Lithium-sulfur batteries(Li–S batteries) are promising candidates for the next generation high-energy rechargeable Li batteries due to their high theoretical specific capacity(1672 m Ahg-1) and energy density(2500 Wh...Lithium-sulfur batteries(Li–S batteries) are promising candidates for the next generation high-energy rechargeable Li batteries due to their high theoretical specific capacity(1672 m Ahg-1) and energy density(2500 Wh kg-1). The commercialization of Li–S batteries is impeded by several key challenges at cathode side, e.g. the insulating nature of sulfur and discharged products(Li2S 2 and Li2S), the solubility of long-chain polysulfides and volume variation of sulfur cathode upon cycling. Recently, the carbonbased derivatives from metal-organic frameworks(MOFs) has emerged talent in their utilization as cathode hosts for Li–S batteries. They are not only highly conductive and porous to enable the acceleration of Li +/e-transfer and accommodation of volumetric expansion of sulfur cathode during cycling, but also enriched by controllable chemical active sites to enable the adsorption of polysulfides and promotion of their conversion reaction kinetics. In this review, based on the types of MOFs(e.g. ZIF-8, ZIF-67, Prussian blue, Al-MOF, MOF-5, Cu-MOF, Ni-MOF), the synthetic methods, formation process and morphology, structural superiority of MOFs-derived carbon frameworks along with their electrochemical performance as cathode host in Li–S batteries are summarized and discussed.展开更多
Metal-organic frameworks(MOFs)have favorable characteristics such as large specific surface area,high porosity,structural diversity,and pore surface modification,giving them great potential for development and attract...Metal-organic frameworks(MOFs)have favorable characteristics such as large specific surface area,high porosity,structural diversity,and pore surface modification,giving them great potential for development and attractive prospects in the research area of modern materials electrocatalysis.However,unsatisfactory catalytic activity and poor electronic conductivity are the main challenges facing MOFs.This review focuses on MOF-based materials used in electrocatalysis,based on the types of catalytic reactions that have used MOF-based materials in recent years along with their applications,and also looks at some new electrocatalytic materials and their future development prospects.展开更多
以Solid works软件为工具建立玉米收获机割台框架的三维模型,以由于路面不平而引起的不规则振动为激励,利用Solid works Simulation对玉米收获机割台框架进行静力分析,获取到关键部位的应力、应变强度等相关信息;同时以静力分析为基础,...以Solid works软件为工具建立玉米收获机割台框架的三维模型,以由于路面不平而引起的不规则振动为激励,利用Solid works Simulation对玉米收获机割台框架进行静力分析,获取到关键部位的应力、应变强度等相关信息;同时以静力分析为基础,根据Q235钢材料的疲劳曲线对割台框架进行疲劳分析,得到损坏图解等相关数据。其结果在理论上对于以后进行同类产品的设计、检验、改进及安全评估具有一定的参考价值。展开更多
In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec han...In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.展开更多
虚拟展示是以可视化图形技术为基础、以计算机辅助设计技术为依托的一种产品展示手段。常用产品虚拟展示方法有虚拟现实法、全息投影法和计算机辅助虚拟展示法。主要介绍计算机辅助虚拟展示法的应用,分析了基于Solid Works Composer的...虚拟展示是以可视化图形技术为基础、以计算机辅助设计技术为依托的一种产品展示手段。常用产品虚拟展示方法有虚拟现实法、全息投影法和计算机辅助虚拟展示法。主要介绍计算机辅助虚拟展示法的应用,分析了基于Solid Works Composer的产品虚拟展示动画的分类、关键帧的组合应用以及虚拟展示动画的编辑要点,为虚拟展示方法在产品设计中的应用提供参考。展开更多
The development of high order thinking has been considered as a national priority of learning. By using three iteration action research in six elementary schools in Guangzhou, China for about 1 year and a half, we fou...The development of high order thinking has been considered as a national priority of learning. By using three iteration action research in six elementary schools in Guangzhou, China for about 1 year and a half, we found that visual thinking tools can improve students＇ high order thinking ability and change the traditional teaching method. By using this activity frame work, the teachers can better understand what are the students thinking about and the students can use the thinking tools to help themselves solve complex problems and discuss with other people. The reason we do this research is to improve the high-order thinking ability of primary student. In this paper, we summarize an activity frame work of using visual thinking tools to improve students thinking ability. And the frame work can be divided into three stages： preparatory stage, implementation stage and assessment stage. And different stage has different activity. Though this activity frame work is not perfect enough, we will improve it in our future study.展开更多
Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia off...Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia officinalis residues(MOR)as an example.The reluctant structure of MOR was first destroyed by alkali pretreatment to release the functional ingredients(magnolol and honokiol)originally remaining in MOR and to make MOR more accessible for hydrolysis.A metal–organic frame material MIL-101(Cr)with a maximum absorption capacity of 255.64 mg g^(-1)was synthesized to absorb the released honokiol and magnolol from the pretreated MOR solutions,and 40 g L^(-1)reducing sugars were obtained with 81.8%enzymatic hydrolysis rate at 10%MOR solid loading.Finally,382 mg L-1β-amyrin was produced from MOR hydrolysates by an engineered yeast strain.In total,1 kg honokiol,8 kg magnolol,and 7.64 kg β-amyrin could produce from 1 ton MOR by this cleaner process with a total economic output of 170,700 RMB.展开更多
基金supported by National Key R&D Program of China(2016YFB0901600)the National Natural Science Foundation of China(51772313 , U1830113 and 51802334)
文摘Lithium-sulfur batteries(Li–S batteries) are promising candidates for the next generation high-energy rechargeable Li batteries due to their high theoretical specific capacity(1672 m Ahg-1) and energy density(2500 Wh kg-1). The commercialization of Li–S batteries is impeded by several key challenges at cathode side, e.g. the insulating nature of sulfur and discharged products(Li2S 2 and Li2S), the solubility of long-chain polysulfides and volume variation of sulfur cathode upon cycling. Recently, the carbonbased derivatives from metal-organic frameworks(MOFs) has emerged talent in their utilization as cathode hosts for Li–S batteries. They are not only highly conductive and porous to enable the acceleration of Li +/e-transfer and accommodation of volumetric expansion of sulfur cathode during cycling, but also enriched by controllable chemical active sites to enable the adsorption of polysulfides and promotion of their conversion reaction kinetics. In this review, based on the types of MOFs(e.g. ZIF-8, ZIF-67, Prussian blue, Al-MOF, MOF-5, Cu-MOF, Ni-MOF), the synthetic methods, formation process and morphology, structural superiority of MOFs-derived carbon frameworks along with their electrochemical performance as cathode host in Li–S batteries are summarized and discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.21677010,51808037)the National Key R&D Program of China(No.2021YFB3500702)the Special Fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04)。
文摘Metal-organic frameworks(MOFs)have favorable characteristics such as large specific surface area,high porosity,structural diversity,and pore surface modification,giving them great potential for development and attractive prospects in the research area of modern materials electrocatalysis.However,unsatisfactory catalytic activity and poor electronic conductivity are the main challenges facing MOFs.This review focuses on MOF-based materials used in electrocatalysis,based on the types of catalytic reactions that have used MOF-based materials in recent years along with their applications,and also looks at some new electrocatalytic materials and their future development prospects.
文摘以Solid works软件为工具建立玉米收获机割台框架的三维模型,以由于路面不平而引起的不规则振动为激励,利用Solid works Simulation对玉米收获机割台框架进行静力分析,获取到关键部位的应力、应变强度等相关信息;同时以静力分析为基础,根据Q235钢材料的疲劳曲线对割台框架进行疲劳分析,得到损坏图解等相关数据。其结果在理论上对于以后进行同类产品的设计、检验、改进及安全评估具有一定的参考价值。
文摘In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.
文摘虚拟展示是以可视化图形技术为基础、以计算机辅助设计技术为依托的一种产品展示手段。常用产品虚拟展示方法有虚拟现实法、全息投影法和计算机辅助虚拟展示法。主要介绍计算机辅助虚拟展示法的应用,分析了基于Solid Works Composer的产品虚拟展示动画的分类、关键帧的组合应用以及虚拟展示动画的编辑要点,为虚拟展示方法在产品设计中的应用提供参考。
文摘The development of high order thinking has been considered as a national priority of learning. By using three iteration action research in six elementary schools in Guangzhou, China for about 1 year and a half, we found that visual thinking tools can improve students＇ high order thinking ability and change the traditional teaching method. By using this activity frame work, the teachers can better understand what are the students thinking about and the students can use the thinking tools to help themselves solve complex problems and discuss with other people. The reason we do this research is to improve the high-order thinking ability of primary student. In this paper, we summarize an activity frame work of using visual thinking tools to improve students thinking ability. And the frame work can be divided into three stages： preparatory stage, implementation stage and assessment stage. And different stage has different activity. Though this activity frame work is not perfect enough, we will improve it in our future study.
基金supported by the National Key Research and Development Project(2019YFC1906601)China the Scientific and Technological Innovation Project of the Chinese Academy of Chinese Medical Sciences(C12021A04111)the Fundamental Research Funds for the Central Public Welfare Research Institutes(ZZ13-YQ-040).
文摘Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia officinalis residues(MOR)as an example.The reluctant structure of MOR was first destroyed by alkali pretreatment to release the functional ingredients(magnolol and honokiol)originally remaining in MOR and to make MOR more accessible for hydrolysis.A metal–organic frame material MIL-101(Cr)with a maximum absorption capacity of 255.64 mg g^(-1)was synthesized to absorb the released honokiol and magnolol from the pretreated MOR solutions,and 40 g L^(-1)reducing sugars were obtained with 81.8%enzymatic hydrolysis rate at 10%MOR solid loading.Finally,382 mg L-1β-amyrin was produced from MOR hydrolysates by an engineered yeast strain.In total,1 kg honokiol,8 kg magnolol,and 7.64 kg β-amyrin could produce from 1 ton MOR by this cleaner process with a total economic output of 170,700 RMB.
