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Evolution of phase and microstructure during carbothermal reduction-nitridation synthesis of Ti(C,N)

MATERIALS CHARACTERIZATION 2008年第3期59卷 241-244页

作者： Xiang, Daoping Liu, Ying Gao, Shengji Tu, Mingjing Sichuan Univ Coll Mat Sci & Engn Chengdu 610065 Peoples R China

In this study, evolution of phase and microstructure during synthesis of Ti(C,N) by carbothermal reduction-nitridation (CRN) of nanosized anatase/carbon black mixture were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate phase evolution sequences are: TiO2(anatase)-> TiO2(rutile)-> Ti5O9 -> Ti4O7 -> Ti3O5 -> Ti(N,O)-> TiN -> Ti(C,N) or TiO2 (anatase)-> TiO2 (rutile)-> Ti5O9 -> Ti4O7 -> Ti2O3 -> Ti(C,N,O)-Ti(C,N). During initial stage of CRN reaction, the pronounced grain growth of the oxide particles was caused by the formation of lower titanium oxides. However, products grain was gradually diminished with the formation of cubic phase. (C) 2007 Elsevier Inc. All rights reserved.

关键词： Ti(C,N) phase evolution X-ray diffraction microstructure scanning electron microscope

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Low-cost urban carbon monitoring network and implications for china: a comprehensive review

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ENVIRONMENTAL science AND POLLUTION RESEARCH 2023年第48期30卷 105012-105029页

作者： Jiang, Hongzhi Han, Yang Zalhaf, Amr S. Yang, Ping Wang, Congling Univ Elect Sci & Technol China Sch Mech & Elect Engn Chengdu 611731 Peoples R China Tanta Univ Fac Engn Elect Power & Machines Engn Dept Tanta 31511 Egypt

The development and renewal of gas sensor technology have enabled more and more low-cost gas sensors to form a carbon monitoring network to meet the requirements of the city. In the context of China's commitment to achieving the "double carbon" target by 2060, this paper reviews the principles of four standard gas sensors and the application of several low-cost sensors in urban carbon monitoring networks, with the aim of providing a practical reference for the future deployment of carbon monitoring networks in Chinese cities. Moreover, the types, prices, and deployment of the sensors used in each project are summarized. Based on this review, non-dispersive infrared sensors have the best performance among the sensors and are commonly used in many cities. Lots of urban climate networks in cities were summarized by many reviews in the literature, but only a few sensors were studied, and they did not consider carbon dioxide (CO2) sensors. This review focuses on the dense CO2 urban monitoring network, and some case studies are also discussed, such as Seoul and San Francisco. To address the issue of how to better ensure the balance between cost and accuracy in the deployment of sensor networks, this paper proposes a method of simultaneously deploying medium-precision and high-precision fixed sensors and mobile sensors to form an urban carbon monitoring network. Finally, the prospects and recommendations, such as different ways to mitigate CO2 and develop an entire carbon monitoring system for future urban carbon monitoring in China, are also presented.

关键词： Carbon dioxide Dense monitoring network Gas sensor Low cost Urban carbon monitoring

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A Survey of Intelligent Chip Design Research Based on Spiking Neural Networks

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IEEE ACCESS 2022年 10卷 89663-89686页

作者： Chen, Lu Xiong, Xingzhong Liu, Jun Sichuan Univ Sci & Engn Sch Automat & Informat Engn Yibin 644000 Peoples R China Artificial Intelligence Key Lab Sichuan Prov Yibin 644000 Peoples R China

The traditional neural network Intelligent chip has the problem of high power consumption due to classical computing architecture, limiting the development of neural network Intelligent chips. Stochastic computing (SC) encodes binary numbers into stochastic pulse sequences in operation, taking advantage of low power consumption and high performance. The application of SC in spiking neural networks (SNNs) Intelligent chips is beneficial to solving the high power consumption of traditional neural network chips. This article first summarizes the basic elements of SNNs and the basic principles of SC. Then, we review the development trends of the stochastic computation-based neural network chips and existing SNN chips under research at home and abroad, respectively, and analyze the current problems. Finally, a review of SNN chips based on SC is highlighted. This paper aims to provide new research directions and to learn ideas for the field of SNN chips through systematic summaries.

关键词： Neurons Biological system modeling Biological neural networks Computational modeling Encoding Hardware Power demand Neural networks Stochastic processes Spiking neural network spiking neuron model neural computing stochastic computing brain-like chip

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Preparation of magnesium hydroxide from leachate of dolomitic phosphate ore with dilute waste acid from titanium dioxide production

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HYDROMETALLURGY 2014年 142卷 137-144页

作者： Xiong, Yang Wu, Bin Zhu, Jiawen Fan, Xianguo Cai, Pingxiong Wen, Jun Liu, Xiang E China Univ Sci & Technol Chem Engn Res Ctr Shanghai 200037 Peoples R China Sichuan Lomon Corp Mian Zhu 618200 Peoples R China

A novel method for the removal of magnesium from dolomitic phosphate ores by using dilute waste acid (DWA) from titanium dioxide pigment production was experimentally studied in this work. The pH of liquid phase and particle size of granulized phosphate ore have been found to be crucial to the efficient removal of magnesium from phosphate ore. Operating under the optimum leaching conditions, a 98.31% removal of Mg with 0.02% P2O5 loss was obtained. It was demonstrated that dolomite can be selectively dissolved by H+ in the DWA and the ability of H+ to attack the apatite is inhibited by the strong interionic strength of DWA. By using the solubility differences of corresponding elements, a two-step precipitation process was presented to remove Fe selectively from Mg. A process for further purifying the synthetic leachate by a precipitation/leaching method and oxidation was also investigated. Subsequently, magnesium hydroxide (Mg(OH)(2)) was prepared by precipitation from the refined solution with ammonia as the precipitant and sodium dodecyl sulfate (SDS) as the modifier. The phase structure and morphology of Mg(OH)(2) were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The prepared nanoparticles of Mg(OH)(2) were found to exhibit a column-shaped structure, demonstrating that the anions of DS- adsorbed onto the surface of Mg(OH)(2) nucleus contribute to the stacking of Mg(OH)(2) regular-hexagon platelets along the c-axis perpendicular to the [001] plane. The adsorption of SDS on the surface of Mg(OH)(2) was supported by Fourier transform infrared spectroscopy (FTIR). (C) 2013 Elsevier B.V. All rights reserved.

关键词： Phosphate ore Dolomite Dilute waste acid Selective precipitation Magnesium hydroxide

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Facile Construction of Benzo[d]oxazocine: Reductive Radical Dearomatization of N-Alkyl Quinoline Quaternary Ammonium Salts

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ORGANIC LETTERS 2024年第10期26卷 1996-2001页

作者： Li, Fu-Yu Xiao, Yao Huang, Dong-Wei Luo, Meng Li, Lu Xu, Hong Wang, Bei Wang, Ji-Yu Xihua Univ Dept Chem Chengdu 610039 Peoples R China Chinese Acad Sci Chengdu Inst Organ Chem Chengdu 610041 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Reductive radical dearomatization N-alkyl quinoline quaternary ammonium salts to synthesize structurally complex and challenging polysubstituted benzo[d][1,3]oxazocines was first reported. The mechanism showed various allyl alcohols can be converted into alkyl radicals under reduction conditions of iron/silane. These radicals then nucleophilically attack the C4 site of N-alkyl quinoline quaternary ammonium salts, and intramolecular cyclization of the resulting intermediate generates the target product. This method not only produced a series of novel polysubstituted benzo[d][1,3]oxazocines but also prepared polycyclic benzo[d][1,3]oxazocines. Finally, this strategy made up for the lack of reductive radical reports on N-alkylquinolinium salts and also had the advantages of mild reaction conditions, wide substrate range, and novel product structure.

关键词： Alcohols Allyl group Cations Quinolines Salts

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Anti-fouling coating with ROS-Triggered On-Demand regulation of inflammation to favor tissue healing on vascular devices

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CHEMICAL ENGINEERING JOURNAL 2024年 490卷

作者： Yan, Hui Wang, Lietao Wu, Haoshuang An, Yongqi Qin, Yumei Xiang, Zhen Wan, Huining Tan, Yanfei Yang, Li Zhang, Fanjun Jiang, Qing Luo, Rifang Wang, Yunbing Sichuan Univ Coll Mat Sci & Engn Chengdu 610065 Peoples R China Sichuan Univ Natl Engn Res Ctr Biomat Chengdu 610065 Peoples R China Sichuan Univ West China Hosp Dept Crit Care Med Chengdu 610041 Peoples R China

Unhealthy vascular tissue healing after stenting is primarily triggered by endothelial dysfunction and excessive smooth muscle cell proliferation, which is induced and aggravated by local thrombosis and excessive inflammation. Excessive inflammatory response is closely related to elevated concentrations of reactive oxygen species (ROS). Here, an environment-friendly coating strategy termed "Anti-fouling plus" with inflammatory selfregulation ability was proposed. Upon this, membrane-mimicking copolymer MA(PCLA) served as the antifouling coating, effectively inhibiting coagulation and inflammation during the early stage of implantation. Furthermore, a ROS-responsive prodrug was drawn into the coating to promote tissue healing. A molecular prodrug of thioketal-bearing dexamethasone was engineered to be released in a controlled and responsive manner in response to externally high levels of ROS. The released dexamethasone exhibited highly effective antiinflammation properties after implantation. The combination of ROS-responsive prodrug and membranemimicking antifouling interface strategy intelligently integrated inflammation responsiveness and regulation, which could mediate a gentle vascular microenvironment and thus promote vascular remodeling. In vivo stent implantation studies demonstrated that the proposed "Anti-fouling plus" coating effectively inhibited neointima hyperplasia, modulated the inflammatory response and promoted endothelialization, offering promising surface modification approaches for vascular stents.

关键词： Cardiovascular stents Membrane -mimicking antifouling polymers ROS-responsive Inflammatory regulation Anti -coagulation

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A SVM-based implicit stochastic joint scheduling method for `wind-photovoltaic-cascaded hydropower stations' systems

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ENERGY REPORTS 2022年 8卷 811-823页

作者： Li, Jidong Luo, Guangjie Hu, Wenbin Chen, Shijun Liu, Xing Gao, Lu Sichuan Agr Univ Coll Water Conservancy & Hydropower Engn Yaan 625014 Sichuan Peoples R China Sichuan Univ Coll Water Resource & Hydropower State Key Lab Hydraul & Mt River Engn Chengdu 610065 Sichuan Peoples R China

With the gradual expansion of the development scale of wind power and photovoltaic (PV) power plants, the multienergy complementary power generation system, typically represented by hydro-PV/hydro-wind/hydro-wind-PV, has become an important part of modern power systems. Aiming at the joint operation of the cascaded hydropower stations after wind-PV grid connection, a medium- and long-term implicit stochastic joint dispatching function model for wind-PV-cascaded hydropower stations based on the SVM(support vector machine) method is developed in this paper, which selects the final water levels of the reservoirs as the dependent variables, and the initial water levels of the reservoirs, the reservoir inflow, the interval inflow as well as the wind and PV output are independent variables. First, the optimization of main parameters C (Penalty coefficient), g (Kernel function parameter) and p (Insensitive loss coefficient) of the model are achieved by particle swarm algorithm. The Gaussian radial basis function is then used to fit the scheduling function proposed in this paper. Finally, the rolling simulation calculation and correction of the obtained scheduling function are realized by C# programming language of VS2017 platform. The results show that the proposed scheduling function is an effective method for scheduling decision-making, and the revised water level process, output process as well as annual electricity production of the scheduling model are not significantly different from the optimal scheduling results. Moreover, the simulation results conform to the existing scheduling rules, which has shown it can be used to inform the operation of cascaded hydropower stations under the multi-energy complementary system. (C) 2022 The Author(s). Published by Elsevier Ltd.

关键词： Wind-photovoltaic (PV)-hydropower complementary system Cascaded hydropower stations Implicit stochastic scheduling SVM Joint operation function

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Crystallization Behavior of Poly(Tetramethylene Oxide) Influenced by the Crystallization Condition of Poly(Butylene Succinate) in Their Copolymers

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Journal of Wuhan University of technology(Materials science) 2019年第2期34卷 496-506页

作者：黄勇 LIU Junhong ZHANG Aimin 周涛 College of Chemical Engineering Sichuan University of Science & Engineering Department of Chemical Engineering Sichuan Vocational College of Chemical Technology State Key Laboratory of Polymer Materials Engineering of China Polymer Research Institute Sichuan University

The effect of crystallization conditions of poly(butylene succinate)(PBS) component on the crystallization of poly(tetramethylene oxide)(PTMO) component in their segment block copolymer, with a higher PTMO content(PTMO mass fraction is 67%), was investigated by DSC and temperature-dependent FTIR. It is found that the isothermal crystallization time(tIC) of PBS has an effect on the crystallization behavior of PTMO component. Perturbation correlation move-window two-dimensional(PCMW2 D) correlation analysis and generalized 2 D correlation analysis(2 DIR) were performed to explore the origin of this phenomenon. The PCMW2 D and 2 DIR results show that the correlation intensity peak observed at around 20 ℃ for PTMO is due to the PTMO chains movements forced by the PBS chains folded movements. If tIC of PBS at temperature of 20 ℃ is prolonged, more PTMO components are incorporated in the region between PBS lamellae and the peak at-7.6 ℃(belonging to less-constricted PTMO chains) changes smaller and even disappears, while the peak at-16.3 ℃ belonging to more-constricted PTMO chains gets bigger. A crystallization model was also established in this study. The results of tensile testing showed that tensile strength slightly increased and elongation at break decreased with increasing heat treatment time at 40 ℃.

关键词： PBS/PTMO segment block copolymer crystallization behavior perturbation correlation move-window two-dimensional correlation analysis

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Generation of an Ultra-Long Optical Needle Induced by an Azimuthally Polarized Beam

IEEE PHOTONICS JOURNAL

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IEEE PHOTONICS JOURNAL 2021年第1期13卷 1-12页

作者： Liu, Liwei Shi, Lifang Li, Fanxing Yu, Siyang Wang, Simo Du, Jialin Liu, Min Qi, Bo Yan, Wei Chinese Acad Sci Inst Opt & Elect Chengdu 610209 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

In this manuscript, a method of generating an ultra-long optical needle (depth-to-width ratio 37.5:1) is proposed and demonstrated by focusing an azimuthally polarized beam. In theory, the action mechanism between the incident beam and the amplitude modulation element, the spiral phase modulation element, the focusing lens were studied based on the Richards and Wolf's theory. The relationship between the intensity distribution of the optical needle and the structure parameter of the element were obtained, thus leading to the complete design model and design standard. In experiment, the annular amplitude modulation element and spiral phase modulation element were fabricated by lithography. The optical needle was obtained based on a custom-designed optical setup in our laboratory. The optical system consists of an annular aperture (3.9-mm inner diameter, 80-mu m annular width), a spiral phase plate (topological charge of 1), and an objective lens with numerical aperture of 0.95. Finally, an optical needle with a subwavelength size (0.416 lambda) and an ultra-long depth of focus (15.6 lambda) was obtained, showing an excellent agreement with our theoretical model.

关键词： Vector light field optical needles azimuthally polarized beam light field modulation

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Higher N-terminal pro-brain natriuretic peptide level at onset of peritoneal dialysis-related peritonitis is a risk factor for technique failure

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BMC NEPHROLOGY 2024年第1期25卷 1页

作者： Ma, Niya Zang, Zhiyun Liu, Xia Zhang, Yunyun Zhou, Xueli Tang, Yi Li, Zi Sichuan Univ Dept Nephrol West China Hosp Guoxue Lane 37 Chengdu 610041 Peoples R China Third Peoples Hosp Chengdu Dept Nephrol Chengdu 610014 Peoples R China Sichuan Univ West China Hosp West China Sch Nursing Chengdu 610041 Peoples R China

Background Recent studies have suggested that the N-terminal fragment of B-type natriuretic peptide (NT-proBNP) level serve as a significant risk factor for mortality in patients with end-stage renal disease. However, the relationship between NT-proBNP levels and technique failure in peritoneal dialysis-associated peritonitis (PDAP) remains unclear. This study investigated the relationship between NT-proBNP levels at the onset of PDAP and the risk of technique failure in patients with PDAP. Methods A retrospective analysis was conducted on patients with PDAP from December 1, 2009, to December 31, 2021, at our peritoneal dialysis center. We recorded all demographic and baseline clinical data at the time of admission for each PDAP episode. Logistic and Cox regression analyses were performed to assess the association between NT-proBNP levels and technique failure. Results Of 485 PDAP episodes included in this study, 130 episodes of technique failure were observed. Multivariate logistic analysis revealed that hospital stay, Na and NT-proBNP levels, and peritoneal dialysate white blood cell counts on days 3 and 5 were independently associated with technique failure. The receiver operating characteristic curve demonstrated that the NT-proBNP level was a better indicator than the other four variables in indicating technique failure. In the multivariate Cox regression analysis, after adjusting for confounding factors, higher NT-proBNP levels (HR of 3.020, 95% CI 1.771, 5.150, P < 0.001) were associated with PDAP technique failure. Conclusions This retrospective study identified the serum NT-proBNP level at the onset of PDAP as an independent risk factor for technique failure in these patients.

关键词： N-terminal fragment of B-type natriuretic peptide Outcome Peritoneal dialysis-associated peritonitis

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