检索结果-南通市图书馆

Gas–liquid two-phase flow in serpentine microchannel with different wall wettability

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第7期25卷 874-881页

作者： Yunlong zhou He chang Tianyu Qi Energy and Power Engineering College Northeast Dianli University Institute of Energy Environment and Economy Tsinghua University

Gas–liquid flow in serpentine microchannel with different surface properties exhibits drastically different flow behavior. With water and air as working fluids, the method of numerical simulation was adopted in this paper based on CLSVOF(coupled level set and volume of fluid method) multiphase model. After verifying the reasonability of the model through experiment, by changing wall properties and Re number(Re<1500), the influences of contact angle and surface roughness on flow regime and Po number were discussed. Moreover, the difference of pressure drop between curve and straight microchannel was also calculated. Beyond that, the combined effect of curve channel and wall properties on flow resistance was analyzed. This paper finds that wall properties have great influence on gas–liquid flow in microchannels not only on flow regime but also flow characteristics. Meanwhile, the pressure drop in curve microchannels is larger than straight. It is more beneficial for fluid flowing when the straight part of microchannel is hydrophilic smooth wall and curve part is hydrophobic with large roughness.

关键词： Serpentine microchannel Computational fluid dynamics Gas-liquid flow Microfluidics

Medium Effects on Dynamical Properties of the Fermion and Mesons in the Gauged Nambu- Jona-Lasinio Model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1998年第9期15卷 639-641页

作者： JIANG Wei-zhou QIU xi-jun Shanghai Institute of Nuclear Research Chinese Academy of SciencesShanghai 201800 Department of Physics Shanghai UniversityShanghai 201800

The gap equation for the fermion in the gauged Nambu-Jona-Lasinio(NJL)model is derived in nuclear medium with flavors Nf=*** on the gap equation,the fermion mass in nuclear medium is obtained and used to determine the properties of the scalar and pseudoscalar *** contrast to the NJL model,the gluonic part has the one-fourth contribution to the fermion *** critical density with the chiral symmetry restored is about 6ρ0.

关键词： scalar equation Fermi

Even-odd-dependent optical transitions of zigzag monolayer black phosphorus nanoribbons

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2021年第1期64卷 91-101页

作者： Pu Liu xianZhe Zhu xiaoYing zhou GuangHui zhou Kai chang Department of Physics Key Laboratory for Low-Dimensional Structures and Quantum Manipulation(Ministry of Education)Synergetic Innovation Center for Quantum Effects and Applications of HunanHunan Normal UniversityChangsha410081China SKLSM Institute of SemiconductorsChinese Academy of SciencesBeijing100083China

We analytically study the electronic structure and optical properties of zigzag-edged phosphorene nanoribbons(ZPNRs) using the tight-binding Hamiltonian and Kubo formula. By directly solving the discrete Schrodinger equation, we obtain the energy spectra and wavefunctions for N-ZPNR(where N is the number of transverse zigzag atomic chains) and classify the eigenstates according to the lattice symmetry. Then, we obtain the optical transition selection rule of ZPNRs on the basis of symmetry analysis and analytical expressions of optical transition matrix elements. Under incident light that is linearly polarized along the ribbon, we determine that the optical transition selection rule for N-ZPNR with even-or odd-N is qualitatively different. Specifically, for even-N ZPNRs, the inter-(intra-) band selection rule is ?n =odd(even) because the parity of the wavefunction corresponding to the n-th subband in the conduction(valence) band is(-1)~n[(-1)~((n+1))] owing to the presence of C(2x) symmetry. However, the optical transitions between any subbands are possible owing to the absence of C(2x) symmetry. Our results provide a further understanding on the electronic states and optical properties of ZPNRs, which are useful for explaining the optical experiment data on ZPNR samples.

关键词： zigzag-edged phosphorene nanoribbons band structure light absorption selection rules

Total Saponin Fraction of Dioscorea Nipponica Makino Improves Gouty Arthritis Symptoms in Rats via M1/M2 Polarization of Monocytes and Macrophages Mediated by Arachidonic Acid Signaling

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2023年第11期29卷 1007-1017页

作者： zhou Qi SUN Hui-juan ZHANG xi-wu Research Institute of Chinese Medicine Heilongjiang University of Chinese MedicineHarbin(150040)China Graduate School Heilongjiang University of Chinese MedicineHarbin(150040)China

Objective:To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino(TSDN)on M1/M2 polarization of monocytes/macrophages and arachidonic acid(AA)pathway in rats with gouty arthritis(GA).Methods:Seventy-two Sprague Dawley rats were randomly divided into 4 groups(n=18 in each):normal,model,TSDN at 160 mg/kg,and celecoxib at 43.3 mg/*** urate crystal(MSU)was injected into the rats’ankle joints to induce an experimental GA *** and tissue samples were collected on the 3rd,5th,and 8th days of drug *** changes in the synovium of joints were observed via hematoxylin and eosin(HE)*** expression levels of arachidonic acid(AA)signaling pathway were assessed via real-time polymerase chain reaction(q PCR)and Western *** cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral *** enzyme-linked immunosorbent assay(ELISA)was used to detect interleukine(IL)-1β,tumor necrosis factoralpha(TNF-α),IL-4,IL-10,prostaglandin E_(2)(PGE_(2)),and leukotriene B4(LTB4).Results:HE staining showed that TSDN improved the synovial tissue.q PCR and Western blot showed that on the 3rd,5th and 8th days of drug administration,TSDN reduced the m RNA and protein expressions of cyclooxygenase(COX)2,microsomal prostaglandin E synthase-1 derived eicosanoids(m PGES-1),5-lipoxygenase(5-LOX),recombinant human mothers against decapentaplegic homolog 3(Smad3),nucleotide-binding oligomerization domain-like receptor protein 3(NALP3),and inducible nitric oxide synthase(i NOS)in rats’ankle synovial tissues(P<0.01).TSDN decreased COX1 m RNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day(both P<0.01).It lowered CD68 protein expression on days 3(P<0.01),as well as m RNA and protein expression on days 5 and 8(P<0.01).On the 3rd,5th,and 8th days of drug administration,TSDN elevated the m RNA and protein expression of Arg1 and CD163(P<0.01).F

关键词： Smad3 Blood mother

在线全文

学校读者我要写书评

暂无评论

基于密度泛函理论纤维素热解机理热力学研究

原子与分子物理学报 2025年第5期42卷 1-6页

作者：周俊杰陈曦汤松臻李智聪郑州大学机械与动力工程学院郑州450001

为了探究纤维素的热解机理,参考相关的实验结果,以纤维素单体模化物为研究对象,采用密度泛函理论的方法,以b3lyp/6-31++g(d,p)为基,对纤维素单体热解反应生成乙醇醛和CO_(2)小分子的反应机理进行动力学研究.纤维素单体热解生成乙醇醛和C... 详细信息

为了探究纤维素的热解机理,参考相关的实验结果,以纤维素单体模化物为研究对象,采用密度泛函理论的方法,以b3lyp/6-31++g(d,p)为基,对纤维素单体热解反应生成乙醇醛和CO_(2)小分子的反应机理进行动力学研究.纤维素单体热解生成乙醇醛和CO_(2)的反应路径为纤维素单体首先开环,之后裂解生成四糖片段M2和乙醇醛P1,能垒最高为339.1 kJ/mol,四糖片段M2经过脱水形成烯酮结构后再与水分子作用生成羧基,最后发生脱羧反应生成CO_(2),能垒较高为290.1 kJ/mol,不容易发生,整个过程放出98.9 kJ/mol的热量,并对路径反应物、中间体和过渡态进行几何构型全优化,过渡态的振动和频率计算,同时进行不同温度下(400 K、600 K、800 K、1000 K、1200 K)热解过程的热力学分析,对纤维素的热解机理研究将对生物质的热裂解机理研究有重要的意义.

关键词：纤维素热解密度泛函理论反应机理

Intrinsic defects and the influences on electrical transport properties in quaternary diamond-like compounds:Cd_(2)Cu_(3)In_(3)Te_(8)as an example

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of Materiomics 2022年第6期8卷 1222-1229页

作者： Jianxin Zhang zhou Zhang Lili xi Jinyang xi Jiong Yang Materials Genome Institute Shanghai UniversityShanghai200444China Zhejiang Laboratory HangzhouZhejiang311100China

Over the years,the fact that the quaternary diamond-like thermoelectric materials show much lower carrier mobilities than ternary compounds remains *** this work,by adopting first-principles defect chemistry and electrical transport calculations,the fundamental origin of the difference on carrier mobility between quaternary and ternary diamond-like compounds is addressed,exemplified by Cd_(2)Cu_(3)In_(3)Te_(8).The results of defect chemistry show that the main intrinsic defects in quaternary compound Cd_(2)Cu_(3)In_(3)Te_(8) are substitutional defects,i.e.,CdIn and CdCu,differing from the copper vacancy defect in ternary Cu-based compound such as CuInTe_(2).The low defect formation energies in Cd_(2)Cu_(3)In_(3)Te_(8) result in high defect concentrations,which is caused by the similar atomic radii and electronegativities between CdeIn and *** calculations show that the low-energy defects are mainly located around the valence band maximum in Cd_(2)Cu_(3)In_(3)Te_(8).The electrical transport calculations,considering both the acoustic phonon scattering and ionized impurity scattering,demonstrate that mainly due to the higher concentration of the ionized defects,the mobility of the quaternary Cd_(2)Cu_(3)In_(3)Te_(8) is much lower than that of ternary *** work sheds light on the intrinsic defects in quaternary diamond-like compounds and their influence on charge transport.

关键词： Intrinsic defect Quaternary diamond-like compound Mobility Ionized impurity scattering

Ground-State Bands of Fm and No Isotopes in Cluster Model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2006年第3X期46卷 533-537页

作者： XU chang Zhong-zhou Department of Physics Nanjing University Nanjing 210008 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator. Lanzhou 730000. China

We investigate the ground-state rotational bands of nuclei with Z 〉 100 using cluster model proposed by Buck et al. [Phys. Rev. Left. 94 （2005） 202501]. The core-duster decomposition of each nucleus is determined by the corresponding electric quadrupole transition strength B（E2 ： 2^＋ → 0^＋）. The theoretical spectra of fermium and nobelium isotopes are compared with available experimental data. Good agreement between model and data is obtained.

关键词： cluster model rotational band

Compressive strength prediction and optimization design of sustainable concrete based on squirrel search algorithm-extreme gradient boosting technique

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2023年第9期17卷 1310-1325页

作者： Enming LI Ning ZHANG Bin xi Jian zhou xiaofeng GAO ETSI Minas y Energía Universidad Politécnica de MadridMadrid 28003Spain Leibniz Institute of Ecological Urban and Regional Development(IOER) Dresden 01217Germany Department of Civil and Environmental Engineering Politecnico Di MilanoMilano 20133Italy School of Resources and Safety Engineering Central South UniversityChangsha 410083China Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment(Ministry of Education) College of Environment and EcologyChongqing UniversityChongqing 400045China

Concrete is the most commonly used construction ***,its production leads to high carbon dioxide(CO_(2))emissions and energy ***,developing waste-substitutable concrete components is *** the sustainability and greenness of concrete is the focus of this *** this regard,899 data points were collected from existing studies where cement,slag,fly ash,superplasticizer,coarse aggregate,and fine aggregate were considered potential influential *** complex relationship between influential factors and concrete compressive strength makes the prediction and estimation of compressive strength *** of the traditional compressive strength test,this study combines five novel metaheuristic algorithms with extreme gradient boosting(XGB)to predict the compressive strength of green concrete based on fly ash and blast furnace *** intelligent prediction models were assessed using the root mean square error(RMSE),coefficient of determination(R^(2)),mean absolute error(MAE),and variance accounted for(VAF).The results indicated that the squirrel search algorithm-extreme gradient boosting(SSA-XGB)yielded the best overall prediction performance with R^(2) values of 0.9930 and 0.9576,VAF values of 99.30 and 95.79,MAE values of 0.52 and 2.50,RMSE of 1.34 and 3.31 for the training and testing sets,*** remaining five prediction methods yield promising ***,the developed hybrid XGB model can be introduced as an accurate and fast technique for the performance prediction of green ***,the developed SSA-XGB considered the effects of all the input factors on the compressive *** ability of the model to predict the performance of concrete with unknown proportions can play a significant role in accelerating the development and application of sustainable concrete and furthering a sustainable economy.

关键词： sustainable concrete fly ash slay extreme gradient boosting technique squirrel search algorithm parametric analysis

Full Characterization of the Work-Hardening Behavior of Metals:An Accurate and Explicit Approach

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2020年第4期33卷 479-486页

作者： Zan zhou Siyu Wang Lin Zhan Huifeng xi Heng xiao School of Mechanics and Construction Engineering and MOE Key Lab of Disaster Forecast and Control in Engineering Jinan UniversityGuangzhou 510632China Shanghai Institute of Applied Mathematics and Mechanics&School of Mechanics and Engineering Science Shanghai UniversityShanghai 200072China

A new approach is proposed to characterize the work-hardening behavior of metals based on the stress-strain data from uniaxial extension *** this new approach,the yield strength as a function of the plastic work can be determined by directly fitting a wellchosen single-variable shape function to any given uniaxial data from the initial yielding up to the strength limit,in an explicit sense with no need to carry out the usual tedious trial-and-error procedures in treating nonlinear elastoplastic rate equations toward identifying numerous unknown *** examples show that the simulation results with the new approach are in accurate agreement with the test data.

关键词： Metals Elastoplasticity Finite strain Work-hardening Yield strength Strength limit Explicit characterization