Numerical Analysis of the Adhesive Forces in Nano-Scale Structure

Nanohairs, which can be found on the epidermis of Tokay gecko＇s toes, contribute to the adhesion by means of van der Waals force, capillary force, etc. This structure has inspired many researchers to fabricate the attachable nano-scale structures. However, the efficiency of artificial nano-scale structures is not reliable sufficiently. Moreover, the mechanical parameters related to the nano-hair attachment are not yet revealed qualitatively. The mechanical parameters which have influence on the ability of adhesive nano-hairs were investigated through numerical simulation in which only van der Waals force was considered. For the numerical analysis, finite element method was utilized and van der Waals force, assumed as 12-6 Lennard-Jones potential, was implemented as the body force term in the finite element formulation.

A Study of the Industrial Circular Economy Using an Essence Analysis Model

The concept of a circular economy can be applied to different business fields.The development of the existing industrial cycles with an overemphasis on economic development and the twisting concept of a circular economy,has limited any substantial contribution of the circular economy to environmental resources.In some cases,resources are even being consumed to create resource recycling.This puts a greater burden on the environment.To gain an understanding of the actual value of a circular economy to the environment and resources,an“Essence Analysis Model”has been used in this study.This combines sustainable development issues in a multi-faceted and multi-leveled analysis of the industrial circular economy model to guide its development more directly towards fundamentals.An analysis of the results of the“Essence Analysis Model”was used to find and change the original strategy,and develop a means of improving the circular economy model.The results of the study make an essential contribution to the sustainable development of environmental resources and the reduction of greenhouse gas emission.

“Products-Knowledge” Two-Dimensional Increment Model of Fashion Industry Value Chain Based on Industry Analysis

Fashion industry has a complex characteristic for it spans the first, second, and third industries. In addition, the characteristic of creative industry has high value-added for its knowledge outputting, which makes the traditional value-added analysis based on supply chain not easy and good enough to interpret its industry value-added features. From the perspective of "products-knowledge" two-dimensional analysis,a fashion industry value chain increment model is built,by simulating the process of "product flow" and "information flow" value-added. The fashion industry value chain increment model provides an effective way for the enterprise strategy formulation and production strategy adjustment.

Security Risk Analysis Model for Identification and Resolution System of Industrial Internet

Identification and resolution system of the industrial Internet is the“neural hub”of the industrial Internet for coordination.Catastrophic damage to the whole industrial Internet industry ecology may be caused if the identification and resolution system is attacked.Moreover,it may become a threat to national security.Therefore,security plays an important role in identification and resolution system of the industrial Internet.In this paper,an innovative security risk analysis model is proposed for the first time,which can help control risks from the root at the initial stage of industrial Internet construction,provide guidance for related enterprises in the early design stage of identification and resolution system of the industrial Internet,and promote the healthy and sustainable development of the industrial identification and resolution system.

Numerical Analysis of an Industrial Polycrystalline Silicon Photovoltaic Module Based on the Single-Diode Model Using Lambert W Function

It is adopted the single-diode solar cell model and extended for a PV module. The current vs. voltage (I-V) characteristic based on the Lambert W-function was used. The estimation parameters for the simulation approach of the photovoltaic (PV) module make use of Levenberg-Marquardt method. It was considered an industrial polycrystalline silicon photovoltaic (PV) module and the simulated results were compared with the experimental ones extracted from a specific datasheet. The I-V characteristic for the analysed PV module and its maximum output power are investigated for different operating conditions of incident solar radiation flux and temperature, as well as parameters related to the solar cells material and technology (series resistance, shunt resistance and gamma factor). The analysis gives indications and limitations for design and optimization of the performance for industrial PV modules. This study can be implemented in any type of PV module.

The Study of the Operating Performance of Marine Industry in the Blue Economic Zone: An Empirical Analysis Based on DEA and Tobit Model

The marine industry plays an important role in promoting the development of the blue economic zone,and the study of the operating performance of marine industry is of important practical significance. Using DEA method,this article measures the operating performance of marine industry in the blue economic zone. On this basis,using Tobit model,it analyzes the factors influencing the operating performance of marine industry. The results show that the industries of high carbon emission performance are basically the industries of high energy consumption,high emission and high pollution; the level of economic development and the number of important technological achievements can both significantly increase the pure technical efficiency; the sustainable environmental carrying capacity and the number of employees are conducive to improving the technological progress index and overall efficiency; the level of social infrastructure plays a role in promoting the overall efficiency,but the role is not obvious.

Study on Model Tests and Hydrodynamic Force Models for Free Spanning Submarine Pipelines Subjected to Earthquakes

A test rig is built to model the dynamic response of submarine pipelines with an underwater shaking table in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, China. Model tests are carried out to consider the effects of exciting wave directions and types. Based on the experimental results, two hydrodynamic force models derived from Morisen equation and Wake model are presented respectively. By use of hydrodynamic force models suitable for free spanning submarine pipelines under earthquakes, diseretized equations of motion are obtained and finite element models are established to analyze dynamic response of free spanning submarine pipeline subjected to multi-support seismic excitations. The comparison of numerical results with experimental results shows that the improved Morison and Wake hydrodynamic force models could satisfactorily predict dynamic response on the free spanning submarine pipelines subjected to earthquakes.

A model study of the effect of weather forcing on the ecology of a meromictic Siberian lake

We used a Lake Shira numerical model to estimate the response of the ecosystem of a saline meromictic lake to variations in weather parameters during the growing season. The sensitivity analysis of the model suggests that compared to other external(nutrient inflows) and internal(spring biomasses of food-web components) factors, weather parameters are among the most influential for both mixolimnetic(phyto-and zooplankton) and monimolimnetic(purple sulfur bacteria, sulfur reducing bacteria and hydrogen sulfide) food-web components. Calculations with different weather scenarios shows how changes in the water temperature and mixing depth af fect mixolimnetic and monimolimnetic food-web components and the depth of the oxic-anoxic interface in a meromictic lake. When weather forcing stimulates an increase in the biomass of food-web components in the mixolimnion, it produces cascading effects that lead to three results: 1) a higher content of detritus in the water column; 2) a higher content of hydrogen sulfide in the monimolimnion; 3) raising of the oxic-anoxic interface closer to the water-air surface. This cascading effect is complicated by the negative correlation between two light dependent primary producers located at diff erent depths—phytoplankton in the mixolimnion and purple sulfur bacteria at the oxic-anoxic interface. Thus, weather conditions that stimulate higher phytoplankton biomass are associated with a higher detritus content and lower biomass of purple sulfur bacteria, a higher content of hydrogen sulfide and a shallower oxic-anoxic interface. The same weather conditions(higher wind, lower cloud cover, and lower air temperature) promote a scenario of less stable thermal stratification. Thus, our calculations suggest that weather parameters during the summer season strongly control the mixing depth, water temperature and the mixolimnetic food web. An effect of biogeochemical and physical interactions on the depth of the oxicanoxic interface is also detectable. However, intra-and interannual climate and weather effects will be more important for the control of meromixis stability.

Large Deformation Analysis and Synthesis of Elastic Closed-loop Mechanism Made of a Certain Spring Wire Described by Free Curves

Recently novel mechanisms with compact size and without many mechanical elements such as bearing are strongly required for medical devices such as surgical operation devices. This paper describes analysis and synthesis of elastic link mechanisms of a single spring beam which can be manufactured by NC coiling machines. These mechanisms are expected as disposable micro forceps. Smooth Curvature Model（SCM） with 3rd order Legendre polynomial curvature functions is applied to calculate large deformation of a curved cantilever beam by taking account of the balance between external and internal elastic forces and moments. SCM is then extended to analyze large deformation of a closed-loop curved elastic beam which is composed of multiple free curved beams. A closed-loop elastic link is divided into two free curved cantilever beams each of which is assumed as serially connected free curved cantilever beams described with SCM. The sets of coefficients of Legendre polynomials of SCM in all free curved cantilever beams are determined by taking account of the force and moment balance at connecting point where external input force is applied. The sets of coefficients of Legendre polynomials of a nonleaded closed-loop elastic link are optimized to design a link mechanism which can generate specified output motion due to input force applied at the assumed dividing point. For example, two planar micro grippers with a single pulling input force are analyzed and designed. The elastic deformation analyzed with proposed method agrees very well with that calculated with FEM. The designed micro gripper can generate the desired pinching motion. The proposed method can contribute to design compact and simple elastic mechanisms without high calculation costs.

The driving force of water resource stress change based on the STIRPAT model:take Zhangye City as a case study

A prominent contradiction between supply and demand of water resources has restricted local development in social and economic aspects of Zhangye City,located in a typical arid region of China.Our study quantified the Water Resource Stress Index(WRSI)from 2003 to 2017 and examined the factors of population,urbanization level,GDP per capita,Engel coefficient,and water consumption per unit of GDP by using the extended stochastic impact by regression on population,affluence and technology(STIRPAT)model to find the key factors that impact WRSI of Zhangye City to relieve the pressure on water resources.The ridge regression method is applied to improve this model to eliminate multicollinearity problems.The WRSI system was developed from the following three aspects:water resources utilization(WR),regional economic development water use(WU),and water environment stress(WE).Results show that the WRSI index has fallen from 0.81(2003)to 0.17(2017),with an average annual decreased rate of 9.8%.Moreover,the absolute values of normalized coefficients demonstrate that the Engel coefficient has the largest positive contribution to increase WRSI with an elastic coefficient of 0.2709,followed by water consumption per unit of GDP and population with elastic coefficients of 0.0971 and 0.0387,respectively.In contrast,the urbanization level and GDP per capita can decrease WRSI by−0.2449 and−0.089,respectively.The decline of WRSI was attributed to water-saving society construction which included the improvement of water saving technology and the adjustment of agricultural planting structures.Furthermore,this study demonstrated the feasibility of evaluating the driving forces affecting WRSI by using the STIRPAT model and ridge regression analysis.

Structural Analysis of Platforms with the Effect of Joint Flexibility

A modified space beam element is presented in this paper to consider the local joint flexibility of T, Y tubular joints subjected to axial forces and in-plane bending moments for analysis of platforms. Two numerical examples are shown to verify the efficiency and validity of the method presented here.

Assessment of pipeline stability in the Gulf of Mexico during hurricanes using dynamic analysis

Pipelines are the critical link between major offshore oil and gas developments and the mainland. Any inadequate on-bottom stability design could result in disruption and failure, having a devastating impact on the economy and environment. Predicting the stability behavior of offshore pipelines in hurricanes is therefore vital to the assessment of both new design and existing assets. The Gulf of Mexico has a very dense network of pipeline systems constructed on the seabed. During the last two decades, the Gulf of Mexico has experienced a series of strong hurricanes, which have destroyed, disrupted and destabilized many pipelines. This paper first reviews some of these engineering cases. Following that, three case studies are retrospectively simulated using an in-house developed program. The study utilizes the offshore pipeline and hurricane details to conduct a Dynamic Lateral Stability analysis, with the results providing evidence as to the accuracy of the modeling techniques developed.

Influencing factors and contribution analysis of CO_(2) emissions originating from final energy consumption in Sichuan Province,China

Within the context of CO_(2)emission peaking and carbon neutrality,the study of CO_(2)emissions at the provincial level is few.Sichuan Province in China has not only superior clean energy resources endowment but also great potential for the reduction of CO_(2)emissions.Therefore,using logarithmic mean Divisia index(LMDI)model to analysis the influence degree of different influencing factors on CO_(2)emissions from final energy consumption in Sichuan Province,so as to formulate corresponding emission reduction countermeasures from different paths according to the influencing factors.Based on the data of final energy consumption in Sichuan Province from 2010 to 2019,we calculated CO_(2)emission by the indirect emission calculation method.The influencing factors of CO_(2)emissions originating from final energy consumption in Sichuan Province were decomposed into population size,economic development,industrial structure,energy consumption intensity,and energy consumption structure by the Kaya-logarithmic mean Divisia index(LMDI)decomposition model.At the same time,grey correlation analysis was used to identify the correlation between CO_(2)emissions originating from final energy consumption and the influencing factors in Sichuan Province.The results showed that population size,economic development and energy consumption structure have positive contributions to CO_(2)emissions from final energy consumption in Sichuan Province,and economic development has a significant contribution to CO_(2)emissions from final energy consumption,with a contribution rate of 519.11%.The industrial structure and energy consumption intensity have negative contributions to CO_(2)emissions in Sichuan Province,and both of them have significant contributions,among which the contribution rate of energy consumption structure was 325.96%.From the perspective of industrial structure,secondary industry makes significant contributions and will maintain a restraining effect;from the perspective of energy consumption structure,industry sector has a significant contribution.The results of this paper are conducive to the implementation of carbon emission reduction policies in Sichuan Province.

Models for Analyzing the Driving Force of Cultivated Land Supply Change

This paper focuses on a series of quantitative an al ysis models, such as grey relational analysis model, hierarchical cluster an alysis model, principal component analysis model, linear regression model and elastic coefficient model. These models are used to analyze the comprehensive function and effect of driving forces systemically, including analysis on featur es, analysis for differentiating the primary and the secondary, analysis on comp rehensive effects, analysis of elasticity, analysis of prediction. The primary a nd characteristic factors can be extracted by analysis of features and analysis for differentiating the primary and the secondary. Analysis on prediction an d elasticity can predict the area of cultivated land in the future and find out which factors exert great influence on the cultivated land supply.

Spatial restructuring and the logic of industrial land redevelopment in urban China: Ⅳ. A case study of jointly redevelopment by multi-actors

Within the inventory era, urban shrinkage characterized by economic decline and space decay has been widely witnessed in China. The modes and trajectories of urban redevelopment have thus become areas of major concern for both policymakers and scholars. Taking the multi-actor participation nature of redevelopment, this paper stemming from the game-theoretical approach demonstrates in empirical terms on two major fronts. First, the redevelopment of industrial land without the transfer of land use right is shown to be deadlocked by the incapacitation of the original land-user and unlocked with the participation of the new developer. Second, the preference of the original land-user to maximize its interests by operating by itself rather than continue to cooperate with the new developer is observed in the post-redevelopment stage. Therein, the entrepreneurial local government acts only as a “mediator” between the two market entities and tends not to directly intervene in their cooperation. Thus that, it is the reasonable distribution of potential benefits or the pricing of different rights in the land property right bundle rather than their definition that matters more for land redevelopment. Because the delineation of land property rights has never been a problem in a mature land market, particularly for stock industrial land.

高铁开通对物流业发展影响的实证研究

促进物流业的高质量发展是建设现代化产业体系的一个重要方面,也是内循环发展格局的重要环节,高铁网建设的不断进展使铁路运输能力得到质的飞跃,探讨和分析高铁货运以及高铁开通对物流业的影响具有现实意义和必要性。依据运输业和物流业发展现状及规划发展的相关文件,论证了高铁开通对物流业的影响机制,建立物流业综合水平测度指标,通过PSM-DID模型实证分析高铁对物流发展的影响,进行异质性检验、机制检验等。研究表明:高铁开通对城市区域物流发展水平整体上具有促进作用;高铁对物流业的影响与该城市的规模、等级、地理位置以及运输业市场结构密切相关;高铁对物流业的影响主要通过区域经济增长、货运运输量提升、物流人力资本提升等途径实现。

四川省种植业碳排放现状、动态演进及预测

加强种植业碳排放测算,可为推进种植业绿色低碳转型提供重要依据。本文针对种植业从投入到产出的全过程,基于农地利用碳排放、稻田CH4排放和农地N2O排放3类主要来源,运用碳排放系数法测算2010—2021年四川省种植业碳排放量,从时序特征和地区差异揭示四川省种植业碳排放特征,采用核密度分析法剖析四川省种植业碳排放动态演进趋势,运用灰色预测模型预测2022—2030年四川省种植业碳排放量和碳排放强度。结果表明:1)四川省种植业碳排放量在2010—2016年间呈波动上升趋势,2016年以后呈波动下降趋势,其碳排放强度在2010—2021年间持续降低,四川省种植业碳排放以农地利用和稻田CH_(4)碳排放为主,2021年较2010年农地利用碳排放和稻田CH_(4)排放比重均略有减少,而农地N_(2)O排放比重有所上升。2)四川省各市(自治州)种植业碳排放量和强度差异明显,2021年碳排放量最高的南充市比最低的甘孜高24.69倍,碳排放强度最高的巴中市比最低的甘孜高2.8倍。3)四川省五大区域种植业碳排放动态演进呈差异化特征,成都平原、川南、川东北、攀西和川西北五大区域种植业碳排放强度总体均呈下降趋势,但下降速度和变化幅度各异,总体上五大区域内碳排放强度的差距在逐步缩小。4)四川省种植业碳排放量和碳排放强度预计保持稳步下降态势,估计到2025年和2030年四川省种植业碳排放量将分别减少约68.72万t和137.84万t,碳排放强度将分别减少约0.13 t·万元^(-1)和0.26 t·万元^(-1)。基于此,四川省种植业碳减排应主要关注源于化肥投入和稻田CH4碳排放,因此需因地制宜采取差异化的减排措施,强化农业科技创新和推广,提升四川省种植业绿色低碳整体发展水平。

山区铁路隧道工程资源环境影响效应评估研究

山区地质复杂、环境敏感、生态脆弱,致使铁路隧道建设难度大,且在资源节约、环境保护等方面面临较高要求。绿色设计作为绿色建设的先行环节,对减少隧道建设对资源环境的扰动作用,达到资源节约、环境友好的目的起关键引领作用。为定量评估山区铁路隧道工程的资源环境影响效应、衡量隧道设计的绿色程度,提出一种山区铁路隧道工程资源环境影响效应分析方法。首先,基于“驱动力-状态-响应”模型(Driving force-State-Response,DSR),以隧道设计参数为驱动力指标、资源环境状况为状态指标、隧道设计措施为响应指标,构建山区铁路隧道工程资源环境影响效应评估指标体系,并建立各指标分级标准;其次,运用一种具有自学习自调整能力的支持向量回归模型(Support Vector Regression,SVR)对隧道工程的资源环境影响效应进行评估;再次,以驱动力指标和响应指标为分析对象,运用考虑指标间关联关系及叠加效应的敏感性分析法,甄别对隧道工程资源环境影响效应优化具有重要影响的隧道设计因素;最后,以某山区铁路隧道工程为例,得到该隧道工程的资源环境影响效应值为4.7157,对应等级为较好,表明该隧道工程绿色设计水平较好,资源集约节约利用较合理、环境保护力度较大,可为其他类似工况隧道工程的绿色设计提供借鉴。此外,分析结果显示,注浆加固效果是导致该隧道工程资源环境影响效应变化最敏感的因素,其次为清污分流比例,可着重从这2个方面进行优化设计,以实现隧道工程资源环境影响效应的进一步优化。研究结果验证了本文研究方法的适用性和可操作性,可为山区铁路隧道工程资源环境影响效应评估及明确隧道工程优化设计方向提供科学依据。

发展交通运输领域新质生产力的内在逻辑、作用机理与推进路径

以新质生产力推动交通运输高质量发展是理论演进、技术变革、宏观要求和行业转型等共同的方向,在逻辑上有其必然性。通过分析交通运输与新质生产力的作用机理,认为发展交通运输领域新质生产力与加快建设交通强国、构建现代综合交通运输体系一脉相承,是交通运输高质量发展途径、方法的呈现形式,交通运输对于其他领域新质生产力培育也有很大的助力。新质生产力在交通运输领域的表现形式有交通运输新技术(新动能)、新模式(新业态)、新产业等三种。结合新质生产力对劳动者、生产资料和劳动对象的新要求,从人才、技术、产业和市场等角度研究并提出了交通运输领域新质生产力的推进路径,为发展交通运输领域新质生产力、推动交通运输高质量发展提供参考。