检索结果-南通市图书馆

Lewis Base Catalyzed Selenofunctionalization of Alkynes with Acid-Controlled Divergent Chemoselectivity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第14期42卷 1623-1629页

作者： ling-ling Chen Ren-Fei Cao Hua ke Zhi-Min Chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai200240 China Engineering Technology Research Center for Environmental Protection Materials Pingxiang UniversityPingxiangJiangxi337055 China

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first *** selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z *** the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.

关键词： Alkynes Electrophilic addition Chemoselectivity Lewis base catalysis Selenofunctionalization

Reinforcement Learning-Based Dynamic Order Recommendation for On-Demand Food Delivery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第2期29卷 356-367页

作者： Xing Wang ling Wang Chenxin Dong Hao Ren ke Xing Department of Automation Tsinghua UniversityBeijing 100080China School of Mechanical and Automotive Engineering Qingdao Hengxing University of Science and TechnologyQingdao 266100China Meituan Beijing 100015China

On-demand food delivery(OFD)is gaining more and more popularity in modern *** a kernel order assignment manner in OFD scenario,order recommendation directly influences the delivery efficiency of the platform and the delivery experience of *** paper addresses the dynamism of the order recommendation problem and proposes a reinforcement learning solution *** actor-critic network based on long short term memory(LSTM)unit is designed to deal with the order-grabbing conflict between different ***,three rider sequencing rules are accordingly proposed to match different time steps of the LSTM unit with different *** test the performance of the proposed method,extensive experiments are conducted based on real data from Meituan delivery *** results demonstrate that the proposed reinforcement learning based order recommendation method can significantly increase the number of grabbed orders and reduce the number of order-grabbing conflicts,resulting in better delivery efficiency and experience for the platform and riders.

关键词： on-demand food delivery order recommendation reinforcement learning actor-critic network long short term memory

Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture:Three case reports

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第15期12卷 2664-2671页

作者： pei-Xin Shangguan ke-Chun Zhou Department of Emergency Lishui Municipal Central HospitalLishui 323000Zhejiang ProvinceChina

BACKGROUND Traumatic internal carotid artery(ICA)occlusion is a rare complication of skull base fractures,characterized by high mortality and disability rates,and poor ***,timely discovery and correct management are crucial for saving the lives of such patients and improving their *** article retrospectively analyzed the imaging and clinical data of three patients,to explore the imaging characteristics and treatment strategies for carotid artery occlusion,combined with severe skull base *** SUMMARY This case included three patients,all male,aged 21,63,and 16 *** underwent plain film skull computed tomography(CT)examination at the onset of their illnesses,which revealed fractures at the bases of their ***,these cases were definitively diagnosed through CT angiography(CTA)*** first patient did not receive surgical treatment,only anticoagulation therapy,and recovered smoothly with no residual limb dysfunction(Case 1).The other two patients both developed intracranial hypertension and underwent decompressive *** of these patients had high intracranial pressure and significant brain swelling postoperatively,leading the family to choose to take him home(Case 2).The other patient also underwent decompressive craniectomy and recovered well postoperatively with only mild limb motor dysfunction(Case 3).We retrieved literature from PubMed on skull base fractures causing ICA occlusion to determine the imaging characteristics and treatment strategies for this type of *** For patients with cranial trauma combined with skull base fractures,it is essential to complete a CTA examination as soon as possible,to screen for blunt cerebrovascular injury.

关键词： Skull base fracture Traumatic internal carotid artery occlusion Blunt cerebrovascular injury Imaging Case report

AWG-based large dynamic range fiber Bragg grating interrogation system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年第3期20卷 129-134页

作者： LI Shufeng YUAN pei LI ke LI Ting ZHU Lianqing key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Beijing Information Science&Technology UniversityBeijing 100192China Beijing Laboratory of Optical Fiber Sensing and System Beijing Information Science&Technology UniversityBeijing 100016China

Arrayed waveguide gratings(AWGs) are extensively employed in fiber Bragg grating(FBG) interrogation systems due to their compact size, lightweight nature, and excellent interrogation performance. The resolution and total measurement range of AWG-based FBG interrogation systems are constrained by the output properties of AWG. We proposed an AWG-based large dynamic range interrogation system. The temperature dependence of AWG is exploited to achieve continuous interrogation. The test results show that the interrogation system has a dynamic range of 28.67 nm, an interrogation accuracy better than 25 pm, and a wavelength resolution of 6 pm.

关键词： fiber waveguide AWG

Observation of ballistic-diffusive thermal transport in GaN transistors using thermoreflectance thermal imaging

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 389-394页

作者： Zhi-ke Liu Yang Shen Han-ling Li Bing-Yang Cao key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

To develop effective thermal management strategies for gallium-nitride (GaN) transistors, it is essential to accurately predict the device junction temperature. Since the width of the heat generation in the devices is comparable to phonon mean free paths (MFPs) of GaN, phonon ballistic transport exists and can significantly affect the heat transport process.

关键词： temperature. transistors GaN

Dominant negative effect as a novel mechanism of SPAST gene mutation in a large family with hereditary spastic paraplegia

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第5期11卷 74-77页

作者： ke Deng Haibo Ruan Feifei Yu Zhenle pei Congjian Xu Shuo Zhang Shanghai Ji Ai Genetics&IVF Institute Obstetrics and Gynecology Hospital of Fudan UniversityShanghai 200000China Shanghai key Laboratory of Female Reproductive Endocrine Related Diseases Shanghai 200000China The First People’s Hospital of Wenling WenlingZhejiang 317500China Rushan Hospital of Traditional Chinese Medicine RushanShandong 264599China Department of Obstetrics and Gynecology Fudan UniversityShanghai 200000China.

Hereditary spastic paraplegia(HSP)is a group of disorders with genetic heterogeneity,lower-extremity weakness,and spasticity are the most common signs and *** is the most frequently disease-causing *** is a microtubule-severing enzyme encoded by SPAST that cleaves long microtubules into short fragments by interacting with other proteins or *** spastic paraplegia type 4(SPG4),which is autosomal dominant,is the clinical subtype associated with SPAST ***4 accounts for up to one-third of all HSP cases and usually presents with isolated lower extremity spasticity,with or without bladder or sensory dysfunction.1 The main cause of SPG4 is believed to be spastin haploinsufficiency,which results from mutations in the SPAST gene.

关键词： bladder insufficiency clinical

Pharmacotherapy of urethral stricture

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2024年第1期26卷 1-9页

作者： Hui Luo ke-Cheng Lou ling-Yu Xie Fei Zeng Jun-Rong Zou The First Clinical College Gannan Medical UniversityGanzhou 341000China Department of Urology The First Affiliated Hospital of Gannan Medical UniversityGanzhou 341000China Institute of Urology The First Affiliated Hospital of Gannan Medical UniversityGanzhou 341000China Jiangxi Engineering Technology Research Center of Calculi Prevention Ganzhou 341000China

Urethral stricture is characterized by the chronic formation of fibrous tissue,leading to the narrowing of the urethral *** the availability of various endoscopic treatments,the recurrence of urethral strictures remains a common *** pharmacotherapy targeting tissue fibrosis is a promising option for reducing recurrence *** drugs cannot replace surgery,they can be used as adjuvant therapies to improve *** this regard,many drugs have been proposed based on the mechanisms underlying the pathophysiology of urethral *** studies have obtained substantial progress in treating urethral strictures,highlighting the potential for improved drug effectiveness through appropriate clinical delivery ***,this review summarizes the latest researches on the mechanisms related to the pathophysiology of urethral stricture and the drugs to provide a theoretical basis and new insights for the effective use and future advancements in drug therapy for urethral stricture.

关键词： adjuvant therapy pathophysiology pharmacotherapy urethra urethral stricture

Two sandwich-type uranyl-containing polytungstates catalyze aerobic synthesis of benzimidazoles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1316-1322页

作者： Yu-Feng Liu Qi-Long Hu Xue-Jiao Chen ke Li pei Luo Guo-Ping Yang School of Chemistry and Material Science Jiangxi Province Key Laboratory of Synthetic ChemistryJiangxi Key Laboratory for Mass Spectrometry and InstrumentationEast China University of TechnologyNanchang330013China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen518055China

Diversified synthetic strategies are extremely important for the structural diversity of uranium-containing polyoxometalates(U-POMs)and their functional ***,two sandwich-type U-POMs were reported,which are Na_(5.6)K_(6.4)[(UO_(2))(H_(2)O)(TeW_(9)O_(33))]_(2)·21H_(2)O(UTeW_(9))and Na_(8.9)K_(2.7)H_(1.19)[K_(0.79)(UO_(2))_(2.21)(PW_(9)O_(34))_(2)]·12H_(2)O(UPW_9)using in-situ strategy and lacunary precursor strategy,***_9 shows a typical keggin-typeopen or half-sandwich configuration.

关键词： configuration expansion sandwich

Recent Progress in Fabrication and Structural Design of Thermal Conductive Polymer Composites

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第3期42卷 277-291,I0004页

作者： Yuan-Kai Du Zheng-Xue Shi Shan Dong Hui Jin Xue ke.pei Zhao Bing-Bing Jiang Feng You Hubei key Laboratory of Plasma Chemistry and Advanced Materials School of Material Science and EngineeringWuhan Institute of TechnologyWuhan 430205China key Laboratory of Green Preparation and Application of Functional Materials Ministry of EducationHubei UniversityWuhan 430062China Institute of Molecular Aggregation Science Tianjin UniversityTianjin 300072China

In recent years, the demand direction for electronic equipment has expanded into embedded and miniaturized devices. The heat radiation problem has become one of the most significant factors for hindering the development of electronic devices. Since heat radiation material is one of the important components in electronic devices, the demand for enhancing thermal conductivity is also increasingly urgent. Research on thermal conductive polymer composites has become a major direction for developing functional composites. This work reviewed the recent progress in the fabrication of thermal conductive polymer composites. Five different structures are presented, including the using of single fillers,hybrid fillers, double threshold percolation structure, segregated structure and other complex multiphase structures. Specifically, the preparation of high-performance thermal conductive polymer composites was introduced through the combination of various thermal conductive ***, the development direction of high thermal conductive polymer composites was briefly explored.

关键词： Thermal conductive polymer Hybrid fillers Polymer composite Thermal resistance