检索结果-南通市图书馆

Underwater Directional Acoustic Source Based on Pentamode Material

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第1期37卷 1-9页

作者： Binghao Zhao peng wang Dongwei wang Gengkai Hu School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Wuhan Second Ship Design and Research Institute Wuhan 430205China

An underwater directional acoustic emitter is conceived with a highly anisotropic lattice material,whose acoustic characteristics manifest strong dependence on the orientation of the lattice material’s principal axis.Exploiting these features,a cylindrical structure made of such anisotropic lattice material is engineered to possess distinct impedance values in different directions,thereby facilitating wave emission along the principal axis while inducing reflection in other directions.Notably,through numerical simulations,it is demonstrated that the emission direction can be effectively manipulated by adjusting the principal axis orientation,concurrently enhancing the emitted power.In contrast to previous directional acoustic structures,the compact emitter presented in this study can get rid of the size-wavelength constraint,enabling effective control of low-frequency waves.

关键词： Underwater Directional emission Pentamode material Broadband frequency

Stochastic Flexibility Evaluation for Virtual Power Plants by Aggregating Distributed Energy Resources

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 988-999页

作者： Siyuan wang Wenchuan Wu Qizhan Chen Junjie Yu peng wang Department of Electrical Engineering Tsinghua UniversityBeijing 100084China Zhongshan Power Supply Bureau of the Guangdong Power Grid Corporation Zhongshan 528400China Beijing Qingda Gaoke System Control Company Beijing 102208China CSEE IEEE

To manage a large amount of flexible distributed energy resources(DERs)in the distribution networks,the virtual power plant(VPP)is introduced into the industry.The VPP can optimally dispatch these resources in a cluster manner and provide flexibility for the power system operation as a whole.Most existing studies formulate the equivalent power flexibility of the aggregating DERs as deterministic optimization models without considering their uncertainties.In this paper,we introduce the stochastic power flexibility range(PFR)and timecoupling flexibility(TCF)to describe the power flexibility of VPP.In this model,both operational constraints and the randomness of the DERs’output are incorporated,and a combined model and data-driven solution is proposed to obtain the stochastic PFR,TCF,and cost function of VPP.The aggregating model can be easily incorporated into the optimization model for the power system operator or market bidding,considering uncertainties.Finally,a numerical test is performed.The results show that the proposed model not only has higher computational efficiency than the scenario-based methods but also achieves more economic benefits.

关键词： Chance constrained optimization combined model and data-driven stochastic power flexibility virtual power plant

Outcomes of endoscopic sclerotherapy for jejunal varices at the site of choledochojejunostomy (with video): 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 Gastroenterology 2024年第14期30卷 2059-2067页

作者： Jun Liu peng wang Li-Mei wang Jing Guo Ning Zhong Department of Gastroenterology Qilu Hospital of Shandong UniversityJinan 250012Shandong ProvinceChina

BACKGROUND Hemorrhage associated with varices at the site of choledochojejunostomy is an unusual,difficult to treat,and often fatal manifestation of portal hypertension.So far,no treatment guidelines have been established.CASE SUMMARY We reported three patients with jejunal varices at the site of choledochojejun-ostomy managed by endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoacrylate injection at our institution between June 2021 and August 2023.We reviewed all patient records,clinical presentation,endoscopic findings and treatment,outcomes and follow-up.Three patients who underwent pancre-aticoduodenectomy with a Whipple anastomosis were examined using conven-tional upper gastrointestinal endoscopy for suspected hemorrhage from the afferent jejunal loop.Varices with stigmata of recent hemorrhage or active he-morrhage were observed around the choledochojejunostomy site in all three patients.Endoscopic injection of lauromacrogol/α-butyl cyanoacrylate was carried out at jejunal varices for all three patients.The bleeding ceased and patency was observed for 26 and 2 months in two patients.In one patient with multiorgan failure and internal environment disturbance,rebleeding occurred 1 month after endoscopic sclerotherapy,and despite a second endoscopic sclero-therapy,repeated episodes of bleeding and multiorgan failure resulted in eventual death.CONCLUSION We conclude that endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoac-rylate injection can be an easy,effective,safe and low-cost treatment option for jejunal varicose bleeding at the site of choledochojejunostomy.

关键词： Endoscopic sclerotherapy Jejunal varices Choledochojejunostomy Portal vein hypertension Case report

Feature-Grounded Single-Stage Text-to-Image Generation

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 469-480页

作者： Yuan Zhou peng wang Lei Xiang Haofeng Zhang School of Artificial Intelligence Nanjing University of Information Science and TechnologyNanjing 210044China School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

Recently,Generative Adversarial Networks(GANs)have become the mainstream text-to-image(T2I)framework.However,a standard normal distribution noise of inputs cannot provide sufficient information to synthesize an image that approaches the ground-truth image distribution.Moreover,the multistage generation strategy results in complex T2I applications.Therefore,this study proposes a novel feature-grounded single-stage T2I model,which considers the“real”distribution learned from training images as one input and introduces a worst-case-optimized similarity measure into the loss function to enhance the model's generation capacity.Experimental results on two benchmark datasets demonstrate the competitive performance of the proposed model in terms of the Frechet inception distance and inception score compared to those of some classical and state-of-the-art models,showing the improved similarities among the generated image,text,and ground truth.

关键词： text-to-image(T2I) feature-grounded single-stage generation Generative Adversarial Network(GAN)

Machine learning model based on non-convex penalized huberized-SVM

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 Electronic Science and Technology 2024年第1期22卷 81-94页

作者： peng wang Ji Guo Lin-Feng Li School of Finance and Economics Xizang Minzu UniversityXianyang712082China Research Center for Quality Development of Xizang Special Industries Xianyang712082China School of Computer Science and Technology Xinjiang UniversityUrumqi830017China

The support vector machine(SVM)is a classical machine learning method.Both the hinge loss and least absolute shrinkage and selection operator(LASSO)penalty are usually used in traditional SVMs.However,the hinge loss is not differentiable,and the LASSO penalty does not have the Oracle property.In this paper,the huberized loss is combined with non-convex penalties to obtain a model that has the advantages of both the computational simplicity and the Oracle property,contributing to higher accuracy than traditional SVMs.It is experimentally demonstrated that the two non-convex huberized-SVM methods,smoothly clipped absolute deviation huberized-SVM(SCAD-HSVM)and minimax concave penalty huberized-SVM(MCP-HSVM),outperform the traditional SVM method in terms of the prediction accuracy and classifier performance.They are also superior in terms of variable selection,especially when there is a high linear correlation between the variables.When they are applied to the prediction of listed companies,the variables that can affect and predict financial distress are accurately filtered out.Among all the indicators,the indicators per share have the greatest influence while those of solvency have the weakest influence.Listed companies can assess the financial situation with the indicators screened by our algorithm and make an early warning of their possible financial distress in advance with higher precision.

关键词： Huberized loss Machine learning Non-convex penalties Support vector machine(SVM)

An ultra-porous g-C_(3)N_(4) micro-tube coupled with MXene(Ti_(3)C_(2)TX)nanosheets for efficient degradation of organics under natural sunlight

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 Environmental Sciences 2024年第3期137卷 258-270页

作者： Zongyang Ya Qiyou wang Jingjin Cai peng wang Xinyu Jiang Zhiyin Cai Shanglin Xiang Tingwei wang Dongyu Cai College of Materials Science&Engineering Nanjing Tech University30 South PuZhu RoadNanjing 211816China Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech University30 South PuZhu RoadNanjing 211816China

It remains as a challenge for realizing efficient photo-responsive catalysts towards largescale degradation of organic pollutants under natural sunlight.This work reports a new pore engineering strategy for creating ultra-porous g-C_(3)N_(4) micro-tubes with an unprecedentedly high specific surface area of 152.96 m^(2)/g.This is mainly associated with releasing internal vapor pressure in the autoclave where the hydrothermal treatment of the urea/melamine mixture is processed.Supported by microscopic observation,porosity measurement and spectroscopic characterization,it is found that releasing the pressure at halfway of hydrothermal process is vital for forming exfoliated rod-like precursors and the de-aggregation of these rods presents substantial benefits on the production of mesopores on g-C_(3)N_(4) microtubes during the calcination of precursors.This offers a large number of reactive sites required by photocatalytic reaction.Coupling these micro-tubes with Ti_(3)C_(2)T_(X) nanosheets via electrostatic interaction yields a 1D/2D heterojunction with a close interfacial contact.The addition of metallically conductive Ti_(3)C_(2)T_(X) nanosheets accelerates the separation between electrons and holes,and also enhances the light absorption.All these merits of structural design lead to forming a group of highly efficient catalysts demonstrating an excellent photocatalytic degradation rate of k=0.0560 min^(-1)for RhB dyes under 100 mW/cm~2 visible light radiation that micks sunlight outdoors.This laboratory valuation is further supported by an outdoor test that shows a fast degradation rate of 0.0744 min^(-1)under natural sunlight.

关键词： Carbon nitride MXene Heterojunction Photocatalysis

2D–3D dual carbon layer confined ultrasmall VN nanoparticles for improving lithium-ion storage in hybrid capacitors

维普期刊数据库

同方期刊数据库评论

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 65-75页

作者： Zhao-Wei Hu Hui-Fang Li peng wang Wan-Li wang Lei Yang Xiao-Jun wang Zhi-Ming Liu College of Electromechanical Engineering Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon-MaterialsQingdao University of Science&TechnologyQingdao 266061China Research Center for Intelligent and Wearable Technology College of Textiles and ClothingQingdao UniversityQingdao 266071China

Lithium-ion capacitors(LICs) of achieving high power and energy density have garnered significant attention. However, the kinetics unbalance between anode and cathode can impede the application of LICs. Vanadium nitride(VN) with a high theoretical specific capacity(~ 1200 m Ah·g^(-1)) is a better pseudocapacitive anode to match the response of cathode in LICs. However, the insertion/extraction of Li-ions in VN's operation results in significant volume expansion. Herein, the VN/N-r GO-5composite that three-dimentional(3D) dicyandiamidederived-carbon(DDC) tightly wrapped VN quantum dots(VN QDTs) on two-dimentional(2D) reduced graphene oxid(r GO) was prepared by a facile strategy. The VN QDTs can reduce ion diffusion length and improve charge transfer kinetics. The 2D r GO as a template provides support for nanoparticle dispersion and improves electrical conductivity. The 3D DDC tightly encapsulated with VN QDTs mitigates agglomeration of VN particles as well as volume expansion. Correspondingly, the LICs with VN/Nr GO-5 composite as anode and activated carbon(AC) as cathode were fabricated, which exhibits a high energy density and power density. Such strategy provides a perspective for improving the electrochemical properties of LIC anode materials by suppressing volume expansion and enhancing conductivity.

关键词： Vanadium nitride(VN)quantum dots Reduced graphene oxide(rGO)nanosheets Dicyandiamide-derived-carbon 2D–3D dual carbon layer Lithium-ion capacitors

Single-incision laparoscopic transabdominal preperitoneal repair in the treatment of adult female patients with inguinal hernia

维普期刊数据库

同方期刊数据库评论

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1期16卷 49-58页

作者： Xiao-Jun Zhu Jing-Yi Jiao Hui-Min Xue peng Chen Chang-Fu Qin peng wang Department of General Surgery The Affiliated Hospital of Nantong UniversityNantong 226001Jiangsu ProvinceChina Medical School Nantong UniversityNantong 226001Jiangsu ProvinceChina Department of Hernia and Abdominal Wall Surgery Peking University People's HospitalBeijing 100044China

BACKGROUND Women have a 3%lifetime chance of developing an inguinal hernia,which is not as common in men.Due to its cosmetic benefits,single-incision laparoscopic transabdominal preperitoneal(SIL-TAPP)inguinal hernia repair is becoming in-creasingly popular in the management of inguinal hernia in women.However,there are no studies comparing the safety and applicability of SIL-TAPP repair with conventional laparoscopic transabdominal preperitoneal(CL-TAPP)inguinal hernia repair for the treatment of inguinal hernia in women.AIM To compare the outcomes of SIL-TAPP and CL-TAPP repair in adult female patients with inguinal hernia and to estimate the safety and applicability of SIL-TAPP repair in adult female inguinal hernia patients.METHODS We retrospectively compared the clinical information and follow-up data of fe-male inguinal hernia patients who underwent SIL-TAPP inguinal hernia repair and those who underwent CL-TAPP inguinal hernia repair at the Affiliated Hos-pital of Nantong University from February 2018 to December 2020 and assessed the long-term and short-term outcomes of both cohorts.RESULTS This study included 123 patients,with 71 undergoing SIL-TAPP repair and 52 un-dergoing CL-TAPP repair.The two cohorts of patients and inguinal hernia charac-teristics were similar,with no statistically meaningful difference.The rate of intraoperative inferior epigastric vessel injury was lower in patients in the SIL-TAPP cohort(0,0%)than in patients in the CL-TAPP cohort(4,7.7%)and was significantly different(P<0.05).In addition,the median[interquartile range(IQR)]total hospitalization costs were significantly lower in patients in the SIL-TAPP cohort[$3287(3218-3325)]than in patients in the CL-TAPP cohort[$3511(3491-3599)].Postoperatively,the occurrence rate of trocar site hernia was lower in the SIL-TAPP cohort(0,0%)than in the CL-TAPP cohort(4,7.7%),and the median(IQR)cosmetic score was significantly higher in the SIL-TAPP cohort[10(10-10)]than in the CL-TAPP cohort[9(9-10)].CONCLUSION SIL-TAPP repair did not increas

关键词： Single-incision Groin hernia Female Inguinal hernia Laparoscopic transabdominal preperitoneal inguinal hernia repair

Human-robot object handover:Recent progress and future direction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomimetic Intelligence & Robotics 2024年第1期4卷 1-13页

作者： Haonan Duan Yifan Yang Daheng Li peng wang Institute of Automation Chinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Centre for Artificial Intelligence and Robotics Hong Kong Institute of Science and InnovationChinese Academy of SciencesHong Kong 999077China

Human-robot object handover is one of the most primitive and crucial capabilities in human-robot collaboration.It is of great significance to promote robots to truly enter human production and life scenarios and serve human in numerous tasks.Remarkable progressions in the field of human-robot object handover have been made by researchers.This article reviews the recent literature on human-robot object handover.To this end,we summarize the results from multiple dimensions,from the role played by the robot(receiver or giver),to the end-effector of the robot(parallel-jaw gripper or multi-finger hand),to the robot abilities(grasp strategy or motion planning).We also implement a human-robot object handover system for anthropomorphic hand to verify human-robot object handover pipeline.This review aims to provide researchers and developers with a guideline for designing human-robot object handover methods.

关键词： Human-robot interactions Object handover