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Science China Chemistry 2024年第11期67卷 3791-3797页

作者： Debasis Pal Kirana D.Veeranna Yuk Fai Wong P.Andrew evans Department of Chemistry Queen's University Xiangya School of Pharmaceutical Sciences Central South University

The Reformatsky reagent derived from ethyl bromoacetate circumvents the challenge associated with the direct regio-and enantioselective iridium-catalyzed allylic alkylation with an unstabilized aliphatic ester enolate. Notably, this work represents the first example of using a Reformatsky reagent in a metal-allyl reaction, which permits the direct construction of enantioenriched β-stereogenic homoallylic esters without preactivation of the pronucleophile or post-reaction modification of the product(e.g., thermal decarboxylation of a 1,3-dicarbonyl). Moreover, the process allows the coupling of a broad range of sterically and electronically diverse electrophiles bearing aryl, heteroaryl and alkenyl derivatives, including the significantly more challenging alkyl-substituted allylic carbonates. The versatility of the ester product is exemplified by a series of functional group manipulations and the development of a concise and efficient enantioselective total synthesis of the natural product,(+)-descurainolide A. Finally, mechanistic studies indicate that the zinc enolate behaves as a soft nucleophile that undergoes outer-sphere alkylation.

关键词： allylic substitution asymmetric catalysis mechanistic studies natural product synthesis Reformatsky reagent

Identification of earthquake induced structural damage based on synchroextracting transform

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 475-487页

作者： Roshan Kumar Gaurav Kumar Wei Zhao Arvind R Yadav Gang Yu Jayendra Kumar evans Amponsah Department of Electronic and Information Technology Miami College of Henan UniversityHenan 475004China Alliance University Alliance College of Engineering and DesignBanglore 562106India Department of Electronics and Comm Parul UniversityVadodra 391760India School of Electrical Engineering University of JinanJinan 250022China Department of Electronics and Comm NIT JamshedpurJamshedpur 831014India Department of Civil engineering Kwame Nkrumah University of Science and TechnologyKumasi 10959Ghana

Several popular time-frequency techniques,including the Wigner-Ville distribution,smoothed pseudo-Wigner-Ville distribution,wavelet transform,synchrosqueezing transform,Hilbert-Huang transform,and Gabor-Wigner transform,are investigated to determine how well they can identify damage to *** this work,a synchroextracting transform(SET)based on the short-time Fourier transform is proposed for estimating post-earthquake structural *** performance of SET for artificially generated signals and actual earthquake signals is examined with existing *** other tested techniques,SET improves frequency resolution to a great extent by lowering the influence of smearing along the time-frequency ***,interpretation and readability with the proposed method are improved,and small changes in the time-varying frequency characteristics of the damaged buildings are easily detected through the SET method.

关键词： cross-term damage detection earthquake signal synchroextracting transform time-frequency

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Equal Opportunities

英语世界 2024年第4期 126-128页

作者： Russell evans

Pre-reading task Youaregoingtoreadanarticleabout ***,thinkaboutyourown *** equal opportunities policy? Why? Which groups of people do you think have been helped by equal opportunities law?

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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

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Giving Food a Fiber Boost: Adding High Beta-Glucan Ingredient from Barley to Everyday Foods

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Food and Nutrition Sciences 2024年第4期15卷 277-289页

作者： Gongshe Hu Sherry Ellberg Kathy Satterfield Chris evans USDA ARS Pacific West Area 1691 S. 2700 W Aberdeen Idaho USA

Lack of dietary fiber contributes to many health issues, particularly chronic vascular diseases. Mixed linkage β-1.3 - 1.4 beta-glucan (beta-glucan, in this paper) is a confirmed beneficial ingredient for the human diet through reduction of cholesterol and the glycemic index. Barley contains the highest beta-glucan content of all the grains, and in this study, a percentage of flour from two high beta glucan lines was, each, added to an array of wheat-based food products to measure how it impacted total dietary fiber. Results showed that beta-glucan content was higher in all the products containing the added high beta-glucan flour, along with increased total dietary fiber content. Protein content in the food products is also increased with the higher protein in the barley flours added. Beta-glucan content in the barley-added products increased to 1.2% - 4.0% versus 0.2% - 0.5% in the pure wheat products, while the dietary fibers increased to 3.5% - 24.4% versus 2.1% - 9.1% in pure wheat product controls. This research provided experimental evidence that using a high beta-glucan barley ingredient in food can increase dietary fiber to benefit health.

关键词： Food High Fiber Barley Ingredient Beta-Glucan Human Health

Dark Matter Density Profiles of Selected Spiral Galaxies

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International Journal of Astronomy and Astrophysics 2024年第3期14卷 172-183页

作者： Alberto Sadun Brittany Salmon Conor evans Masoud Asadi-Zeydabadi Department of Physics University of Colorado Denver Denver USA

Understanding the dark matter distribution throughout a galaxy can provide insight into its elusive nature. Numerous density profiles, such as the Navarro, Frenk and White model, have been created in an attempt to study this distribution through analyzing orbital velocities of luminous matter and modeling dark matter distributions to explain these observations. However, we are interested in a simple model to consider the significant fluctuations in rotation curves at larger radii. Therefore, our model is much simpler compared to those previously mentioned. Our model used all the observational data available for four selected galactic rotation curves. These data present a significant variation in the orbital velocity of matter at the same distances. By running real observational data through our model, we show that the density of the dark matter within them shows real complex structure, which is not suggested by other computational models. Our aim of this paper is to model this structure and then speculate as to the cause and implications of these density fluctuations.

关键词： Dark Matter Density Galactic Rotation Curves Spiral Galaxies NGC 2841 NGC 4527 NGC 4945 NGC 3198

Microbial Degradation of Organic Contaminants in Streambed/Floodplain Sediments in Passaic River—New Jersey Area

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American Journal of Analytical Chemistry 2024年第4期15卷 139-150页

作者： Taheim evans English Meghann Trombetta Alyssa Beres Yusuf Yildiz Department of Science Manchester Regional High School Haledon USA Department of Earth and Science Montclair University Montclair USA

This paper is intended to explore soil organic matter and carbon isotope fractionation at three locations of the Passaic River to determine if microbial degradation of organic contaminants in soil is correlated to the surrounding physical environment. Microbial degradation of organic contaminants is important for the detoxification of toxic substances thereby minimizing stagnation in the environment and accumulating in the food chain. Since organic contaminants are not easily dissolved in water, they will penetrate sediment and end up enriching the adjacent soil. The hypothesis that we are testing is microbial activity and carbon isotope fractionation will be greater in preserved soils than urban soils. The reason why this is expected to be the case is the expectation of higher microbial activity in preserved environments due to less exposure to pollutants, better soil structure, higher organic matter content, and more favorable conditions for microbial growth. This is contrasted with urban soils, which are impacted by pollutants and disturbances, potentially inhibiting microbial activity. We wish to collect soil samples adjacent to the Passaic River at a pristine location, Great Swamp Wildlife Refuge, a suburban location, Goffle Brook Park, Hawthorne NJ, and an urban location, Paterson NJ. These soil samples will be weighed for soil organic matter (SOM) and weighed for isotope ratio mass spectrometry (IRMS) to test organic carbon isotopes. High SOM and δ13C depletion activity indicate microbial growth based on the characteristics of the soil horizon rather than the location of the soil sample which results in degradation of organic compounds.

关键词： Organic Contaminant PCBs Microbial Degradation Passaic River

Message from Editors-in-Chief:Exploring the Frontiers of Artificial Intelligence and Data Dynamics

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Journal of Social Computing 2024年第2期5卷 I0001-I0001页

作者： James evans Xiaoming Fu Jar-Der Luo 不详

In this edition of our journal,we present a compelling collection of papers that delve into the transformative impact of artificial intelligence(AI)and the intricate dynamics of data-driven *** authors have explored diverse aspects of these cutting-edge fields,offering insights and methodologies that promise to shape future research and applications.

关键词： networks. offering journal

Message from Editors-in-Chief

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Journal of Social Computing 2024年第1期5卷 I0001-I0001页

作者： evans, James Fu, Xiaoming Luo, Jar-Der

Dear Readers,We are thrilled to present the 1st issue of the 5th volume of the Journal of Social Computing,featuring a diverse array of research papers that delve into pivotal issues at the intersection of technology,society,and economics in the context of social *** paper offers solutions and insights into critical societal challenges,contributing to our understanding of complex socio-technical phenomena and paving the way for change.

关键词： insight change. intersection

Navigating Market Choices: Understanding Carrot Market Outlet Selection among Smallholder Farmers in Kenya

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Agricultural Sciences 2024年第6期15卷 676-703页

作者： Hillary Kiprotich Ngeno Ngenoh evans Oscar Ayuya Ingasia Hillary K. Bett State Department for Crop Development and Agricultural Research Ministry of Agriculture Livestock Fisheries and Cooperatives Nairobi Kenya Department of Agricultural Economics and Agribusiness Management Egerton University Egerton Kenya Brooklyn Economic Consulting Limited Nairobi Kenya

This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the factors influencing the selection of marketing outlets among carrot farmers. The findings unveil that a significant majority (81%) of surveyed farmers actively participate in diverse market outlets, encompassing the farm gate, cleaning point, local market, external market, and export market. Notably, pivotal buyers include aggregators, brokers, wholesalers, retailers, and consumers, with transactions predominantly occurring at the farm level. Additionally, the analysis discerns substantial influences of socio-economic characteristics, experiential factors, and geographical proximity on farmers’ choices of market outlets. Specifically, gender, age, land size, farming experience, and distance to markets emerge as critical determinants. Moreover, the study delves into the examination of market margins along the carrot value chain, shedding light on the potential profitability of carrot farming in the region. Remarkably, higher average gross margins are identified in export and external markets, signaling lucrative prospects for farmers targeting these segments. However, disparities in profit distribution between farmers and traders underscore the necessity for interventions to ensure equitable value distribution throughout the value chain. These findings underscore the imperative for tailored interventions to tackle challenges and foster inclusive agricultural development. Strategies such as farmer organizations, contracting, and vertical integration are advocated to enhance market access and profitability for smallholder carrot farmers. Thus, this study enriches our comprehension of the dynamics within carrot value chains and provides valuable insights for policymakers and development practitioners aiming to uplift rural livelihoods and bolster food security.

关键词： Market Outlet Selection Smallholder Farmers Multinomial Logit Model Determinants Carrot Value Chain