检索结果-南通市图书馆

Structures and magnetic properties of several novel lanthanide coordination polymers based on thiophene-2,5-dicarboxylic acid

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2012年第6期55卷 1073-1078页

作者： REN Jia LIU yue chen zhi XIONG Gang ZHAO Bin Department of Chemistry Nankai University Tianjin 300071 China

Eight novel lanthanide complexes： {Ln（TDA）I.5（H20）2 },, （Ln = Pr（la）, Nd（2a）） and { Ln（TDA）（Ac）（H2O）}n （Ln = Pr（1）, Nd（2） Eu（3）, Gd（4）, Tb（5）, Dy（6）; TDA = Thiophene-2,5-dicarboxylic acid anion） have been constructed by hydrothermal reaction. Structural analyses reveal that complexes Ia and 2a belong to the space group C2/c, exhibiting three-dimensional （3D） frame- works. Complexes 1-6 with P2t/c space group were prepared in the presence of excessive ammonium acetate, giving rise to interesting 3D frameworks different from those of la and 2a. Magnetic property studies of 4-6 reveal the weak antiferromag- netic interaction exists between adjacent Gd3＋ in 4. The complex 6 displays rather rare slow magnetization relaxation behavior in 3D frameworks.

关键词： thiophene-2 5-dicarboxylic acid lanthanide complexes slow magnetic relaxation

A personalized electronic textile for ultrasensitive pressure sensing enabled by biocompatible MXene/ PEDOT:PSS composite

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第3期6卷 224-238页

作者： Yahua Li Wentao Cao zhi Liu yue Zhang Ziyan chen Xianhong Zheng Department of Interventional Radiology The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina School of Textile and Garment Anhui Polytechnic UniversityWuhuAnhuiChina Department of Prosthodontics Shanghai Stomatological Hospital and School of StomatologyFudan UniversityShanghaiChina College of Chemistry Chemical Engineering and BiotechnologyDonghua UniversityShanghaiChina

Flexible,breathable,and highly sensitive pressure sensors have increasingly become a focal point of interest due to their pivotal role in healthcare monitoring,advanced electronic skin applications,and disease ***,traditional methods,involving elastomer film-based substrates or encapsulation techniques,often fall short due to mechanical mismatches,discomfort,lack of breathability,and limitations in sensing ***,there is a pressing need,yet it remains a significant challenge to create pressure sensors that are not only highly breathable,flexible,and comfortable but also sensitive,durable,and ***,we present a biocompatible and breathable fabric-based pressure sensor,using nonwoven fabrics as both the sensing electrode(coated with MXene/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate[PEDOT:PSS])and the interdigitated electrode(printed with MXene pattern)via a scalable spray-coating and screen-coating *** resultant device exhibits commendable air permeability,biocompatibility,and pressure sensing performance,including a remarkable sensitivity(754.5 kPa^(−1)),rapid response/recovery time(180/110 ms),and robust cycling ***,the integration of PEDOT:PSS plays a crucial role in protecting the MXene nanosheets from oxidation,significantly enhancing the device's long-term *** outstanding features make this sensor highly suitable for applications in fullrange human activities detection and disease *** study underscores the promising future of flexible pressure sensors in the realm of intelligent wearable electronics,setting a new benchmark for the industry.

关键词： biocompatibility MXene pressure sensor screen printing textile

Non-monotonic behavior of jam probability and stretchedexponential distribution in pedestrian counterflow

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9期33卷 259-266页

作者： Ze-Hao chen zhi-Xi Wu Jian-yue Guan College of Physical Science and Technology Guangxi Normal UniversityGuilin 541004China Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory for Quantum Theory and Applications of the Ministry of EducationLanzhou UniversityLanzhou 730000China

We adopt a floor field cellular automata model to study the statistical properties of bidirectional pedestrian flow movingin a straight corridor. We introduce a game-theoretic framework to deal with the conflict of multiple pedestrians tryingto move to the same target location. By means of computer simulations, we show that the complementary cumulative distributionof the time interval between two consecutive pedestrians leaving the corridor can be fitted by a stretched exponentialdistribution, and surprisingly, the statistical properties of the two types of pedestrian flows are affected differently by theflow ratio, i.e., the ratio of the pedestrians walking toward different directions. We also find that the jam probability exhibitsa non-monotonic behavior with the flow ratio, where the worst performance arises at an intermediate flow ratio of around0.2. Our simulation results are consistent with some empirical observations, which suggest that the peculiar characteristicsof the pedestrians may attributed to the anticipation mechanism of collision avoidance.

关键词： traffic and crowd dynamics evolutionary game theory

Enhanced memristor performance via coupling effect of oxygen vacancy and ferroelectric polarization

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第4期171卷 139-146页

作者： zhi Yun yue zhi Dong Zhang Zhan Jie Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

As a new type of nonvolatile memory,the resistive memristor has broad application prospects in in-formation storage and neural computing based on its excellent resistive switching(RS)*** present,it is still a great challenge to improve both ferroelectric polarization and leakage current to achieve a high RS on/offratio of ferroelectric ***,epitaxial Pb(Zr_(0.40)Ti_(0.60))O_(3)(PZT)thin films with low content Ca doping were deposited on the Nb:SrTiO_(3)substrate to prepare PCZT/NSTO het-erostructures and their RS behaviors were *** research findings show that compared with pure PZT film,the ferroelectric polarization of 1-mol%-Ca-doped PZT film is slightly improved,while the leak-age current is increased by three orders of ***,the RS on/offratio reaches 2.5×10^(5),about three orders of magnitude higher than pure PZT *** theoretical analysis reveals that the RS behavior of PCZT/NSTO heterostructures is controlled by the PCZT/NSTO interfacial barrier and the space charge-limited current *** results demonstrate that the ferroelectricity and electricity of ferroelectric thin films can be improved simultaneously by doping low-content Ca ions to increase the RS performance,which provides a good reference for the development of high-performance ferroelectric memristor devices.

关键词： Ferroelectric memristor Ca-doped PZT Ferroelectric polarization Oxygen vacancies Resistive switching

Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

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

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 82-90页

作者： zhi-Zeng Si yue-yue Wang Chao-Qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are *** this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are *** generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three *** and negative dispersion lead to different group velocities of *** presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an *** an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental *** work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

关键词： multi-wavelength fiber laser soliton explosion chaos state switching real-time dynamics

Cone-beam computed tomography noise reduction method based on U-Net with convolutional block attention module in proton therapy

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 89-100页

作者： Xing-yue Ruan Xiu-Fang Li Meng-Ya Guo Mei chen Ming Lv Rui Li zhi-Ling chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201800China University of Chinese Academy of Sciences Beijing100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China Department of Radiation Oncology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China Shanghai Key Laboratory of Proton therapy Shanghai201801China

Cone-beam computed tomography(CBCT) is mostly used for position verification during the treatment process. However,severe image artifacts in CBCT hinder its direct use in dose calculation and adaptive radiation therapy re-planning for proton therapy. In this study, an improved U-Net neural network named CBAM-U-Net was proposed for CBCT noise reduction in proton therapy, which is a CBCT denoised U-Net network with convolutional block attention modules. The datasets contained 20 groups of head and neck images. The CT images were registered to CBCT images as ground truth. The original CBCT denoised U-Net network, sCTU-Net, was trained for model performance comparison. The synthetic CT(SCT) images generated by CBAM-U-Net and the original sCTU-Net are called CBAM-SCT and U-Net-SCT images, respectively. The HU accuracies of the CT, CBCT, and SCT images were compared using four metrics: mean absolute error(MAE), root mean square error(RMSE), peak signal-to-noise ratio(PSNR), and structure similarity index measure(SSIM). The mean values of the MAE, RMSE, PSNR, and SSIM of CBAM-SCT images were 23.80 HU, 64.63 HU, 52.27 dB, and 0.9919, respectively,which were superior to those of the U-Net-SCT images. To evaluate dosimetric accuracy, the range accuracy was compared for a single-energy proton beam. The γ-index pass rates of a 4 cm × 4 cm scanned field and simple plan were calculated to compare the effects of the noise reduction capabilities of the original U-Net and CBAM-U-Net on the dose calculation results. CBAM-U-Net reduced noise more effectively than sCTU-Net, particularly in high-density tissues. We proposed a CBAM-U-Net model for CBCT noise reduction in proton therapy. Owing to the excellent noise reduction capabilities of CBAM-U-Net, the proposed model provided relatively explicit information regarding patient tissues. Moreover, it maybe be used in dose calculation and adaptive treatment planning in the future.

关键词： Proton therapy Cone-beam CT CBAM-U-Net γ-index

Age of Information for Short-Packet Covert Communication with Time Modulated Retrodirective Array

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第4期21卷 23-37页

作者： Ma yue Ma Ruiqian Lin zhi Yang Weiwei Cai yueming Miao chen Wu Wen Key Laboratory of Near-Range RF Sensing ICs&Microsystems(NJUST) Ministry of EducationSchool of Electronic and Optical EngineeringNanjing University of Science and TechnologyNanjing 210094China College of Electronic Engineering National University of Defense TechnologyHefei 230037China College of Communications Engineering Army Engineering University of PLANanjing 210007China

In this paper,the covert age of information(CAoI),which characterizes the timeliness and covertness performance of communication,is first investigated in the short-packet covert communication with time modulated retrodirective array(TMRDA).Specifically,the TMRDA is designed to maximize the antenna gain in the target direction while the side lobe is sufficiently *** this basis,the covertness constraint and CAoI are derived in closed *** facilitate the covert transmission design,the transmit power and block-length are jointly optimized to minimize the CAoI,which demonstrates the trade-off between covertness and *** results illustrate that there exists an optimal block-length that yields the minimum CAoI,and the presented optimization results can achieve enhanced performance compared with the fixed block-length ***,we observe that smaller beam pointing error at Bob leads to improvements in CAoI.

关键词： age of information covert communication retrodirective array time modulation

Nanopore design of sulfur doped hollow carbon nanospheres for superior potassium-ion battery anodes

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 2103-2114页

作者： Zhen-Dong Liu Hui-Yan Feng Yu-chen Wang Fei Wang yue Liu Jian-Xiao Yang yue Gu Jun Tan Chong Ye cheng-zhi Zhang Ji Hua Laboratory Foshan 528000China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and EngineeringHunan UniversityChangsha 410082China

Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term *** design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling ***,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic *** finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.

关键词： Nanopore Carbon materials Sulfur doping Anode Potassium-ionbatteries

Semaphorin 4D and hypoxia-inducible factor-1α overexpression is related to prognosis in colorectal carcinoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2015年第7期21卷 2191-2198页

作者： Jin-Shen Wang Chang-Qing Jing Ke-Shu Shan yue-zhi chen Xiao-Bo Guo zhi-Xin Cao Lin-Jun Mu Li-Pan Peng Ming-Liang Zhou Le-Ping Li Department of Gastrointestinal Surgery Provincial Hospital Affiliated to Shandong University Department of Pathology Provincial Hospital Affiliated to Shandong University

AIM:To investigate semaphorin 4D(Sema4D)and hypoxia-inducible factor-1α(HIF-1α)expression in colorectal carcinoma and evaluate their clinicopathological and prognostic ***:Eighty-six curatively resected colorectal carcinoma patients at different stages of disease were randomly selected from the group of patients who underwent surgery,and none of them received preoperative *** proximal adjacent bowel tissue,which served as an internal control,was obtained from 52 randomly selected *** was performed to analyze the expression of Sema4D and the tumor angiogenesisrelated protein HIF-1αin normal colorectal tissues and colorectal carcinoma *** relationships between the expression and clinical characters and prognosis were ***:HIF-1αand Sema4D were positively expressed in 58%and 60%of colorectal carcinoma tissues,*** lower expression levels were observed in normal mucosa(8%and 12%,respectively).HIF-1αand Sema4D expression was closely correlated with histological tumor type,tumornode-metastasis(TNM)stage,and lymphatic metastasis(P0.05).HIF-1αand Sema4D protein expression was significantly correlated with prognosis of colorectal carcinoma,as determined by Spearman rank correlation analysis(r=0.567;P<0.01).Multivariate Cox analysis revealed that only Sema4D expression played a significant role in predicting patient prognosis(P<0.05).CONCLUSION:These findings suggest that HIF-1αand Sema4D expression correlates with histological tumor type,TNM stage,and lymphatic metastasis in colorectal carcinoma and that Sema4D is a prognostic indicator of colorectal carcinoma.

关键词： Colorectal carcinoma Immunohistochemical staining