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Iteration framework for solving mixed lubrication computation problems

《机械工程前沿（英文）》 2021年第16卷第3期页码 635-648 doi: 10.1007/s11465-021-0632-8

摘要： The general discrete scheme of time-varying Reynolds equation loses the information of the previous step, which makes it unreasonable. A discretization formula of the Reynolds equation, which is based on the Crank–Nicolson method, is proposed considering the physical message of the previous step. Gauss–Seidel relaxation and distribution relaxation are adopted for the linear operators of pressure during the numerical solution procedure. In addition to the convergent criteria of pressure distribution and load, an estimation framework is developed to investigate the relative error of the most important term in the Reynolds equation. Smooth surface with full contacts and mixed elastohydrodynamic lubrication is tested for validation. The asperity contact and sinusoidal wavy surface are examined by the proposed discrete scheme. Results show the precipitous decline in the boundary of the contact area. The relative error suggests that the pressure distribution is reliable and reflects the accuracy and effectiveness of the developed method.

关键词： mixed lubrication discretization formula relative error Reynolds equation asperity

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连轧张力公式的实验验证和分析

张进之,赵厚信,王喆,王保罗

《中国工程科学》 2008年第10卷第4期页码 73-77

摘要：

连轧张力公式是连轧理论和实践的核心问题，该问题国内外都有大量的研究，20世纪60年代笔者推导了连轧张力微分方程、多机架动态张力公式、稳态张力公式，理论上已作过深入、广泛的分析讨论。日本在20世纪70年代对连轧张力公式进行了理论上的推导和实验验证，特别是浅川基男等人的连轧实验结果更为重要。为此引用了浅川基男的实验数据和宝钢2 050 mm热连轧机上的实测数据，验证了连轧张力公式。

关键词：连轧张力公式实验验证解析解定常性

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以土体应力状态计算边坡安全系数的方法

王国体

《中国工程科学》 2006年第8卷第12期页码 80-84

摘要：

土坡的稳定分析一直是沿着条分法的思路发展的。由于对土体应力状态条件的忽视和条分法本身的缺陷，使得条分法得到的安全系数在工程中的应用面临激烈的挑战。土体不同条件下的应力状态表现为K₀效应和变化，它对坡体的安全度影响不可忽视。笔者以考虑土体应力状态为条件，应用土的库伦强度定律和摩尔-库伦准则，推导出平面土坡的安全系数计算公式，与条分法的安全系数对比结果说明这种方法具有概念明确、计算简便、定性可靠的重要特点，可以直接提供于工程应用和参考。

关键词：侧应力系数K₀ 初始应力状态稳定安全系数公式

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Study on rigid-flexible coupling dynamics of hub-plate system

ZHAO Feiyun, XIE Yongcheng, ZHANG Ming, HE Yinbiao

《能源前沿（英文）》 2007年第1卷第2期页码 181-188 doi: 10.1007/s11708-007-0023-9

摘要： Dynamic modeling of a rotating flexible hub-plate system is investigated by using Jourdain s variation principle in which the finite element method (FEM) is used as discretization method for a flexible plate. Different from the previous modeling of a plate with a prescribed large overall motion, the coupling between large overall motion of the system and elastic deformation of the flexible plate is taken into account in the proposed coupling model. The quadratic terms are included in the strain-displacement expression, such that the dynamic stiffening terms are included. Simulation of a rotating hub-plate system indicates that the linear model based on linear strain-displacement assumption may lead to erroneous results in the case of high rotation speed. Conservation of energy verifies the validity of the proposed model. Furthermore, frequency analysis of a hub-plate system shows the difference between the frequencies of the system with free and prescribed large overall motion, and parameter analysis of the system reveals the coupling characteristics of the rotational motion and the deformation.

关键词： discretization erroneous Furthermore Different Conservation

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Lingguizhugan Decoction, a Chinese herbal formula, improves insulin resistance in overweight/obese subjects

《医学前沿（英文）》 2022年第16卷第5期页码 745-759 doi: 10.1007/s11684-021-0880-3

摘要： Lingguizhugan Decoction (LGZG) has been investigated in basic studies, with satisfactory effects on insulin resistance in non-alcoholic fatty liver disease (NAFLD). This translational approach aimed to explore the effect and underlying mechanism of LGZG in clinical setting. A randomized, double-blinded, placebo-controlled trial was performed. A total of 243 eligible participants with NAFLD were equally allocated to receive LGZG (two groups: standard dose and low dose) or placebo for 12 weeks on the basis of lifestyle modifications. The primary efficacy variable was homeostasis model assessment of insulin resistance (HOMA-IR). Analyses were performed in two populations in accordance with body mass index (BMI; overweight/obese, BMI ≥ 24 kg/m²; lean, BMI < 24 kg/m ²). For overweight/obese participants, low-dose LGZG significantly decreased their HOMA-IR level compared with placebo (−0.19 (1.47) versus 0.08 (1.99),P = 0.038). For lean subjects, neither dose of LGZG showed a superior effect compared with placebo. Methylated DNA immunoprecipitation sequencing and real-time qPCR found that the DNA N6-methyladenine modification levels of protein phosphatase 1 regulatory subunit 3A (PPP1R3A) and autophagy related 3 (ATG3) significantly increased after LGZG intervention in overweight/obese population. Low-dose LGZG effectively improved insulin resistance in overweight/obese subjects with NAFLD. The underlying mechanism may be related to the regulation of DNA N6-methyladenine modification of PPP1R3A and ATG3. Lean subjects may not be a targeted population for LGZG.

关键词： insulin resistance non-alcoholic fatty liver disease Chinese herbal medicine randomized controlled trial DNA N6-methyladenine modification

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Computational fluid dynamic analysis of flutter characteristics for self-anchored suspension bridges

ZHU Zhiwen, WANG Zhaoxiang, CHEN Zhengqing

《结构与土木工程前沿（英文）》 2008年第2卷第3期页码 267-273 doi: 10.1007/s11709-008-0034-6

摘要： This paper outlines the essentials and procedures of computational fluid dynamics (CFD) simulation applicable to evaluating flutter derivatives of bridge decks. An arbitrary Lagrangian-Eulerian (ALE) description of the flow around the moving rigid box girder combined with the finite volume discretization and multi-grid algorithm is presented. The proposed methods are employed to identify flutter derivatives of the bridge deck of the Sanchaji Self-anchored Suspension Bridge. The results agree well with ones from wind tunnel tests. It demonstrates accuracy and efficiency of the present method.

关键词： discretization computational description Self-anchored Suspension simulation applicable

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水电站叠梁门多层取水下泄水温公式

高学平,陈弘,宋慧芳

《中国工程科学》 2011年第13卷第12期页码 63-67

摘要：

对于温度成层型水库，水电站进水口分层取水方式通常被采用，目的是有选择地取用水库的不同层水体，减免下泄低温水对下游河流环境的负面影响。目前缺乏简单实用的分层取水下泄水温的预测公式。笔者针对糯扎渡水电站工程，试验模拟水库水温分布，量测下泄水温；依据大量的试验数据，建立下泄水温预测公式；所提出的公式得到了锦屏一级电站下泄水温试验数据的验证。

关键词：温度成层型水库水电站进水口叠梁门下泄水温公式模型试验

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Recovery of NH

Yang ZHANG,Zifu LI,Ibrahim B MAHMOOD

《环境科学与工程前沿（英文）》 2014年第8卷第6期页码 825-834 doi: 10.1007/s11783-014-0682-9

摘要： ion, a main pollutant in aquatic systems, not only causes eutrophication in rivers and lakes but also contributes to fish toxicity. In this study, an eco-friendly biosorbent was prepared from the pyrolysis of corn cob, a low-cost agricultural residue. The biochars produced by pyrolysis of corn cob at 400°C and 600°C were characterized and investigated as adsorbents for from an aqueous solution. The biochars were characterized through elemental analysis, Brunauer–Emmett–Teller–N surface area analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. Batch experiments were conducted to investigate the adsorption process of the corn cob biochars. The Freundlich isotherm model fitted the adsorption process better than the Langmuir and Dubinin–Radushkevich isotherm models. Moreover, the adsorption process was well described by a pseudo-second-order kinetic model. Results of thermodynamic analysis suggested that adsorption was a nonspontaneous exothermic process. Biochars produced at 400°C had higher adsorption capacity than those produced at 600°C because of the presence of polar functional groups with higher acidity. The exhausted biochar can be potentially used as soil conditioner, which can provide 6.37 kg (N fertilizer per ton of biochar).

关键词： corn cob biochar isotherm model kinetic model

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基于转录组学及多尺度生物测定多模态鉴定宣肺败毒方抑制巨噬细胞免疫反应的活性成分 Article

赵璐, 刘豪, 王迎超, 王书芳, 荀得金, 王毅, 程翼宇, 张伯礼

《工程（英文）》 2023年第20卷第1期页码 63-76 doi: 10.1016/j.eng.2021.09.007

摘要：

宣肺败毒方（XFBD）是一种临床用于治疗新型冠状病毒肺炎（COVID-19）病患的中药方剂，在临床实践中表现出了显著的疗效，但对其潜在的药理学机制尚不清楚。本研究结合网络药理学、转录组学和多模型系统生物测定等综合研究方法，研究了XFBD生物活性物质及其药理作用机制。通过高分辨质谱与分子网络相结合，对XFBD中的主要活性物质进行了分析，共鉴定或初步鉴定了104种化合物，包括黄酮类、萜类、羧酸类和其他类型的成分。基于所鉴定的XFBD化学组分，开展了网络药理学分析并将炎症相关通路确定为主要靶点。在脂多糖诱导的急性炎症小鼠模型中，XFBD明显减轻了肺部炎症，降低了血清促炎细胞因子水平。转录组学分析表明，经XFBD治疗后，与巨噬细胞功能相关的基因表达水平发生改变。在巨噬细胞细胞系和斑马鱼创伤模型中，XFBD对巨噬细胞的激活和迁移均有很强的抑制作用。最终，通过多模型系统筛选，发现XFBD中虎杖、芦根、化橘红显著下调巨噬细胞活化，虎杖苷、异甘草苷、毛蕊花糖苷为活性化合物；青蒿和麻黄显著抑制内源性巨噬细胞迁移，麻黄碱、白术内酯和山奈酚为活性化合物。综上所述，本研究通过多模态方法研究了XFBD调节炎症的活性成分以及相关药理学机制，从而为XFBD的临床疗效提供了生物学例证。

关键词：炎症巨噬细胞活化巨噬细胞迁移多模态鉴定宣肺败毒方

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Explicit finite element method for calculation and analysis to the elasto-plastic dynamic response of fluid-saturated porous media

LI Liang, DU Xiuli, LI Liyun, ZHAO Chenggang

《结构与土木工程前沿（英文）》 2007年第1卷第4期页码 436-442 doi: 10.1007/s11709-007-0059-2

摘要： In order to describe the elasto-plastic dynamic response of fluid-saturated porous media, the incremental elasto-plastic wave propagation equations of fluid-saturated porous media are developed by the fundamental theory of continuum mechanics and appointing to the characteristic of fluid-saturated porous media. Then, the space discretization of these equations is performed to get their Galerkin formula. At last, the time discretization of this formula is carried out with the integral method which consists of central difference method and Newmark constant average acceleration method to get the explicit time integral formula for solving the wave propagation equations of porous media. On the basis of the integral formula mentioned above, the time-domain explicit finite element method is developed for calculation and analysis of the elasto-plastic dynamic response of fluid-saturated porous media. In this method, the decoupling technique is adopted and it does not need to solve simultaneous linear equations in each time step, so the computational effort and memory requirement can be reduced considerably by using this method.

关键词： discretization computational calculation integral requirement

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Development of a seismic design method based on response spectra for building structures

ZHOU Xiyuan, YU Ruifang

《结构与土木工程前沿（英文）》 2007年第1卷第2期页码 129-141 doi: 10.1007/s11709-007-0014-2

摘要： The assumption and problem of the mode-superposition response spectrum method in seismic design code is discussed based on a brief review of the development of the seismic design method for building structures. The scope of application for the classical damping theory is analyzed and the necessity of the research on mode-superposition method for non-classical damping is presented. The progresses on the mode superposition response spectrum theory are discussed. This includes: 1) the complex mode superposition method (in real form) for the non-classically damped linear system and the general calculation formula for the application of code; 2) the complex complete quadratic combination (CCQC) method for the non-classically damped linear system, which is based on the same assumptions as in deducing the complete quadratic combination (CQC) method which is popularly used in seismic design codes of many countries; 3) the complex complete quadratic combination with three components (CCQC3) method, which is a generalization of the CCQC method to the case of multi-components and multiple-support seismic excitations and deducing corresponding method; 4) the approach for calculation of seismic response of the non-classically damped system with overcritical damping and the calculation method of seismic response for the linear system with multiple eigenvalues; 5) the time-dependent CCQC (t) algorithm considering nonstationary earthquake ground motion; 6) an applied and effective method to solve the low order complex vector basis for the large linear non-classically damped system, which can be expediently used in practice to avoid the unknown errors coming from the forced uncoupling method; 7) bringing forward the concept of partial quadratic combination in order to reduce the calculation amount of CQC and CCQC methods, and studying the primary estimation-criterion. The reasonability and applicable scope of these methods are also briefly discussed in this paper.

关键词： generalization classical damping mode-superposition response calculation formula damping theory

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Flexural-torsional buckling behavior of aluminum alloy beams

Xiaonong GUO,Zhe XIONG,Zuyan SHEN

《结构与土木工程前沿（英文）》 2015年第9卷第2期页码 163-175 doi: 10.1007/s11709-014-0272-8

摘要： This paper presents an investigation on the flexural-torsional buckling behavior of aluminum alloy beams (AAB). First, based on the tests of 14 aluminum alloy beams under concentrated loads, the failure pattern, load-deformation curves, bearing capacity and flexural-torsional buckling factor are studied. It is found that all the beam specimens collapsed in the flexural-torsional buckling with excessive deformation pattern. Moreover, the span, loading location and slenderness ratio influence the flexural-torsional buckling capacity of beams significantly. Secondly, besides the experiments, a finite element method (FEM) analysis on the flexural-torsional buckling behavior of AAB is also conducted. The main parameters in the FEM analysis are initial imperfection, material property, cross-section and loading scheme. According to the analytical results, it is indicated that the FEM is reasonable to capture mechanical behavior of AAB. Finally, on the basis of the experimental and analytical results, theoretical formulae to estimate the flexural-torsional buckling capacity of AAB are proposed, which could improve the application of present codes for AAB.

关键词： flexural-torsional buckling aluminum alloy beams (AAB) finite element method (FEM) theoretical formula

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Inverse kinematics analysis and numerical control experiment for PRS-XY style hybrid machining tool

JIA Dongyong, ZHANG Jianmin, SUN Hongchang, NIU Zhigang

《机械工程前沿（英文）》 2007年第2卷第2期页码 235-238 doi: 10.1007/s11465-007-0041-7

摘要： This paper analyzed the inverse kinematics for the new Parallel rotate slider- axes (PRS-) style hybrid machining tool and educed the five axes linkage inverse kinematics transform formula on the basis of the coordinates of the and virtual axes. The program for the PRS-XY style hybrid machining tool in accordance with the program manner for the common numerical control (NC) machine tool was made. The results of the experiments prove that the inverse kinematics transform formula is correct.

关键词： numerical accordance transform formula virtual slider-

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spp., foodborne pathogens threatening neonates and infants

Qiming CHEN, Yang ZHU, Zhen QIN, Yongjun QIU, Liming ZHAO

《农业科学与工程前沿（英文）》 2018年第5卷第3期页码 330-339 doi: 10.15302/J-FASE-2018208

摘要：

Cronobacter spp. (formerly Enterobacter sakazakii) are special foodborne pathogens. Cronobacter infection can cause necrotizing enterocolitis, sepsis and meningitis in all age groups, especially neonates and infants, with a high fatality of up to 80%, although the infection is rare. Outbreaks of Cronobacter infection are epidemiologically proven to be associated with contaminated powdered infant formula (PIF). Cronobacter spp. can resist dry environments and survive for a long period in food with low water activity. Therefore, Cronobacter spp. have become serious pathogens of neonates and infants, as well as in the dairy industry. In this review, we present the taxonomy, pathogenesis, resistance, detection and control of Cronobacter spp.

关键词： Cronobacter spp. desiccation resistance pathogen control pathogen detection powdered infant formula

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Enhancing compressive strength and durability of self-compacting concrete modified with controlled-burnt sugarcane bagasse ash-blended cements

《结构与土木工程前沿（英文）》 2022年第16卷第2期页码 161-174 doi: 10.1007/s11709-021-0796-7

摘要： In sugar industries, the growing amount of sugarcane bagasse ash (SBA), a byproduct released after burning bagasse for producing electricity, is currently causing environmental pollution. The residual ash displays a pozzolanic potential; and hence, it has potential as a cement addictive. This study focuses on enhancing suitability of SBA through incorporating ground blast furnace slag (BFS) in manufacturing self-compacting concretes (SCCs). For this purpose, SBA was processed by burning at 700 °C for 1 h, before being ground to the cement fineness of 4010 cm²/g. SCC mixtures were prepared by changing the proportions of SBA and BFS (i.e., 10%, 20%, and 30%) in blended systems; and their performance was investigated. Test results showed that the presence of amorphous silica was detected for the processed SBA, revealing that the strength activity index was above 80%. The compressive strength of SCC containing SBA (without BFS) could reach 98%−127% of that of the control; combination of SBA and 30% BFS gets a similar strength to the control after 28 d. Regarding durability, the 10%SBA + 30%BFS mix exhibited the lowest risk of corrosion. Moreover, the joint use of SBA and BFS enhanced significantly the SCC’s sulfate resistance. Finally, a hyperbolic formula for interpolating the compressive strength of the SBA-based SCC was proposed and validated with error range estimated within ±10%.

关键词： sugarcane bagasse ash self-compacting concrete compressive strength sulfate resistance water absorption strength formula