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Modeling radiative effects of haze on summer-time convective precipitation over North China： a case study

Frontiers of Environmental Science & Engineering 2016年第4期10卷 105-114页

作者： Xuying WANG Bin zhang School of Environment Tsinghua University Beijing 100084 China Chinese Academy for Environmental Planning Beijing 100012 China Ministry of Education Key Laboratory for Earth System Modeling Center for Earth System Science Institute for Global Change Studies Tsinghua University Beijing 100084 China

The impact of haze radiative effect on summertime 24-h convective precipitation over North China was investigated using WRF model （version 3.3） through model sensitivity studies between scenarios with and without aerosol radiative effects. The haze radiative effect was represented by incorporating an idealized aerosol optical profile, with AOD values around 1, derived from the aircraft measurement into the WRF shortwave scheme. We found that the shortwave heating induced by aerosol radiative effects would significantly reduce heavy rainfalls, although its effect on the post-frontal localized thunderstorm precipitation was more diverse. To capture the key factors that determine whether precipitation is enhanced or suppressed, model grids with 24-h precipitation difference between the ：two scenarios exceeding certain threshold （〉30 mm or〈 -30 mm） were separated into two sets. Analyses of key meteorological variables between the enhanced and suppressed regimes suggested that atmospheric convection was the most important factor that determined whether precipitation was enhanced or suppressed during summertime over North China. The convection was stronger over places with precipitation enhancement over 30 mm. Haze weakened the convection over places with precipitation suppression exceeding 30 mm and caused less water vapor to rise to a higher level and thus further suppressed precipitation. The suppression of precipitation was often accompanied with relatively high convective available potential energy （CAPE）, relative humidity （RH） and updraft velocities.

关键词： Haze Aerosol radiative effects Convective precipitation

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Strain modulation on graphene/ZnO nanowire mixed- dimensional van der Waals heterostructure for high- performance photosensor

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Nano Research 2017年第10期10卷 3476-3485页

作者： Shuo Liu Qingliang Liao Zheng zhang Xiankun zhang Shengnan Lu Lixin Zhou Mengyu Hong Zhuo Kang Yue zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Municipal Key Laboratory for Advanced Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

The mixed-dimensional van der Waals （vdW） heterostructure is a promising building block for strained electronics and optoelectronics because it avoids the bond fracture and atomic reconstruction under strain. We propose a novel mixed-dimensional vdW heterostructure between two-dimensional graphene and a one-dimensional ZnO nanowire for high-performance photosensing. By utilizing the piezoelectric properties of ZnO, strain modulation was accomplished in the mixed-dimensional vdW heterostructure to optimize the device performance. By combining the ultrahigh electrons transfer speed in graphene and the extremely long life time of holes in ZnO, an outstanding responsivity of 1.87 ×10^5 A/W was achieved. Under a tensile strain of only 0.44% on the ZnO nanowire, the responsivity was enhanced by 26%. A competitive model was proposed, in which the performance enhancement is due to the efficient promotion of the injection of photogenerated electrons from the ZnO into the graphene caused by the strain-induced positive piezopotential. Our study provides a strain-engineering strategy for controlling the behavior of the photocarriers in the mixed-dimensional vdW heterostructure, which can be also applied to other similar systems in the future.

关键词： graphene ZnO nanowire vdW heterostructure strain modulation photosensor

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Geometric error measuring,modeling,and compensation for CNC machine tools:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： Zhao zhang Feng JIANG Ming LUO Baohai WU Dinghua zhang Kai TANG Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine *** that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining *** have studied how to measure,detect,model,identify,reduce,and compensate the geometric *** paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric *** advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated ***,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically ***,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation Error identification Error measurement Error modeling Geometric error Machine tools

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Hierarchical porous carbon derived from one-step self-activation of zinc gluconate for symmetric supercapacitors with high energy density

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Frontiers of Chemical Science and Engineering 2023年第4期17卷 387-394页

作者： Junlei Xiao Hua zhang Yifan Wang Chunmei zhang Shuijian He Shaohua Jiang Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022China Institute of Materials Science and Devices School of Materials Science and EngineeringSuzhou University of Science and TechnologySuzhou 215009China

Porous carbons with high specific area surfaces are promising electrode materials for ***,their production usually involves complex,time-consuming,and corrosive ***,a straightforward and effective strategy is presented for producing highly porous carbons via a self-activation procedure utilizing zinc gluconate as the *** volatile nature of zinc at high temperatures gives the carbons a large specific surface area and an abundance of mesopores,which avoids the use of additional activators and ***,the obtained porous carbon electrode delivers a satisfactory specific capacitance and outstanding cycling durability of 90.9%after 50000 cycles at 10 A·g^(-1).The symmetric supercapacitors assembled by the optimal electrodes exhibit an acceptable rate capability and a distinguished cycling stability in both aqueous and ionic liquid ***,capacitance retention rates of 77.8%and 85.7%are achieved after 50000 cycles in aqueous alkaline electrolyte and 10000 cycles in ionic liquid ***,the symmetric supercapacitors deliver high energy/power densities of 49.8 W·h·kg^(-1)/2477.8 W·kg^(-1) in the Et4NBF4 electrolyte,outperforming the majority of previously reported porous carbon-based symmetric supercapacitors in ionic liquid electrolytes.

关键词： self-activation zinc organic salts abundant mesopores symmetric supercapacitor liquid electrolyte

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A triple-combination nanotechnology platform based on multifunctional RNA hydrogel for lung cancer therapy

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Science China Chemistry 2020年第4期63卷 546-553页

作者： Junwei Li Dandan Yuan Xiangjiang Zheng Xinyue zhang Xuemei Li Shusheng zhang Collaborative Innovation Center of Tumor Marker Detection Technology Equipment and Diagnosis-Therapy Integration in Universities of ShandongShandong Province Key Laboratoty of Detection Technology for Tumor MakersSchool of Chemistry and Chemical EngineeringLinyi UniversityLinyi 276005China College of Chemistry Chemical Engineering and Materials ScienceCooperative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongShandong Normal UniversityJinan 250014China

Conventional cancer combination therapy usually involves systemic delivery of anticancer drugs which may lead to the destruction of normal cells and physiological toxicity due to the lack of targeting ability and toxicity of drug carriers. In the present study, a triple combination nanosystem of gene therapy, chemotherapy and phototherapy delivered by multifunctional RNA nanohydrogels(RNA NHs) was established. By taking the advantages of DNA nanotechnology and rolling circle transcription(RCT), three lung cancer inhibitor microRNA(let-7 a, microRNA 34 a, microRNA 145) hairpins were integrated in one RNA NH nanoparticle, leading to the simultaneous silencing of three targeted m RNAs. Meanwhile, RNA NH carried doxorubicin(DOX, a chemotherapy drug) as well as 5,10,15,20-tetrakis(1-methylpyridinium-4-yl) porphyrin(TMPyP4, a photosensitizer) and delivered these drugs to cancer cells. It was demonstrated that lung cancer inhibitor microRNAs integrated in RNA NHs, DOX and TMPyP4 could play a synergistic anti-cancer role in multi-drug resistance cancer cells. Under the action of aptamer sequence S6 that was modified with cholesterol, the resulting RNA NHs were condensed to feasible size without the assistance of polyelectrolyte condensation reagents and showed cancer-specific cellular targeting. Subsequently, thousands of copies of miRNA together with chemotherapy drug as well as photosensitizer were delivered to cancer cells specifically, and an ideal synergistic treatment effect was achieved in vivo, thus playing a combined role of gene therapy, chemotherapy and phototherapy. Through this study, it can be concluded that the triple combination therapy nanosystem can overcome the multidrug resistance caused by the malfunction of genes in chemotherapy and shows a great potential in the field of multifunctional synergistic cancer treatment.

关键词： RNA nanohydrogel phototherapy drug delivery gene therapy lung cancer

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Influence of reclaimed water discharge on the dissemination and relationships of sulfonamide, sulfonamide resistance genes along the Chaobai River, Beijing

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Frontiers of Environmental Science & Engineering 2019年第1期13卷 87-98页

作者： Ning zhang Xiang Liu Rui Liu Tao zhang Miao Li Zhuoran zhang Zitao Qu Ziting Yuan Hechun Yu School of Environment Tsinghua University Beijing 100084 China Division of Environment and Resources Research Transport Planning and Research Institute Ministry of Transport Beijing 100028 China Chinese Academy for Environmental Planning Beijing 100012 China Institute of Chemistry Industrial Chemistry Technical University of Munich (Asian Campus) Singapore 139660 Singapore School of Water Resources and Environment China University of Geosciences (Beijing) Beijing 100083 China

Reclaimed water represents an important source of antibiotics and antibiotic resistance genes, threatening the ecological safety of receiving environments, while alleviating water resource shortages. This study investigated the dissemination of sulfonamide (SAs), sulfonamide resistance genes (SRGs), and class one integrons (intl1) in the surface water of the recharging area of the Chaobai River. The three antibiotics sulfamethoxazole, trimethoprim, and sulfadiazine had the highest abundance. The highest absolute abundances were 2.91×10^6, 6.94×10^6, and 2.18×10^4 copies/mL for sul1, sul2, and intl 1 at the recharge point, respectively. SRGs and intl1 were widespread and had high abundance not only at the recharging point, but also in remote areas up to 8 km away. Seasonal variations of SRGs abundance followed the order of summer>autumn>spring>winter. Significant correlations were found between SRGs and intl1 (a = 0.887 and 0.786, p<0.01), indicating the potential risk of SRGs dissemination. Strong correlations between the abundance of SRGs and environmental factors were also found, suggesting that appropriate environmental conditions favor the spread of SRGs. The obtained results indicate that recharging with reclaimed water causes dissemination and enrichment of SAs and SRGs in the receiving river. Further research is required for the risk assessment and scientific management of reclaimed water.

关键词： Sulfonamide residues Sulfonamide resistance genes Reclaimed water recharge Surface water Class one integrons

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Molecular composition and structure of organic matter in density fractions of soils amended with corn straw for five years

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Pedosphere 2023年第2期33卷 372-380页

作者： Batande Sinovuyo NDZELU Sen DOU Xiaowei zhang Yifeng zhang College of Resource and Environmental Science Jilin Agricultural UniversityChangchun 130118(China)

Corn straw is an important source of carbon(C),and when applied to soil,it alters the accumulation and distribution of organic ***,the mechanistic pathways by which newly added C is stored and stabilized in soil remain a subject of interest and debate among *** this study,we investigated the chemistry of organic matter in different density fractions of Haplic Cambisol(sandy clay loam)in a field experiment with corn straw at8900 kg ha^(-1)year^(-1)under no tillage(NT),minimum tillage(MT),and conventional tillage(CT).After five years of corn(Zea mays L.)monocropping,soils were collected from the 0-20 and 20-40 cm depths and processed to obtain the organic matter in light fraction(LFOM),occluded particulate(oPOM),and heavy fraction(HFOM)in the *** results showed that compared with conventional tillage without corn straw return(CT0),corn straw return(i.e.,NT,MT,and CT)increased soil organic C content by 11.55%-16.58%.Thermogravimetric and Fourier transform infrared analyses demonstrated that the HFOM was characterized by a greater proportion of easily biodegradable substances,which may be due to the deposition of microbially processed materials on the surface of soil *** LFOM and o POM were distinguished by greater phenolic,aromatic C,and thermally stable *** with CT0,the NT and MT fields showed higher abundances of hydrophobic,aliphatic,and thermally unstable organic compounds,which increased soil C content and stability in the ***,NT and MT may be ideal practices to increase soil organic C content.

关键词： heavy fraction organic matter light fraction organic matter occluded particulate organic matter soil organic carbon tillage intensity

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A Web-like Three-dimensional Binder for Silicon Anode in Lithium-ion Batteries

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Energy & Environmental Materials 2024年第1期7卷 21-27页

作者： Liyuan Li Tao Li Yifan Sha Baozeng Ren Lan zhang Suojiang zhang CAS Key Laboratory of Green Process and Engineering Beijing Key Laboratory of Ionic Liquids Clean ProcessState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China Langfang Green Industrial Technology Center Langfang 065001China Henan Key Laboratory of Energy Storage Materials and Processes Zhengzhou Institute of Emerging Industrial TechnologyZhengzhou 450003China

Si anode is of paramount importance for advanced energy-dense lithium-ion batteries(LIBs).However,the large volume change as well as stress generates during its lithiation-delithiation process poses a great challenge to the long-term cycling and hindering its *** this work,a composite binder is prepared with a soft component,guar gum(GG),and a rigid linear polymer,anionic polyacrylamide(APAM).Rich hydroxy,carboxyl,and amide groups on the polymer chains not only enable intermolecular crosslinking to form a web-like binder,A2G1,but also realize strong chemical binding as well as physical encapsulating to Si *** resultant electrode shows limited thickness change of merely 9%on lithiation and almost recovers its original thickness on *** demonstrates high reversible capacity of 2104.3 mAh g^(-1)after 100 cycles at a current density of 1800 mA g^(-1),and in constant capacity(1000 mAh g^(-1))test,it also shows a long life of 392 ***,this soft-hard combining web-like binder illustrates its great potential in the future applications.

关键词： anionic polyacrylamide lithium-ion batteries Si anode thickness change web-like binder

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Broadband and efficient second harmonic generation in LiNbO_(3)-LiTaO_(3) composite ridge waveguides at telecom-band

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Chinese Physics B 2021年第1期30卷 256-261页

作者： Xin-Tong zhang Department of Optics and Optical Engineering University of Science and Technology of ChinaHefei 230026China

Broadband nonlinear frequency conversions of optical waves are widely employed in multiple areas of optics and photonics. However, the broadening of conversion bandwidth is often at a cost of reduction in efficiency, which may induce a limitation on practical applications. Here we theoretically propose a novel design of LiNbO_(3) ridge waveguides on LiTaO_(3) substrates which can be used for efficient and broadband second harmonic generation. Through group velocity engineering of the ridge waveguides, acceptance bandwidth over 20 nm with a high conversion efficiency of > 25%W^(-1)·cm^(-2) is achieved at telecom-band.

关键词： second harmonic generation lithium niobate ridge waveguide dispersion manipulation

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Investigation of shunt solar cells’ currents based on equivalent circuit model

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Science China(Technological Sciences) 2016年第9期59卷 1391-1398页

作者： YI ShiGuang zhang WanHui SHEN Hui zhang WenJie LUO ZhiRong CHEN Le College of Physical Science and Technology Engineering Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Large Data Processing Yulin Normal University Yulin 537000 China Institute for Solar Energy Systems Sun Yat-sen University Guangzhou 510275 China Guangdong Testing Institute of Product Quality Supervision Foshan 528300 China

In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equivalent one-diode circuit of the solar cell and the analysis of the two-body model. At first, the equations of current and voltage are deduced from the related electrical laws and the circuit diagram of the two solar cells connected in parallel. Then, according to the experimentally measured data of typical single-crystalline silicon solar cells (125 mm×125 mm), we select the appropriate simulation parameters. Following this, by using the photo-generated current, the shunt resistance, and the serial resistance of one of the shunt solar cells and the load resistance as independent variables, in turn, the changing characteristics of each branch current in the two shunt solar cells are numerically discussed and analyzed for these four cases for the first time. At the same time, we provide a simple physical explanation for the modeling results. Our analyses show that these parameters have different impacts on the internal currents of solar cells connected in parallel. These results provide a reference to solve the problem of connecting solar cells and to develop higher efficiency solar cells and systems. Meanwhile, the results will contribute to a better comprehension of the reasons for efficiency loss of solar cells and systems, and deepen the understanding of the electrical of solar cells behavior for high performance photovoltaic applications.

关键词： solar cells mismatch losses internal currents

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