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Nickel-catalyzed enantioselective reductive amination of benzylic ketones in alcohols

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Science China Chemistry 2024年第8期67卷 2566-2570页

作者： Xiuhua Wang Jianrong steve Zhou State Key Laboratory of Chemical Oncogenomics School of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Asymmetric reductive amination directly converts ketones and amines to alkylamines, which are important motifs in *** report that cationic nickel complexes of chiral diphosphines promote enantioselective reductive amination of benzylic ketones with both arylamines and benzhydrazide. Isopropanol was used as a safe and cheap source of hydrogen instead of formic acid. The reaction can be readily applied to a concise synthesis of diarylethylamines, a class of neuroactive substances.

关键词： transfer hydrogenation nickel catalysis chiral alkylamine reductive amination synthetic method

Mshpy23:a user-friendly,parameterized model of magnetosheath conditions

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Earth and Planetary Physics 2024年第1期8卷 89-104页

作者： Jaewoong Jung Hyunju Connor Andrew Dimmock steve Sembay Andrew Read Jan Soucek NASA Goddard Space Flight Center GreenbeltMDUSA Department of Astronomy University of MarylandCollege ParkMDUSA Swedish Institude of Space Physics UppsalaSweden University of Leicester LeicesterUK Institute of Atmospheric Physics Academy of Sciences of the Czech Republic

Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind−Magnetosphere−Ionosphere Link Explorer(SMILE)will observe magnetosheath and its boundary motion in soft X-rays for understanding magnetopause reconnection modes under various solar wind conditions after their respective launches in 2024 and *** conditions,namely,plasma density,velocity,and temperature,are key parameters for predicting and analyzing soft X-ray images from the LEXI and SMILE *** developed a userfriendly model of magnetosheath that parameterizes number density,velocity,temperature,and magnetic field by utilizing the global Magnetohydrodynamics(MHD)model as well as the pre-existing gas-dynamic and analytic *** this parameterized magnetosheath model,scientists can easily reconstruct expected soft X-ray images and utilize them for analysis of observed images of LEXI and SMILE without simulating the complicated global magnetosphere ***,we created an MHD-based magnetosheath model by running a total of 14 OpenGGCM global MHD simulations under 7 solar wind densities(1,5,10,15,20,25,and 30 cm)and 2 interplanetary magnetic field Bz components(±4 nT),and then parameterizing the results in new magnetosheath *** compared the magnetosheath model result with THEMIS statistical data and it showed good agreement with a weighted Pearson correlation coefficient greater than 0.77,especially for plasma density and plasma ***,we compiled a suite of magnetosheath models incorporating previous magnetosheath models(gas-dynamic,analytic),and did two case studies to test the *** MHD-based model was comparable to or better than the previous models while providing self-consistency among the magnetosheath ***,we constructed a tool to calculate a soft X-ray image from any given vantage point,which can support the planning and data analysis of the aforementioned LEXI and SMILE missions.A release of the code has been uploaded to a Git

关键词： magnetosheath python modeling

How Can Practitioners Support Citizen Volunteers in Disaster Risk Reduction? Insight from “Good and Ready” in Aotearoa New Zealand

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International Journal of Disaster Risk Science 2024年第3期15卷 374-387页

作者： Lo?c Le Dé steve Ronoh Ei Mon Thinn Kyu Brigitte Rive School of Public Health and Interdisciplinary Studies Auckland University of Technology Pacific Health Research Centre Auckland University of Technology New Zealand Red Cross

Global and national policy frameworks emphasize the importance of people's participation and volunteers' role in disaster risk reduction. While research has extensively focused on volunteers in disaster response and recovery, less attention has been paid on how organizations involved in disaster risk management can support volunteers in leading and coordinating communitybased disaster risk reduction. In 2019, the New Zealand Red Cross piloted the Good and Ready initiative in Auckland,Aotearoa New Zealand, with the objective to empower local people in resilience building with a focus on volunteers and community participation. This research examined the positive and negative outcomes of Good and Ready and investigated volunteers' experiences in the disaster resilience initiative. It involved the codesign of a questionnaire-based survey using participatory methods with Good and Ready volunteers, the dissemination of the survey to gather volunteers' viewpoints, and a focus group discussion with participatory activities with Red Cross volunteers. The findings highlight that a key challenge lies in finding a balance between a program that provides flexibility to address contextual issues and fosters communities' ownership, versus a prescriptive and standardized approach that leaves little room for creativity and self-initiative. It pinpoints that supporting volunteers with technical training is critical but that soft skills training such as coordinating, communicating,or facilitating activities at the local level are needed. It concludes that the sustainability of Good and Ready requires understanding and meeting volunteers' motivations and expectations and that enhancing partnerships with local emergency management agencies would strengthen the program.

关键词： Community-based approach Disaster risk reduction New Zealand Participation Volunteers

Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background

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Earth and Planetary Physics 2024年第1期8卷 119-132页

作者： YingJie Zhang TianRan Sun JenniferACarter WenHao Liu steve Sembay ShuiNai Zhang Li Ji Chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth and Planetary Sciences The University of Chinese Academy of SciencesBeijing 100190China School of Physics and Astronomy The University of LeicesterLeicesterUK Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China

Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft ***,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray *** better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed *** two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral *** method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS *** method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind *** show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet *** the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted *** difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX *** addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the

关键词： solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft X-ray X-ray imaging magnetosphere

Ka-band thin film lithium niobate photonic integrated optoelectronic oscillator

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Photonics Research 2024年第6期12卷 1283-1293页

作者： RUI MA ZIJUN HUANG SHENGQIAN GAO JINGYI WANG XICHEN WANG XIAN ZHANG PENG HAO X.steve YAO XINLUN CAI State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China Photonics Information Innovation Center and Hebei Provincial Center for Optical Sensing College of Physics Science and TechnologyHebei UniversityBaoding 071002China NuVison Photonics Inc.Las VegasNevada 89109USA

Photonics integration of an optoelectronic oscillator(OEO)on a chip is attractive for fabricating low cost,compact,low power consumption,and highly reliable microwave sources,which has been demonstrated recently in silicon on insulator(SOI)and indium phosphide(InP)platforms at X-band around 8 *** we demonstrate the first integration of OEOs on the thin film lithium niobate(TFLN)platform,which has the advantages of lower Vπ,no chirp,wider frequency range,and less sensitivity to *** have successfully realized two different OEOs operating at Ka-band,with phase noises even lower than those of the X-band OEOs on SOI and InP *** is a fixed frequency OEO at 30 GHz realized by integrating a Mach–Zehnder modulator(MZM)with an add-drop microring resonator(MRR),and the other is a tunable frequency OEO at 20–35 GHz realized by integrating a phase modulator(PM)with a notch *** work marks the first step of using TFLN to fabricate integrated OEOs with high frequency,small size,low cost,wide range tunability,and potentially low phase noise.

关键词： optoelectronic modulator resonator

数字化能源管理系统促进工业界节能减碳的分析与建议

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中国科学院院刊 2024年第2期39卷 311-322页

作者：耿端阳许通朱庆华 steve EVANS 英国剑桥大学工程系制造研究所剑桥CB30FS 英国剑桥大学土地经济系环境能源与自然资源管理中心剑桥CB33QZ 上海交通大学安泰经济与管理学院上海200030

工业生产是碳排放的主要来源。减少能源浪费、达成生产节能对实现我国“双碳”目标至关重要。随着数字化技术进步,数字化能源管理系统可通过将不可见的能源可视化,促进企业节能。文章分析了英国、美国、德国、日本和瑞典应用能源管理系... 详细信息

工业生产是碳排放的主要来源。减少能源浪费、达成生产节能对实现我国“双碳”目标至关重要。随着数字化技术进步,数字化能源管理系统可通过将不可见的能源可视化,促进企业节能。文章分析了英国、美国、德国、日本和瑞典应用能源管理系统的现状,总结了其特点与应用条件,与我国在此方面的发展进行了对比,并探讨了我国在部署能源管理系统过程中所面临的挑战。文章还提出从“工厂、产线和设备”到“产品”角度分析能耗,构建“基于生产步骤的单位产品能耗标签”的方法论框架。探讨了政府、企业等利益相关者在该方法论中的角色,并提出了政府支持发展数字化能源管理系统的对策,包括推动系统建设、支持合作、确定能耗基准和引导企业对标行业最优实践。

关键词：数字化技术能源浪费能源管理能源系统碳中和

维普期刊数据库博看期刊

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综述杂豆酚类化合物多样性的影响因素

中国食品学报 2024年第1期24卷 390-406页

作者：李昱昊宋萧萧聂少平 Cui steve W. 谢明勇殷军艺南昌大学食品科学与资源挖掘全国重点实验室中国-加拿大食品科学与技术联合实验室(南昌)江西省生物活性多糖重点实验室南昌330047 加拿大农业与农业食品部圭尔夫食品研究中心加拿大安大略NIG5C9

杂豆酚类化合物种类繁多,并影响杂豆的外观、感官特征及营养特性。杂豆酚类化合物多样性是杂豆营养特性研究的重点。本文总结杂豆酚类化合物多样性的影响因素,发现合理的提取与分析方法有利于酚类化合物提取的完整性以及表征的正确性。... 详细信息

杂豆酚类化合物种类繁多,并影响杂豆的外观、感官特征及营养特性。杂豆酚类化合物多样性是杂豆营养特性研究的重点。本文总结杂豆酚类化合物多样性的影响因素,发现合理的提取与分析方法有利于酚类化合物提取的完整性以及表征的正确性。在此基础上,指出种属与产地、生长与贮藏及加工过程影响杂豆酚类化合物的合成、溶出与释放,并促使酚类化合物多样性的形成。最后介绍杂豆酚类化合物多样性的代谢组学技术在杂豆多样性研究方面的贡献与优势,提出今后工作的重点与挑战,以期为杂豆酚类化合物的变化机制、加工利用及育种等提供参考。

关键词：杂豆酚类化合物多样性提取方法定性与定量影响因素

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微塑料和纳米塑料威胁青藏高原环境

Science Bulletin 2024年第5期69卷 589-592页

作者：张玉兰康世昌罗犀 Tanuj Shukla 高坛光 Deonie Allen steve Allen Melanie Bergmann State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China School of Geography Earth and Environmental SciencesUniversity of BirminghamBirmingham 200003UK Ocean Frontiers Institute Dalhousie UniversityHalifax B3H 4R2Canada Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung Bremerhaven D-27515Germany University of Chinese Academy of Sciences Beijing 100049China

Plastic pollution is a planetary level threat which affects Earth’s environment and *** the poles to deep ocean basins,the growth of plastic waste has already exceeded its *** projected increase of plastic production and waste generation over the coming years makes the situation even more *** after stagnation in 2020 due to the COVID-19 pandemic,the global plastic production has also increased from 335 to 391 million metric tons(Mt)between 2016 and 2021(Fig.S1 online);yet currently post-consumer recycled and bio-based/attributed plastics only accounts~9%of the world’s plastic production[1].Statistically.

关键词：微塑料 attributed plastics

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凝聚社群意识,共谱美好乐章

空中英语教室（高级版．彭蒙惠英语） 2024年第1期 32-33,48,49页

作者： steve Lopez 不详

26快没时间了。在宽的音乐厅准备了半年之久,如今距离这场重要音乐会只剩不到一个星期的时间,星期一将是加州这个独一无二的管弦乐团最后的排练日。

关键词：社群意识音乐厅管弦乐团音乐会独一无二美好