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Single event transients induced by pulse laser in Ge pMOSFETs and its supply voltage dependence

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Science China(Information Sciences) 2022年第8期65卷 295-296页

作者： Jingyi LIU Xia AN Gensong LI Zhexuan REN Ming LI Xing ZHANG Ru HUANG Institute of Microelectronics Peking University

Dear editor,Germanium(Ge) has been considered as a promising candidate of channel material for sub-7 nm owing to its high carrier mobility and good compatibility with conventional Si CMOS process [1]. Although Ge-based technology is still under development and not in massive production, it is quite meaningful to explore its single event effect(SEE) before potential space applications.

关键词： CHARGE COLLECTION bulk

Effect of initial material bulk density and easily-degraded organic matter content on temperature changes during composting of cucumber stalk

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Journal of Environmental Sciences 2019年第6期31卷 306-315页

作者： Ruixue Chang Qiuyue Guo Qing Chen Maria Pilar Bernal Qian Wang Yanming Li College of Resource and Environmental Science China Agricultural University Department of Soil and Water Conservation and Organic Waste Management Centro Edafologia y Biologia Applicada del SeguraCSIC

To inactivate the potentially pathogenic microorganisms and safely utilize vegetable waste compost, ultra-high temperatures(> 70°C) should be maintained during the composting without having an inhibitory effect on maturity. This study investigated the influence of bulk density(part 1) and easily-degraded organic matter content(EDOMC, part 2) on temperature evolution during vegetable waste composting: Part 1: corn straw with different particle sizes was used to achieve different bulk densities in the composting material(BD1–BD3); Part 2: partial or total substitution of the corn straw by corn starch was carried out to obtain different EDOMC(ED1–ED4). The composting experiments were conducted in a labscale reactor(1.75 kg material) and lasted for 30 d. Temperature and CO2 emission were recorded daily, and the organic matter, lignocellulose, microbial activity, germination index(GI) and C/N of the samples were measured at different stages. The highest temperature(65.7°C) in part 1 occurred in the treatment with the bulk density of 0.35 g/cm3, which also had the longest thermophilic phase. bulk density was found to seriously influence the utilization efficiency of O2 and heat transfer through materials, rather than heat production from organic matter degradation. In experiment part 2, the highest temperature was obtained with EDOMC of 45%(71.4°C). Therefore, adjusting the bulk density to 0.35 g/cm3 and the easily-degraded organic matter content of the initial material to 45% was the best combination for reaching temperatures above 70°C during composting, with no inhibitory effect on the maturity of the compost product.

关键词： Compost 70℃ Vegetable waste bulk density Easily-degraded organic matter con tent Cucumber stalk

What is the mass of loess in the Loess Plateau of China?

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Science Bulletin 2019年第8期64卷 534-539页

作者： Yuanjun Zhu Xiaoxu Jia Jiangbo Qiao Ming'an Shao State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources College of Resources and Environment University of Chinese Academy of Sciences Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

The Loess Plateau of China(LP) has the largest and thickest loess deposits in the world. Quantifying the amount of loess in the LP is crucial for investigating the accumulation and erosion of loess, and determining the regional soil and water resource capacity. We used loess thickness data, a pedotransfer function for bulk density(BD), and the clay content data observed in 242 sites across the LP to derive the BD of loess and then estimate the loess mass and its distribution across the LP. The results indicated that the average BD of loess between the surface and bedrock is 1.58 g cm^(-3), varying from 1.18 to 1.87 g cm^(-3).The total loess mass is approximately 5.45 ? 10^(13) t, and the average loess mass over an area of 1 m^2 is 169 t, ranging from 1.36 to 585 t. The greatest mass of loess is in the south-central of the LP while the lowest mass of loess is in the northwest and river valley areas. Our estimate of loess mass provides key data for calculating water, carbon, and nutrient storages in the LP, which improves our understanding of soil-water processes and ecohydrological systems in this landscape.

关键词： The Loess Plateau Loess mass Pedotransfer function Soil erosion bulk density

Experimental Study of Air Layer Drag Reduction with Bottom Cavity for A bulk Carrier Ship Model

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China Ocean Engineering 2019年第5期33卷 554-562页

作者： WU Hao OU Yong-peng Key Laboratory of High Performance Ship Technology (Wuhan University of Technology) Ministry of Education Wuhan 430063 China School of Transportation Wuhan University of Technology Wuhan 430063 China College of Naval Architecture and Ocean Engineering Naval University of Engineering Wuhan 430033 China

Air lubrication by means of a bottom cavity is a promising method for ship drag reduction. The characteristics of the bottom cavity are sensitive to the flow field around the ship hull and the effect of drag reduction, especially the depth of the bottom cavity. In this study, a ship model experiment of a bulk carrier is conducted in a towing tank using the method of air layer drag reduction (ALDR) with different bottom cavity depths. The shape of the air layer is observed, and the changes in resistance are measured. The model experiments produce results of approximately 20% for the total drag reduction at the ship design speed for a 25-mm cavity continuously supplied with air at Cq = 0.224 in calm water, and the air layer covers the whole cavity when the air flow rate is suitable. In a regular head wave, the air layer is easily broken and reduces the drag reduction rate in short waves, particularly when λ/Lw1 is close to one;however, it still has a good drag reduction effect in the long waves.

关键词： air layer drag reduction bulk carrier model test depth of cavity air layer shape

Microstructure and compressive/tensile characteristic of large size Zr-based bulk metallic glass prepared by laser solid forming

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Journal of Materials Science & Technology 2019年第2期35卷 328-335页

作者： Xin Lin Yuanyuan Zhang Gaolin Yang Xuehao Gao Qiao Hu Jun Yu Lei Wei Weidong Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical University Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT China Northwestern Polytechnical University

The large size, crack-free Zr_(55)Cu_(30)Al_(10)Ni_(5) bulk metallic glass(BMGs) with the diameter of 54 mm and the height of 15 mm was built by laser solid forming additive manufacturing technology, whose size is larger than the critical diameter by casting. The microstructure, tensile and compressive deformation behaviors and fracture morphology of laser solid formed Zr_(55)Cu_(30)Al_(10)Ni_5 BMGs were investigated. It is found that the crystallization mainly occurs in the heat-affected zones of deposition layers, which consist of Al_5Ni_3Zr_2, NiZr_2, ZrCu, CuZr_2 phases. The content of amorphous phase in the deposit is about 63%.Under the compressive loading, the deposit presents no plasticity before fracture occurs. The fracture process is mainly controlled by the shear stress and the compressive shear fracture angles of about39?. The compressive strength reaches 1452 MPa, which is equivalent to that of as-Cast Zr_(55)Cu_(30)Al_(10)Ni_5 BMGs, and there exist vein-like patterns, river-like patterns and smooth regions at the compressive fractography. Under the tensile loading, the deposit presents the brittle fracture pattern without plastic deformation. The fracture process exhibits normal fracture model, and the tensile shear fracture angle of about 90?. The tensile strength is only about 609 MPa, and the tensile fractography mainly consists of micro-scaled cores and vein-like patterns, dimple-like patterns, chocolate-like patterns and smooth regions. The results further verified the feasibility and large potential of laser additive manufacturing on fabrication and industrial application of large-scale BMGs parts.

关键词： Zr-based bulk metallic glass Laser solid forming Additive manufacturing Microstructure Compressive and tensile behavior

Serration and shear avalanches in a ZrCu based bulk metallic glass composite in different loading methods

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Journal of Materials Science & Technology 2019年第9期35卷 2079-2085页

作者： Haichao Sun Zhiliang Ning Jingli Ren Weizhong Liang Yongjiang Huang Jianfei Sun Xiang Xue Gang Wang School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China School of Materials Science and Engineering Heilongjiang University of Science and TechnologyHarbin 150027China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China

In the current research, serrated flow is investigated under tensile and compressive loading in a ZrCubased bulk metallic glass composite (BMGC) that is well known for its plastic deformability, which is higher than that of metallic glasses. Statistical analysis on serrations shows a complex, scale free process, in which shear bands are highly correlated. The distribution of the elastic-energy density stored in each serration event follows a power-law relationship, showing a randomly generated serrated event under both tension and compression tests. The plastic deformation in the temporal space is explored by a timeseries analysis, which is consistent with the trajectory convergent evolution in critical dynamic behavior even in the low strain rate regime in both tests. The results demonstrate that the secondary phase in the BMGC can stabilize the shear band extension and facilitate the critical behavior in the low strain rate regime. This study provides a strong evidence of serrated flow phenomenon in BMGC under tension test, and offers a deep understanding of the correlation between serrations and shear banding in temporal space.

关键词： Metallic glass bulk metallic glass composites Serrated flow Shear avalanches Statistical analysis Critical behavior

Tunable Curie temperature and magnetocaloric effect of FeCrMoCBYNi bulk metallic glass with different crystallized phases

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Journal of Rare Earths 2019年第4期37卷 404-409页

作者： Yuanbin Lv Qingjun Chen Youlin Huang School of Materials Science and Engineering Nanchang Hangkong University

The investigation on Curie temperature and magnetocaloric effect of the FeCrMoCBYNi bulk metallic glass(BMG) with different crystallized phases was carried out by XRD,TEM and PPMS. The experimental results show that the Curie temperature(T_c) of Fe_(45)Cr_(15)Mo_(14)C_(15)B_6 Y_2 Ni_3 BMG with different annealing condition reaches a highest value of 95 K. The value of magnetic entropy change △S_M(T) of Sample 3 reaches a maxima of 0.48 J/(kg·K) at Tc temperature, which result from the interaction among the precipitated phases of(Fe,Cr)_(23)(C,B)_6, Fe_3 Mo_3 C and residual amorphous phase. Based on the experiment results, it can be obtained that the Curie temperature, magnetocaloric effect can reach their optimal value at low temperature, when the content of amorphous phase and precipitated phases type run up to certain value. The magnetic properties of Sample 1 with full amorphous phase and Sample 4 with full crystalline phase will both decrease.

关键词： bulk metallic glass Crystallization Curie temperature Magnetocaloric effect Rare earths

Organic nitrogen components in soils from southeast China

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第4期14卷 259-269页

作者： Xian-you CHEN Liang-huan WU Xiao-chuang CAO Yuan-hong ZHU Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health College of Environmental and Resource SciencesZhejiang University Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition College of Environmental and Resource SciencesZhejiang University Department of Crop and Soil Sciences the Pennsylvania State UniversityUniversity ParkPennsylvania PA 16802USA

Objective:To investigate the amounts of extractable organic nitrogen(EON),and the relationships between EON and total extractable nitrogen(TEN),especially the amino acids(AAs) adsorbed by soils,and a series of other hydrolyzed soil nitrogen indices in typical land use soil types from southeast China.Under traditional agricultural planting conditions,the functions of EON,especially AAs in the rhizosphere and in bulk soil zones were also investigated.Methods:Pot experiments were conducted using plants of pakchoi(Brassica chinensis L.) and rice(Oryza sativa L.).In the rhizosphere and bulk soil zone studies,organic nitrogen components were extracted with either distilled water,0.5 mol/L K2SO4or acid hydrolysis.Results:K2SO4-EON constituted more than 30% of TEN pools.K2SO4-extractable AAs accounted for 25% of EON pools and nearly 10% of TEN pools in rhizosphere soils.Overall,both K2SO4-EON and extractable AAs contents had positive correlations with TEN pools.Conclusions:EON represented a major component of TEN pools in garden and paddy soils under traditional planting conditions.Although only a small proportion of the EON was present in the form of water-extractable and K2SO4-extractable AAs,the release of AAs from soil exchangeable sites might be an important source of organic nitrogen(N) for plant growth.Our findings suggest that the content of most organic forms of N was significantly greater in rhizosphere than in bulk soil zone samples.However,it was also apparent that the TEN pool content was lower in rhizosphere than in bulk soil samples without added N.

关键词： Extractable organic nitrogen Amino acids Rhizosphere bulk soil

Nanomorphology in A–D–A type small molecular acceptors-based bulk heterojunction polymer solar cells

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Journal of Energy Chemistry 2019年第8期28卷 104-123,I0001,I0005页

作者： Delong Liu Ying Zhang Gang Li The Department of Electronic and Information Engineering The Hong Kong Polytechnic UniversityHong Kong 999077 China The Department of Electronic and Information Engineering The Hong Kong Polytechnic University Shenzhen Research InstituteShenzhen 518057Guangdong China

Recent developments in acceptor–donor–acceptor(A–D–A) type non-fullerene acceptors have led to substantial improvements in bulk-heterojunction polymer solar cells efficiency. The device performance strongly depends on photoactive layer morphology, as the molecular packing, donor–acceptor interface and phase separation significantly affect the charge-transfer states and charge carrier dynamics. In this review, we start with a brief introduction of the techniques most effectively utilized to characterize multiphase morphology. Then, we summarize recent progress in A–D–A type acceptors, with the emphasis on understanding the molecular structure–morphology–performance relationships. Finally, an outlook on correlating morphological characteristics with photovoltage losses is presented for further improving device performance.

关键词： Polymer solar cells bulk heterojunction Nanomorphology Non-fullerene acceptor A–D–A type small molecules