检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

大型担子菌中二萜化合物生物合成研究进展

菌物学报 2023年第1期42卷 101-117页

作者：周一鸣祁建钊段应策赵敏刘成伟东北林业大学生命科学学院黑龙江哈尔滨150040 黑龙江省酶与类酶工程重点实验室黑龙江哈尔滨150040 西北农林科技大学化学与药学院陕西杨凌712100

大型担子菌分布广泛,种类繁多,它们是重要的食药用资源的宝库。萜类化合物是其主要活性成分之一,包括倍半萜、二萜和三萜等,这些化合物具有预防、缓解或治疗癌症、抑郁症、糖尿病和高脂血症等多种疾病的功效。目前,从担子菌中分离出的... 详细信息

大型担子菌分布广泛,种类繁多,它们是重要的食药用资源的宝库。萜类化合物是其主要活性成分之一,包括倍半萜、二萜和三萜等,这些化合物具有预防、缓解或治疗癌症、抑郁症、糖尿病和高脂血症等多种疾病的功效。目前,从担子菌中分离出的二萜类化合物基本骨架结构特征主要为鸟巢烷(cyathanes)型、截短侧耳素(pleuromutilins)型、guanacastanes型、海松烷(pimaranes)型、松香烷(abietanes)型和毛皮伞烷(crinipellins)型6大类型。本文综述了担子菌中二萜类化合物的结构特点、生物活性和生物合成的研究进展,对参与担子菌中二萜化合物生物合成的二萜合成酶进行了分类,对两种重要的二萜化合物生物合成途径进行了系统总结和论述。本文将为未知二萜化合物生物合成途径及关键基因功能解析提供参考。

关键词：担子菌二萜二萜合成酶生物活性生物合成

An ensemble and cost-sensitive learning-based root cause diagnosis scheme for wireless networks with spatially imbalanced user data distribution

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 331-332页

作者： qi WANG Zhiwen PAN Nan LIU National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories

Root cause diagnosis, a key component of self-healing, plays a vital role in fault management. The spatially imbalanced network key performance indicators (KPIs) reported by users increase the difficulty of identifying root *** [1,2], the image inpainting technique is inspired to address issues caused by sparse reports across the coverage area.

关键词： Wireless networks

Robust Regularization Design of Graph Neural Networks Against Adversarial Attacks Based on Lyapunov Theory

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第3期33卷 732-741页

作者： Wenjie YAN Ziqi LI Yongjun qi School of Artificial Intelligence Hebei University of Technology School of Computer Science and Engineering of North China Institute of Aerospace Engineering

The robustness of graph neural networks（GNNs） is a critical research topic in deep *** researchers have designed regularization methods to enhance the robustness of neural networks,but there is a lack of theoretical analysis on the principle of *** order to tackle the weakness of current robustness designing methods,this paper gives new insights into how to guarantee the robustness of GNNs.A novel regularization strategy named Lya-Reg is designed to guarantee the robustness of GNNs by Lyapunov *** results give new insights into how regularization can mitigate the various adversarial effects on different graph *** experiments on various public datasets demonstrate that the proposed regularization method is more robust than the state-of-theart methods such as L1-norm,L2-norm,L2-norm,Pro-GNN,PA-GNN and GARNET against various types of graph adversarial attacks.

关键词： Training Deep learning Garnets Robustness Graph neural networks

Research progress on semi-continuous casting of magnesium alloys under external field

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第5期21卷 516-524页

作者： qi-yu Liao qi-chi Le Da-zhi Zhao Lei Bao Tong Wang Yong-hui Jia Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Key Laboratory of Lightweight Structural Materials Liaoning ProvinceNortheastern UniversityShenyang 110819China Key Laboratory of Light-weight Materials Nanjing Tech UniversityNanjing 210009China

High-performance magnesium alloys are moving towards a trend of being produced on a large scale and in an integrated *** foundational key to their successful production is the high-quality cast *** alloys produced through the conventional semi-continuous casting process inevitably contain casting defects,which makes it challenging to manufacture high-quality *** integration of external field assisted controlled solidification technology,which combines physical fields such as electromagnetic and ultrasonic fields with traditional semi-continuous casting processes,enables the production of high-quality magnesium alloy ingots characterized by a homogeneous microstructure and absence of *** article mainly summarizes the technical principles of those external field assisted casting *** focus is on elaborating the refinement mechanism of different types of electromagnetic fields,ultrasonic fields,and combined physical fields during the solidification of magnesium ***,the development prospects of producing highquality magnesium alloy ingots through semi-continuous casting under the external field were discussed.

关键词： semi-continuous casting electromagnetic field ultrasonic field magnesium alloys refinement mechanism

500kV同塔双回输电线路电磁环境的影响因素分析

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

河北电力技术 2011年第3期30卷 32-34页

作者：齐建召张国华河北省电力勘测设计研究院石家庄050031

介绍我国工频电磁场环境的相关规定及工频电场强度、工频磁场强度的计算公式,通过分析相序排列和对地距离等因素对500 kV同塔双回输电线路电磁环境影响的规律,得到对电磁环境影响最小的相序排列和满足环保要求的最小对地距离。

关键词： 500kV输电线路工频电场强度工频磁场强度相序排列对地距离

Constructing hierarchical arrays with core-shell metal oxides@metal coordination polymers for efficient and stable overall water splitting

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 4882-4888页

作者： Shuai qi Jinlian Liao Kunzhong Chen Senkai Li Jinwen Zhao Tianchi Huang Na Meng Hengpan Yang qi Hu Chuanxin He College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Developing non-precious metal-based bifunctional electrocatalysts capable for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is essential to achieve efficient water electrolysis for mass hydrogen production,however it remains ***,we report the synthesis of hierarchical nanorod arrays comprising core-shell structured P-doped NiMoO4@NiFe-coordination polymer(denoted as P-NiMoO4@NiFeCP)as bifunctional electrocatalysts for water ***,we systematically investigate the influence of NiFeCP shell thickness on electrocatalytic activity,manifesting the presence of strong interfacial synergetic effect between P-NiMoO4 and NiFeCP for boosting both the HER and *** advantageous hierarchical architectures and unique core-shell structures,optimized P-NiMoO_(4)@NiFeCP-7.3(7.3 is the shell thickness in nm)requires overpotentials of merely 256 and 297 mV to yield a current density of 1000 mA·cm^(−2)for the HER and OER in 1 M KOH,*** importantly,it can serve as a bifunctional electrocatalyst for efficient and sustainable overall water electrolysis,delivering large current densities of 500 and 1000 mA·cm^(−2)at low cell voltages of 1.804 and 1.865 V,along with high stability of over 500 h at 1000 mA·cm−2,demonstrating the great potential of this electrocatalyst towards practical applications.

关键词： hydrogen evolution reaction oxygen evolution reaction overall water splitting non-precious metal-based electrocatalysts core-shell structures

A UWB/IMU-Assisted Fingerprinting Localization Framework with Low Human Efforts

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

China Communications 2024年第6期21卷 40-52页

作者： Pan Hao Chen Yu qi Xiaogang Liu Meili School of Mathematics and Statistics Xidian UniversityXi’an 710126China Science and Technology on Near-Surface Detection Laboratory Wuxi 214035China School of Software Nanchang Hangkong UniversityNanchang 330063China

With the rapid development of smart phone,the location-based services(LBS)have received great attention in the past *** to the widespread use of WiFi and Bluetooth devices,Received Signal Strength Indication(RSSI)fingerprintbased localization method has obtained much development in both academia and *** this work,we introduce an efficient way to reduce the labor-intensive site survey process,which uses an UWB/IMU-assisted fingerprint construction(UAFC)and localization framework based on the principle of Automatic radio map generation scheme(ARMGS)is proposed to replace the traditional manual *** be specific,UWB devices are employed to estimate the coordinates when the collector is moved in a reference point(RP).An anchor self-localization method is investigated to further reduce manual measurement work in a wide and complex environment,which is also a grueling,time-consuming process that is lead to artificial ***,the measurements of IMU are incorporated into the UWB localization algorithm and improve the label accuracy in *** addition,the weighted k-nearest neighbor(WKNN)algorithm is applied to online localization ***,filed experiments are carried out and the results confirm the effectiveness of the proposed approach.

关键词： indoor localization machine learning ultra wideband WiFi fingerprint

An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第9期67卷 2998-3003页

作者： qi Liu Xue-Dong Li Liang Cheng Li Liu Beijing National Laboratory for Molecular Sciences(BNLMS) CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral ***,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination *** this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent *** addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis *** methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion

Compare clinical efficacy and safety of neoadjuvant therapy and neoadjuvant chemoradiotherapy for locally advanced rectal cancer: Meta-analysis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第6期16卷 1845-1856页

作者： Ying Wang Yan Yang qi-qi Liu Shao-Zhao Wang Department of Anus Intestinal Surgery Feicheng People’s HospitalFeicheng 271600Shandong ProvinceChina Department of Gastroenterology Qingdao Hospital of University of Health and Rehabilitation Sciences(Qingdao Municipal Hospital)Qingdao 266011Shandong ProvinceChina Department of Gastrointestinal Surgery Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Department of Anorectal Words Central Hospital Affiliated Shandong First Medical UniversityJinan 250013Shandong ProvinceChina

BACKGROUND To compare the efficacy and safety of total neoadjuvant therapy(TNT)and neoadjuvant chemoradiotherapy(nCRT)in the treatment of middle and low locally advanced rectal *** study will systematically collect and integrate studies to evaluate the ability of these two treatments to improve tumor shrinkage rates,surgical resection rates,tumor-free survival,and severe adverse *** To provide clinicians and patients with more reliable treatment options to optimize treatment outcomes and quality of life for patients with locally advanced rectal cancer by comparing the advantages and disadvantages of the two treatment *** A full search of all clinical studies on the effectiveness and safety of TNT and nCRT for treating locally advanced rectal cancer identified in Chinese(CNKI,Wanfang,China Biomedical Literature Database)and English(PubMed,Embase)databases was *** system assessors independently screened the studies according to the inclusion and exclusion *** evaluation and RESULTS Finally,14 studies were included,six of which were randomized controlled studies.A total of 3797 patients were included,including 1865 in the TNT group and 1932 in the nCRT *** two sets of baseline data were *** results of the meta-analysis showed that the pCR rate[odds ratio(OR)=1.57,95%confidence interval(CI):1.30-1.90,P<0.00001],T stage degradation rate(OR=2.16,95%CI:1.63-2.57,P<0.00001),and R0 resection rate(OR=1.42,95%CI:1.09-1.85,P=0.009)were significantly greater in the nCRT group than in the nCRT *** was no significant difference in the incidence of grade 3/4 acute toxicity or perioperative complications between the two *** 5-year OS[hazard ratio(HR)=0.84,95%CI:0.69-1.02,P=0.08]and DFS(HR=0.94,95%CI:0.03-1.39,P=0.74)of the TNT group were similar to those of the nCRT *** TNT has greater clinical efficacy and safety than nCRT in the treatment of locally advanced rectal cancer.

关键词： Neoadjuvant therapy Neoadjuvant chemoradiotherapy Advanced rectal cancer Clinical efficacy Meta-analysis