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Economic Growth Model Based on Six Basic Factors of Production—Xu Growth Rate Equation

Shou-bo Xu,Zong-yuan Huang

《工程管理前沿（英文）》 2014年第1卷第2期页码 160-175 doi: 10.15302/J-FEM-2014024

摘要： This paper proposes an economic growth model based on the Six Basic Factors of Production and Xu Growth Rate Equation for the first time, which fills-in the deficits of the New Classical Economic Growth Model based on the Solow Model. The empirical analysis indicates that over the past three decades, the consumption of six basic factors of production had complicated relations with economic growth. In some years, the consumption rate of the basic factors of production was meager, but the economy witnessed relatively rocketing growth rate; in some years, the factors of production consumption rate was very high, but the economy growth rate slowed down. In general, economy grows at the expenses of huge consumption of four factors. There is an obvious characteristic of huge input and low efficiency. The average contribution rate of technological advance peaks in the middle, while it drops down at two ends. Noticeably, since 2004, the technology contribution rate generally shows a downward trend, reasons of which should be explored systematically in aspects like economic policy and industry structure with a view to boost further transformation of the macro-economy scientific growth model.

关键词： six basic factors of production economic growth model Xu Growth Rate Equation

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Effect of seismic wave propagation in massed medium on rate-dependent anisotropic damage growth in concrete

Alireza DANESHYAR, Hamid MOHAMMADNEZHAD, Mohsen GHAEMIAN

《结构与土木工程前沿（英文）》 2021年第15卷第2期页码 346-363 doi: 10.1007/s11709-021-0694-z

摘要： Seismic modeling of massive structures requires special caution, as wave propagation effects significantly affect the responses. This becomes more crucial when the path-dependent behavior of the material is considered. The coexistence of these conditions renders numerical earthquake analysis of concrete dams challenging. Herein, a finite element model for a comprehensive nonlinear seismic simulation of concrete gravity dams, including realistic soil–structure interactions, is introduced. A semi-infinite medium is formulated based on the domain reduction method in conjunction with standard viscous boundaries. Accurate representation of radiation damping in a half-space medium and wave propagation effects in a massed foundation are verified using an analytical solution of vertically propagating shear waves in a viscoelastic half-space domain. A rigorous nonlinear finite element model requires a precise description of the material response. Hence, a microplane-based anisotropic damage–plastic model of concrete is formulated to reproduce irreversible deformations and tensorial degeneration of concrete in a coupled and rate-dependent manner. Finally, the Koyna concrete gravity dam is analyzed based on different assumptions of foundation, concrete response, and reservoir conditions. Comparison between responses obtained based on conventional assumptions with the results of the presented comprehensive model indicates the significance of considering radiation damping and employing a rigorous constitutive material model, which is pursued for the presented model.

关键词： soil–structure interaction massed foundation radiation damping anisotropic damage

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Creep-fatigue crack growth behavior in GH4169 superalloy

Dianyin HU, Xiyuan WANG, Jianxing MAO, Rongqiao WANG

《机械工程前沿（英文）》 2019年第14卷第3期页码 369-376 doi: 10.1007/s11465-018-0489-7

摘要： This study aims to examine the crack growth behavior of turbine disc GH4169 superalloy under creep-fatigue loading. Crack growth experiments were performed on compact tension specimens using trapezoidal waveform with dwell time at the maximum load at 650 °C. The crack growth rate of GH4169 superalloy significantly increased with dwell time. The grain boundaries oxidize during the dwell process, thereby inducing an intergranular creep-fatigue fracture mode. In addition, testing data under the same dwell time showed scattering at the crack growth rate. Consequently, a modified model based on the Saxena equation was proposed by introducing a distribution factor for the crack growth rate. Microstructural observation confirmed that the small grain size and high volume fraction of the d phase led to a fast creep-fatigue crack growth rate at 650 °C, thus indicating that two factors, namely, fine grain and presence of the d phase at the grain boundary, increased the amount of weakened interface at high temperature, in which intergranular cracks may form and propagate.

关键词： crack growth rate creep-fatigue GH4169 superalloy CT specimen dwell time

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roughening transition and missing regime transition of melt crystallized polybutene-1 tetragonal phase: growth

Motoi YAMASHITA

《化学科学与工程前沿（英文）》 2009年第3卷第2期页码 125-134 doi: 10.1007/s11705-009-0001-3

摘要： The morphology and lateral growth rate of polybutene-1 ( -PB1) have been investigated for crystallization from the melt over a wide range of crystallization temperatures from 50 to 110°C. The morphology of -PB1 crystals is a rounded shape at crystallization temperatures lower than 85°C, while lamellar single crystals possess faceted morphology at higher crystallization temperatures. The kinetic roughening transition occurs around 85°C. The nucleation and growth mechanism for crystallization does not work below 85°C, since the growth face is rough. However, the growth rate shows the supercooling dependence derived from the nucleation and growth mechanism. The nucleation theory seems still to work even for rough surface growth. Possible mechanisms for the crystal growth of this polymer are discussed.

关键词： isotactic polybutene-1 tetragonal phase (form Ⅱ) melt crystallization growth rate kinetic roughening morphology

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性能化防火设计中火灾场景设置初步研究

徐亮,张和平,杨昀,朱五八

《中国工程科学》 2004年第6卷第1期页码 64-67

摘要：

火灾场景的设置是性能化设计的关键步骤，重点介绍了常用的火灾增长曲线设计方法，并且以高架仓库火灾设计为例，说明了如何灵活运用火灾设计方法。

关键词：火灾场景设置火灾增长曲线热释放速率

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Comparison of growth and lipid accumulation properties of two oleaginous microalgae under different nutrient

Qiao ZHANG,Yu HONG

《环境科学与工程前沿（英文）》 2014年第8卷第5期页码 703-709 doi: 10.1007/s11783-014-0649-x

摘要： This study compared the growth and lipid accumulation properties of two oleaginous microalgae, namely, sp. LX1 and sp. HQ, under different nutrient conditions. Both algal species obtained the highest biomass, lipid content and lipid yield under low-nutrient conditions (mBG11 medium). The biomass, lipid content and lipid yield of sp. LX1 were 0.42 g·L , 22.5% and 93.8 mg·L , respectively. These values were relatively higher than those of sp. HQ (0.30 g·L , 17.1% and 51.3 mg·L , respectively). These algae were then cultivated in an SE medium that contained more nutrients; as a result, the biomass and lipid yield of sp. LX1 reduced more significantly than those of sp. HQ. Opposite results were observed in lipid and triacylglycerols (TAGs) contents. The cell sizes of both algal species under low-nutrient conditions were larger than those under high-nutrient conditions. sp. HQ cells did not aggregate, but sp. LX1 cells flocculated easily, particularly under low-nutrient conditions. In summary, low-nutrient conditions favour the growth and lipid production of both algae, but sp. LX1 outperforms sp. HQ.

关键词： Scenedesmus sp. LX1 Chlorella sp. HQ growth rate algal biomass lipid accumulation triacylglycerols (TAGs)

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穿越“环境高山”——论经济增长过程中环境负荷的上升与下降

陆钟武,毛建素

《中国工程科学》 2003年第5卷第12期页码 36-42

摘要：

把描绘发达国家经济增长过程中的环境负荷曲线比喻成“环境高山”。强调了发展中国家，尤其是中国，发展经济的正确之路是：从“环境高山”的半山腰穿过去，走新型工业化道路。推导了环境负荷与GDP之间的关系式，其中GDP年增长率g和单位GDP环境负荷年下降率t是两个关键变量。以一些国家和中国的一些省份为实例，分析了经济增长与能源消费量之间的关系。在不同的假设条件下，计算了2005，2010，2020年中国的环境负荷，并以能源消耗为例，做了进一步的说明。

关键词：环境高山” 环境负荷 GDP年增长率单位GDP环境负荷单位GDP环境负荷的年下降率

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Availability growth models and verification of power equipment

Jinyuan SHI, Jiamin XU

《能源前沿（英文）》 2021年第15卷第2期页码 529-538 doi: 10.1007/s11708-019-0624-0

摘要： The general availability growth models for large scale complicated repairable system such as electric generating units, power station auxiliaries, and transmission and distribution installations are presented. The calculation formulas for the maintenance coefficient, mathematical expressions for general availability growth models, ways for estimating, and fitting on checking the parameters of the model are introduced. Availability growth models for electric generating units, power station auxiliaries, and transmission and distribution installations are given together with verification examples for availability growth models of 320–1000 MW nuclear power units and 1000 MW thermal power units, 200–1000 MW power station auxiliaries, and 220–500 kV transmission and distribution installations. The verification results for operation availability data show that the maintenance coefficients for electric generating units, power station auxiliaries, transmission and distribution installations conform to the power function, and general availability growth models conform to rules of availability growth tendency of power equipment.

关键词： repairable system power equipment electric generating unit power station auxiliary transmission and distribution installation reliability availability availability growth model

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Stable expression and control parameters in the numerical simulation of unsaturated flow

Zhiyuan ZHANG; Xu LI; Yongkang WU; Xiaokang LI

《结构与土木工程前沿（英文）》 2022年第16卷第12期页码 1501-1514 doi: 10.1007/s11709-022-0893-2

摘要： The Richards’ equation describes the flow phenomenon in unsaturated porous media and is essential to hydrology and environmental science. This study evaluated the numerical stability of two different forms of the Richards’ equation. Sensitivity analyses were performed to investigate the control parameters of the equation. The results show that the h-form Richards’ equation has better applicability for calculating variable saturation flows than the θ-form Richards’ equation. For the h-form Richards’ equation, the hydraulic conductivity of the soil in the low-suction range and the specific moisture capacity in the high-suction range primarily influenced the solution. In addition, sensitivity analyses indicated that the saturated hydraulic conductivity, initial condition, and air-entry pressure have a higher sensitivity to the simulation results than the saturated water content, rainfall intensity, and decline rate of hydraulic conductivity. Moreover, their correctness needs to be guaranteed first in numerical simulations. The research findings can provide a helpful reference for improving the reliability of numerical simulations of unsaturated flows.

关键词： Richards’ equation sensitivity analysis unsaturated soil hydraulic diffusivity seepage simulation

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Key features of new particle formation events at background sites in China and their influence on cloud condensation nuclei

Xiaojing SHEN,Junying SUN,Xiaoye ZHANG,Yangmei ZHANG,Lu ZHANG,Ruxia FAN

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0833-2

摘要： New particle formation (NPF) event at multi rural sites in China Identifying the characteristics of NPF event Comparing NPF event between clean and polluted conditions Quantifying contribution to the cloud condensation nuclei Implication of climate and air quality Long-term continuous measurements of particle number size distributions with mobility diameter sizes ranging from 3 to 800 nm were performed to study new particle formation (NPF) events at Shangdianzi (SDZ), Mt. Tai (TS), and Lin’an (LAN) stations representing the background atmospheric conditions in the North China Plain (NCP), Central East China (CEC), and Yangtze River Delta (YRD) regions, respectively. The mean formation rate of 3-nm particles was 6.3, 3.7, and 5.8 cm ·s , and the mean particle growth rate was 3.6, 6.0, and 6.2 nm·h at SDZ, TS, and LAN, respectively. The NPF event characteristics at the three sites indicate that there may be a stronger source of low volatile vapors and higher condensational sink of pre-existing particles in the YRD region. The formation rate of NPF events at these sites, as well as the condensation sink, is approximately 10 times higher than some results reported at rural/urban sites in western countries. However, the growth rates appear to be 1–2 times higher. Approximately 12%–17% of all NPF events with nucleated particles grow to a climate-relevant size (>50 nm). These kinds of NPF events were normally observed with higher growth rate than the other NPF cases. Generally, the cloud condensation nuclei (CCN) number concentration can be enhanced by approximately a factor of 2–6 on these event days. The mean value of the enhancement factor is lowest at LAN (2–3) and highest at SDZ (~4). NPF events have also been found to have greater impact on CCN production in China at the regional scale than in the other background sites worldwide.

关键词： New particle formation Regional background Cloud condensation nuclei Growth rate Formation rate

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钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

《中国工程科学》 2010年第12卷第6期页码 4-11

摘要：

分两步解析钢产量的增长机制，首先在若干假设条件下提出了钢产量增长的基准模式，其主要特点是钢产量与GDP同步增长，分析了基准模式下的钢产量、在役钢量、GDP以及它们的年增长率；然后讨论偏离基准模式的各种可能性，及其对钢产量增速的影响。在此基础上得到了钢产量年增长率的基本计算式。分析了偏离基准模式对单位GDP钢产量的影响。在对钢产量增长机制进行解析的基础上，广泛联系全社会发生的各种现象，提出使我国钢产量增速远远超过GDP增速的16种现象，提出在宏观调控工作中，要区别对待这些现象。从中、日、美三国单位GDP钢产量数据对比可见，我国降低单位GDP钢产量的空间很大。文章为我国钢铁行业的宏观调控提供了新思路。

关键词：钢产量在役钢量 GDP 年增长率机制基准模式

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Improvement in growth yield of single-walled carbon nanotubes with narrow chirality distribution by pulse

Bin Xu, Toshiro Kaneko, Toshiaki Kato

《化学科学与工程前沿（英文）》 2019年第13卷第3期页码 485-492 doi: 10.1007/s11705-019-1831-2

摘要： A pulse plasma chemical vapor deposition (CVD) technique was developed for improving the growth yield of single-walled carbon nanotubes (SWNTs) with a narrow chirality distribution. The growth yield of the SWNTs could be improved by repetitive short duration pulse plasma CVD, while maintaining the initial narrow chirality distribution. Detailed growth dynamics is discussed based on a systematic investigation by changing the pulse parameters. The growth of SWNTs with a narrow chirality distribution could be controlled by the difference in the nucleation time required using catalysts comprising relatively small or large particles as the key factor. The nucleation can be controlled by adjusting the pulse on/off time ratio and the total processing time.

关键词： single-walled carbon nanotubes chirality-controlled synthesis pulse plasma chemical vapor deposition

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An artificial neural network based deep collocation method for the solution of transient linear and nonlinear partial differential equations

《结构与土木工程前沿（英文）》 2024年第18卷第8期页码 1296-1310 doi: 10.1007/s11709-024-1011-4

摘要： A combined deep machine learning (DML) and collocation based approach to solve the partial differential equations using artificial neural networks is proposed. The developed method is applied to solve problems governed by the Sine–Gordon equation (SGE), the scalar wave equation and elasto-dynamics. Two methods are studied: one is a space-time formulation and the other is a semi-discrete method based on an implicit Runge–Kutta (RK) time integration. The methodology is implemented using the Tensorflow framework and it is tested on several numerical examples. Based on the results, the relative normalized error was observed to be less than 5% in all cases.

关键词： collocation method artificial neural networks deep machine learning Sine–Gordon equation transient wave equation dynamic scalar and elasto-dynamic equation Runge–Kutta method

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Effects of operating conditions on membrane charge property and nanofiltration

Li XU, Li-Shun DU, Jing HE

《化学科学与工程前沿（英文）》 2011年第5卷第4期页码 492-499 doi: 10.1007/s11705-011-1143-7

摘要： The effects of the operating pressure, cross flow velocity, feed concentration, and temperature on the streaming and Zeta potential of the membranes were studied. The permeate flux and the retention rate under different nanofiltration operating conditions were also investigated. The results show that the higher pressure, feed concentration, temperature, and lower cross flow velocity lead to the higher absolute value of streaming and Zeta potential. The permeate flux of the nanofiltration decreases with the feed concentration and increases with not only the pressure but also the cross flow velocity and temperature. The higher the pressure and the cross flow velocity, the higher the retention rate. The lower feed concentration and higher temperature leads to lower retention rate. The effects of the operating conditions on the permeate flux and the retention rate were explained by the variation of the membrane charge property.

关键词： nanofiltration membrane streaming potential Zeta potential permeate flux retention rate

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Tumor growth and metastasis can be inhibited by maintaining genomic stability in cancer cells

null

《医学前沿（英文）》 2015年第9卷第1期页码 57-62 doi: 10.1007/s11684-015-0389-8

摘要：

The existence of cancer stem cells, stem-like cancer cells (SLCCs), or tumor-initiating cells is considered as the cause of tumor formation and recurrence, indicating the importance of studying novel therapy that targets SLCCs. The origin of SLCCs is controversial because of two competing hypotheses: SLCCs are either transformed from tissue adult stem cells or dedifferentiated from transformed progenitor cells. Our previous research demonstrates that SLCCs are inducible by increasing genomic instability in cancer cells. In this study, to block the emergence of SLCCs, aminoethyl isothiourea (AET), a compound that clears free radicals and is used to protect patients from radioactive exposure, was used as an agent that maintains genomic stability in combination with mitomycin C (MMC), a commonly used chemotherapeutic drug that damages DNA. Using a rabbit tumor model with VX2 hepatic carcinoma, we found that MMC alone increased lung metastases and disadvantaged survival outcome, but the combination of MMC and AET reversed this effect and even prolonged overall survival. Moreover, in a VX2 xenograft model by immunocompromised mice, MMC alone enriched tumor-initiating cells, but the administration of MMC in combination with AET eliminated tumor cells effectively. Furthermore, MMC alone enhanced genomic instability, but MMC combined with AET attenuated the extent of genomic instability in primary VX2 tumor tissue. Taken together, our data suggest that the genomic protector AET can inhibit the induction of SLCCs, and this combination treatment by AET and cytotoxic agents should be considered as a promising strategy for future clinical evaluation.

关键词： rabbit VX2 liver tumor mitomycin C AET stem-like cancer cells genomic instability