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Effects of Si and Mn Contents on Low-Temperature Toughnes of 10CrSiNiCu Steel

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Journal of Iron and Steel Research International 1999年第1期6卷 43-47页

作者： Yang Caifu, zhang Yongquan, Liu tianjun Central Iron & Steel Research InstituteBeijing100081 钢铁研究总院北京 100081 钢铁研究总院北京

Effects of Si and Mn contents on lowtemperature toughness of 10CrSiNiCu steel were studied in this paper. The results indicated that by properly lowering Si content and increasing Mn content, the strength is increased slightly, and the lowtemperature toughness is improved markedly. When Si content decreased from 096 % to 072 % or 042 mass%, the 50 % FATT dropped by 50 and the crack propagation energy in the process of impact increased obviously. The main reason for the improvement of toughness lies in the refining of grain size and the decreasing of the deteriorative effect of Si.

关键词： content toughness strength crack propagation

Assessing the Performance of CMIP6 Models in Simulating Droughts across Global Drylands

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Advances in Atmospheric Sciences 2024年第2期41卷 193-208页

作者： Xiaojing YU Lixia zhang tianjun ZHOU Jianghua ZHENG LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China College of Geography&Remote Sensing Sciences Xinjiang UniversityUrumqi 830046China

Both the attribution of historical change and future projections of droughts rely heavily on climate modeling. However,reasonable drought simulations have remained a challenge, and the related performances of the current state-of-the-art Coupled Model Intercomparison Project phase 6(CMIP6) models remain unknown. Here, both the strengths and weaknesses of CMIP6 models in simulating droughts and corresponding hydrothermal conditions in drylands are *** the general patterns of simulated meteorological elements in drylands resemble the observations, the annual precipitation is overestimated by ~33%(with a model spread of 2.3%–77.2%), along with an underestimation of potential evapotranspiration(PET) by ~32%(17.5%–47.2%). The water deficit condition, measured by the difference between precipitation and PET, is 50%(29.1%–71.7%) weaker than observations. The CMIP6 models show weaknesses in capturing the climate mean drought characteristics in drylands, particularly with the occurrence and duration largely underestimated in the hyperarid Afro-Asian areas. Nonetheless, the drought-associated meteorological anomalies, including reduced precipitation, warmer temperatures, higher evaporative demand, and increased water deficit conditions, are reasonably reproduced. The simulated magnitude of precipitation(water deficit) associated with dryland droughts is overestimated by 28%(24%) compared to observations. The observed increasing trends in drought fractional area,occurrence, and corresponding meteorological anomalies during 1980–2014 are reasonably reproduced. Still, the increase in drought characteristics, associated precipitation and water deficit are obviously underestimated after the late 1990s,especially for mild and moderate droughts, indicative of a weaker response of dryland drought changes to global warming in CMIP6 models. Our results suggest that it is imperative to employ bias correction approaches in drought-related studies over drylands by using CMIP6 o

关键词： droughts hydrothermal conditions drylands CMIP6 model evaluation

The dry-hot feedback between soil moisture and atmosphere and the accelerated global warming

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Science China Earth Sciences 2024年第3期67卷 890-891页

作者： tianjun ZHOU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Greenhouse gas (GHG) emissions have been increasing due to human activities since the Industrial Revolution, resulting in continuous warming of the global climate system and significant drought over a large parts of global land, both have shown a non-linear growth trend in recent decades(Berg et al., 2017;Zhou et al., 2019;IPCC, 2021).

关键词： warming moisture drought

Convection-Permitting Simulations of Current and Future Climates over the Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第10期41卷 1901-1916页

作者： Liwei ZOU tianjun ZHOU LASG Institute of Atmospheric Physics Chinese Academy of Sciences

The Tibetan Plateau（TP） region, also known as the “Asian water tower”, provides a vital water resource for downstream regions. Previous studies of water cycle changes over the TP have been conducted with climate models of coarse resolution in which deep convection must be parameterized. In this study, we present results from a first set of highresolution climate change simulations that permit convection at approximately 3.3-km grid spacing, with a focus on the TP,using the Icosahedral Nonhydrostatic Weather and Climate Model（ICON）. Two 12-year simulations were performed,consisting of a retrospective simulation（2008–20） with initial and boundary conditions from ERA5 reanalysis and a pseudoglobal warming projection driven by modified reanalysis-derived initial and boundary conditions by adding the monthly CMIP6 ensemble-mean climate change under the SSP5-8.5 scenario. The retrospective simulation shows overall good performance in capturing the seasonal precipitation and surface air temperature. Over the central and eastern TP, the average biases in precipitation（temperature） are less than-0.34 mm d-1（-1.1℃） throughout the year. The simulated biases over the TP are height-dependent. Cold（wet） biases are found in summer（winter） above 5500 m. The future climate simulation suggests that the TP will be wetter and warmer under the SSP5-8.5 scenario. The general features of projected changes in ICON are comparable to the CMIP6 ensemble projection, but the added value from kilometer-scale modeling is evident in both precipitation and temperature projections over complex topographic regions. These ICON-downscaled climate change simulations provide a high-resolution dataset to the community for the study of regional climate changes and impacts over the TP.

关键词： convection-permitting dynamical downscaling pseudo-global warming Tibetan Plateau

Unraveling templated-regulated distribution of isolated SiO4 tetrahedra in silicoaluminophosphate zeolites with high-throughput computations

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National Science Review 2022年第9期9卷 19-27页

作者： Yan Li Chao Shi Lin Li Guoju Yang Junyan Li Jun Xu Qinfen Gu Xingxing Wang Ji Han tianjun zhang Yi Li Jihong Yu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry Jilin University School of Textile and Clothing Yancheng Institute of Technology State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics National Center for Magnetic Resonance in Wuhan Wuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of Sciences Australian Synchrotron International Center of Future Science Jilin University

Silicoaluminophosphate(SAPO) zeolites are well-known catalytic materials because of the mild acidity originating from the isolated SiO4tetrahedra in their frameworks. Regulating the distribution of isolated SiO4tetrahedra in SAPO zeolites is formidably challenging because SiO4tetrahedra tend to agglomerate to form Si islands and the isolated SiO4tetrahedra are difficult to determine using conventional characterization techniques. Here we synthesized Si-island-free SAPO-35 zeolites by using N-methylpiperidine as a new template, which exhibited excellent thermal stability compared to conventional SAPO-35 zeolites and a substantially improved methanol-to-olefins catalytic lifetime even comparable to that of commercial SAPO-34 zeolites. More strikingly, with the aid of high-throughput computations on 44 697 structure models combined with various state-of-the-art characterization techniques, for the first time, we reveal that the host–guest interactions between template molecules and SAPO frameworks determine the specific distributions of isolated SiO4tetrahedra, which are responsible for the improvement in the chemical properties of zeolites. Our work provides an insight into the template-based regulation of isolated SiO4tetrahedra in SAPO zeolites, which opens a new avenue in the discovery of promising zeolite catalysts with optimal Si O4distribution.

关键词： acidity computational chemistry heterogeneous catalysis structure–activity relationships zeolites

Selective oxygen electroreduction to hydrogen peroxide in acidic media:The superiority of single-atom catalysts

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Nano Research 2024年第6期17卷 4668-4681页

作者： Ergui Luo Tongtong Yang Jingyi Liang Yuhong Chang Junming zhang tianjun Hu Junjie Ge Jianfeng Jia Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Electroanalytic Chemistry Jilin Province Key Laboratory of Low Carbon Chemistry PowerChangchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Two-electron oxygen reduction reaction(2e-ORR)provides an environmentally friendly direction for the on-site production of hydrogen peroxide(H_(2)O_(2)).Central to this technology is the exploitation of efficient,economical,and safe 2e-ORR *** overview starts with the fundamental chemistry of ORR to highlight the decisive role of adsorbing intermediates on the reaction pathway and activity,followed by a comprehensive survey of the tuning strategies to favor 2e-ORR on traditional precious *** latest achievements in designing efficient and selective precious-metal-based single-atom catalysts(SACs)and metal-nitrogen-carbon(M-Nx/C)catalysts,from the aspects of material synthesis,theoretical calculations,and mass transport promotion,are systematically *** introductions on the evaluation metrics for 2e-ORR catalysts and the primary reactor designs for cathodic H_(2)O_(2)synthesis are also *** conclude this review with an outlook on the challenges and direction of efforts to advance electrocatalytic 2e-ORR into realistic H_(2)O_(2)production.

关键词： oxygen reduction reaction H_(2)O_(2)production single-atom catalysts selectivity

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生香酵母在青稞酒中的应用研究

酿酒科技 2024年第8期 56-59页

作者：张天俊唐东恒喇录忠薛晓晴赵文娟李玉英青海互助天佑德青稞酒股份有限公司青海互助810500

运用清蒸清烧四次清传统工艺在酿造七车间开展生香酵母应用于青稞酒酿造的应用实验。实验结果表明,原酒中乙酸乙酯、乳酸、乙酯等风味物质的含量变化明显,比对比组中乙酸乙酯含量提高了83%,总酸含量提高了20.1%,杂醇油含量下降了7.5%,... 详细信息

运用清蒸清烧四次清传统工艺在酿造七车间开展生香酵母应用于青稞酒酿造的应用实验。实验结果表明,原酒中乙酸乙酯、乳酸、乙酯等风味物质的含量变化明显,比对比组中乙酸乙酯含量提高了83%,总酸含量提高了20.1%,杂醇油含量下降了7.5%,使得原酒更加协调,清香纯正、突出。青稞香型原酒的特点雏形正在建立,此实验的开展可丰富原酒基酒种类。

关键词：青稞生香酵母发酵蒸馏品评分析

Triplet-triplet annihilation upconversion materials as electrophoretic inks

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Chinese Chemical Letters 2024年第3期35卷 439-442页

作者： Qiaoyu zhang Guiwen Luo Jinping Chen tianjun Yu Rui Hu Guoqiang Yang Yi Zeng Yi Li Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Key Laboratory of Photochemistry Institute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Luminescent materials that can be reversibly switched by electric field stimulation are attractive since the potential application for optoelectronic *** we report a triplet-triplet annihilation upconversion(TTA-UC)system with electrophoretic response which is developed as the electrophoretic *** TTA-UC system consists of an ionic derivative of 9,10-diphenyl anthracene(DPA)as the annihilator and Pt(II)octaethylporphyrin(PtOEP)as the *** applying an electric field,migration and enrichment of positively charged DPA derivatives towards the cathode results in a 20%enhancement of TTA-UC.A quasi-solid film for electrically writing is made using the electrophoretic TTA system as the ink and a platinum electrode as a *** prototype of TTA-UC ink demonstrates unique luminescence functions upon electrically writing and erasing,providing a promising strategy to develop electronic devices for display,information storage and encryption.

关键词： Triplet-triplet annihilation Photon upconversion Electrophoresis Electrophoretic ink Luminescence display

Revisiting the N=1 supersymmetric trinification models from intersecting D6-branes

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Communications in Theoretical Physics 2024年第9期76卷 27-36页

作者： Adeel Mansha tianjun Li Mudassar Sabir Department of Physics Zhejiang Normal UniversityJinhua 321004China Zhejiang Institute of Photoelectronics Zhejiang Normal UniversityJinhua 321004China Centre For High Energy Physics University of the PunjabLahore 54590Pakistan CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijingChina School of Physics University of Electronic Science and Technology of ChinaChengduSichuan 611731China

We revisit the construction of the N=1 supersymmetric trinification models with gauge group U(3)_(C)×U(3)_(L)×U(3)_(R) in TypeⅡA string theory on T^(6)(Z_(2)×Z_(2))orientifold with intersecting *** non-trivial K-theory conditions and tadpole cancellation conditions severely restrict the number of allowed models even for the case of rectangular *** a supervised search algorithm,we find a few four-family models where the highest wrapping number is *** these models,we present the complete particle spectra and the gauge coupling relations at the string-scale.

关键词： string phenomenology D branes trinification