检索结果-南通市图书馆

A multi-enzymatic cascade reaction for the synthesis of bioactive C-oligosaccharides

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 451-455页

作者： Kebo Xie Qian Zhang Fei Ye Jungui dai State Key Laboratory of Bioactive Substance and Function of Natural Medicines CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs and NHC Key Laboratory of Biosynthesis of Natural ProductsInstitute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

C-Oligosaccharides are rare in nature and possess diverse ***,their chemical synthesis faces many *** this work,enzymatic introduction of C-linked sugar chains to target aglycones was successfully achieved by multi-enzymatic cascade reactions.A C-glycosyltransferase from Aloe barbadensis was employed to introduce the first C-linked glucose and then a cyclomaltodextrin glucanotransferase from Bacillus licheniformis was used to extend the sugar chain.A total of twenty C-oligosaccharides with 2-6 sugars were synthesized from scale-up reactions and exhibited good water solubility and sodium-dependent glucose transporter 2(SGLT2)inhibitory ***,a glucoamylase was used to control the length of the sugar chain and the C-maltosides were efficiently *** findings not only expanded the structural diversity of C-oligosaccharides,but also provided a strategy for the modification of C-glycoside drugs to improve the druggability.

关键词： C-Oligosaccharides C-Glycosyltransferase Cyclomaltodextrin glucanotransferase Glucoamylase Enzymatic synthesis SGLT2 inhibitory activity

Ultralow-phase-noise and broadband frequency-hopping coupled optoelectronic oscillator under quiet point operation

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第8期12卷 1785-1793页

作者： HUI LIU MINGYANG GUO TIAN ZHANG JIAN dai KUN XU State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Advancements in microwave photonics have yielded novel approaches for generating high-purity microwave *** these,optoelectronic oscillators(OEOs)and coupled optoelectronic oscillators(COEOs)have demonstrated the capability to generate frequency-independent microwaves with exceptionally low phase ***,the tunability of the oscillators is rather limited due to the necessity for narrowband electronic bandpass filters,presenting challenges in achieving both wide and rapid tuning ***,we present a COEO featuring ultralow phase noise,flexible tuning capability,and high *** is achieved through a quiet point(QP)-operated harmonic mode-locked fiber laser,which effectively mitigates optical amplifier noise and supermode competition,thus significantly diminishing the necessity for ultra-narrow electronic *** to the liberated tuning ability,we present an oscillator that can be tuned from 2 GHz to 18 GHz,with phase noise as low as-140 d Bc/Hz at 10 k Hz under the QP *** then illustrate the practical application of the proposed oscillator in generating frequency-hopping signals with consistent spurious modes less than-85 d Bc,absolute phase noise below-135 d Bc/Hz at 10 k Hz,hopping resolution of 1.25 MHz,and fractional frequency stability below 6.1×10^(-12)at 1 s averaging time when locked to a *** presented COEO structure emerges as a compelling solution for agile and low-noise microwave sources in advanced wireless communication and radar systems.

关键词： optoelectronic tuning amplifier

Non-Gaussian feature of the output field from a double qubit-cavity ultrastrong coupling system

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第7期76卷 30-36页

作者： Sheng-wen Xu Shi-yu dai Teng Zhao Center for Quantum Science and Technology Jiangxi Normal UniversityNanchang 330022China

We investigate the non-Gaussian feature of radiation in a circuit quantum electrodynamics(QED)system where two qubits are strongly coupled to a single-mode *** the regime of ultrastrong coupling(USC),the rotating-wave approximation is not valid,and the Rabi Hamiltonian contains counter-rotating wave terms,leading to level crossing and avoided crossings in the energy *** further analyze the intensity-amplitude correlation of the output field in these two novel *** the USC regime,the creation and annihilation operators in the correlation function are replaced,allowing for the identification of non-Gaussian features in the output *** findings reveal that despite the absence of squeezing effects in the output light,significant non-Gaussian characteristics are ***,we demonstrate that as the driving or coupling strength increases,the non-Gaussian features of the output field become more *** suggests that USC systems hold broad potential applications in the realms of nonlinear optics and the generation of non-Gaussian states.

关键词： ultrastrong coupling non-Gaussian intensity-amplitude correlation

Tactile Paving Recognition Method Based on Improved YOLOv7

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Research and Application 2024年第4期8卷 22-27页

作者： chengyi Shi Qun Zhao Nan Fang Yufeng Mao School of Computer Engineering Nanjing Institute of TechnologyNanjing 211167China NR Electric Co. Ltd.Nanjing 211102China

Tactile paving is a professional road facility to ensure the safe travel of people with visual ***,there are many problems with tactile paving travel in *** one,some tactile paving is seriously damaged,and the other is the accumulation of *** to help visually impaired people recognize and locate obstacles in tactile paving is a problem worth *** this paper,image recognition technology is used to recognize the tactile paving pictures with obstacles,and an attention mechanism is used to optimize samples to improve recognition accuracy.

关键词： YOLOv7 Tactile paving recognition Attention mechanism

Scraping therapy for knee osteoarthritis: a systematic review and Meta-analysis

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

Journal of Traditional Chinese Medicine 2024年第4期44卷 633-641页

作者： CHEN Dandan JIN Qianhong SHEN Yuanjuan WANG Qing dai Zhengxiang School of Nursing Guangxi University of Chinese MedicineNanning 530200China School of Nursing Nanjing University of Chinese MedicineNanjing 210023China General Surgery Department Jiangsu Province Hospital of Chinese MedicineNanjing 210004China Hospital Infection Control Office Jiangsu Province Hospital of Chinese MedicineNanjing 210004China

OBJECTIVE:To systematically evaluate the efficacy of scraping therapy on knee osteoarthritis(KOA).METHODS:A computerized search was conducted in several databases,including PubMed,Web of Science,Cochrane Library,China National Knowledge Infrastructure Database,China Science and Technology Journal Database,Wanfang,and Chinese BioMedical Literature Database,from the establishment date of these databases to April 9,*** controlled trials(RCTs)on scraping therapy for KOA were collected in accordance with the“Participants-Intervention-Control-Outcome-Study design”*** methodological evaluation of the included studies was carried out using RoB 2.0,and Meta-analysis was conducted using *** Grades of Recommendations Assessment,Development and Evaluation(GRADE System)was applied to grade the quality of ***:A total of 12 RCTs with 997 subjects were included in the *** indicated that compared with the control group,the scraping therapy treatment group exhibited increased Lysholm scores[mean difference(MD)=4.96,95%confidence intervals(CI)(3.18,6.74),P<0.00001]and Hospital for Special Surgery scores[MD=8.35,95%CI(3.92,12.78),P=0.0002]and decreased visual analog scale scores[MD=-2.11,95%CI(-3.79,-0.44),P=0.01]and Western Ontario and McM aster University Osteoarthritis Index scores[MD=-6.77,95%CI(-8.99,-4.56),P<0.00001)].The quality of evidence obtained in this Meta-analysis was low according to the GRADE ***:The available evidence suggests that scraping therapy may have certain clinical efficacy in the treatment of ***,further high-quality RCTs are needed to confirm the findings.

关键词： osteoarthritis,knee scraping Meta-analysis systematicreview

在线全文

学校读者我要写书评

暂无评论

超大型卧式滤器的设计开发及实际运行

水处理技术 2020年第7期46卷 113-117页

作者：柴子绯徐子丹戴诚怿康晓晖杭州(火炬)西斗门膜工业有限公司杭州水处理技术研究开发中心有限公司浙江杭州310012

研究了超大型卧式滤器设计开发中的结构设计、滤料选取、辅控设置等要点;计算确定了超大型卧式滤器进水布水方式、反洗流量及布水布气方式,完成了结合压力式滤器和重力式滤池优点的超大型卧式滤器开发生产,并于工程实践中应用。实践结... 详细信息

研究了超大型卧式滤器设计开发中的结构设计、滤料选取、辅控设置等要点;计算确定了超大型卧式滤器进水布水方式、反洗流量及布水布气方式,完成了结合压力式滤器和重力式滤池优点的超大型卧式滤器开发生产,并于工程实践中应用。实践结果表明,本滤器的处理水量和出水水质都完全满足设计目标,工程设备运行稳定。

关键词：卧式滤器大处理量结构设计布水设计大过滤面积

A Constraint Adaptive Multi-Tasking Differential Evolution Algorithm:Designed for Dispatch of Integrated Energy System in Coal Mine

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第2期29卷 368-385页

作者： Canyun dai Xiaoyan Sun Hejuan Hu Yong Zhang Dunwei Gong School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China School of Information Science and Technology Qingdao University of Science and TechnologyQingdao 266061China

The dispatch of integrated energy systems in coal mines(IES-CM)with mine-associated supplies is vital for efficient energy utilization and carbon emissions ***,IES-CM dispatch is highly challenging due to its feature as multi-objective and strong *** constrained multi-objective evolutionary algorithms often fall into locally feasible domains with poorly distributed Pareto front,which greatly deteriorates dispatch *** tackle this problem,we transform the traditional dispatch model of IES-CM into two tasks:the main task with all constraints and the helper task with constraint *** we propose a constraint adaptive multi-tasking differential evolution algorithm(CA-MTDE)to optimize these two tasks *** helper task with constraint adaptive is developed to obtain infeasible solutions near the feasible *** purpose of this infeasible solution is to transfer guiding knowledge to help the main task move away from local ***,a dynamic dual-learning strategy using DE/current-to-rand/1 and DE/current-to-best/1 is developed to maintain task diversity and ***,we comprehensively evaluate the performance of CA-MTDE by applying it to a coal mine in Shanxi Province,considering two IES-CM *** demonstrate the feasibility of CA-MTDE and its ability to generate a Pareto front with exceptional convergence,diversity,and distribution.

关键词： dispatch integrated energy system coal mine evolutionary multi-tasking constraint differential evolution

Ultrafast photoemission electron microscopy:A multidimensional probe of nonequilibrium physics

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

Chinese Physics B 2024年第3期33卷 24-57页

作者：戴亚南 Department of Physics Southern University of Science and Technology (SUSTech)Shenzhen 518055China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong) Shenzhen 518045China

Exploring the realms of physics that extend beyond thermal equilibrium has emerged as a crucial branch of condensed matter physics *** aims to unravel the intricate processes involving the excitations,interactions,and annihilations of quasi-and many-body particles,and ultimately to achieve the manipulation and engineering of exotic non-equilibrium quantum phases on the ultrasmall and ultrafast spatiotemporal *** the inherent complexities arising from many-body dynamics,it therefore seeks a technique that has efficient and diverse detection degrees of freedom to study the underlying *** combining high-power femtosecond lasers with real-or momentum-space photoemission electron microscopy(PEEM),imaging excited state phenomena from multiple perspectives,including time,real space,energy,momentum,and spin,can be conveniently achieved,making it a unique technique in studying physics out of *** this context,we overview the working principle and technical advances of the PEEM apparatus and the related laser systems,and survey key excited-state phenomena probed through this surface-sensitive methodology,including the ultrafast dynamics of electrons,excitons,plasmons,spins,etc.,in materials ranging from bulk and nano-structured metals and semiconductors to low-dimensional quantum *** this review,one can further envision that time-resolved PEEM will open new avenues for investigating a variety of classical and quantum phenomena in a multidimensional parameter space,offering unprecedented and comprehensive insights into important questions in the field of condensed matter physics.

关键词： ultrafast photoemission electron microscopy ultrafast momentum microscopy excited state physics

Viscoacoustic generalized screen propagator in constant-Q model

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2356-2369页

作者： Zhong-Kui dai Jia-Chun You Xing-Guo Huang Wei Liu College of Geophysics Chengdu University of Technology College of Instrumentation and Electrical Engineering Jilin University

When seismic waves propagate through the geological formation, there is a significant loss of energy and a decrease in imaging resolution, because of the viscoacoustic properties of subsurface medium. This profoundly impacts seismic wavefield propagation, imaging and interpretation. To accurately image the true structure of subsurface medium, the consensus among geophysicists is to no longer treat subsurface medium as ideal homogeneous medium, but rather to incorporate the viscoacoustic properties of subsurface medium. Based on the generalized screen propagator using conventional acoustic wave equation(acoustic GSP), our developed method introduces viscoacoustic compensation strategy, and derives a one-way wave generalized screen propagator based on time-fractional viscoacoustic wave equation(viscoacoustic GSP). In numerical experiments, we conducted tests on two-dimensional multi-layer model and the Marmousi model. When comparing with the acoustic GSP using the acoustic data, we found that the imaging results of the viscoacoustic GSP using the viscoacoustic data showed a significant attenuation compensation effect, and achieved imaging results for both algorithms were essentially consistent. However, the imaging results of acoustic GSP using viscoacoustic data showed significant attenuation effects, especially for deep subsurface imaging. This indicates that we have proposed an effective method to compensate the attenuated seismic wavefield. Our application on a set of real seismic data demonstrated that the imaging performance of our proposed method in local areas surpassed that of the conventional acoustic GSP. This suggests that our proposed method holds practical value and can more accurately image real subsurface structures while enhancing imaging resolution compared with the conventional acoustic GSP. Finally, with respect to computational efficiency, we gathered statistics on running time to compare our proposed method with conventional Q-RTM, and it is evid

关键词： One-way wave equation Viscoacoustic wave equation Generalized screen propagator Attenuation and dispersion effects