计算结果可以看出,元素Cu掺杂后Mo2C具有更深的缺陷能级,该能级对吸附水具有促进作用.利用原位红外光谱对样品进行了水蒸气吸附测试,结果表明,Mo2C,Fe-Mo2C,Co-Mo2C,Ni-Mo2C和Cu-Mo2C样品依次的吸附水性能提升.综上,我们利用3d金属对助催化剂进行了缺陷调控来调变其对水的起始吸附过电位,该工作对设计性能优异的光解水助催化剂具有一定的借鉴意义. 展开更多
关键词 3d金属 掺杂 Mo2C TIO2 光催化 水分解 产氢
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Perovskite–A wonder catalyst for solar hydrogen production 被引量:1
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作者 Hui Bian Deng Li +1 位作者 junqing yan Shengzhong(Frank)Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第6期325-340,I0008,共17页
Hydrogen generation via artificial photosynthesis paves a promising way to remit the ever-increasing energy crisis and deteriorative environmental issues.Among all the materials utilized for solar hydrogen production,... Hydrogen generation via artificial photosynthesis paves a promising way to remit the ever-increasing energy crisis and deteriorative environmental issues.Among all the materials utilized for solar hydrogen production,perovskite has emerged as a rising star due to its superior optoelectronic properties.This manuscript aims to provide a comprehensive review summarizing the recent inspiring advancements on perovskite-based solar hydrogen production systems,including the particulate photocatalysis,photoelectrochemical cells,and photovoltaic-electrocatalytic cells.We start with a brief introduction of the advantages of perovskites for solar hydrogen production and the basic principles of the three most prominent solar hydrogen production systems.The representative progresses in this field are then detailed with a special emphasis on the strategies to improve the efficiency and the stability of the systems.Finally,challenges and opportunities for the further development of the PVK-based solar hydrogen production systems are presented with perspective given on outlook,performance,cost and stability. 展开更多
关键词 PEROVSKITE Solar hydrogen production PHOTOCATALYSIS PHOTOELECTROCATALYSIS Photovoltaic-electrocatalysis
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Self-assembled CoOOH on TiO_(2) for enhanced photoelectrochemical water oxidation 被引量:1
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作者 Xiangrong Ren Yujin Ji +5 位作者 Yiyue Zhai Ningyi Yuan Jianning Ding Youyong Li junqing yan Shengzhong Frank Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第9期512-521,共10页
Providing efficient charge transfer through the interface between the semiconductor and co-catalyst is greatly desired in photoelectrocatalytic (PEC) energy conversion.Herein,we excogitate a novel and facile means,via... Providing efficient charge transfer through the interface between the semiconductor and co-catalyst is greatly desired in photoelectrocatalytic (PEC) energy conversion.Herein,we excogitate a novel and facile means,via electrochemical activation,to successfully load the amorphous CoOOH layer architecture onto the surface of TiO_(2).Intriguingly,the as-obtained 6%CoOOH-TiO_(2)photoelectrode manifests optimal PEC performance with a high photocurrent density of 1.3 mA/cm~2,3.5 times higher than that of pristine TiO_(2).Electrochemical impedance spectroscopy (EIS),Tafel analysis and cyclic voltammetry (CV) methods show that the carrier transfer barrier within the electrode and the transition of Co^(3+)OOH to Co^(4+)OOH have the dominating effects on the PEC performance.Theoretical calculation reveals that the interface between the CoOOH and TiO_(2)improves the homogeneity of effective d-orbital electronic-transfer ability among Co sites.This research sheds light on the water oxidation reaction and the design of more favorable PEC cocatalysts. 展开更多
关键词 AMORPHOUS CO-CATALYST Water oxidation Mechanism TiO_(2)
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Fabrication of nanoporous Ni and NiO via a dealloying strategy for water oxidation catalysis 被引量:1
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作者 Xiangrong Ren Yiyue Zhai +2 位作者 Qi Zhou junqing yan Shengzhong Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第11期125-134,共10页
Nickel oxides and(oxy)hydroxides are promising replacements for noble-metal-based catalysts owing to their high activity and good long-term stability for the oxygen evolution reaction(OER). Herein, we developed nanopo... Nickel oxides and(oxy)hydroxides are promising replacements for noble-metal-based catalysts owing to their high activity and good long-term stability for the oxygen evolution reaction(OER). Herein, we developed nanoporous Ni by a method of combined rapid solidification and chemical dealloying. Subsequently,nanoporous Ni O was obtained via heating treatment, the macropore and skeleton sizes of the NiO originated from Ni10Al90 alloy are 100–300 nm and 80–200 nm, respectively. Benefiting from the multi-stage nanoporous structure and high specific surface area, the nanoporous NiO demonstrates an outstanding OER, reaching 20 mA cm-2 at an overpotential of 356 mV in 1 M KOH. The corresponding Tafel slope and apparent activation energy are measured to be 76.73 mV dec-1 and 29.0 kJ mol-1, respectively. Moreover,kinetic analysis indicates that the Ni O catalyst shows pseudocapacitive characteristics, and the improved current is attributed to the high-rate pseudocapacitive behavior that efficiently maintains increased nickel redox cycling to accelerate the reaction rates. After 1000 cycles of voltammetry, the overpotential of the NiO decreases by 22 mV(j = 10 mA cm-2), exhibiting excellent stability and durability. 展开更多
关键词 Rapid solidification DEALLOYING Nanoporous Ni ELECTROCATALYST OER
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基于血清学指标的联合模型诊断代偿期肝硬化轻微型肝性脑病的价值 被引量:2
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作者 刘尚豪 祖红梅 +65 位作者 黄燕 郭小青 向慧玲 党彤 李晓燕 严兆兰 李雅静 刘菲 孙佳 宋瑞欣 闫俊卿 叶青 王晶 孟宪梅 王海英 江振宇 黄磊 孟繁平 张国 王文娟 杨少奇 呼圣娟 阮继刚 雷创 汪清海 田宏玲 郑琦 李异玲 王宁宁 崔会鹏 王滟萌 瞿章书 袁敏 刘益军 陈颖 夏玉香 刘娅媛 刘莹 曲素萱 陶弘 石瑞春 杨小婷 金丹 苏丹 杨永峰 叶伟 刘娜 唐荣瑜 张权 刘琴 邹高亮 李子月 赵彩彦 赵倩 张清格 高华方 孟涛 李婕 吴卫华 王健 杨传龙 吕卉 刘川 王福生 福军亮 祁小龙 《中华检验医学杂志》 CAS CSCD 北大核心 2023年第1期52-61,共10页
目的探讨血清学指标对代偿期肝硬化轻微型肝性脑病(MHE)的诊断价值,构建基于血清学指标的联合模型并评估其对MHE的诊断价值。方法前瞻性、多中心研究。选取2021年10月至2022年8月来自我国15个省(自治区、直辖市)的23家医院就诊的代偿期... 目的探讨血清学指标对代偿期肝硬化轻微型肝性脑病(MHE)的诊断价值,构建基于血清学指标的联合模型并评估其对MHE的诊断价值。方法前瞻性、多中心研究。选取2021年10月至2022年8月来自我国15个省(自治区、直辖市)的23家医院就诊的代偿期肝硬化患者263例。收集患者临床资料及实验室检查结果,并计算终末期肝病模型(MELD)评分。使用基线血氨测量值/正常参考值上限(AMM-ULN)集中校正各中心血氨测量结果,以我国《肝硬化肝性脑病诊疗指南》标准,数字连接试验-A、数字符号试验均异常作为诊断MHE的标准。基于R语言caret包将患者随机(7∶3)分为训练集(n=185)和验证集(n=78)。通过Logistic回归构建诊断MHE的联合模型;受试者工作特征曲线下面积(AUC)、Hosmer-Lemeshow拟合优度检验及校准曲线图评估诊断性能,并用Bootstrap法(n=200)进行内部验证;Delong检验比较AUC之间的差异。结果训练集中,MHE占37.8%(70/185),MHE组AMM-ULN、白蛋白、血小板、碱性磷酸酶、国际标准化比值、终末期肝病模型评分以及教育年限与无MHE组比较,差异有统计学意义(P均<0.05)。多因素Logistic回归分析显示,AMM-ULN(OR=1.78,95%CI 1.05~3.14,P=0.038)和MELD评分(OR=1.11,95%CI 1.04~1.20,P=0.002)是MHE的独立危险因素,AUC分别为0.663和0.625。联合AMM-ULN、MELD评分和教育年限的联合模型诊断MHE的AUC为0.755,特异度和敏感度分别为85.2%和55.7%。Hosmer-Lemeshow拟合优度检验表明模型具有较好的校准度(P=0.733),联合模型内部验证AUC为0.752。Delong检验显示联合模型诊断效能优于单独使用血氨(P=0.020)和MELD评分(P=0.003)。验证集中,联合模型诊断MHE的AUC为0.794,Hosmer-Lemeshow拟合优度检验显示有较好的校准度(P=0.841)。结论基于AMM-ULN、MELD评分和教育年限的联合模型可提高对MHE的诊断价值。 展开更多
关键词 肝性脑病 肝硬化 血氨 终末期肝病模型评分 诊断模型
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Transition metal phosphides:A wonder catalyst for electrocatalytic hydrogen production 被引量:2
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作者 Mingxuan Du Deng Li +1 位作者 Shengzhong(Frank)Liu junqing yan 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第9期25-33,共9页
Hydrogen evolution from water electrolysis has become an important reaction for the green energy revolution.Traditional precious metals and their compounds are excellent catalysts for producing hydrogen;however,their ... Hydrogen evolution from water electrolysis has become an important reaction for the green energy revolution.Traditional precious metals and their compounds are excellent catalysts for producing hydrogen;however,their high cost limits their large-scale practical application.Therefore,the development of affordable electrocatalysts to replace these precious metals is important.Transition metal phosphides(TMPs)have shown remarkable performance for hydrogen evolution and garnered considerable interest in the field of electrolysis.Based on the detailed introduction of TMPs in previous studies,we have systematically summarized the preparation methods,improvement methods,and development opportunities of TMPs and proposed“stimulatory factors”as a fundamental factor affecting the performance of TMPs herein.As the core of this research,“stimulatory factors”can provide numerous solutions to improve the performance of TMP materials and provide a good starting point for TMP research. 展开更多
关键词 Hydrogen evolution reaction PHOSPHATING DOPING Morphology HETEROJUNCTION Defects
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Recent progress on the modification of high nickel contentNCM:Coating,doping,and single crystallization 被引量:3
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作者 junqing yan Hao Huang +5 位作者 Junfan Tong Wei Li Xiaohang Liu Haoxuan Zhang Heqin Huang Weidong Zhou 《Interdisciplinary Materials》 2022年第3期330-353,共24页
High nickel content layered cathodes,represented by NCM(LiNi_(x)Co_(y)Mn_(z)O_(2),x+y+z=1),are now widely employed in the market of electric vehicles,owing to their high energy density.With the gradual increase of nic... High nickel content layered cathodes,represented by NCM(LiNi_(x)Co_(y)Mn_(z)O_(2),x+y+z=1),are now widely employed in the market of electric vehicles,owing to their high energy density.With the gradual increase of nickel content and capacity,the issues on cycling life and safety become more serious.In this review,various strategies for improving the performance of high nickel NCM are summarized on the aspects of surface coating,ionic doping,and singlecrystal NCM.The coating strategy was separately described according to the physical property of coating species,including inert material coating,Li^(+)-conductor coating,electronic conductor coating,and mixed conductor coating.These coating species help to suppress the interfacial oxidation of electrolytes by NCM,improving the cycling life and safety.The elemental doping in the crystal lattice of NCM is then presented in the aspects of cation,anion,and mixed-ion doping,which are beneficial to stabilize the layered structure during charge–discharge and so promote the electrochemical performance.In quite recent years,the strategy of single-crystal NCM was demonstrated to be a promising pathway,owing to the dramatically reduced surface area and grain boundary.Finally,the remaining unsolved challenges and future strategies for further development of NCM cathode materials are outlined. 展开更多
关键词 COATING DOPING high nickel NCM layered cathode lithium-ion batteries
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