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A double-layer radiative cooling coating that utilizes the refractive index difference between layers to achieve extremely high solar reflectivity

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Science China Technological Sciences 2024年第10期67卷 3182-3189页

作者： WANG FuQiang LI ChunZhe YANG ZhenNing XIE WeiXin LI xiang XU ZengHui YAN YuYing cheng ZiMing School of Energy Science and Engineering Harbin Institute of Technology School of New Energy Harbin Institute of Technology at Weihai China Construction Eco-Environmental Protection Technology Co. Ltd. Faculty of Engineering University of Nottingham

Passive daytime radiative cooling（PDRC） technology has great potential in reducing cooling energy consumption. In order to further improve the spectral performance of PDRC coatings, current researchers mostly focus on the selection and size design of functional particles, while ignoring the optical properties enhancement effect caused by the interlayer binder. In this study, based on the principle that the refractive index difference between layers enhanced the backscattering performance of the solar spectrum, we proposed and manufactured a double-layer PDRC coating with polyvinylidene difluoride（PVDF） as the filmforming material in the upper layer and polydimethylsiloxane（PDMS） as the film-forming material in the lower layer, both filled with Al2O3and SiO2particles. The double-layer PDRC coating exhibited excellent spectral performance that a high solar reflectivity of 98% and an emissivity of 0.95 at the “atmospheric window” band. In comparison, the solar spectrum reflectivity of the single-layer PDRC coatings based on PVDF and PDMS of the same thickness was 95% and 94.7%, respectively. Outdoor tests showed that the PDRC coating achieved a temperature decrease of up to 7.1℃ under direct sunlight at noon time. In addition, the PDRC coating had excellent weather resistance, water resistance, and other basic properties. This article opens up a new idea and provides methodological guidance for the design of double-layer PDRC coatings.

关键词： double-layer radiative cooling coating spectral modulation interlayer refractive index solar energy radiative transfer

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Study of inter-well interference in shale gas reservoirs by a robust production data analysis method based on deconvolution

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Petroleum Science 2024年第4期21卷 2502-2519页

作者： Wen-Chao Liu cheng-cheng Qiao Ping Wang Wen-Song Huang xiang-Wen Kong Yu-Ping Sun He-Dong Sun Yue-Peng Jia School of Civil and Resource Engineering University of Science and Technology Beijing PetroChina Research Institute of Petroleum Exploration and Development

In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering, this study proposes a robust production data analysis method based on deconvolution, which is used for multi-well inter-well interference research. In this study, a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established, and its Laplace solutions under two different outer boundary conditions were obtained. Then, an improved pressure deconvolution algorithm was used to normalize the scattered production data. Furthermore, the typical curve fitting was carried out using the production data and the seepage model solution. Finally,some reservoir parameters and fracturing parameters were interpreted, and the intensity of inter-well interference was compared. The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area. The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging. Besides, by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions, the strength of the interference between wells on the same well platform was well judged. This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells.

关键词： Shale gas Inter-well interference Deconvolution Production data analysis Typical curves Multi-stage fractured horizontal well

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Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

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China Foundry 2024年第1期21卷 11-19页

作者： Wen-ning Liu Wei Zhang Peng-yue Wang Yi-xian Liu xiang-yi Jiao Ao-xiang Wan cheng-gang Wang Guo-dong Tong Shou-mei Xiong School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW Group Co. Ltd.Changchun 130013China China FAW Foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg *** AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg *** elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-*** a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and *** an increase in slow shot speed,the size and number of ESCs and porosities significantly *** addition,the distribution of ESCs is more dispersed and the net-shrinkage *** tensile property is greatly improved by adopting a higher slow shot *** ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property

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Single-wall carbon nanotube fiber non-woven fabrics with a high electrothermal heating response

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Nano Research 2024年第6期17卷 5621-5628页

作者： Xinyu Jiao Lele Xu Xinyang Sun Chao Shi Peng-xiang Hou Chang Liu Hui-Ming cheng 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 ChinaHefei 230026China Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Carbon nanotube(CNT)fibers have great promise for constructing multifunctional fabrics with high electrical conductivity,good electro-heating ability,excellent flexibility,and a low ***,the inter-fiber contacts in the fabric greatly reduce these advantages and limit their ***,a simple pressure-fusing method to fabricate single-wall CNT(SWCNT)fiber non-woven fabrics(NWFs)that are composed of interconnected SWCNT fibers with fused joints is reported,which have good flexibility,a low density of 0.46 g/cm^(3),a high electrical conductivity of 3.7×10^(5)S/m,and a record high specific electrical conductivity of 803(S·m^(2))/*** also showed excellent electrical heating ability,so that a temperature of~160℃was rapidly reached at a low voltage of 2 *** with their low density,the SWCNT fiber NWFs are promising for use as a heating unit for low temperature battery protection and de-icing applications.

关键词： carbon nanotube fiber nonwoven fabrics fusing electrothermal heating

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A novel algorithm for evaluating cement azimuthal density based on perturbation theory in horizontal well

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Petroleum Science 2024年第1期21卷 244-251页

作者： Ji-lin Fan Feng Zhang Qian Chen Hao-Chen Song Lu-Yu Zhong Yue-xiang Dai National Key Laboratory of Deep Oil and Gas School of GeosciencesChina University of Petroleum(East China)Qingdao 266580ShandongChina China National Logging Corporation Xi'an 710076ShaanxiChina Sinopec Matrix Corporation Qingdao 266001ShandongChina

Cement density monitoring plays a vital role in evaluating the quality of cementing projects,which is of great significance to the development of oil and ***,the presence of inhomogeneous cement distribution and casing eccentricity in horizontal wells often complicates the accurate evaluation of cement azimuthal *** this regard,this paper proposes an algorithm to calculate the cement azimuthal density in horizontal wells using a multi-detector gamma-ray detection *** spatial dynamic response functions are simulated to obtain the influence of cement density on gamma-ray counts by the perturbation theory,and the contribution of cement density in six sectors to the gamma-ray recorded by different detectors is obtained by integrating the spatial dynamic response *** with the relationship between gamma-ray counts and cement density,a multi-parameter calculation equation system is established,and the regularized Newton iteration method is employed to invert casing eccentricity and cement azimuthal *** approach ensures the stability of the inversion process while simultaneously achieving an accuracy of 0.05 g/cm^(3) for the cement azimuthal *** accuracy level is ten times higher compared to density accuracy calculated using calibration ***,this algorithm enhances the accuracy of cement azimuthal density evaluation,provides valuable technical support for the monitoring of cement azimuthal density in the oil and gas industry.

关键词： Cement azimuthal density Perturbation theory Casing eccentricity Spatial dynamic response function Regularized Newton iteration

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A Hybrid Approach for Predicting the Remaining Useful Life of Bearings Based on the RReliefF Algorithm and Extreme Learning Machine

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1405-1427页

作者： Sen-Hui Wang Xi Kang cheng Wang Tian-Bing Ma xiang He Ke Yang School of Mechatronics Engineering Anhui University of Science and TechnologyHuainan232001China Institute of Energy Hefei Comprehensive National Science CenterHefei230031China

Accurately predicting the remaining useful life(RUL)of bearings in mining rotating equipment is vital for mining *** research aims to distinguish the features associated with the RUL of bearings and propose a prediction model based on these selected *** study proposes a hybrid predictive model to assess the RUL of rolling element *** proposed model begins with the pre-processing of bearing vibration signals to reconstruct sixty time-domain *** hybrid model selects relevant features from the sixty time-domain features of the vibration signal by adopting the RReliefF feature selection ***,the extreme learning machine(ELM)approach is applied to develop a predictive model of RUL based on the optimal *** model is trained by optimizing its parameters via the grid search *** training datasets are adjusted to make them most suitable for the regression model using the cross-validation *** proposed hybrid model is analyzed and validated using the vibration data taken from the public XJTU-SY rolling element-bearing *** comparison is constructed with other traditional *** experimental test results demonstrated that the proposed approach can predict the RUL of bearings with a reliable degree of accuracy.

关键词： Bearing degradation remaining useful life estimation RReliefF feature selection extreme learning machine

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p38 Signaling Mediates Naringin-Induced Osteogenic Differentiation of Porcine Metanephric Mesenchymal Cells

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Chinese Journal of Integrative Medicine 2024年第9期30卷 818-825页

作者： JI Peng-cheng XIE Yuan-sheng GUO Wen-kai FU Bo CHEN xiang-mei Chinese PLA Medical School Beijing100853China Department of Nephrology First Medical Center of Chinese PLA General HospitalChinese PLA Institute of NephrologyState Key Laboratory of Kidney DiseasesNational Clinical Research Center for Kidney DiseasesBeijing Key Laboratory of Kidney DiseasesBeijing100853China School of Medicine Nankai UniversityTianjin300071China

Objective:To explore the potential of metanephric mesenchymal cells(MMCs)for osteogenesis and naringin’s ability to enhance this process and its molecular ***:Porcine MMCs at 70 days of gestation were used as tool cells,cultured in osteogenic induction medium,identified by immunocytochemistry *** potential of porcine MMCs and naringin’s ability to enhance this process was tested by detecting changes in cell viability,alkaline phosphatase(ALP)activity,the expression of runt-related transcription factor 2(Runx2),osteopontin(OPN)and osteocalcin(OCN),and the formation of mineralized nodules,and the application of the p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of ***:Immunocytochemical staining showed that the cells were Vimentin and Six2(+),E-cadherin and CK-18(−).Naringin can activate the p38 signaling pathway to enhance the osteogenesis of porcine MMCs by increasing cell viability,ALP activity,the expressions of Runx2,OPN and OCN,and the formation of mineralized nodules(Pling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin,manifested by decreased ALP activity,the expressions of Runx2,OPN and OCN,and the formation of mineralized nodules(Pling pathway.

关键词： metanephric mesenchymal cells naringin osteogenesis differentiation

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Pyridine-regulated Sb@InSbS_(3)ultrafine nanoplates as high-capacity and long-cycle anodes for sodium-ion batteries

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Rare Metals 2024年第5期43卷 2080-2092页

作者： Jia-Ying Ren xiang-lin Yu Chang-Miao Chen Xin-Yu Hu Ting Yang Ming Zhang College of Materials Science and Engineering and College of Science Central South University of Forestry and TechnologyChangsha 410004China College of Semiconductors(College of Integrated Circuits) Changsha Semiconductor Technology and Application Innovation Research InstituteHunan UniversityChangsha 410082China

Sb-based materials exhibit considerable potential for sodium-ion storage owing to their high theoretica ***,the bulk properties of Sb-based materials always result in poor cycling and rate *** overcome these issues,pyridine-regulated Sb@InSbS_(3)ultrafine nanoplates loaded on reduced graphene oxides(Sb@InSbS_(3)@rGO)were designed and *** the synthesis process,pyridine was initially adopted to coordinate with In^(3+),and uniformly dispersed In_(2)S_(3)ultrafine nanoplates on reduced graphene oxide were generated after ***,partial In^(3+)was exchanged with Sb^(3+),and Sb@InSbS_(3)@rGO was obtained by using the subsequent annealing *** unique structure of Sb@InSbS_(3)@rGO effectively shortened the transfer path of sodium ions and electrons and provided a high *** the anode in sodium-ion batteries,the Sb@InSbS_(3)@rGO electrode demonstrated a significantly higher reversible capacity better stability(445 m Ah·g^(-1)at 0.1 A·g^(-1)after 200 cycles and 212 mAh·g^(-1)at 2 A·g^(-1)after 1200 cycles),and superior rate(210 mAh·g^(-1)at 6.4 A·g^(-1))than the electrode without pyridine(355 mAh·g-1at 0.1 A·g-1after 55 cycles and 109 mAh·g^(-1)at 2 A·g^(-1)after 770 cycles)Furthermore,full cells were assembled by using the Sb@InSbS_(3)@rGO as anode and Na_(3)V_(2)(PO_(4))_(3)as cathode which demonstrated good cycling and rate performances and exhibited promising application *** results indicate that adjusting the microstructure of electrode materials through coordination balance is A·good strategy for obtaining high-capacity,high-rate,and longcycle sodium storage performances.

关键词： Sodium-ion battery Sb-based anode material Pyridine coordination Reduced size nanostructure Half/full cell

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Highly crystalline Y3Al5O12:Ce3+ phosphor-in-silica glass ceramics for high-power solid-state lighting

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Journal of Rare Earths 2024年第11期42卷 2051-2057页

作者： Shisheng lin Hang lin Hongyi Yang Pengfei Wang Ping Sui Ju Xu Yao cheng Yuansheng Wang Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Xiamen Institute of Rare-earth Materials Haixi InstitutesChinese Academy of Sciences College of Chemistry and Materials Science Fujian Normal University

The pursuit of high-brightness solid-state lighting（SSL） stimulates the development of all-inorganic color converters with high *** is required that the fluorescent material is able to cope with the extreme condition generated from the irradiation of high-power-density excitation *** such,in this work,we developed a new composite color converter,i,e.,Y3Al5O12:Ce3+phosphor-in-silica glass ceramic(YAG:Ce3+PiSGC).Remarkably,the amorphous SiO2matrix spontaneously transforms into tetragonal SiO2crystallites during co-sintering with crystallization fraction reaching up to>90%（almost full ceramization）.The activation energy for crystallization Ecand Avrami index n of amorphous silica oxide are 298.5 kJ/mol and 1.71,indicating the diffusion-controlled glass crystallization *** fabricated prototype high-power phosphor-converted white light-emitting diode（pc-wLED） and phosphor-converted white laser diode（pc-wLD） based on YAG:Ce3+PiSGC show satisfactory photometric/colorimetric *** developed color co nverters have combined merits of environmental protection property,cost-effective manufacturing,good luminescent performance,and easy *** study highlights a new kind of opto-functional composite material and its application as an efficient color converter in high-power solid-state lightings.

关键词： Glass ceramics Laser-driven white light Rare earths White light-emitting diode Y3Al5O12:Ce3+

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A Differential Privacy Federated Learning Scheme Based on Adaptive Gaussian Noise

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1679-1694页

作者： Sanxiu Jiao Lecai Cai Xinjie Wang Kui cheng xiang Gao College of Automation and Information Engineering Sichuan University of Science and EngineeringYibin644000China Sanjiang Research Institute of Artificial Intelligence and Robotics Yibin UniversityYibin644000China College of Mechanical Engineering Sichuan University of Science and EngineeringYibin644000China

As a distributed machine learning method,federated learning(FL)has the advantage of naturally protecting data *** keeps data locally and trains local models through local data to protect the privacy of local *** federated learning method effectively solves the problem of artificial Smart data islands and privacy protection ***,existing research shows that attackersmay still steal user information by analyzing the parameters in the federated learning training process and the aggregation parameters on the server *** solve this problem,differential privacy(DP)techniques are widely used for privacy protection in federated ***,adding Gaussian noise perturbations to the data degrades the model learning *** address these issues,this paper proposes a differential privacy federated learning scheme based on adaptive Gaussian noise(DPFL-AGN).To protect the data privacy and security of the federated learning training process,adaptive Gaussian noise is specifically added in the training process to hide the real parameters uploaded by the *** addition,this paper proposes an adaptive noise reduction *** the convergence of the model,the Gaussian noise in the later stage of the federated learning training process is reduced *** paper conducts a series of simulation experiments on realMNIST and CIFAR-10 datasets,and the results show that the DPFL-AGN algorithmperforms better compared to the other algorithms.

关键词： Differential privacy federated learning deep learning data privacy

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