检索结果-南通市图书馆

Mineral materials as feasible amendments to stabilize heavy metals in polluted urban soils

Journal of Environmental Sciences 2011年第4期23卷 607-615页

作者： Mingkui zhang jincheng Pu Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition College of Environmental and Resource Sciences Zhejiang University Hangzhou 310058 China.

Four minerals, agricultural limestone （AL）, rock phosphate （RP）, palygorskite （PG）, and calcium magnesium phosphate （CMP）, were evaluated by means of chemical fractions of heavy metals in soils and concentrations of heavy metals in leachates from columns to determine their ability to stabilize heavy metals in polluted urban soils. Two urban soils （calcareous soil and acidic soil） polluted with cadmium, copper, zinc and lead were selected and amended in the laboratory with the mineral materials） for 12 months. Results indicated that application of the mineral materials reduced exchangeable metals in the sequence of Pb, Cd Cu Zn. The reduction of exchangeable fraction of heavy metals in the soils amended with different mineral materials followed the sequence of CMP, PG AL RP. Reductions of heavy metals leached were based on comparison with cumulative totals of heavy metals eluted through 12 pore volumes from an untreated soil. The reductions of the metals eluted from the calcareous soil amended with the RP, AL, PG and CMP were 1.98%, 38.89%, 64.81% and 75.93% for Cd, 8.51%, 40.42%, 60.64% and 55.32% for Cu, 1.76%, 52.94%, 70.00% and 74.12% for Pb, and 28.42%, 52.74%, 64.38% and 49.66% for Zn. Those from the acidic soil amended with the CMP, PG, AL, and RP were 25.65%, 68.06%, 78.01% and 79.06% for Cd, 26.56%, 49.64%, 43.40% and 34.68% for Cu, 44.44%, 33.32%, 61.11% and 69.44% for Pb, and 18.46%, 43.77%, 41.98% and 40.68% for Zn. The CMP and PG treatments were superior to the AL and RP for stabilizing heavy metals in the polluted urban soils.

关键词： heavy metals polluted soil chemical fraction chemical immobilization mineral materials

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The mobility of two-dimensional electron gas in AlGaN/GaN heterostructures with varied Al content

引用

Science in China(Series F) 2008年第6期51卷 780-789页

作者： zhang JinFeng HAO Yue zhang jincheng NI JinYu Key Laboratory of the Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University Xi'an 710071 China

The mobility of the two-dimensional electron gas （2DEG） in AIGaN/GaN hetero-structures changes significantly with AI content in the AIGaN barrier layer, while few mechanism analyses focus on it. Theoretical calculation and analysis of the 2DEG mobility in AIGaN/GaN heterostructures with varied AI content are carried out based on the recently reported experimental data. The 2DEG mobility is modeled analytically as the total effects of the scattering mechanisms including acoustic deformation-potential, piezoelectric, polar optic phonon, alloy disorder, interface roughness, dislocation and remote modulation doping scattering. We show that the increase of the 2DEG density, caused by the ascension of the AI content in the barrier layer, is a dominant factor that leads to the changes of the individual scat- tering processes. The change of the 2DEG mobility with AI content are mainly determined by the interface roughness scattering and the alloy disorder scattering at 77 K, and the polar optic phonon scattering and the interface roughness scattering at the room temperature. The calculated function of the interface roughness pa- rameters on the AI content shows that the stress caused AIGaN/GaN interface degradation at higher AI content is an important factor in the limitation of the in- terface roughness scattering on the 2DEG mobility in AIGaN/GaN heterostructures with high AI content.

关键词： GaN heterostructures 2DEG mobility

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pulsed metal organic chemical vapor deposition of InAlN-based heterostructures and its application in electronic devices

引用

Chinese Science Bulletin 2014年第12期59卷 1228-1234页

作者： Yue Hao Junshuai Xue jincheng zhang Key Laboratory of Wide Band Gap Semiconductor Materials and Devices School of Microelectronics Xidian University

As a promising group III-nitride semiconductor material,InAlN ternary alloy has been attracted increasing interest and widespread research efforts for optoelectronic and electronic applications in the last 5 *** a literature survey of current status and progress of InAlNrelated studies,this paper provides a brief review of some recent developments in InAlN-related III-nitride research in Xidian University,which focuses on innovation of the material growth approach and device structure for electronic applications.A novel pulsed metal organic chemical vapor deposition(PMOCVD)was first adopted to epitaxy of InAlN-related heterostructures,and excellent crystalline and electrical properties were ***,the first domestic InAlN-based high-electron mobility transistor(HEMT)was *** on the PMOCVD in combination with special GaN channel growth approach,high-quality InAlN/GaN double-channel HEMTs were successfully achieved for the first ***,other potentiality regarding to AlGaN channel was demonstrated through the successful realization of nearly lattice-matched InAlN/AlGaN heterostructures suitable for high-voltage switching ***,some advanced device structures and technologies including excellent work from several research groups around the world are summarized based on recent publications,showing the promising prospect of InAlN alloy to push group III-nitride electronic device performance even further.

关键词：化学气相沉积电子应用电子器件异质结构有机金属脉冲高电子迁移率晶体管西安电子科技大学

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High temperature electron transport properties of AlGaN/GaN heterostructures with different Al-contents

引用

Science China(Physics,Mechanics & Astronomy) 2009年第12期52卷 1879-1884页

作者： zhang ZhongFen zhang jincheng XU ZhiHao DUAN HuanTao HAO Yue Key Laboratory of Wide Band Gap Semiconductor Materials and Devices Microelectronics InstituteXidian UniversityXi’an 710071China

Electron transport properties in AlGaN/GaN heterostructures with different Al-contents have been in-vestigated from room temperature up to 680 K. The temperature dependencies of electron mobility have been systematically measured for the samples. The electron mobility at 680 K were measured as 154 and 182 cm2/V.s for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures,respectively. It was found that the electron mobility of low Al-content Al0.15Ga0.85N/GaN heterostructure was less than that of high Al-content Al0.40Ga0.60N/GaN heterostructure at high temperature of 680 K,which is different from that at room temperature. Detailed analysis showed that electron occupations in the first subband were 75% and 82% at 700 K for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures,respectively,and the two dimensional gas (2DEG) ratios in the whole electron system were 30% and near 60%,respectively. That indicated the 2DEG was better confined in the well,and was still dominant in the whole electron system for higher Al-content AlGaN/GaN heterostructure at 700 K,while lower one was not. Thus it had a higher electron mobility. So a higher Al-content AlGaN/GaN heterostructure is more suitable for high-temperature applications.

关键词： AlGaN/GaN heterostructure high-temperature electron-transport

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Role of lateral growth on the structural properties of high temperature GaN layer

引用

Science China(Technological Sciences) 2009年第5期52卷 1242-1247页

作者： GAO ZhiYuan HAO Yue LI PeiXian zhang jincheng Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices School of MicroelectronicsXidian UniversityXi’an 710071China

The role of lateral growth on the structural properties of high temperature (HT) GaN epitaxial layer has been investigated by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). Variations of the lateral growth rate of HT GaN in metal-organic chemical vapor deposition (MOCVD) can be obtained by changing the V/III ratio. It is found that under higher lateral growth rate, dislocation is easier to bend into subgrains away from c axis, and the position where bend occurs is closer to the buffer layer, however, dislocation density does not show to monotonically vary with increasing lateral growth rate. A model concerning the GaN growth dynamics and dislocation bending mechanics has been proposed to explain the correlation between lateral growth and the structural properties of GaN.

关键词： GaN lateral growth dislocation V/III

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interfacial Voids Trigger Carbon-Based, All-Inorganic Cs Pb IBr2 Perovskite Solar Cells with Photovoltage Exceeding 1.33 V

引用

Nano-Micro Letters 2020年第7期12卷 121-134页

作者： Weidong Zhu Zeyang zhang Dandan Chen Wenming Chai Dazheng Chen jincheng zhang Chunfu zhang Yue Hao State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology and Shaanxi Joint Key Laboratory of Graphene School of MicroelectronicsXidian UniversityXi’an 710071People’s Republic of China College of Science Xi’an Shiyou UniversityXi’an 710065ShaanxiPeople’s Republic of China

A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 *** with the general interfacial engineering strategies,this design exempts any extra modification layer in final *** importantly,the interfacial voids produced by thermal decomposition of 2-phenylethylammonium iodide trigger three beneficial e ***,they promote the light scattering in CsPbIBr2 film and thereby boost absorption ability of the resulting CsPbIBr2 ***,they suppress recombination of charge carriers and thus reduce dark saturation current density(J0)of the ***,interfacial voids enlarge built-in potential(Vbi)of the PSCs,awarding increased driving force for dissociating photo-generated charge ***,the PSC yields the optimized e ciency of 10.20%coupled with an open-circuit voltage(Voc)of 1.338 *** Voc achieved herein represents the best value among CsPbIBr2 PSCs reported ***,the non-encapsulated PSCs exhibit an excellent stability against light,thermal,and humidity stresses,since it remains^97%or^94%of its initial e ciency after being heated at 85℃for 12 h or stored in ambient atmosphere with relative humidity of 30–40%for 60 days,respectively.

关键词： All-inorganic perovskite solar cells Cs Pb IBr2 Photovoltage Interfacial engineering Stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of strain relaxation of AlGaN barrier layer on the performance of high Al-content AlGaN/GaN HEMT

引用

Science China(Technological Sciences) 2006年第4期49卷 393-399页

作者： YANG Yan HAO Yue zhang jincheng WANG Chong FENG Qian Key Laboratory of the Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices School of MicroelectronicsXidian UniversityXi'an 710071China

The effects of strain relaxation of AlGaN barrier layer on the conduction band profile,electron concentration and two-dimensional gas(2DEG)sheet charge density in a high Al-content AlGaN/GaN high electron mobility transistor(HEMT)are calculated by self-consistently solving Poisson’s and Schr?dinger’s *** effect of strain re-laxation on dc I-V characteristics of Al_(x)Ga_(1-x)N/GaN HEMT is obtained by developing a nonlinear charge-control model that describes the accurate relation of 2DEG sheet charge density and gate *** model predicts a highest 2DEG sheet charge density of 2.42×10^(13)cm^(-2)and maximum saturation current of 2482.8 mA/mm at a gate bias of 2 V for 0.7μm Al_(0.5)0Ga_(0.50)N/GaN HEMT with strain relaxation r=0 and 1.49×10^(13)cm^(-2)and 1149.7 mA/mm with strain relaxation r=*** comparison between simulations and physical measurements shows a good *** show that the effect of strain relaxation must be considered when analyzing the characteristics of high Al-content AlGaN/GaN HEMT theoretically,and the performance of the devices is improved by decreasing the strain relaxation of AlGaN barrier layer.

关键词： AlGaN/GaN high electron mobility transistor strain relaxation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of reactor pressure on the growth rate and structural properties of GaN films

引用

Chinese Science Bulletin 2009年第15期54卷 2595-2598页

作者： NI JinYu HAO Yue zhang jincheng YANG LinAn Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University Xi'an710071 China

The effect of reactor pressure on the growth rate, surface morphology and crystalline quality of GaN films grown on sapphire by metalorganic chemical vapor deposition is studied. The results show that as the reactor pressure increases from 2500 to 20000 Pa, the GaN surface becomes rough and the growth rate of GaN films decreases. The rough surface morphology is associated with the initial high temperature GaN islands, which are large with low density due to low adatom surface diffusion under high reactor pressure. These islands prolong the occurrence of 2D growth mode and decrease the growth rate of GaN film. Meanwhile, the large GaN islands with low density lead to the reduction of threading dislocation density during subsequent island growth and coalescence, and consequently decrease the full width at half maximum of X-ray rocking curve of the GaN film.

关键词： GaN薄膜增长速度压力上升反应器结构特性金属有机物化学气相沉积表面形貌原子表面扩散

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Small-signal switch model of GaN HEMTs for MMIC applications

引用

The Journal of China Universities of Posts and Telecommunications 2016年第5期23卷 56-60页

作者： Du Lin Yang Xiaofeng Li Yang zhang jincheng Hao Yue Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of Ministry of Education Xidian University School of Electronic Engineering Xi’an University of Posts and Telecommunications

Gallium nitride （GaN） high electron mobility transistor （HEMT） with symmetrical structure as a control device is discussed in this paper. The equivalent circuit model is proposed on the basis of physical and electrical properties of the GaN HEMT device. A transistor with 0.5 μm gate length and 6 x 125 gm gate width is fabricated to verify the model, which can be treated as a single pole single throw （SPST） switch due to the ON state and OFF state. The measurement results show a lzood agreement with the simulation results, which demonstrates the effectiveness of the proposed model.

关键词： GaN HEMT switch model symmetrical structure MMIC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Superior Pseudocapacitive Storage of a Novel Ni3Si2/ NiOOH/Graphene Nanostructure for an All‑Solid‑State Supercapacitor

引用

Nano-Micro Letters 2021年第1期13卷 15-28页

作者： Jing Ning Maoyang Xia Dong Wang Xin Feng Hong Zhou jincheng zhang Yue Hao The State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology Xidian UniversityXi’an 710071People’s Republic of China Shaanxi Joint Key Laboratory of Graphene Xidian UniversityXi’an 710071People’s Republic of China

Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures,doping of thin films,and mechanisms for the construction of threedimensional ***,we synthesize creeper-like Ni3Si2/NiOOH/graphene nanostructures via low-pressure all-solid meltingreconstruction chemical vapor *** a carbon-rich atmosphere,high-energy atoms bombard the Ni and Si surface,and reduce the free energy in the thermodynamic equilibrium of solid Ni–Si particles,considerably catalyzing the growth of Ni–Si *** controlling the carbon source content,a Ni3Si2 single crystal with high crystallinity and good homogeneity is stably *** measurements indicate that the nanostructures exhibit an ultrahigh specific capacity of 835.3 C g^−1(1193.28 F g^−1)at 1 A g^−1;when integrated as an all-solidstate supercapacitor,it provides a remarkable energy density as high as 25.9 Wh kg^−1 at 750 W kg^−1,which can be attributed to the freestanding Ni3Si2/graphene skeleton providing a large specific area and NiOOH inhibits insulation on the electrode surface in an alkaline solution,thereby accelerating the electron exchange *** growth of the high-performance composite nanostructure is simple and controllable,enabling the large-scale production and application of microenergy storage devices.

关键词： Pseudocapacitive storage Creeper-like Ni3Si2 NiOOH Graphene All-solid-state supercapacitors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：