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Journal of wuhan University of Technology(Materials Science) 2015年第5期30卷 908-913页

作者：朱平华 ZHEng Meng 赵善宇 wU junyong 徐海珣 School of Environmental and Safety Engineering Changzhou University Swiss Federal Institute for Materials Science

Silica aerogel materials are well recognized for their superinsulation performance and are regarded as one of the hot candidates to revolutionize building insulation. To date, high production cost related to exorbitant precursors as well as cumbrous multi-step hydrophobization process has often narrowed the field of applications. In this work, granular silica aerogel materials were synthesized by extracting Si O2 from recycled rich silicon coal gangue, followed by one-step hydrophobization and ambient pressure drying. Lightweight(about 0.16 g/cm3) and nanostructural aerogels were obtained through this route. They exhibit a 3D open porous microstructure with around 600 cm2/g surface area and 20 nm of the average pore diameter, thermal conductivity of 4-5 mm packed granules is 20-25 m w/(m·K), which was proved by both guarded hot plate and hot-wire transient methods. This study offers a new facile route for the synthesis of silica aerogel from recycled solid waste coal gangue and suggests a method, which may lead to a cost reduction in terms of industrial production.

关键词： silica aerogel coal gangue thermal insulation one-step hydrophobization

Engineered tunneling layer with enhaneed impact ionization for detection improvement in graphene/silicon heterojunction photodetectors

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Light(Science & Applications) 2021年第6期10卷 1133-1142页

作者： Jun Yin Lian Liu Yashu Zang Anni Ying wenjie Hui Shusen Jiang Chunquan Zhang Tzuyi Yang Yu-Lun Chueh Jing Li junyong Kang Collaborative Inno vation Center for Optoelectr onic Semic on ductors and Efficient Devices Pen-Tung Sah Institute of Micro-Nano Science and Techno logy/Department of PhysicsXiamen UniversityXiamen 361005China. San'an Optoelectronics Co. Ltd.Xiamen 361005China. Department of Materials Science and Engineering Tsing Hua UniversityHsinchu 30013China

Here,an engineered tunneling layer enhanced photocurrent multiplication through the impact ionization effect was proposed and experimentally demonstrated on the graphene/silic on heterojunction *** con sidering the suitable band structure of the insulation material and their special defect states,an atomic layer deposition(ALD)prepared wide-bandgap insulating(wBI)layer of AIN was introduced into the interface of graphene/silicon *** promoted tunneling process from this designed structure dem on strated that can effectively help the impact ionization with photogain not only for the regular minority carriers from silicon,but also for the novel hot carries from *** a result,significantly enhanced photocurrent as well as simultaneously decreased dark current about one order were accomplished in this graphene/insulation/silicon(GIS)heterojunction devices with the optimized AIN thickness of〜15 nm compared to the conventional graphene/silicon(GS)***,at the reverse bias of-10 V,a 3.96-A w_1 responsivity with the photogain of~5.8 for the peak response under 850-nm light illumination,and a 1.03-A w_1 responsivity with~3.5 photogain under the 365 nm ultraviolet(UV)illumination were realized,which are even remarkably higher than those in GIS devices with either AI2O3 or the commonly employed SiO2 insulation *** work dem on strates a universal strategy to fabricate broad ba nd,low-cost and high-performance photo-detecting devices towards the graphene-silicon optoelectronic integration.

关键词： heterojunction Engine tunneling

Strain-induced direct-indirect bandgap transition and phonon modulation in monolayer wS2

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Nano Research 2015年第8期8卷 2562-2572页

作者： Yanlong w.ng Chunxiao Cong weihuang Yang Jingzhi Shang Namphung Peimyoo Yu Chen junyong Kang Jianpu w.ng wei Huang Ting Yu Nanyang Technological University-Nanjing Tech Center of Research and Development Nanjing Tech University Nanjing 211816 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore Fujian Key Laboratory of Semiconductor Materials and Applications Department of Physics Xiamen University Xiamen 361005 China Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM) Jiangsu National Synergetic Center for Advanced Materials (SICAM) Nanjing Tech University (NanjingTech) Nanjing 211816 China Key Laboratory for Organic Electronics & Information Displays (KLOEID) and Institute of Advanced Materials (IAM) Nanjing University ot Posts & Telecommunications 9 Wenyuan Road Nanjing 210046 China

In situ strain photoluminescence （PL） and Raman spectroscopy have been employed to exploit the evolutions of the electronic band structure and lattice vibrational responses of chemical vapor deposition （CVD）-grown monolayer tungsten disulphide （wS2） under uniaxial tensile strain. Observable broadening and appearance of an extra small feature at the longer-wavelength side shoulder of the PL peak occur under 2.5% strain, which could indicate the direct-indirect bandgap transition and is further confirmed by our density-functional-theory calculations. As the strain increases further, the spectral weight of the indirect transition gradually increases. Over the entire strain range, with the increase of the strain, the light emissions corresponding to each optical transition, such as the direct bandgap transition （K-K） and indirect bandgap transition （F-K, ≥2.5%）, exhibit a monotonous linear redshift. In addition, the binding energy of the indirect transition is found to be larger than that of the direct transition, and the slight lowering of the trion dissociation energy with increasing strain is observed. The strain was used to modulate not only the electronic band structure but also the lattice vibrations. The softening and splitting of the in-plane E＇ mode is observed under uniaxial tensile strain, and polarization-dependent Raman spectroscopy confirms the observed zigzag-oriented edge of wS2 grown by CVD in previous studies. These findings enrich our understanding of the strained states of monolayer transition-metal dichalcogenide （TMD） materials and lay a foundation for developing applications exploiting their strain-dependent optical properties, including the strain detection and light-emission modulation of such emerging two-dimensional TMDs.

关键词： monolayer wS2 strain light-emission tuning indirect transition trion crystallographic orientation

The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

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National Science Review 2022年第3期9卷 110-118页

作者： Xiaolei w.ng Ming Tang Jeff Moyen Di w.ng Alfred Kr?ner Chris Hawkesworth Xiaoping Xia Hangqiang Xie Carl Anhaeusser Axel Hofmann junyong Li Linsen Li State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing University School of Earth and Space Sciences Peking University Laboratoire Magmas et Volcans UMR6524 Université de LyonUJM-UCA-CNRS-IRD Institut für Geowissenschaften Universit?t Mainz Department of Earth Sciences University of Bristol State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences SHRIMP Center Institute of Geology Chinese Academy of Geological Sciences Economic Geology Research Unit University of the Witwatersrand Department of Geology University of Johannesburg

The recycling of supracrustal materials, and in particular hydrated rocks, has a profound impact on mantle composition and thus on the formation of continental crust, because water modifies the physical properties of lithological systems and the mechanisms of partial melting and fractional fractionation. On the modern Earth, plate tectonics offers an efficient mechanism for mass transport from the Earth’s surface to its interior, but how far this mechanism dates back in the Earth’s history is still uncertain. Here, we use zircon oxygen(O) isotopes to track recycling of supracrustal materials into the magma sources of early Archean igneous suites from the Kaapvaal Craton, southern Africa. The mean δ18O values of zircon from TTG(tonalite–trondhjemite–granodiorite) rocks abruptly increase at the Paleo-Mesoarchean boundary(ca.3230 million years ago; Ma), from mantle zircon values of 5‰–6‰ to approaching 7.1‰, and this increase occurs in ≤3230 Ma rocks with elevated Dy/Yb ratios. The18O enrichment is a unique signature of low-temperature water–rock interaction on the Earth’s surface. Because the later phase was emplaced into the same crustal level as the older one and TTG magmas would derive from melting processes in the garnet stability field(>40 km depth), we suggest that this evident shift in TTG zircon O isotopic compositions records the onset of recycling of the mafic oceanic crust that underwent seawater hydrothermal alteration at low temperature. The onset of the enhanced recycling of supracrustal materials may also have developed elsewhere in other Archean cratons and reflects a significant change in the tectonic realm during craton formation and stabilization, which may be important processes for the operation of plate tectonics on early Earth.

关键词： zircon oxygen isotopes TTG plate tectonics deep recycling Paleo-Mesoarchean boundary

Ultrafast laser state active controlling based on anisotropic quasi-1D material

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Light(Science & Applications) 2024年第4期13卷 717-726页

作者： Zixin Yang Qiang Yu Jian wu Haiqin Deng Yan Zhang wenchao w.ng Tianhao Xian Luyi Huang Junrong Zhang Shuai Yuan Jinyong Leng Li Zhan Zongfu Jiang junyong w.ng Kai Zhang Pu Zhou College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China. Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China. i-Lab&Key Laboratory of Nanodevices and Applications&Key Laboratory of Nanophotonic Materials and Devices Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China. School of Applied and Engineering Physics Cornell UniversityIthacaNY 14853USA. State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China. Shanghai Key Lab of Modern Optical System University of Shanghai for Science and TechnologyShanghai 200093China

Laser state active controlling is challenging under the influence of inherent loss and other nonlinear effects in ultrafast *** an extension of degree of freedom in optical devices based on low-dimensional materials may be a way ***,the anisotropic quasi-one-dimensional layered material Ta2PdS6 was utilized as a saturable absorber to modulate the nonlinear parameters effectively in an ultrafast system by polarization-dependent *** polarization-sensitive nonlinear optical response facilitates the Ta2PdS6-based mode-lock laser to sustain two types of laser states,i.e.,conventional soliton and noise-like *** laser state was switchable in the single fiber laser with a mechanism revealed by numerical *** coding was further demonstrated in this platform by employing the laser as a codable light *** work proposed an approach for ultrafast laser state active controlling with low-dimensional material,which offers a new avenue for constructing tunable on-fiber devices.

关键词： polarization fiber controlling

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全球高程基准研究进展

武汉大学学报（信息科学版） 2022年第10期47卷 1576-1586页

作者：党亚民蒋涛陈俊勇中国测绘科学研究院北京100830

建立统一的全球高程基准是国际大地测量科学界的核心目标之一,也是全球尺度地球科学研究、跨境工程应用等的必要基础设施。国际大地测量协会(international geodesy association,IAG)2015年发布了国际高程参考系统的定义,并于2019年提... 详细信息

建立统一的全球高程基准是国际大地测量科学界的核心目标之一,也是全球尺度地球科学研究、跨境工程应用等的必要基础设施。国际大地测量协会(international geodesy association,IAG)2015年发布了国际高程参考系统的定义,并于2019年提出了建立国际高程参考框架的目标。从全球高程参考系统的理论基础和定义出发,对国际高程参考系统与框架的理论、方法和实际问题开展论述与研究,主要包括全球大地水准面重力位w的确定、基于高阶重力场模型的重力位确定、基于区域重力场建模的重力位确定,并重点论述和分析了IAG组织的科罗拉多大地水准面建模试验和中国2020珠峰高程测量实现国际高程参考系统2项典型案例研究。结果表明,在平坦地区和一般山区,重力大地水准面模型精度能达到1 cm(重力位0.1 m^(2)/s^(2)),即使在珠穆朗玛峰这样的特大山区,也有望达到2~3 cm精度(重力位0.2~0.3 m^(2)/s^(2))。综合典型案例研究结果、观测技术、数据资源和区域分布等因素,提出了建立国际高程参考框架的初步策略,包括IHRF参考站布设、重力位确定方法、数据要求、应遵循的标准/约定和预期精度指标等,展望了光学原子钟与相对论大地测量对于全球高程基准统一的潜在贡献。

关键词：全球高程基准国际高程参考系统国际高程参考框架地球重力场模型重力位大地水准面

一类线性切换系统的非脆弱鲁棒H∞控制器设计

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东南大学学报（自然科学版） 2013年第A1期43卷 148-152页

作者：王斌翟军勇陈夕松东南大学复杂工程系统测量与控制教育部重点实验室南京210096

研究控制器增益存在加性摄动时的一类线切换系统的非脆弱鲁棒H∞控制问题.首先,利用多Lyapunov函数方法,把状态空间划分为N(子系统个数)个子区域,并以最小Lyapunov函数作为切换规则,研究标称系统的稳定性,而给出的稳定性条件不要求每一... 详细信息

研究控制器增益存在加性摄动时的一类线切换系统的非脆弱鲁棒H∞控制问题.首先,利用多Lyapunov函数方法,把状态空间划分为N(子系统个数)个子区域,并以最小Lyapunov函数作为切换规则,研究标称系统的稳定性,而给出的稳定性条件不要求每一个子系统都是渐近稳定的.然后,考虑系统的不确定性,给出了非脆弱状态反馈控制器和切换律设计方案.通过子系统之间的切换,保证系统对所有允许的不确定性是渐近稳定的且具有H∞性能界,并以线性矩阵不等式组的形式给出控制器增益矩阵存在的充分条件.最后,以数值仿真验证了该方法的有效性.

关键词：多李雅普诺夫函数 H∞控制非脆弱状态反馈

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65Nb钢链板冲裁模具热加工工艺试验

热加工工艺 2009年第14期38卷 152-154页

作者：叶俊勇陈红强杭州东华链条集团有限公司金工模具分厂浙江杭州310021

讨论了链板冲裁模选材、锻加工、球化退火、热处理工艺,重点讨论了6Cr4w3Mo2VNb(65Nb钢)热处理工艺参数对钢的性能和组织的影响。结果表明:通过改进热加工工艺,可改善冷冲模钢的强韧性,大幅度提高链板冲裁模(凸模、凹模、凸凹模)的使用... 详细信息

讨论了链板冲裁模选材、锻加工、球化退火、热处理工艺,重点讨论了6Cr4w3Mo2VNb(65Nb钢)热处理工艺参数对钢的性能和组织的影响。结果表明:通过改进热加工工艺,可改善冷冲模钢的强韧性,大幅度提高链板冲裁模(凸模、凹模、凸凹模)的使用寿命。

关键词： 65Nb钢模具锻造球化退火热处理工艺

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链条销轴切断模热处理工艺实践

金属加工（热加工） 2009年第19期 43-46页

作者：叶俊勇杭州东华链条集团有限公司浙江310021

标准套筒滚子链条销轴都是大批量生产，尤其中小规格链条有的品种每月多达上千万根。链条销轴用专用铡销机或冲床切断。链条销轴切断模一般用w6M05Cr4V2高速钢材料制造，高速铡销机也有用硬质合金做切断模，但使用不够普及。由于生产用... 详细信息

标准套筒滚子链条销轴都是大批量生产，尤其中小规格链条有的品种每月多达上千万根。链条销轴用专用铡销机或冲床切断。链条销轴切断模一般用w6M05Cr4V2高速钢材料制造，高速铡销机也有用硬质合金做切断模，但使用不够普及。由于生产用量大，如何提高w6M05Cr4V2高速钢模具寿命，对提高生产效率、降低生产成本都具有重要意义。

关键词：滚子链条切断模销轴工艺实践热处理大批量生产高速钢材料硬质合金

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基于特征分析的微博炒作账户识别方法

计算机工程 2015年第4期41卷 48-54,59页

作者：张进刘琰罗军勇董雨辰数学工程与先进计算国家重点实验室郑州450002

近年来微博中出现一些炒作账户采用违规手段开展网络公关活动,严重扰乱了正常的互联网秩序,然而传统炒作账户识别方法主要依靠人工分析,其效率低下且不适用于对海量账户进行识别。针对上述问题,提出一种改进的微博炒作账户识别方法,从... 详细信息

近年来微博中出现一些炒作账户采用违规手段开展网络公关活动,严重扰乱了正常的互联网秩序,然而传统炒作账户识别方法主要依靠人工分析,其效率低下且不适用于对海量账户进行识别。针对上述问题,提出一种改进的微博炒作账户识别方法,从账户状态、历史微博以及账户邻居3个方面对炒作账户的特征进行分析,构建炒作账户特征集,并利用数据挖掘中的朴素贝叶斯、支持向量机及K最近邻分类等算法对正常账户和炒作账户进行自动分类。实验结果表明,该方法能有效识别微博中的炒作账户,准确率高达95%。

关键词：微博炒作账户特征分析特征选择数据挖掘分类算法