检索结果-南通市图书馆

Atmospheric reductive catalytic fractionation of lignocellulose integrated with one-pot catalytic conversion of carbohydrate yielding valuable lignin monomers and platform chemicals from corn straw

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2025年第1期10卷 161-172页

作者： Meng-Ying Liu Zhe-Hui Zhang Xue-qi Wang qian sun Chen Zhang Yu Li Zhuohua sun Katalin Barta Feng Peng Tong-qi Yuan State Key Laboratory of Efficient Production of Forest Resources Beijing Forestry UniversityBeijing100083China Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China Department of Chemistry Organic and Bioorganic ChemistryUniversity of GrazHeinrichstrasse 28/II8010 GrazAustria

Developing a cost-effective and environmentally friendly process for the production of valuable chemicals from abundant herbal biomass receives great attentions in recent ***,taking advantage of the“lignin first”strategy,corn straw is converted to valuable chemicals including lignin monomers,furfural and 5-methoxymethylfurfural via a two steps *** key of this research lies in the development of a green and low-cost catalytic process utilizing magnetic Raney Ni catalyst and high boiling point ethylene *** utilization of neat ethylene glycol as the sole slovent under atmospheric conditions obviates the need for additional additives,thereby facilitating the entire process to be conducted in glass flasks and rendering it highly convenient for scaling *** the initial step,depolymerization of corn straw lignin resulted in a monomer yield of 18.1 wt%.Subsequently,in a dimethyl carbonate system,the carbohydrate component underwent complete conversion in a one-pot process,yielding furfural and 5-methoxymethylfurfural as the primary products with an impressive yield of 47.7%.

关键词： Atmospheric reductive catalytic fractionation Corn straw Ethylene glycol Raney Ni 5-Methoxymethylfurfural

在线全文

学校读者我要写书评

暂无评论

人情消费能使我们幸福吗?

消费经济 2017年第2期33卷 17-24页

作者：曾起艳孙凯曾寅初中国人民大学农业与农村发展学院北京100872

本文构建了人情消费与幸福感之间的理论模型,并利用2010年中国综合社会调查数据(CGSS)实证分析了人情消费对中国城乡居民幸福感的影响。结果表明人情消费对幸福感的影响呈倒U形,倒U拐点处人情支出占家庭总支出比重约为23.64%。当人情支... 详细信息

本文构建了人情消费与幸福感之间的理论模型,并利用2010年中国综合社会调查数据(CGSS)实证分析了人情消费对中国城乡居民幸福感的影响。结果表明人情消费对幸福感的影响呈倒U形,倒U拐点处人情支出占家庭总支出比重约为23.64%。当人情支出尚未达到拐点之前,正效应占据主导,增加人情支出有助于情感沟通和人际交往,促进幸福感提升;一旦达到或超过这个拐点,增加人情消费加剧生活负担与压力的负效应反而会降低幸福水平。同时,人情消费与幸福感之间的倒U形关系在城乡居民中均存在,但人情消费给农村居民带来不幸福感的比例高于城市居民,且城乡中低收入群体和中老年群体因人情消费造成的不幸福感比例更高。

关键词：人情消费幸福感中国城乡

Improved reference-frame-independent quantum key distribution with intensity fluctuations

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2025年第2期34卷 48-52页

作者： Zi-qi Chen Hao-Bing sun Ming-Shuo sun qin Wang Institute of Quantum Information and Technology Nanjing University of Posts and TelecommunicationsNanjing 210003China Broadband Wireless Communication and Sensor Network Technology Key Laboratory of Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China

Reference-frame-independent quantum key distribution(RFI-QKD) can avoid real-time calibration operation of reference frames and improve the efficiency of the communication process. However, due to imperfections of optical devices,there will inevitably exist intensity fluctuations in the source side of the QKD system, which will affect the final secure key rate. To reduce the influence of intensity fluctuations, an improved 3-intensity RFI-QKD scheme is proposed in this *** considering statistical fluctuations and implementing global parameter optimization, we conduct corresponding simulation analysis. The results show that our present work can present both higher key rate and a farther transmission distance than the standard method.

关键词： quantum key distribution intensity fluctuations decoy-state method

Exposure of individuals aged 18-44 years to personal care products in Beijing,China:Exposure profiles,possible influencing factors,and risk assessment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第2期148卷 691-701页

作者： Xu Zhang Linxue Han qi sun Xiaochen Wang Xiaojian Hu Xiao Lin Ying Zhu China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 100021China The Bureau for Health Inspection and Supervision of Haidian District Beijing 100037China

Personal care products(PCPs)are a class of emerging pollutants that have attracted public concern owing to their harmful effects on humans and the *** data is valuable for insight the levels of PCPs in the human body and can be crucial for identifying potential health *** gain a better understanding of timely exposure profiles and health risk of reproductive-age population to PCPs,we determined six parabens,six benzophenone-type ultraviolet filters,and three disinfectants in 256 urine samples collected from young adults aged 18-44 years in Beijing,*** urinary levels of benzophenone-3(BP-3)and 4-hydroxybenzophenone(4-OHBP)were significantly higher in summer compared to winter,suggesting these compounds have different seasonal usage ***,the total concentration of 15 PCPs in female was 430 ng/mL,approximately two times higher than that in male.P-chloro-m-xylenol(PCMX),as a new type of antibacterial agent,has the greatest level among all target analytes,indicating the increasingly use of this antibacterial alternative *** potential influencing factors that lead to the elevated exposure level of PCPs were *** 19%of the target population had a high hazard index value(greater than 1)which was attributed to exposure to propyl paraben(PrP),benzophenone-1(BP-1),BP-3 and PCMX,indicating that PCPs may pose a relatively high exposure risk at environmental levels that should be a cause for concern.

关键词： Personal care products Hazard quotient Risk assessment Exposure patterns Urine

Feedback Gain Scheduling Controller Design for Networked Control Systems with Accurate Measurement of QoS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Feedback Gain Scheduling Controller Design for Networked Con...

Introducing strong metal–oxygen bonds to suppress the Jahn-Teller effect and enhance the structural stability of Ni/Co-free Mn-based layered oxide cathodes for potassium-ion batteries

2015年中国智能自动化学术会议

作者： Hong Yao Jian-qiu Deng Cui Hao zeng-qi sun Xin Lu Beijing Institute of Technology School of Aerospace

The networked control system was modeled in this *** to the actual network conditions,the networked-induced time delay is always varying in a certain ***,the networked-induced time delay can be divided into the fixed time delay and the random time *** long time delay can be taken as packet ***’s more,the drive mode,packets disorder,sampling period,and some assumed conditions were considered carefully in this *** order to make the research close to the reality,the round-trip delay of the network between Tsinghua University and Yahoo is measured by sending and receiving data packet every 5 s from Tsinghua *** showed that the modeling method improved the effectiveness of the system.

关键词： Modeling Analysis NCSs Long time delay

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第2期101卷 713-722页

作者： Yicheng Lin Shaohua Luo Pengyu Li Jun Cong Wei Zhao Lixiong qian qi sun Shengxue Yan School of Materials Science and Engineering Northeastern University School of Resources and Materials Northeastern University at Qinhuangdao Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province

Mn-based layered oxides（KMO） have emerged as one of the promising low-cost cathodes for potassiumion batteries（PIBs）.However,due to the multiple-phase transitions and the distortion in the MnO6structure induced by the Jahn-Teller（JT） effect associated with Mn-ion,the cathode exhibits poor structural ***,we propose a strategy to enhance structural stability by introducing robust metal-oxygen（M-O） bonds,which can realize the pinning effect to constrain the distortion in the transition metal（TM） ***,all the elements employed have exceptionally high crustal *** a proof of concept,the designed K0.5Mn0.9Mg0.025Ti0.025Al0.05O2cathode exhibited a discharge capacity of approximately 100 mA h g-1at 20 mA g-1with 79% capacity retention over 50 cycles,and 73% capacity retention over 200 cycles at 200 mA g-1,showcased much better battery performance than the designed cathode with less robust M-O *** properties of the formed M-O bonds were investigated using theoretical *** enhanced dynamics,mitigated JT effect,and improved structural stability were elucidated through the in-situ X-ray diffractometer（XRD）,in-situ electrochemical impedance spectroscopy（EIS）(and distribution of relaxation times（DRT） method),and ex-situ X-ray absorption fine structure（XAFS） *** study holds substantial reference value for the future design of costeffective Mn-based layered cathodes for PIBs.

关键词： Jahn-Teller effect Layered oxide cathodes Low-cost Potassium-ion batteries Robust M–O bonds

Flexible molecules dedicate to release strain of inverted inorganic perovskite solar cell

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 87-93页

作者： Hongrui sun Sanlong Wang Pengyang Wang Yali Liu Shanshan qi Biao Shi Ying Zhao Xiaodan Zhang Institute of Photoelectronic Thin Film Devices and Technology Renewable Energy Conversion and Storage CenterState Key Laboratory of Photovoltaic Materials and CellsNankai UniversityTianjin 300350China Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Tianjin 300350China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Engineering Research Center of Thin Film Photoelectronic Technology of Ministry of Education Tianjin 300350China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

The tensile strain in inorganic perovskite films induced by thermal annealing is one of the primary factors contributing to the inefficiency and instability of inorganic perovskite solar cells(IPSCs),which reduces the defect formation ***,a flexible molecule 5-maleimidovaleric acid(5-MVA)was introduced as a strain buffer to release the residual strain of CsPbI_(2.85)Br_(0.15)*** anhydride and carboxyl groups in 5-MVA interact strongly with the uncoordinated Pb^(2+)through Lewis acid-base reaction,thus tightly“pull”the perovskite *** in-between soft carbon chain increased the structural flexibility of CsPbI_(2.85)Br_(0.15)perovskite materials,which effectively relieved the intrinsic internal strain of CsPbI_(2.85)Br_(0.15),resisted the corrosion of external strain,and also reduced the formation of defects such as VIand *** addition,the introduction of 5-MVA improved crystal quality,passivated residual defects,and narrowed energy level ***,power conversion efficiency(PCE)of NiOxbased inverted IPSCs increased from 19.25%to 20.82%with the open-circuit voltage enhanced from 1.164 V to 1.230 *** release of strain also improved the stability of CsPbI_(2.85)Br_(0.15)perovskite films and devices.

关键词： Inverted inorganic perovskite solar cells Flexible molecules Strain release Crystallization Energy barrier High PCE

In situ measurement of environmental γ radiation dose rates of key nuclides for large radioactive surface sources

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2025年第1期36卷 69-79页

作者： Ze-qian Wu Jian sun Wei-qi Huang Bai-Rong Wang Jin-Xing Cheng Jiang-Feng Wu Yong-Hong Wang Biao Yuan Sheng qi Kun Shan Institute of NBC Defence Beijing 102205China Beijing New-High Technology Academy Beijing 100094China

To monitor nuclear and radiation emergencies,it is crucial to obtain accurate in situ measurements of the environmentalγ radiation dose rate from key radionuclides,particularly for large radioactive surface *** methods currently used for measuring dose rates are inadequate for obtaining the dose rates of key radionuclides and have large angular response errors when monitoring surface *** address this practical problem,this study proposes three methods for measuring the dose rate:the weighted peak total ratio,mean value regression,and numerical integration *** methods are based on energy-spectrum measurement data,and they were theoretically derived and numerically ***,a 1-m-long hexagonal radioactive surface source was integrated into a larger surface *** situ measurement experiments were conducted on a large radioactive surface source using a dose-rate meter and a portable HPGespectrometer to analyze the errors of the three aforementioned methods and verify their validity.

关键词： Environmentalγradiation dose rate HPGespectrometer Key radionuclides Radioactive surface source

Investigations of liquid-liquid transitions in metallic melts by fast differential scanning calorimetry

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年

作者： qi Cheng Yonghao sun Weihua Wang Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Peking University School of Physics and Electronic Information Anhui Normal University Institute of Physics Chinese Academy of Sciences Songshan Lake Materials Lab

Liquid-liquid transition in metallic melts is an intriguing phenomenon often confused with liquid-liquid separation, oxidation or precipitation. Here, we employ a state-of-the-art ultrafast chip-based differential scanning calorimeter to investigate the thermal behavior of six metallic melts, ranging from unary to quinary systems, at temperatures above their liquidus. Calorimetric signals of liquid-liquid transition vary across systems: Sn melts showed no direct endothermic or exothermic events, though liquid-liquid transition influenced solidification and melting temperatures, while Yb-Zn melts exhibited an exothermic peak during cooling,indicating liquid-liquid transition. Thermal signals in other systems including Li, Pd-Ni-P, Yb-Mg-Zn-Cu and Au-Ag-Pd-Cu-Si,are primarily driven by compositional changes. Our in-situ analysis provides new insights into the structural and compositional evolution of metallic melts, offering significant implications for the design and processing of novel materials.

关键词：