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Synthesis and Crystal Structure of (E)2-(3′-Bromo-5′-chloro-salicylidene amino)-4-methyl Pyridine

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Chinese Journal of Structural Chemistry 2008年第2期27卷 191-194页

作者： WANG Nong SHt Qi school of Chemical and Biological engineering Lanzhou Jiaotong University Lanzhou 730070 China school of Civil engineering Lanzhou Jiaotong University Lanzhou 730070 China

A new Schiff base compound, 2-bromo-4-chloro-6-[（4-methylpyridin-2-ylimino）methyl]phenol （C13H10BrClN20）, has been synthesized by the condensation of equimolar 3-bromo-5- chlorosalicylaldehyde and 4-methylpyridin-2-ylamine in a methanol solution. The compound was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21 with a = 6.048（3）, b = 14.063（7）, c = 7.623（4） A,β = 97.703（7）°, Z = 2, V = 642.5（6）A3, Dc = 1.683 g/cm3, Mr=325.59, 2（MoKa） = 0.71073A,μ = 3.395 mm^-1, F（000） = 324, R = 0.0370 and wR = 0.0662. A total of 3879 reflections were collected, of which 1970 with I 〉 2σ（I） were observed. As expected, the molecule adopts a trans configuration about the C=N double bond. The benzene and pyridine rings are nearly coplanar （mean deviation from the combined plane is 0.031（3）A）, with their dihedral angle of 3.3（3）°. The preliminary biological tests show that the compound has excellent antibacterial activities.

关键词： synthesis Schiff base crystal structure antibacterial activity

NONLINEAR INTERNAL RESONANCE OF FUNCTIONALLY GRADED CYLINDRICAL SHELLS USING THE HAMILTONIAN DYNAMICS

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Acta Mechanica Solida Sinica 2014年第6期27卷 635-647页

作者： Changcheng Du Yinghui Li school of mechatronic engineering Southwest Petroleum University school of Mechanics and engineering Southwest Jiaotong University

Internal resonance in nonlinear vibration of functionally graded （FG） circular cylin- drical shells in thermal environment is studied using the Hamiltonian dynamics formulation. The material properties are considered to be temperature-dependent. Based on the Karman-Donnell＇s nonlinear shell theory, the kinetic and potential energy of FG cylindrical thin shells are formu- lated. The primary target is to investigate the two-mode internal resonance, which is triggered by geometric and material parameters of shells. Following a secular perturbation procedure, the underlying dynamic characteristics of the two-mode interactions in both exact and near resonance cases are fully discussed. It is revealed that the system will undergo a bifurcation in near resonance case, which induces the dynamic response at high energy level being distinct from the motion at low energy level. The effects of temperature and volume fractions of composition on the exact resonance condition and bifurcation characteristics of FG cylindrical shells are also investigated.

关键词： functionally graded material cylindrical shells nonlinear vibration internal res-onance Hamiltonian dynamics

Suspension Polymerization of Methyl Methacrylate Stabilized Solely by Palygorskite Nano Fibers

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Chinese Journal of Polymer Science 2014年第2期32卷 123-123,124-129页

作者：黎白钰 Yin-ping Wang Xiao-bin Niu Zai-man Liu The school of Chemical & Biological engineering Lanzhou Jiaotong University

A kind of fibrous clay, palygorskite （PAL）, was used as the sole stabilizer in suspension polymerization without the using of any other stabilizer usually used, especially polymeric stabilizers. In order to improve the compatibility with the organic monomer, PAL nano fibers were organically modified with silane coupling agent methacryloxypropyltrimethoxysilane （MPS）. Transmission electron microscopy （TEM） and Fourier-transform infrared （FTIR） spectroscopy results show that the hydrolyzed MPS was attached onto PAL surface through Si--O--Si bonds formation without morphology change of PAL. At a loading amount of PAL to monomer as low as 0.36 wt%, effective stabilization could be achieved. After suspension polymerization, spherical poly（methyl methacrylate）（PMMA） particles were obtained. Scanning electron microscopy （SEM） analysis on both the outer surface and the inner cracked surface of the spherical PMMA particles indicates that the PAL particles reside on the surface of the PMMA spheres. The densely stacked PAL together with attached silane coupling agent stabilized the droplets throughout the suspension polymerization.

关键词： Palygorskite Attapulgite Clay Poly(methyl methacrylate) Suspension polymerization.

Preparation of Nanosilica-immobilized Antioxidant and the Antioxidation Effects in Polypropylene

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Chinese Journal of Polymer Science 2014年第12期32卷 1602-1609页

作者：刘再满 Yun Liu Nai-pu He Bai-yu Li school of Chemical and Biological engineering Lanzhou Jiaotong University

To improve the dispersion of silica in polypropylene（PP） matrix and to avoid physical loss of the antioxidants, nanosilica with dendric polyamidoamines on the surface（SG-PAMAM） was synthesized by using divergent method. Then nanosilica-immobilized antioxidant（SG-PAMAM-AO） was prepared by grafting 2,6-di-tert-butyl-4-aminophenol which was derived from 2,6-di-tert-butyl-4-phenol（AO）. The SG-PAMAM-AO was added into PP by melt mixing to study the aging property. The oxidation induction time of PP/SG-PAMAM-AO and PP/AO compounds was measured. It was found that the antioxidant property of the SG-PAMAM-AO was superior to that of AO. According to the changes of carbonyl absorption before and after photo-thermal aging, the photo-thermal oxidative stability of PP/SG-PAMAM-AO was much higher than that of PP, PP/SG-PAMAM and PP/AO.

关键词： Silica Antioxidant Polypropylene Antioxidant behavior.

Single-atom Co alloyed Ru for electrocatalytic nitrite reduction to ammonia

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Nano Research 2024年第5期17卷 3660-3666页

作者： Fuzhou Wang Jiaqi Xiang Guike Zhang Kai Chen Ke Chu school of Materials Science and engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical converting NO_(2)^(-)into NH_(3)(NO_(2)RR)holds an enormous prospect to attain efficient NH_(3) electrosynthesis and polluted NO_(2)^(-)***,we report single-atom Co alloyed Ru(Co_(1)Ru)as an efficient and durable NO_(2)RR *** experimental and theoretical investigations reveal that single-atom Co alloying of Ru enables the construction of Co_(1)-Ru heteronuclear active sites to synergistically promote NO_(2)^(-)activation/hydrogenation while suppressing the competitive H_(2) evolution,rendering the greatly enhanced activity and selectivity of Co_(1)Ru towards the NO_(2)***,Co_(1)Ru assembled within a flow cell exhibits an impressive NH_(3) yield rate of 2379.2μmol·h^(-1)·cm^(-2) with an NH_(3)-Faradaic efficiency of 92%at a high current density of 415.9 mA·cm^(-2),which is among the highest NO_(2)RR performances reported to date.

关键词： electrochemical converting NO_(2)-into NH3 single-atom alloys theoretical computations industrial-level current density

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chemistry 2024年第5期67卷 1707-1714页

作者： Ying Zhang Zhuohang Li Wenyu Du Kai Chen Ke Chu school of Materials Science and engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochemical nitrite-to-ammonia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical computations

Numerical Simulation of Mid-Deep Buried Casing Heat Exchanger and its Heating System Application

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Journal of Thermal Science 2023年第4期32卷 1445-1454页

作者： ZHOU Wenhe LI Rui CHEN Yuying ZHU Shiqi school of Environmental and Municipal engineering Lanzhou Jiaotong UniversityLanzhou730070China

Although the mid-deep ground source heat pump could be more excellent for heating compared to other heat pumps,whose well depth is usually 2000-4000 m underground,the references on it is far fewer than the market demand to apply it *** facility the application of the mid-deep ground source heat pump and the heating problem solution to transform the coal-boiler used in a Logistics Park of lanzhou city,firstly,this paper established a three-dimensional numerical model of mid-deep ground source heat exchanger,and analyzed the effects of well flow,diameter and depth on heat pump performance with the help of Fluent *** then,the heating source renovation to mid-deep ground source heat pump was carried out and the test funded by the local government was followed from February 1,2018 to March 31,*** is concluded that the numerical analysis is reasonable and the heating system is effective and reliable,whose average COP(coefficient of performance)and cumulative power consumption is 3.47 and 67727 kWh respectively during the test period.

关键词： heat pump ground source heat pump heat exchanger

Inatorial forecasting method considering macro and micro characteristics of chaotic traffic flow

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Chinese Physics B 2023年第10期32卷 350-362页

作者：侯越张迪李达杨萍 school of Electronics and Information engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Traffic flow prediction is an effective strategy to assess traffic conditions and alleviate traffic congestion. Influenced by external non-stationary factors and road network structure, traffic flow sequences have macro spatiotemporal characteristics and micro chaotic characteristics. The key to improving the model prediction accuracy is to fully extract the macro and micro characteristics of traffic flow time sequences. However, traditional prediction model by only considers time features of traffic data, ignoring spatial characteristics and nonlinear characteristics of the data itself, resulting in poor model prediction performance. In view of this, this research proposes an intelligent combination prediction model taking into account the macro and micro features of chaotic traffic data. Firstly, to address the problem of time-consuming and inefficient multivariate phase space reconstruction by iterating nodes one by one, an improved multivariate phase space reconstruction method is proposed by filtering global representative nodes to effectively realize the high-dimensional mapping of chaotic traffic flow. Secondly, to address the problem that the traditional combinatorial model is difficult to adequately learn the macro and micro characteristics of chaotic traffic data, a combination of convolutional neural network(CNN) and convolutional long short-term memory(ConvLSTM) is utilized for capturing nonlinear features of traffic flow more comprehensively. Finally,to overcome the challenge that the combined model performance degrades due to subjective empirical determined network parameters, an improved lightweight particle swarm is proposed for improving prediction accuracy by optimizing model hyperparameters. In this paper, two highway datasets collected by the Caltrans Performance Measurement System(PeMS)are taken as the research objects, and the experimental results from multiple perspectives show that the comprehensive performance of the method proposed in this

关键词： traffic flow prediction phase space reconstruction particle swarm optimization algorithm deep learning models

Sulfur-deficient Bi_(2)S_(3-x) synergistically coupling Ti_(3)C_(2)T_(x)-MXene for boosting electrocatalytic N_(2) reduction

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Nano Research 2022年第5期15卷 3991-3999页

作者： Yaojing Luo Peng Shen Xingchuan Li Yali Guo Ke Chu school of Materials Science and engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrocatalytic nitrogen reduction reaction(NRR)is an appealing route for the sustainable NH_(3)synthesis,while developing efficientand durable NRR catalysts remains at the heart of achieving high-efficiency N_(2)-to-NH_(3)***,we rationally combine vacancy and interface engineering to design sulfur-deficient Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene as an effective NRR *** developed Bi2S3 nanoparticles decorated Ti_(3)C_(2)T_(x)-MXene(Bi2S3-xTi_(3)C_(2)T_(x))naturally contained abundant S-vacancies and exhibited a dramatically boosted NRR activity with an NH_(3)yield of 68.3μg·h^(-1)mg^(-1)(-0.6 V)and a Faradaic efficiency of 22.5%(-0.4 V),far superior to pure Bi_(2)S_(3)and Ti_(3)C_(2)T_(x)and surpassing almost all ever reported Bi-and MXene-based NRR *** investigations unveiled that the exceptional NRR activity of Bi_(2)S_(3-x)/Ti_(3)C_(2)T_(x)stemmed from its dual-active-center system involving both S-vacancies and interfacial-Bi sites,which could synergistically promote N_(2)adsorption and*N_(2)H formation to result in an energetic-favorable NRR process.

关键词： electrocatalytic nitrogen reduction bismuth catalyst MXene vacancy engineering interface engineering