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二帧变换光源阴影莫尔技术研究

光子学报 2016年第2期45卷 13-18页

作者：周宪杜虎兵王建华西安工业大学机电工程学院西安710021

为了快速测量物体表面三维轮廓,提出一种变换光源位置的相移阴影莫尔技术.该方法通过控制两个光源的亮灭,将相移引入测量视场.使用二维经验模式分解法对条纹图进行正则化,结合螺旋相位变换方法和二帧相移算法对测量高度进行估计,利用发... 详细信息

为了快速测量物体表面三维轮廓,提出一种变换光源位置的相移阴影莫尔技术.该方法通过控制两个光源的亮灭,将相移引入测量视场.使用二维经验模式分解法对条纹图进行正则化,结合螺旋相位变换方法和二帧相移算法对测量高度进行估计,利用发展的迭代自调算法提取精确测量相位.计算机仿真和光学实验结果表明,该方法的解调准确度优于现有的二帧相移解调算法,同时,由于消除了测量过程中必要的机械运动,只需要二帧条纹图进行相位解调,节约了测量时间.

关键词：测量二帧相移阴影莫尔螺旋相位迭代算法

铁炭微电解法、Fenton氧化法处理印染废水的效果比较

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西北农林科技大学学报（自然科学版） 2013年第1期41卷 97-102页

作者：丁绍兰汪晶杜虎陕西科技大学资源与环境学院陕西西安710021

【目的】印染废水具有浓度高、色度高、成分复杂、难降解的特点,比较了铁炭微电解法和Fenton氧化法处理印染废水的效果。【方法】以取自陕西咸阳第二印染厂的综合废水为供试材料,通过单因素试验,分别对铁炭微电解法和Fenton氧化法处理... 详细信息

【目的】印染废水具有浓度高、色度高、成分复杂、难降解的特点,比较了铁炭微电解法和Fenton氧化法处理印染废水的效果。【方法】以取自陕西咸阳第二印染厂的综合废水为供试材料,通过单因素试验,分别对铁炭微电解法和Fenton氧化法处理印染废水的最佳条件进行了研究,并对二者的处理效果进行了比较。【结果】在处理印染废水时,铁炭微电解法的最佳反应条件为:停留时间30min,进水pH=3～4,铁炭体积比1∶1,此时色度去除率达到80%,COD去除率达到60%;Fenton氧化法的最佳反应条件为:pH=3,停留时间45min,H2O2和FeSO4用量分别为20,25mL/L,H2O2分3次加入,此条件下色度去除率达到79%,COD去除率达到80%。【结论】铁炭微电解法和Fenton氧化法对印染废水均有较好的处理效果,可考虑将两者联合运用,以进一步提高处理效果。

关键词：印染废水铁炭微电解法 Fenton氧化法色度 COD 去除率

A Review of Contact Electrification at Diversified Interfaces and Related Applications on Triboelectric Nanogenerator

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Nano-Micro Letters 2024年第1期16卷 106-130页

作者： Jun hu Mitsumasa Iwamoto Xiangyu Chen CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083People’s Republic of China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China Department of Physical Electronics Tokyo Institute of Technology2‑12‑1 S3‑33 O‑OkayamaMeguro‑KuTokyo 152‑8552Japan

The triboelectric nanogenerator(TENG)can effectively collect energy based on contact electrification(CE)at diverse interfaces,including solid–solid,liquid–solid,liquid–liquid,gas–solid,and gas–*** enables energy harvesting from sources such as water,wind,and *** this review,we provide an overview of the coexistence of electron and ion transfer in the CE *** elucidate the diverse dominant mechanisms observed at different interfaces and emphasize the interconnectedness and complementary nature of interface *** review also offers a comprehensive summary of the factors influencing charge transfer and the advancements in interfacial modification ***,we highlight the wide range of applications stemming from the distinctive characteristics of charge transfer at various ***,this review elucidates the future opportunities and challenges that interface CE may *** anticipate that this review can offer valuable insights for future research on interface CE and facilitate the continued development and industrialization of TENG.

关键词： Contact electrification Interfaces Triboelectric nanogenerators Diversified applications

Single and combined effects of secondary polyethylene microplastic on the growth of Pak choi and the soil microbiome composition

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 1-12页

作者： Jiamin hu Zhenwen Xie Jiane Zuo State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen518055China

It has been confirmed that microplastics(MPs)are present in the *** study simulated secondary PE-MPs via aging and mechanical processes to evaluate their effects on Pak choi(Brassica rapa L.)over 21 *** common pollutants,dichlorodiphenyltrichloroethane(DDT)and naphthalene,were used in the combined toxicity *** results indicated that the growth of Pak choi was significantly inhibited after exposure to secondary PE-MPs,and the combined effects were antagonistic,owing to the adsorption capacity of secondary PE-MPs to DDT and *** stress in Pak choi can be markedly affected,leading to oxidative damage to plant *** moisture content,soil bulk density,soil density,cation exchange capacity(CEC),and FDA hydrolase in the planted soils increased in the treated groups,and the TOC content changed *** also found that the microbial composition of the soil in the DDT and naphthalene groups showed more significant alterations than that in the other *** diversity analysis showed that species diversity increased in the combined groups but indicated a clear downward trend in the single MPs *** study suggests that secondary PE-MPs harm the growth of Pak choi and can change soil properties,revealing the harm to the ecosystem of MPs in the soil.

关键词： Secondary PE-MPs Combined effects Oxidative stress Soil properties Bacterial community

A wide-linear-range and low-hysteresis resistive strain sensor made of double-threaded conductive yarn for human movement detection

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Journal of Materials Science & Technology 2024年第5期172卷 202-212页

作者： Fei huang Jiyong hu Xiong Yan Shanghai Frontier Science Research Center for Modern Textiles Donghua UniversityShanghai 201620China

Yarn-based flexible strain sensors with advantages in wearability and integrability have attracted wide ***,it is still a big challenge to achieve yarn-based strain sensors with a wide linear strain range,low hysteresis,and durability synchronously that can be used for full range detection of human body ***,a new structure,double-threaded conductive yarn with rhythmic strain distribu-tion,is reported to markedly widen the linear strain range of microcrack-based stretchable strain sensors.A new method of winding and thermally adhering hot-melt filaments on the surface of the elastic fiber is used to achieve double-threaded yarn(DTY)with rhythmic strain *** proposed strategy,the integration of heterogeneous materials,is reported to significantly reduce the mechanical hysteresis of composite *** strain distribution of the DTY during stretching causes multi-level micro-cracks in different regions of the carbon nanotube(CNT)conductive layer deposited on the surface of the ***,the sensing performance of DTY-based strain sensor can be adjusted by designing the structural *** final prepared flexible strain sensor has the advantages of a wide linear strain range(100%),great sensitivity(GF=12.43),low hysteresis,rapid response(158 ms),high repeatability(>2000 cycles at 50%strain),and hydrophobicity,*** sensor can monitor human motion repeatedly and stably well,and shows great advantages in flexible wearable devices.

关键词： Double-threaded yarn Strain redistribution Hysteresis human motion monitoring

Numerical simulation study on the hygrothermal performance of building exterior walls under dynamic wind-driven rain condition

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Building Simulation 2024年第2期17卷 207-221页

作者： Xing hu huibo Zhang hui Yu School of Design Shanghai Jiao Tong UniversityShanghai200240China

Wind-driven rain(WDR)has a significant influence on the hygrothermal performance,durability,and energy consumption of building *** calculation of WDR loads using semi-empirical models has been incorporated into the boundary conditions of coupled heat and moisture transfer ***,prior research often relied on fixed WDR absorption ratio,which fail to accurately capture the water absorption characteristics of porous building materials under rainfall ***,this study aims to investigate the coupled heat and moisture transfer of exterior walls under dynamic WDR boundary conditions,utilizing an empirically obtained WDR absorption ratio model based on field *** developed coupled heat and moisture transfer model is validated against the HAMSTAD *** findings reveal that the total WDR flux calculated with the dynamic WDR boundary is lower than that obtained with the fixed WDR boundary,with greater disparities observed in orientations experiencing higher WDR *** variations in moisture flow significantly impact the surface temperature and relative humidity of the walls,influencing the calculation of cooling and heating loads by different *** to the transient heat transfer model,the coupled heat and moisture transfer model incorporating dynamic WDR boundary exhibits maximum increases of 17.6%and 16.2%in cooling and heating loads,*** dynamic WDR boundary conditions provide more precise numerical values for surface moisture flux,offering valuable insights for the thermal design of building enclosures and load calculations for HVAC systems.

关键词： wind-driven rain building component hygrothermal model transient simulation cooling and heating loads

CRD-CGAN:category-consistent and relativistic constraints for diverse text-to-image generation

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Frontiers of Computer Science 2024年第1期18卷 61-75页

作者： Tao hu Chengjiang LONG Chunxia XIAO College of Intelligent Systems Science and Engineering Hubei Minzu UniversityEnshi 445000China School of Computer Science Wuhan UniversityWuhan 430072China Key Laboratory of Performing Art Equipment&System Technology Ministry of Culture and TourismBeijing 100007China Meta Reality Labs BurlingameCA94010USA

Generating photo-realistic images from a text description is a challenging problem in computer *** works have shown promising performance to generate synthetic images conditional on text by Generative Adversarial Networks(GANs).In this paper,we focus on the category-consistent and relativistic diverse constraints to optimize the diversity of synthetic *** on those constraints,a category-consistent and relativistic diverse conditional GAN(CRD-CGAN)is proposed to synthesize K photo-realistic images *** use the attention loss and diversity loss to improve the sensitivity of the GAN to word attention and ***,we employ the relativistic conditional loss to estimate the probability of relatively real or fake for synthetic images,which can improve the performance of basic conditional ***,we introduce a category-consistent loss to alleviate the over-category issues between K synthetic *** evaluate our approach using the Caltech-UCSD Birds-200-2011,Oxford 102 flower and MS COCO 2014 datasets,and the extensive experiments demonstrate superiority of the proposed method in comparison with state-of-the-art methods in terms of photorealistic and diversity of the generated synthetic images.

关键词： text-to-image diverse conditional GAN relativi-stic category-consistent

Granular collapse in fluids:Dynamics and flow regime identification

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Particuology 2024年第9期92卷 30-41页

作者： hu Tang Bisong Lin Dengming Wang Department of Mechanics and Engineering Science School of Civil Engineering and MechanicsKey Laboratory of Mechanics on Disaster and Environment in Western China of Ministry of EducationLanzhou UniversityLanzhou730000China

The collapse of granular material in fluids is a prevalent phenomenon in both natural and industrial processes,displaying a notable sensitivity to initial configuration of the *** study is specifically oriented towards falling process of collapsing material under various fluid conditions,employing the computational fluid dynamics-discrete element method(CFD-DEM)to primarily investigate the dynamics and scaling laws of deposit morphology of collapsed *** a comprehensive analysis of particle sedimentation in fluids,we introduce a refined inertial characteristic time for granular collapse within the inertial ***,we propose modifications to conventional fluid-particle density ratio and Reynolds number,aiming to enhance the accuracy of depicting collapse dynamics and identifying flow regimes across diverse column heights and fluid ***,we construct a phase diagram of flow regimes using modified dimensionless numbers,emphasizing the role of column height in transition between viscous and inertial *** parameters demonstrate enhanced relevance in governing the collapse of immersed granular columns,thereby contributing to a more nuanced understanding of fluid-particle interations in dense granular flows under different regimes.

关键词： Immersed granular material Collapse Dynamic Flow regime Computational fluid dynamics-discrete element method

Initial costates derived by near-optimal reference sequence and least-squares method

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Chinese Journal of Aeronautics 2024年第5期37卷 377-391页

作者： Shaozhao LU Yao ZHANG Quan hu School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

In this paper,we present a novel initial costates solver for initializing time-optimal trajectory problems in relative motion with continuous low *** proposed solver consists of two primary components:training a Multilayer Perceptron(MLP)for generating reference sequence and Time of Flight(TOF)to the target,and deriving a system of linear algebraic equations for obtaining the initial *** overcome the challenge of generating training samples for the MLP,the backward generation method is proposed to obtain five different training *** training database and sample form are determined by analyzing the input and output correlation using the Pearson correlation *** best-performing MLP is obtained by analyzing the training results with various hyper-parameter combinations.A reference sequence starting from the initial states is obtained by integrating forward with the near-optimal control vector from the output of ***,a system of linear algebraic equations for estimating the initial costates is derived using the reference sequence and the necessary conditions for *** results demonstrate that the proposed initial costates solver improves the convergence ratio and reduce the function calls of the shooting ***,Monte-Carlo simulation illustrates that the initial costates solver is applicable to different initial velocities,demonstrating excellent generalization ability.

关键词： Relative motion Expanding training database Multilayer perceptron Initial costates Least-squares method