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A Unifi ed View of Carbon Neutrality:Solar-Driven Selective Upcycling of Waste Plastics
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作者 Zhiyong Zhao Shuai Yue +2 位作者 Gaohua Yang pengfei wang Sihui Zhan 《Transactions of Tianjin University》 EI CAS 2024年第1期1-26,共26页
With the rapid development of plastic production and consumption globally,the amount of post-consumer plastic waste has reached levels that have posed environmental threats.Considering the substantial CO_(2)emissions ... With the rapid development of plastic production and consumption globally,the amount of post-consumer plastic waste has reached levels that have posed environmental threats.Considering the substantial CO_(2)emissions throughout the plastic lifecycle from material production to its disposal,photocatalysis is considered a promising strategy for eff ective plastic recycling and upcycling.It can upgrade plastics into value-added products under mild conditions using solar energy,realizing zero carbon emissions.In this paper,we explain the basics of photocatalytic plastic reformation and underscores plastic feedstock reformation pathways into high-value-added products,including both degradation into CO_(2)followed by reformation and direct reformation into high-value-added products.Finally,the current applications of transforming plastic waste into fuels,chemicals,and carbon materials and the outlook on upcycling plastic waste by photocatalysis are presented,facilitating the realization of carbon neutrality and zero plastic waste. 展开更多
关键词 PHOTOCATALYSIS Photoreforming Plastics upcycling Carbon neutrality Energy storage and conversion
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Research progress of alkaline earth metal iron-based oxides as anodes for lithium-ion batteries
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作者 Mingyuan Ye Xiaorui Hao +6 位作者 Jinfeng Zeng Lin Li pengfei wang Chenglin Zhang Li Liu Fanian Shi Yuhan Wu 《Journal of Semiconductors》 EI CAS CSCD 2024年第2期21-33,共13页
Anode materials are an essential part of lithium-ion batteries(LIBs),which determine the performance and safety of LIBs.Currently,graphite,as the anode material of commercial LIBs,is limited by its low theoretical cap... Anode materials are an essential part of lithium-ion batteries(LIBs),which determine the performance and safety of LIBs.Currently,graphite,as the anode material of commercial LIBs,is limited by its low theoretical capacity of 372 mA·h·g^(−1),thus hindering further development toward high-capacity and large-scale applications.Alkaline earth metal iron-based oxides are considered a promising candidate to replace graphite because of their low preparation cost,good thermal stability,superior stability,and high electrochemical performance.Nonetheless,many issues and challenges remain to be addressed.Herein,we systematically summarize the research progress of alkaline earth metal iron-based oxides as LIB anodes.Meanwhile,the material and structural properties,synthesis methods,electrochemical reaction mechanisms,and improvement strategies are introduced.Finally,existing challenges and future research directions are discussed to accelerate their practical application in commercial LIBs. 展开更多
关键词 alkali-earth metal iron-based oxides anodes lithium-ion batteries electrochemical energy storage
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Adaptive H_(∞)Filtering Algorithm for Train Positioning Based on Prior Combination Constraints
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作者 Xiuhui Diao pengfei wang +2 位作者 Weidong Li Xianwu Chu Yunming wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1795-1812,共18页
To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior in... To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior information with other sensor information in the form of constraints.Firstly,the train precise track constraint method of the train is proposed,and the plane position constraint and train motion state constraints are analysed.A model for combining prior information with constraints is established.Then an adaptive H∞filter with combination constraints is derived based on the adaptive adjustment method of the robustness factor.Finally,the positioning effect of the proposed algorithm is simulated and analysed under the conditions of a straight track and a curved track.The results show that the positioning accuracy of the algorithm with constrained filtering is significantly better than that of the algorithm without constrained filtering and that the algorithm with constrained filtering can achieve better performance when combined with track and condition information,which can significantly reduce the train positioning error.The effectiveness of the proposed algorithm is verified. 展开更多
关键词 Train positioning combination constraint adaptive H_(∞)filter
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混凝土3D打印建造蒙古包技术展望
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作者 徐海海 王廷 +2 位作者 许宁波 王鹏飞 张志华 《新疆钢铁》 2024年第1期147-149,共3页
本文以蒙古包为研究对象,探讨了使用混凝土3D打印技术建造蒙古包的可行性与优势。通过分析现有的混凝土3D打印技术和相关应用案例,提出了建造蒙古包的具体实施方案,并对其技术、经济和环境影响等进行了评估。研究结果表明,使用混凝土3D... 本文以蒙古包为研究对象,探讨了使用混凝土3D打印技术建造蒙古包的可行性与优势。通过分析现有的混凝土3D打印技术和相关应用案例,提出了建造蒙古包的具体实施方案,并对其技术、经济和环境影响等进行了评估。研究结果表明,使用混凝土3D打印技术建造蒙古包具有高效、节能、环保等优势,有望成为未来低成本、快速建造传统建筑的一种重要方法。 展开更多
关键词 混凝土3D打印技术 蒙古包 建造技术
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上海市虹口区社区老人轻度认知障碍患病现状及影响因素分析
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作者 王鹏飞 刘馨雅 +4 位作者 杨婷婷 阮晔 孙双圆 杨颖华 王颖 《阿尔茨海默病及相关病杂志》 2023年第2期97-103,共7页
目的:据调查上海市虹口区社区老人的轻度认知障碍(MCI)患病现状,分析MCI的危险及保护因素,为MCI的早期发现与精准干预提供科学依据。方法:2020年12月~2021年8月期间,采用整群随机抽样抽取60岁及以上的上海市虹口区社区老人2500人,使用M... 目的:据调查上海市虹口区社区老人的轻度认知障碍(MCI)患病现状,分析MCI的危险及保护因素,为MCI的早期发现与精准干预提供科学依据。方法:2020年12月~2021年8月期间,采用整群随机抽样抽取60岁及以上的上海市虹口区社区老人2500人,使用MMSE量表判断MCI,并通过logistic回归分析MCI的影响因素。结果:上海市虹口区社区老人的MCI患病率为12.1%。高龄、子女见面频率低、抑郁、低躯体疼痛、失能为MCI患病危险因素,高文化程度、中等强度的体育锻炼、较高的生理功能和生理职能以及较好的总体健康为MCI患病保护因素。结论:上海市虹口区社区老人的MCI患病率较全国其他地区略低。子女提高对老人的关注、增强体育锻炼、加强对抑郁等心理健康问题的筛查与干预及生理功能干预有利于预防MCI。 展开更多
关键词 轻度认知障碍 患病率 影响因素
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Improved RF power performance of InAlN/GaN HEMT by optimizing rapid thermal annealing process for high-performance low-voltage terminal applications
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作者 周雨威 宓珉瀚 +9 位作者 王鹏飞 龚灿 陈怡霖 陈治宏 刘捷龙 杨眉 张濛 朱青 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期474-480,共7页
Improved radio-frequency(RF)power performance of InAlN/GaN high electron mobility transistor(HEMT)is achieved by optimizing the rapid thermal annealing(RTA)process for high-performance low-voltage terminal application... Improved radio-frequency(RF)power performance of InAlN/GaN high electron mobility transistor(HEMT)is achieved by optimizing the rapid thermal annealing(RTA)process for high-performance low-voltage terminal applications.By optimizing the RTA temperature and time,the optimal annealing condition is found to enable low parasitic resistance and thus a high-performance device.Besides,compared with the non-optimized RTA HEMT,the optimized one demonstrates smoother ohmic metal surface morphology and better heterojunction quality including the less degraded heterojunction sheet resistance and clearer heterojunction interfaces as well as negligible material out-diffusion from the barrier to the channel and buffer.Benefiting from the lowered parasitic resistance,improved maximum output current density of 2279 mA·mm^(-1)and higher peak extrinsic transconductance of 526 mS·mm^(-1)are obtained for the optimized RTA HEMT.In addition,due to the superior heterojunction quality,the optimized HEMT shows reduced off-state leakage current of 7×10^(-3)mA·mm^(-1)and suppressed current collapse of only 4%,compared with those of 1×10^(-1)mA·mm^(-1)and 15%for the non-optimized one.At 8 GHz and V_(DS)of 6 V,a significantly improved power-added efficiency of 62%and output power density of 0.71 W·mm^(-1)are achieved for the optimized HEMT,as the result of the improvement in output current,knee voltage,off-state leakage current,and current collapse,which reveals the tremendous advantage of the optimized RTA HEMT in high-performance low-voltage terminal applications. 展开更多
关键词 InAlN/GaN rapid thermal annealing low voltage RF power performance terminal applications
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Pyramiding of multiple genes generates rapeseed introgression lines with clubroot and herbicide resistance, high oleic acid content, and early maturity
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作者 Zhaoyang wang Fucai wang +6 位作者 Zihan Yu Xiaorui Shi Xianming Zhou pengfei wang Yixian Song Dengfeng Hong Guangsheng Yang 《The Crop Journal》 SCIE CSCD 2023年第3期895-903,共9页
Clubroot and herbicide resistance,high oleic acid(OA)content,and early maturity are targets of rapeseed(Brassica napus L.)breeding.The objective of this study was to develop new male-fertility restorer lines by pyrami... Clubroot and herbicide resistance,high oleic acid(OA)content,and early maturity are targets of rapeseed(Brassica napus L.)breeding.The objective of this study was to develop new male-fertility restorer lines by pyramiding favorable genes to improve these traits simultaneously.Seven elite alleles for the four traits were introduced into the restorer line 621R by speed breeding with marker-assisted and phenotypic selection.Six introgression lines(ILs)were developed with four-to seven-gene combinations and crossed with two elite parents to develop hybrids.All ILs and their corresponding hybrids displayed high resistance to both clubroot pathotype 4 and sulfonylurea herbicides.Three ILs and their hybrids showed large increases in OA contents and four showed earlier maturity.These new ILs may be useful in rapeseed hybrid breeding for the target traits. 展开更多
关键词 Clubroot resistance Herbicide resistance Oleic acid content Flowering time Pyramid breeding
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UOUU:User-Object Distance and User-User Distance Combined Method for Collaboration Task
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作者 Xiangdong Li pengfei wang +1 位作者 Hanfei Xia Yuting Niu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期3213-3238,共26页
Augmented reality superimposes digital information onto objects in the physical world and enables multi-user collaboration.Despite that previous proxemic interaction research has explored many applications of user-obj... Augmented reality superimposes digital information onto objects in the physical world and enables multi-user collaboration.Despite that previous proxemic interaction research has explored many applications of user-object distance and user-user distance in an augmented reality context,respectively,and combining both types of distance can improve the efficiency of users’perception and interaction with task objects and collaborators by providing userswith insight into spatial relations of user-task object and user-user,less is concerned about howthe two types of distances can be simultaneously adopted to assist collaboration tasks acrossmulti-users.To fulfill the gap,we present UOUU,the user-object distance and user-user distance combined method for dynamically assigning tasks across users.We conducted empirical studies to investigate how the method affected user collaboration tasks in terms of collaboration occurrence and overall task efficiency.The results show that the method significantly improves the speed and accuracy of the collaboration tasks as well as the frequencies of collaboration occurrences.The study also confirms the method’s effects on stimulating collaboration activities,as the UOUU method has effectively reduced the participants’perceived workload and the overall moving distances during the tasks.Implications for generalising the use of the method are discussed. 展开更多
关键词 Augmented reality proximity interaction computer supported cooperative work user-object distance user-user distance
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A spin-based magnetic scanning microscope for in-situ strain tuning of soft matter
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作者 丁哲 孙豫蒙 +8 位作者 王孟祺 余佩 郑宁冲 臧一鹏 王鹏飞 王亚 聂越峰 石发展 杜江峰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期102-107,共6页
We present a magnetic scanning microscope equipped with a nitrogen-vacancy(NV) center scanning probe that has the ability to mechanically tune the strain of soft matter in-situ. The construction of the microscope and ... We present a magnetic scanning microscope equipped with a nitrogen-vacancy(NV) center scanning probe that has the ability to mechanically tune the strain of soft matter in-situ. The construction of the microscope and a continuous straintuning sample holder are discussed. An optically detected magnetic resonance protocol utilized in the imaging is described.In order to show the reliability of this microscope, the strain conduction is estimated with finite element simulation, and xray diffraction is required for calibration when freestanding crystal films are under consideration. A magnetic imaging result is displayed to demonstrate the nano-scale imaging capability. The microscope presented in this work is helpful in studying strain-coupled magnetic physics such as magnetic phase transition under strain and strain-tuned cycloidal orientation tilting. 展开更多
关键词 nitrogen-vacancy(NV)center ANTIFERROMAGNETISM strain tuning soft matter
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Enlarging Zn deposition space via regulating Sn-induced effective interface for high areal capacity zinc-based flow battery
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作者 Yuning Sun Siyu Zhang +5 位作者 Qiming Zhang Lantong Cui pengfei wang Yanbin Yin Qian wang Qinzhi Lai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期579-586,I0012,共9页
Zinc-based flow batteries(ZFBs)have aroused great favor in large-scale energy storage due to the high security and low cost.However,the low areal capacity arising from the limited space for Zn plating hinders the furt... Zinc-based flow batteries(ZFBs)have aroused great favor in large-scale energy storage due to the high security and low cost.However,the low areal capacity arising from the limited space for Zn plating hinders the further development.Herein,a novel carbon felt-Sn-carbon felt sandwich host(CSCH)is designed and constructed.Benefiting from the strong chemical absorption and the dehydration effect on Zn(H_(2)O)_(6)^(2+),the Sn activation layer in the CSCH demonstrates the lowest comprehensive resistance for Zn deposition.Thus,Zn is induced to nucleate preferentially on the Sn activation layer,and grows towards the membrane,regulating the spatial distribution of Zn electrochemical deposits,which remarkably improves the areal capacity and cyclic stability of Zn anode.Consequently,the zinc-bromine flow batteries equipped with CSCH electrodes can achieve the ultra-high areal capacity of 120 mA h cm^(-2)at 80 mA cm^(-2),and run stably for 140 h with average energy efficiency of 80.3%in the extreme condition(80 mA cm^(-2),80 mA h cm^(-2)).This innovative work will inspire future advanced designs for high areal capacity electrodes in ZFBs. 展开更多
关键词 Zinc-based flow batteries High areal capacity Sn-induced deposition Zn deposition depth
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Moiré Synaptic Transistor for Homogeneous-Architecture Reservoir Computing
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作者 王鹏飞 陈墨雨 +6 位作者 谢永勤 潘晨 Kenji Watanabe Takashi Taniguchi 程斌 梁世军 缪峰 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第11期100-107,共8页
Reservoir computing has been considered as a promising intelligent computing paradigm for effectively processing complex temporal information.Exploiting tunable and reproducible dynamics in the single electronic devic... Reservoir computing has been considered as a promising intelligent computing paradigm for effectively processing complex temporal information.Exploiting tunable and reproducible dynamics in the single electronic device have been desired to implement the “reservoir” and the “readout” layer of reservoir computing system.Two-dimensional moiré materials,with an artificial lattice constant many times larger than the atomic length scale,are one type of most studied artificial quantum materials in community of material science and condensed-matter physics over the past years.These materials are featured with gate-tunable periodic potential and electronic correlation,thus varying the electric field allows the electrons in the moiré potential per unit cell to exhibit distinct and reproducible dynamics,showing great promise in robust reservoir computing.Here,we report that a moiré synaptic transistor can be used to implement the reservoir computing system with a homogeneous reservoir-readout architecture.The synaptic transistor is fabricated based on an h-BN/bilayer graphene/h-BN moiré heterostructure,exhibiting ferroelectricity-like hysteretic gate voltage dependence of resistance.Varying the magnitude of the gate voltage enables the moiré transistor to switch between long-term memory and shortterm memory with nonlinear dynamics.By employing the short-and long-term memories as the reservoir nodes and weights of the readout layer,respectively,we construct a full-moiré physical neural network and demonstrate that the classification accuracy of 90.8% can be achieved for the MNIST(Modified National Institute of Standards and Technology) handwritten digits database.Our work would pave the way towards the development of neuromorphic computing based on moiré materials. 展开更多
关键词 TRANSISTOR TUNABLE RESERVOIR
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Research on the Necessity of Building National-level Grape and Cherry Germplasm Resources Bank in Shandong Province 被引量:4
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作者 pengfei wang Fengshan REN +7 位作者 Yongmei wang Xinying WU Xilong JIANG Yingchun CHEN Shan wang Qian MU Liying YANG Wanjun CHEN 《Agricultural Biotechnology》 CAS 2018年第2期36-39,共4页
At present,the grape and cherry industries in Shandong are in the leading position in China and have driven the development of related high-end manufacturing industries such as wine,brandy,preserved fruit processing,f... At present,the grape and cherry industries in Shandong are in the leading position in China and have driven the development of related high-end manufacturing industries such as wine,brandy,preserved fruit processing,fruit juice processing and health products. Therefore,vigorously developing the grape and cherry industries in Shandong Province and carrying out development and innovation are important parts of Shandong Province in responding to the strategy of national new and old kinetic energy conversion. However,currently the germplasm resources preserved in the fruit tree resources banks in China are only 45% of those in the US and 27. 2% of those in the EU. Moreover,the development of fruit trees resources banks in Shandong is relatively backward in China,and there is still no banks related with grape and cherry germplasm resources in Shandong. Therefore,importance can be attached to the agriculture,forestry,and animal husbandry to build germplasm resources banks for grape and cherry industries in Shandong Province. Building the national-level grape and cherry germplasm resources bank in Shandong Province can also promote the utilization of wild and farm germplasm resources in the future; advance the research on the genes related to disease resistance,stress resistance and quality of grapes and cherries; push forward the construction and development of cherry and grape mutants banks. It is conducive to the research on the agronomic traits of grapes and cherries,and can provide the parents resources for planting innovation and improving the quality of grapes and cherries,as well as promote the development and application of molecular markers of grapes and cherries,including the identification of lines and crossbreeding. Thereby,it cannot only promote the industry development,but also achieve the development of cultivation,breeding and basic research in an all-round way and the development of " production,study and research" going side by side. 展开更多
关键词 果树资源 山东省 葡萄 银行 公民 工业发展 白兰地酒 应用程序
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短10元环孔道片状垂直交错ZSM-5分子筛合成 被引量:1
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作者 展恩胜 熊志平 +4 位作者 周燕 李名润 王鹏飞 樊卫斌 申文杰 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第7期1132-1139,共8页
分子筛酸性位位于其亚纳米孔道中,赋予其独特的择型催化特性,在烃类催化转化中有重要应用.但传统分子筛的晶体尺寸通常在微米尺度,因此狭长的孔道结构使得分子与活性位的接触受到扩散限制.通过控制分子筛晶体生长习性,选择性暴露分子筛... 分子筛酸性位位于其亚纳米孔道中,赋予其独特的择型催化特性,在烃类催化转化中有重要应用.但传统分子筛的晶体尺寸通常在微米尺度,因此狭长的孔道结构使得分子与活性位的接触受到扩散限制.通过控制分子筛晶体生长习性,选择性暴露分子筛孔道开口晶面,截短分子筛孔道长度,可以有效解决扩散问题.例如通过控制ZSM-5分子筛沿b轴的生长,合成了具有单晶胞层厚度(2 nm)的二维片层状分子筛,有效的促进了分子扩散、大大提高了其在甲醇转化中的寿命.但这类ZSM-5分子筛的合成需要使用特殊的多头季铵盐模版剂,且一般SiO2/Al2O3比大于100,不利于其实际应用推广.本文开发了一种使用简单有机胺模版剂(TEDA)合成片状垂直交错结构ZSM-5的新方法,并采用电子显微分析对所制ZSM-5分子筛晶体生长方向进行了表征,测试了其催化甲醇制汽油反应性能.结果表明,所得ZSM-5具有良好的结晶性和典型微孔分子筛吸附特征,微孔表面积和微孔体积分别为251 m2/g和0.12 cm3/g.电镜结果表明,其晶体结构特征为:一簇平行子片垂直生长于一个母片上的交错结构,母片呈现异于常见六边形MFI的八边形结构,大小约3-5μm,子片大小约1-2μm,子片和母片的厚度均约为100-200 nm.母片平行于MFI晶体的(010)平面,因此母片表面暴露直孔道开口,且其直孔道长度约100-200 nm.子片与母片连接处的选区电子衍射(电子束沿[010]方向入射)与母片的选区电子衍射完全一致,子片垂直于[100]方向,且子片相互间以平行方式排列,这些证据均说明子片在母片上的生长方式很可能是外延生长,而非粒子堆积机理.因此,子片平行于MFI的(100)晶面,表面暴露之字形孔道开口,且之字形孔道长度约100-200 nm.进一步通过表征不同水热晶化时间的样品,研究了其可能的生长机制.结果表明,水热晶化72 h后,XRD图出现微弱的MFI晶体特征衍射峰,SEM显示有少量片状晶体生成,但无交错结构;晶化96 h后,XRD衍射峰增强,片状结构比例增加,且有交错结构出现;晶化120 h后,XRD呈现完美的MFI晶体衍射结构,SEM图显示均匀的交错片状结构.72和96 h的样品均为无定形物和片状(或交错片状)物共存,说明片状(或交错片状)结构的形成不是同步进行的;样品从开始结晶到完成结晶所需的时间较长,不同于分子筛结晶中常见的自催化结晶方式.我们推测,交错片状ZSM-5的形成发生在无定形物与溶液相界面处,遵循匀相成核机理.该方法得到的ZSM-5分子筛SiO2/Al2O3约为40,且固体核磁表明,ZSM-5中Al主要以骨架四配位形式存在,HZSM-5催化剂上四配位Al的比例高达95%以上,因此其骨架有丰富的酸性位.甲醇制汽油反应性能显示,在363oC,0.4 MPa条件下,甲醇转化量240 g时催化剂仍未失活,表现出典型纳米ZSM-5分子筛的高稳定性特征,这可能归结于片状ZSM-5具有短的(100-200 nm)直孔道或之字形孔道,可以有效促进反应物和产物的扩散,抑制积碳的生成. 展开更多
关键词 ZSM-5 片状结构 垂直交错生长 孔道长度 多级结构 分子扩散
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春光油田储层砂岩地震岩石物理模型构建及其应用 被引量:1
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作者 肖学 杨振峰 +2 位作者 杨春峰 王鹏飞 李锋 《石油天然气学报》 CAS 2018年第5期33-43,共11页
地震岩石物理模型是分析储层岩石地震弹性性质变化规律及烃类预测的重要工具。现有方法在构建岩石物理模型时较少考虑储层岩石复杂孔隙结构特征,从而造成预测结果存在一定误差。在实验室内对新疆车排子地区春光油田沙湾组储层砂岩样品... 地震岩石物理模型是分析储层岩石地震弹性性质变化规律及烃类预测的重要工具。现有方法在构建岩石物理模型时较少考虑储层岩石复杂孔隙结构特征,从而造成预测结果存在一定误差。在实验室内对新疆车排子地区春光油田沙湾组储层砂岩样品进行了系统地震岩石物理试验,在确定储层砂岩中不同孔隙类型组成的条件下,基于非接触模型,综合考虑储层砂岩孔隙度以及孔隙形状对于干燥岩石骨架弹性性质的影响,并利用试验结果对模型参数进行标定,进而建立表征目标储层岩石骨架地震弹性性质的岩石物理模型,模型结果与试验结果符合良好。依据试验及模型结果,利用喷射流作用模型替代传统Gassmann方程进行流体替换,能够更好地对流体饱和砂岩样品超声频率试验结果进行解释。 展开更多
关键词 孔隙结构 岩石物理建模 非接触模型 喷射流作用模型
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6G异构边缘计算 被引量:4
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作者 王鹏飞 邸博雅 +1 位作者 宋令阳 韩竹 《物联网学报》 2020年第1期121-130,共10页
随着物联网的发展,在未来6G通信中,将会产生众多实时性应用场景。在低时延的数据处理需求的驱动下,移动边缘计算将成为提升用户体验和降低网络成本的重要技术。然而,单一的边缘服务器计算能力有限,很难满足计算密集型应用的低时延数据... 随着物联网的发展,在未来6G通信中,将会产生众多实时性应用场景。在低时延的数据处理需求的驱动下,移动边缘计算将成为提升用户体验和降低网络成本的重要技术。然而,单一的边缘服务器计算能力有限,很难满足计算密集型应用的低时延数据处理需求。设计了一种异构的多层边缘计算(HetMEC,heterogeneous multi-layer mobile edge computing)网络架构,综合利用云计算中心和多层边缘服务器的计算和传输资源,通过合理分割卸载计算任务,共同为边缘应用提供可靠、高效的计算服务。实验证明,HetMEC网络架构可以有效降低处理时延,提升网络处理速率和稳健性。 展开更多
关键词 物联网 异构网络 移动边缘计算 任务卸载 资源分配
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Flavonoid content and radical scavenging activity in fruits of Chinese dwarf cherry(Cerasus humilis) genotypes 被引量:8
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作者 pengfei wang Xiaopeng Mu +6 位作者 Junjie Du Yu Gary Gao Donghai Bai Luting Jia Jiancheng Zhang Haiyan Ren Xiaofang Xue 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第1期55-63,共9页
The Chinese dwarf cherry(Cerasus humilis(Bge.) Sok.) is a small shrub with edible fruits. It is native to northern and western China. This species was included as a medicinal plant in the ‘‘Chinese Pharmacopeia'... The Chinese dwarf cherry(Cerasus humilis(Bge.) Sok.) is a small shrub with edible fruits. It is native to northern and western China. This species was included as a medicinal plant in the ‘‘Chinese Pharmacopeia'' and has emerged as an economically important crop for fresh fruit consumption, processing into juice and wine and nutraceutical products as well. To gain a better understanding of flavonoid biosynthesis and help develop value added products and better cultivars with greater health benefits, we analyzed total flavonoid content(TFC), composition, and radical scavenging activities in fruit extracts of 16 Chinese dwarf cherry genotypes. Fruit peel TFC ranged from 33.5 to72.8 mg/g REáFW(RE: rutin equivalent, FW: fresh weight)while fruit flesh TFC ranged from 4.3 to 16.9 mg/g REáFW.An HPLC analysis revealed that fruit extracts contained 14 flavonoids with considerable variation in their profiles across genotypes. The most abundant flavonoids in most genotypes were proanthocyanidin B1(PA-B1), proanthocyanidin B2(PA-B2), phloretin 20-O-glucoside(PG), and phloretin 20,40-O-diglucoside(PDG). Principal component analysis showed that PG, PA-B1, and PA-B2 had large,positive factor loading values in the first principal component for each genotype. Increased scavenging activity of2,2-diphenyl-1-picrylhydrazyl(DPPH) radicals was apparent in genotypes ‘Nongda 4', ‘Nongda 3', ‘Nongda 6',‘Wenfenli', and '10-32', suggesting promising applications in the production of nutraceutical products. In summary, our results will aid in breeding, fruit processing, and developing medicinal uses of the Chinese dwarf cherry. 展开更多
关键词 新鲜水果 遗传型 樱桃 清除 汉语 主要部件 栽培变种 HPLC
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The China Alzheimer Report 2022 被引量:24
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作者 Rujing Ren Jinlei Qi +21 位作者 Shaohui Lin Xinya Liu Peng Yin Zhihui wang Ran Tang Jintao wang Qiang Huang Jianping Li Xinyi Xie Yongbo Hu Shishuang Cui Yuan Zhu Xiaoping Yu pengfei wang Yikang Zhu Yiran wang Yanyan Huang Yisong Hu Ying wang Chunbo Li Maigeng Zhou Gang wang 《General Psychiatry》 CSCD 2022年第1期1-19,共19页
China’s population has rapidly aged over the recent decades of social and economic development as neurodegenerative disorders have proliferated,especially Alzheimer’s disease(AD)and related dementias(ADRD).AD’s inc... China’s population has rapidly aged over the recent decades of social and economic development as neurodegenerative disorders have proliferated,especially Alzheimer’s disease(AD)and related dementias(ADRD).AD’s incidence rate,morbidity,and mortality have steadily increased to make it presently the fifth leading cause of death among urban and rural residents in China and magnify the resulting financial burdens on individuals,families and society.The‘Healthy China Action’plan of 2019-2030 promotes the transition from disease treatment to health maintenance for this expanding population with ADRD.This report describes related epidemiological trends,evaluates the economic burden of the disease,outlines current clinical diagnosis and treatment status and delineates existing available public health resources.More specifically,it examines the public health impact of ADRD,including prevalence,mortality,costs,usage of care,and the overall effect on caregivers and society.In addition,this special report presents technical guidance and supports for the prevention and treatment of AD,provides expertise to guide relevant governmental healthcare policy development and suggests an information platform for international exchange and cooperation. 展开更多
关键词 ALZHEIMER MORTALITY PREVENTION
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Simulation of recovery of upper remnant coal pillar while mining the ultra-close lower panel using longwall top coal caving 被引量:5
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作者 Guorui Feng pengfei wang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2020年第1期55-61,共7页
With the depletion of easily minable coal seams,less favorable reserves under adverse conditions have to be mined out to meet the market demand.Due to some historical reasons,large amount of remnant coal was left unre... With the depletion of easily minable coal seams,less favorable reserves under adverse conditions have to be mined out to meet the market demand.Due to some historical reasons,large amount of remnant coal was left unrecovered.One such case history occurred with the remnant rectangular stripe coal pillars using partial extraction method at Guandi Mine,Shanxi Province,China.The challenge that the coal mine was facing was that there is an ultra-close coal seam right under it with an only 0.8–1.5 m sandstone dirt band in between.The simulation study was carried out to investigate the simultaneous recovery of upper remnant coal pillars while mining the ultra-close lower panel using longwall top coal caving(LTCC).The remnant coal pillar was induced to cave in as top coal in LTCC system.Physical modelling shows that the coal pillars are the abutments of the stress arch structure formed within the overburden strata.The stability of overhanging roof strata highly depends on the stability of the remnant coal pillars.And the gob development(roof strata cave-in)is intermittent with the cave-in of these coal pillars and the sandstone dirt band.FLAC3D numerical modelling shows that the multi-seam interaction has a significant influence on mining-induced stress environment for mining of lower panels.The pattern of the stress evolution on the coal pillars with the advance of the lower working face was found.It is demonstrated that the stress relief of a remnant coal pillar enhances the caveability of the pillars and sandstone dirt band below. 展开更多
关键词 SIMULATION REMNANT COAL pillars Ultra-close Dirt band LONGWALL top COAL caving
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Stress environment of entry driven along gob-side through numerical simulation incorporating the angle of break 被引量:5
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作者 Guorui Feng pengfei wang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2020年第2期189-196,共8页
Angle of break(AOB)is the acute angle created by the coal seam bedding plane and caving line formed by roof strata movement after extraction of a longwall panel.It has a significant influence on stress redistribution ... Angle of break(AOB)is the acute angle created by the coal seam bedding plane and caving line formed by roof strata movement after extraction of a longwall panel.It has a significant influence on stress redistribution both in the gob and abutment.Throughout numerical simulation investigations up to now,little attention has been paid to it or an AOB of 90°was used,which however,is not realistic.This paper presents a detailed numerical modelling incorporating the AOB against Zhenchengdi Coal Mine.The AOB was obtained through cross-measure boreholes.Hoek-Brown constitutive model was used to simulate the rock masses.Double-yield constitutive model,which was best fitted by Salamon's model,was used to simulate the gob.The results show that a‘‘/\shape"shear failure zone develops around the gob.The shear failure in the floor along the panel edge is due to opposite shear of rock mass on two sides of the caving line,and the number of yielded zones within the gob floor close to the gob edge is smaller.According to the research,the entry was determined to be driven under the gob edge employing splitlevel longwall panel layout(SLPL).The other numerical simulation for SLPL shows that stress around the god-side entry is much smaller than pre-mining stress,and the area of intact rock mass at the elevating section is larger than conventional layout.Numerical modelling was then validated by field observation. 展开更多
关键词 STRESS ENVIRONMENT ANGLE of BREAK Gob-side Numerical simulation Double-yield
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Dust removal efficiency of high pressure atomization in underground coal mine 被引量:5
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作者 pengfei wang Xuanhao Tan +2 位作者 Weimin Cheng Gang Guo Ronghua Liu 《International Journal of Mining Science and Technology》 EI CSCD 2018年第4期677-682,共6页
To master theoretical calculation for dust removal efficiency of high pressure atomization in an underground coal mine, the corresponding atomization characteristics and dust removal efficiency were both comprehensive... To master theoretical calculation for dust removal efficiency of high pressure atomization in an underground coal mine, the corresponding atomization characteristics and dust removal efficiency were both comprehensively studied in theory by virtue of related theories of hydromechanics and aerosol.According to actual measurements of flow coefficients and atomization angles of X-type swirl nozzle,computational formula was derived for atomized particle sizes of such a nozzle in conjunction with relevant empirical equation. Moreover, a mathematical model for applying high pressure atomization to dust removal in underground coal mine was also established to deduce theoretical computation formula of fractional efficiency. Then, Matlab was adopted to portray the relation curve between fractional efficiency and influence factors. In addition, a theoretical formula was also set up for removal efficiency of respirable dust and total coal dust based on dust size and frequency distribution equations. In the end,impacts of dust characteristic parameters on various dust removal efficiencies were analyzed. 展开更多
关键词 移动效率 高压力 原子 粉碎 煤矿 理论计算公式 MATLAB 实验方程
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