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Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： tian-hao Yang Tong Wu Qiang Fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Effect of Fe Addition on Dehydrogenation Performance of Methylcyclohexance over Pt/Al_(2)O_(3)

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 12-18页

作者： Tong Fengya tian hao Wang hao Miao Changxi Song Lei Shanghai Research Institute of Petrochemical Technology SINOPEC Shanghai201208

Catalysts with varying Fe contents were prepared using a sequential impregnation method to investigate the effects of Fe addition on the physicochemical properties of Pt/Al_(2)O_(3) and their performance in methylcyclohexane(MCH)*** results demonstrated that the addition of Fe to Pt/Al_(2)O_(3) enhanced the electron density of Pt and improved catalytic activity,while exhibiting negligible influence on the catalytic selectivity for *** the Fe content was 0.057%,the catalyst exhibited the highest MCH consumption rate,which was approximately two times higher than that of the catalyst without ***,the incorporation of Fe inhibited the formation of coke and reduced the quantity of coke deposits on the catalyst,thereby improving its catalytic ***,Fe shows promise as a prospective secondary element for Pt/Al_(2)O_(3) to enhance the MCH dehydrogenation performance.

关键词： methylcyclohexane dehydrogenation hydrogen storage deactivation Fe addition

An analytical model of hot rolling force for a thick plate by combining globally optimal approximation yield criterion and egg-circular velocity field

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Journal of Iron and Steel Research International 2024年第3期31卷 647-659页

作者： Shun-hu Zhang Yi Zhang Wen-hao tian Yan Li Shagang School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

For the sake of solving the problem that it is difficult to be integrated for the Mises specific plastic power due to its nonlinearity,a new linear criterion,named the globally optimal approximation criterion,is constructed by the polygonal approximation to the Mises *** new criterion is proved to be the linear function of the principal stress componentsσ1,σ2 andσ3 and the trajectory of it on theπ-plane is a non-equiangular but equilateral dodecagon intersecting the Mises *** theoretical results of the current criterion described by the Lode stress parameters are in excellent accordance with the experimental ***,according to the trend that the metallic flow velocity between rollers aggrandizes gradually from the inlet to the outlet during the hot rolling of a thick plate,a biomimetic velocity field is proposed in which the horizontal velocity component fits the egg-circular curve *** velocity field and its simulated results agree quite ***,using the determined linear criterion,energy analysis of the constructed velocity field is utilized to obtain the interior deformation power,while the vector decomposition approach is utilized to obtain the frictional power and shear *** this basis,the overall power is obtained and the analytical solutions are generated for the rolling torque,rolling force and the coefficient of the stress state under different egg curves by minimizing the neutral ***,the parameter optimization of the characteristic parameterρwhich affects the slope of the egg-circular curve is carried out and the best egg-circular curve which can minimize the energy consumption is *** best agreement between the theoretical and observed values of rolling force and rolling torque is under this curve,and the mean relative errors of the rolling torque and rolling force are no more than 2.93%,while the maximum error is no more than 8.35%.

关键词： Yield criterion Plastic deformation Rolling force Velocity field Analytical solution

A new integrated model of deformation resistance and its application in prediction of rolling force of a thick plate

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Journal of Iron and Steel Research International 2024年第4期31卷 882-893页

作者： Shun-hu Zhang Yan Li Li-zhi Che Wen-hao tian Shagang School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

The prediction accuracy of existing models of the rolling force of a thick plate is always very *** address this problem,a high-precision genetic algorithm-backpropagation network(GA-BP)model of deformation resistance was built,and its integration with the traditional fitted model was further ***,a novel rolling force model was obtained by embedding the integration model of deformation resistance in the original model of rolling *** to this research idea,the industrial data are normalized at *** this basis,the interactions among the process parameters were disclosed through the variance analysis,and then described by various virtual *** factors are set as part of input ***,the optimal structure of the GA-BP model of deformation resistance was determined and an integration model of deformation resistance was ***,a novel rolling force model is obtained by substituting the traditional fitted deformation resistance into the Sims model with the integration model of the deformation *** results proves that the introduction of virtual factors can increase the hit rate of±5%from 75.8%to 78%and can reduce the root mean square error from 4.72%to 4.48%.Besides,it is found that the mean relative error of the traditional fitted deformation resistance is 0.142,while that of the modified deformation resistance is only *** addition,the mean relative error in the original rolling force model is 0.145,while that of the present model is only 0.03.

关键词： Integration model-Deformation resistance Variance analysis Virtual factor Genetic algorithm-backpropagation network model

Kinetic Insights into Boron-Based Materials Catalyzed Oxidative Dehydrogenation of Light Alkanes

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Precision Chemistry 2024年第5期2卷 182-192页

作者： hao tian Bingjun Xu Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China School of Chemistry and Chemical Engineering Shandong UniversityJinanShandong 250100China

High selectivity toward alkenes in oxidative dehydrogenation(ODH)of light alkanes makes boron-based materials promising ***,many key mechanistic aspects are still debated due to the challenge of capturing fleeting reaction *** analysis,including determining reaction orders and activation energy,could be informative for reactions involving radical intermediates but has not been extensively *** Review summarizes the current understanding of the apparent alkane reaction order and the apparent activation energy in the boron-catalyzed *** varying compositions and structures,a majority of boron-based catalysts share many common features,induding alkene selectivity,the evolution and the formation of active site,and the apparent kinetic *** common trends could be attributed to the shared gas-phase radical mediated reaction pathways and the formation of active hydroxylated boron oxide species on boron-containing materials under ODH *** of apparent alkane reaction orders and apparent activation energies are sensitive and reliable experimental measures of the contributions of the gas-phase radical-mediated and surface mediated pathways,suggesting the outline of a general mechanistic framework of the boron-catalyzed ODH.

关键词： oxidative dehydrogenation reaction order kinetic analysis radicals-mediated pathway surface-mediated pathway

Promising real-time fruit and vegetable quality detection technologies applicable to manipulator picking process

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 14-26页

作者： Jintao Feng Qinyi Yang hao tian Zhipeng Wang Shijie tian Huirong Xu College of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058China Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province Hangzhou 310058China

In recent years,worldwide research on fruit and vegetable quality detection technology includes machine vision,spectroscopy,acoustic vibration,tactile sensors,*** technologies have also been gradually applied to fruit and vegetable grading and sorting lines in recent years,greatly improving the income of *** have been numerous reviews of these *** of the published research on fruit and vegetable quality detection technology is still carried out in the *** emphases have been on quality feature extraction,model establishment and experimental *** successful application in the fruit and vegetable sorting production line proves that these studies have high application potential and value,and we look forward to the performance of these sensing technologies in the fruit and vegetable picking ***,in this paper,based on the future highly automated fruit and vegetable picking mode,we will focus on three kinds of fruit and vegetable quality detection technologies including machine vision,tactile sensor and spectroscopy,to provide some reference for future *** there are currently limited cases of detecting quality during the fruit and vegetable picking,experiments performed on prototypes of manipulator,or devices such as Nanocilia sensors,portable spectrometers,etc.,which are compact and convenient to mount on manipulator will be *** tables and mosaics showing the performance of the three technologies in the detection of fruit and vegetable quality over the past five years have been *** performance of each sensing technology was relatively satisfactory in the laboratory in ***,in the picking scenario,there are still many challenges to be *** from industrial environments,agricultural scenarios are complex and *** and vulnerable agricultural products pose another *** development of portable devices and nanomaterials have become important

关键词： fruit and vegetable quality detection machine vision spectroscopy tactile sensors picking scenario

Modeling method for SSC prediction in pomelo using Vis-NIRS with wavelength selection and latent variable updating

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 251-260页

作者： hao tian Shuai Wang Huirong Xu Yibin Ying College of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058China Key Laboratory of On-Site Processing Equipment for Agricultural Products Ministry of Agriculture and Rural AffairsHangzhou 310058China College of Food Science Shihezi UniversityShihezi 832003XinjiangChina

The aim of this study was in-line,rapid,and non-destructive detection for soluble solid content(SSC)in pomelos using visible and near-infrared spectroscopy(Vis-NIRS).However,the large size and thick rind of pomelo affect the stability of spectral acquisition and the biological variabilities affect the robustness of *** these issues,in this study,an efficient prototype in-line detection system in transmittance mode was designed and evaluated in comparison with an off-line detection *** from the years 2019 and 2020 were used for modeling and the external validation data were obtained by the inline detection system in *** wavelength selection methods of changeable size moving window(CSMW),random frog(RF),and competitive adaptive reweighted sampling(CARS)were used to improve the prediction accuracy of partial least squares regression(PLSR)*** best performance of internal prediction was obtained by CARS-PLSR and the determination coefficient of prediction(),root mean square error of prediction(RMSEP),and residual predictive deviation(RPD)were 0.958,0.204%,and 4.821,***,all models obtained large prediction biases in external *** latent variable updating(LVU)method was proposed to update models and improve the performance in external *** samples from the external validation set were randomly selected to update the *** with the recalibration method,LVU could effectively modify the original models which matched the SSC range of the external validation *** CSMW-PLSR models were more robust in external *** off-line model with LVU performed best with a root mean square error of validation(RMSEV)of 0.599%and the in-line model with recalibration obtained RMSEV of 0.864%.These results demonstrated the application potential of the transmittance Vis-NIRS for in-line rapid prediction of SSC in pomelos and the modeling and updating methods could be applied to samples with biological variabi

关键词： Vis-NIRS in-line detection external validation wavelength selection model updating pomelo SSC

Facile Synthesis of Polyisothioureas via Alternating Copolymerization of Aziridines and Isothiocayanates

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Chinese Journal of Polymer Science 2024年第3期42卷 292-298,I0005页

作者： hao-tian Zhang Ming-Xin Niu Qi Zhang Chen-Yang Hu Xuan Pang Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Materials Science and Engineering Jilin UniversityChangchun 130025China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits a number of interesting properties. However, there is no access to synthesizing well-defined polyisothiourea, and currently isothiourea-containing polymers are mainly prepared by immobilizing onto other polymer's side chain. Herein, we report the first facile synthesis of polyisothioureas via alternating copolymerization of aziridines and isothiocayanates. Mediated by the catalytic system of phosphazene superbases/alcohol, a broad scope of aziridines and isothiocayanates could be transformed into polyisothioureas with adjustable substitutions(11 examples). The structures of obtained polyisothioureas were fully characterized with ^(1)H-NMR, ^(13)C-NMR, and ^(1)H-^(13)C HMBC NMR. Moreover, the polyisothioureas show tunable thermal properties depending on substitutions on the isothiourea linkages. The novel structure of these polyisothioureas will enable a powerful platform for the discovery of nextgeneration functional plastics.

关键词： Polyisothioureas Alternative copolymer Aziridines Isothiocayanates

Essential oils improve nursery pigs'performance and appetite via modulation of intestinal health and microbiota

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Animal Nutrition 2024年第1期16卷 174-188页

作者： Bi-Chen Zhao tian-hao Wang Jian Chen Bai-hao Qiu Ya-Ru Xu Jin-Long Li College of Veterinary Medicine Northeast Agricultural UniversityHarbin150030China Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine Northeast Agricultural UniversityHarbin150030China Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment Northeast Agricultural UniversityHarbin150030China

Optimal intestinal health and functionality are essential for animal health and performance,and simultaneously intestinal nutrient transporters and intestinal peptides are also involved in appetite and feed intake control *** the potential of essential oil(EO)in improving animal performance and improving feed palatability,we hypothesized that dietary supplementation of cinnamaldehyde and carvacrol could improve performance and appetite of nursery pigs by modulating intestinal health and ***(100 mg/kg),carvacrol(100 mg/kg),and their mixtures(including 50 mg/kg cinnamaldehyde and 50 mg/kg carvacrol)were supplemented into the diets of 240 nursery pigs for 42 d,and data related to performance were ***,the influence of EO on intestinal health,appetite and gut microbiota and their correlations were *** supplementation increased(P<0.05)the body weight,average daily gain(ADG)and average daily feed intake(ADFI)of piglets,and reduced(P<0.05)diarrhea rates in nursery ***,EO increased(P<0.05)the intestinal absorption area and the abundance of tight junction proteins,and decreased(P<0.05)intestinal permeability and local *** terms of intestinal development and the mucus barrier,EO promoted intestinal development and increased(P<0.05)the number of goblet ***,we found that piglets in the EO-supplemented group had upregulated(P<0.05)levels of transporters and digestive enzymes in the intestine,which were significantly associated with daily gain and feed *** addition,EO supplementation somewhat improved appetite in nursery pigs,increased the diversity of the gut microbiome and the abundance of beneficial bacteria,and there was a correlation between altered bacterial structure and appetite-related *** findings indicate that EO is effective in promoting growth performance and nutrient absorption as well as in regulating appetite by improving intestinal health and ba

关键词： Nursery pig Essential oil Intestinal health Appetite Microbiota