期刊文献+
共找到2,338篇文章
< 1 2 117 >
每页显示 20 50 100
Financial Calculation Problems and Countermeasure Analysis of Large-Scale Engineering Construction Projects
1
作者 Qiong Hou 《Proceedings of Business and Economic Studies》 2024年第2期15-21,共7页
The financial aspects of large-scale engineering construction projects profoundly influence their success.Strengthening cost control and establishing a scientific financial evaluation system can enhance the project’s... The financial aspects of large-scale engineering construction projects profoundly influence their success.Strengthening cost control and establishing a scientific financial evaluation system can enhance the project’s economic benefits,minimize unnecessary costs,and provide decision-makers with a robust financial foundation.Additionally,implementing an effective cash flow control mechanism and conducting a comprehensive assessment of potential project risks can ensure financial stability and mitigate the risk of fund shortages.Developing a practical and feasible fundraising plan,along with stringent fund management practices,can prevent fund wastage and optimize fund utilization efficiency.These measures not only facilitate smooth project progression and improve project management efficiency but also enhance the project’s economic and social outcomes. 展开更多
关键词 large-scale engineering construction projects Financial calculation Fund management
下载PDF
Modular Extremely Large-Scale Array Communication:Near-Field Modelling and Performance Analysis 被引量:1
2
作者 Xinrui Li Haiquan Lu +2 位作者 Yong Zeng Shi Jin Rui Zhang 《China Communications》 SCIE CSCD 2023年第4期132-152,共21页
This paper investigates the wireless communication with a novel architecture of antenna arrays,termed modular extremely large-scale array(XLarray),where array elements of an extremely large number/size are regularly m... This paper investigates the wireless communication with a novel architecture of antenna arrays,termed modular extremely large-scale array(XLarray),where array elements of an extremely large number/size are regularly mounted on a shared platform with both horizontally and vertically interlaced modules.Each module consists of a moderate/flexible number of array elements with the inter-element distance typically in the order of the signal wavelength,while different modules are separated by the relatively large inter-module distance for convenience of practical deployment.By accurately modelling the signal amplitudes and phases,as well as projected apertures across all modular elements,we analyse the near-field signal-to-noise ratio(SNR)performance for modular XL-array communications.Based on the non-uniform spherical wave(NUSW)modelling,the closed-form SNR expression is derived in terms of key system parameters,such as the overall modular array size,distances of adjacent modules along all dimensions,and the user's three-dimensional(3D)location.In addition,with the number of modules in different dimensions increasing infinitely,the asymptotic SNR scaling laws are revealed.Furthermore,we show that our proposed near-field modelling and performance analysis include the results for existing array architectures/modelling as special cases,e.g.,the collocated XL-array architecture,the uniform plane wave(UPW)based far-field modelling,and the modular extremely large-scale uniform linear array(XL-ULA)of onedimension.Extensive simulation results are presented to validate our findings. 展开更多
关键词 modular extremely large-scale array practical deployment projected apertures non-uniform spherical wave near-field modelling
下载PDF
Large-scale gas accumulation mechanisms and reservoir-forming geological effects in sandstones of Central and Western China 被引量:1
3
作者 LI Wei WANG Xueke +3 位作者 ZHANG Benjian CHEN Zhuxin PEI Senqi YU Zhichao 《Petroleum Exploration and Development》 2020年第4期714-725,共12页
Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects.Based on the geological theory and method of nat... Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects.Based on the geological theory and method of natural gas reservoir formation,this study examined the regional geological and structural background,formation burial evolution,basic characteristics of gas reservoirs,and fluid geology and geochemistry of typical petroliferous basins.The results show that the geological processes such as structural pumping,mudstone water absorption,water-soluble gas degasification and fluid sequestration caused by uplift and denudation since Himalayan stage all can form large-scale gas accumulation and different geological effects of gas accumulation.For example,the large-scale structural pumping effect and fluid sequestration effect are conducive to the occurrence of regional ultra-high pressure fluid and the formation of large-scale ultra-high pressure gas field;mudstone water absorption effect in the formation with low thickness ratio of sandstone to formation is conducive to the development of regional low-pressure and water free gas reservoir;the water-soluble gas degasification effect in large-scale thick sandstone can not only form large-scale natural gas accumulation;moreover,the degasification of water-soluble gas produced by the lateral migration of formation water will produce regional and regular isotopic fractionation effect of natural gas,that is,the farther the migration distance of water-soluble gas is,the heavier the carbon isotopic composition of methane formed by the accumulation. 展开更多
关键词 Central and Western China basins large-scale natural gas accumulation mechanism structural pumping effect mudstone water absorption effect water-soluble gas degasification effect fluid sequestration effect natural gas reservoir formation
下载PDF
A Fluid Experiment of Large-Scale Topography Effect on Baroclinic Wave Flows
4
作者 李国庆 Robin Kung Richard L.Pfeffer 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1992年第1期17-28,共12页
The effects of topography on baroclinic wave flows are studied experimentally in a thermally driven rotating annulus of fluid.Fourier analysis and complex principal component (CPC) analysis of the experimental data sh... The effects of topography on baroclinic wave flows are studied experimentally in a thermally driven rotating annulus of fluid.Fourier analysis and complex principal component (CPC) analysis of the experimental data show that, due to topographic forcing, the flow is bimodal rather than a single mode. Under suitable imposed experimental parameters, near thermal Rossby number ROT = 0.1 and Taylor number Ta = 2.2 × 107, the large-scale topography produces low-frequency oscillation in the flow and rather long-lived flow pattern resembling blocking in the atmospheric circulation. The 'blocking' phenomenon is caused by the resonance of travelling waves and the quasi-stationary waves forced by topography.The large-scale topography transforms wavenumber-homogeneous flows into wavenumber-dispersed flows, and the dispersed flows possess lower wavenumbers. 展开更多
关键词 A Fluid Experiment of large-scale Topography effect on Baroclinic Wave Flows
下载PDF
The Phenomena of Bifurcation and Catastrophe of Large-Scale Horizontal Motion in the Atmosphere under the Effect of Rossby Parameter
5
作者 万军 杨芳林 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第4期409-422,共14页
The stability question of large-scale horizontal motion in the atmosphere under the effect of Rossby parameter is discussed in this paper by using the qualitative analysis theory of ordinary differential equations. Th... The stability question of large-scale horizontal motion in the atmosphere under the effect of Rossby parameter is discussed in this paper by using the qualitative analysis theory of ordinary differential equations. The following aspects are reviewed: The stability of large-scale horizontal motion in the atmosphere accords with the common inertial stability criterion when the effect of Rossby parameter is not considered (Yang, 1983), and that, on the other hand, the motion will bifurcate two times with the variation of absolute vorticity of basic Zephyr flow at the initial position under the effect of Rossby parameter. Furthermore, in the inertial stable region, if the effect of geostrophic deviation at the initial position is considered, the motion will not only bifurcate but also generate a catastrophe. 展开更多
关键词 The Phenomena of Bifurcation and Catastrophe of large-scale Horizontal Motion in the Atmosphere under the effect of Rossby Parameter
下载PDF
Comparing the bullwhip effect under different inventory policies in engineering project supply chains 被引量:1
6
作者 张守健 薛小龙 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第6期761-765,共5页
Measuring bullwhip effect is useful for making better controls on production planning and enhancing the supply chain operating efficiency.First,this article establishes the comparative analysis model of bullwhip effec... Measuring bullwhip effect is useful for making better controls on production planning and enhancing the supply chain operating efficiency.First,this article establishes the comparative analysis model of bullwhip effect between(s,S)and Periodic Review(PR)inventory policy based on the quantitative bullwhip effect model under different inventories.Then,the impacts of lead time,inventory review time,autocorrelation coefficient,and the number of samples on the gap of bullwhip effect under(s,S)and PR IP are analyzed.The results show that bullwhip effect in PR is more intense than(s,S)inventory policy.Contractors should pay more attention to control bullwhip effect when adopting PR inventory policy to enhance the total operating efficiency of the engineering project supply chains. 展开更多
关键词 engineering project project efficiency supply chain bullwhip effect inventory policy
下载PDF
Capture-aware Bayesian RFID Tag Estimate for Large-scale Identification 被引量:1
7
作者 Haifeng Wu Yang Wang Yu Zeng 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期119-127,共9页
Dynamic framed slotted Aloha algorithm is one of popular passive radio frequency identification(RFID) tag anticollision algorithms. In the algorithm, a frame length requires dynamical adjustment to achieve higher iden... Dynamic framed slotted Aloha algorithm is one of popular passive radio frequency identification(RFID) tag anticollision algorithms. In the algorithm, a frame length requires dynamical adjustment to achieve higher identification efficiency.Generally, the adjustment of the frame length is not only related to the number of tags, but also to the occurrence probability of capture effect. Existing algorithms could estimate both the number of tags and the probability of capture effect. Under large-scale RFID tag identification, however, the number of tags would be much larger than an initial frame length. In this scenario, the existing algorithm's estimation errors would substantially increase. In this paper, we propose a novel algorithm called capture-aware Bayesian estimate, which adopts Bayesian rules to accurately estimate the number and the probability simultaneously. From numerical results, the proposed algorithm adapts well to the large-scale RFID tag identification. It has lower estimation errors than the existing algorithms. Further,the identification efficiency from the proposed estimate is also higher than the existing algorithms. 展开更多
关键词 ALOHA BAYESIAN capture effect large-scale radio frequency identification(RFID)
下载PDF
Macro mechanical parameters’ size effect of surrounding rock of Shuibuya project’s underground power station 被引量:1
8
作者 郭志华 周创兵 +2 位作者 周火明 盛谦 冷先伦 《Journal of Coal Science & Engineering(China)》 2005年第1期9-12,共4页
Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, cla... Scale effect is one of the important aspects in the macro mechanical parame- ters’ research of rock mass, from a new point of view, by means of lab and field rock me- chanics test, establishment of E^Vp relation, classification of engineering rock mass, nu- merical simulation test and back analysis based on surrounding rock’s displacement monitoring results of Shuibuya Project’s underground power station, rock mass deforma- tion module’s size effect of surrounding rock of Shuibuya Project’s undegroud power sta- tion was studied. It’s shown that rock mass deformation module’s scale effect of sur- rounding rock of Shuibuya Project’s undeground power station is obvious, the rock mass deformation module to tranquilization is 20% of intact rock’s. Finally the relation between rock mass deformation modules and the scale of research was established. 展开更多
关键词 岩石力学 位移反演 抗压强度 尺寸效应
下载PDF
Effectiveness of Using Project Method in Teaching Professional Foreign Language 被引量:1
9
作者 Marina Karachevtseva 《Sino-US English Teaching》 2013年第1期72-76,共5页
关键词 外语教学 专业英语教学 教学过程 学习 能力
下载PDF
Exploration and development of China's large-scale blast furance
10
作者 ZHU Renliang,ZHU Jinming and LI Jun Baosteel Ironmaking Plant,Baoshan Iron & Steel Co.,Ltd.,Shanghai 200941,China 《Baosteel Technical Research》 CAS 2010年第S1期10-,共1页
Large-scale BF is the tendency of domestic and foreign Iron-making technology.Due to the limit of resource,technology and equipment,we can not reach the planned goal after putting the big BF into production,it is of g... Large-scale BF is the tendency of domestic and foreign Iron-making technology.Due to the limit of resource,technology and equipment,we can not reach the planned goal after putting the big BF into production,it is of great significance to explore the key technologies again for the sound development of the large-scale BF.The paper highlights the unique advantages of large-scale BF and the practical performance of BFs in Baosteel,and explores the related parameter choice,comprehensively matched longevity technology optimization and tapping-stability improvement in terms of structure-design,longevity and equipments etc.The author stresses BF centered basic working regulation,hoping it can exert positive effect on the scientific development of large scale BF in China. 展开更多
关键词 large-scale blast furnace planned goal working regulation positive effect
下载PDF
Henan Cultural Information Resources Sharing Project Persistent Effect Mechanism Research
11
作者 Weigong CUI Hui JIAN +2 位作者 Yuan GAN Zhen ZHANG Yanfeng LIU 《Intelligent Information Management》 2009年第1期18-23,共6页
In order to reduce east--west section area of “digital divider” in China, Ministry of Culture laun- ches the National Cultural Information Resources Sharing Project in the mid-west provinces, and the state finance g... In order to reduce east--west section area of “digital divider” in China, Ministry of Culture laun- ches the National Cultural Information Resources Sharing Project in the mid-west provinces, and the state finance gives certain funds subsidy in the project construction period. Embarks highly from strategy during construction plan chosen and operational system management, as while as union digital library to construct a persistent effect mechanism. With the principle of state guidance, enterprise operation and benefit farmers, expand culture industry within the provincial and safeguard Cultural Information Resources Sharing Project sustainable development's, then promotes the rural economy culture full scale development. 展开更多
关键词 CULTURAL information resources SHARING project PERSISTENT effect mechanism RESEARCH IPTV digital LIBRARY CULTURAL industry
下载PDF
Effects of Sunspot on the Multi-Decadal Climate Projections
12
作者 ZHAO Zong-Ci LUO Yong HUANG Jian-Bin 《Advances in Climate Change Research》 SCIE 2014年第1期51-56,共6页
Most model generated projections of climate change for the future decades only consider anthropogenic activities.It is hard to think about the effects of solar activity and volcano effects,because the predictions of b... Most model generated projections of climate change for the future decades only consider anthropogenic activities.It is hard to think about the effects of solar activity and volcano effects,because the predictions of both solar activity and volcano effects are difficult.But as we know,the sun is the source of energy for the Earth’s climate system,and 展开更多
关键词 RCP effects of Sunspot on the Multi-Decadal Climate projections QBO cycle CESM Figure
下载PDF
For the Greater Good?—A Critical Reflection on Assessing Indirect Economic Effects Caused by Large Transport Projects
13
作者 Delphine   Patrick Witte +2 位作者 Thomas Hartmann Tejo Spit Annelies Zoomers 《Open Journal of Civil Engineering》 2019年第2期135-156,共22页
Investing in large transport projects affects the (potential) economic development of metropolitan areas. Yet, very little critical research has been performed to understand how to assess these effects. The relationsh... Investing in large transport projects affects the (potential) economic development of metropolitan areas. Yet, very little critical research has been performed to understand how to assess these effects. The relationship between infrastructure investments and regional economic development is complex and indirect, and many theoretical and methodological difficulties remain. On the one hand, the assumption that investing in infrastructure is important to sustain economic growth is sometimes doubted. On the other hand, it is argued that investments in infrastructure enhance the accessibility of urban regions and that in the slipstream of such investments, social problems in urban regions can be tackled as well. Despite these contrasting views, there is at least a consensus that transport infrastructure development depends on economic development and vice versa. Yet, in many cases, the method of assessing economic impacts highly affects the results. Therefore, this paper focuses on a critical reflection of methods for estimating economic effects of infrastructure investments. A critical evaluation is made based on Indonesian and Japanese cases. After conducting in-depth desk research on both cases, we found that the broader effects on affected group of people tend to be overlooked due to the problems of time and space dimensions, the chain reaction of effects, and inappropriate data practices. The assessment on the appraisal processes tends to overlook the broader economic implication due to narrow focus and the concept of efficiency of economic theory. 展开更多
关键词 LARGE Infrastructure projectS High-Speed Railways ECONOMIC effects Transport INVESTMENT ECONOMIC Assessment
下载PDF
Expanded models of the project portfolio selection problem with learning effect
14
作者 Li Wang Xingmei Li +1 位作者 Lu Zhao Zailing Liu 《CAAI Transactions on Intelligence Technology》 2019年第3期142-147,共6页
This research develops two new models for project portfolio selection, in which the candidate projects are composed of multiple repetitive units. To reflect some real situations, the learning effect is considered in t... This research develops two new models for project portfolio selection, in which the candidate projects are composed of multiple repetitive units. To reflect some real situations, the learning effect is considered in the project portfolio selection problem for the first time. The mathematical representations of the relationship between learning experience and investment cost are provided. One numerical example under different scenarios is demonstrated and the impact of considering learning effect is then discussed. 展开更多
关键词 Expanded MODELS the project PORTFOLIO SELECTION PROBLEM LEARNING effect
下载PDF
Characterization and Modeling of Large-Scale Fading for Radio Propagation in Rwanda
15
作者 Uwayezu Jean de Dieu Nsengiyumva Jean Marie Vianney 《Communications and Network》 2016年第1期22-30,共9页
Radio links are extensively used for voice and data communications at long distance. We analyze the radio propagation parameters that affect the received signal level on radio links in Rwanda and we determine the best... Radio links are extensively used for voice and data communications at long distance. We analyze the radio propagation parameters that affect the received signal level on radio links in Rwanda and we determine the best path loss model for prediction of the received signal level. Various models of propagation and the mathematical expressions of path loss are described here in order to come to the prediction of those propagation effects. By analyzing data collected for two links of MTN Rwanda: Gahengeri-Kibungo and Gahengeri-Jali, we find that the best predicting model is the normal distribution. 展开更多
关键词 Fading effects Radio Link Design Diffraction Fading Path Loss large-scale Fading
下载PDF
Performance of a Large-Scale Medical Waste Incinerator in a Referral Hospital
16
作者 Veilla E. Matee Samwel V. Manyele 《Engineering(科研)》 2015年第10期676-690,共15页
The aim of the study was to analyze the performance of large scale incinerator installed in a referral hospital. The study involved weighing and loading infectious waste of different composition (sharps and other wast... The aim of the study was to analyze the performance of large scale incinerator installed in a referral hospital. The study involved weighing and loading infectious waste of different composition (sharps and other waste), recording temperatures in the primary and secondary chamber with time, fuel used and collecting and weighing the bottom ash for 65 days. The analysis shows that the incinerator on average uses 362 L/day (45 L/h) to incinerate 945 kg of medical waste (40.8 kg/day of sharps waste and 904 kg/day of other waste), generating 51.2 kg of ash daily. The observed fuel consumption rate was too high necessitating corrective action. The average weight reduction was 94.6%. The study shows that the average sharps waste composition for medical waste incinerated was 4.3% and other waste was 95.7%. The incinerator capacity ranged between 100 and 130 kg/h. The fuel effectiveness ranged between 2.0 and 3.0 liters of diesel per kg of waste incinerated. The fuel effectiveness increased linearly with total waste incinerated and incinerator capacity, respectively, depending on the fuel consumption rate. 展开更多
关键词 Medical WASTE INCINERATOR large-scale INCINERATOR Sharps WASTE FUEL Consumption FUEL effectiveness INCINERATOR Capacity INCINERATOR ASH
下载PDF
Correlations between the Global Earth Healing and Global Consciousness Projects—Brain-Mind-Matter-Interactions through Physical Noise Generators
17
作者 Marcus Schmieke 《Natural Science》 2023年第5期191-198,共8页
Inspired by Roger Nelson’s Global Consciousness Project (GCP), the Global Earth Healing Project (GEHP) uses a network of several hundred physical noise generators to amplify the combined intentions of their users in ... Inspired by Roger Nelson’s Global Consciousness Project (GCP), the Global Earth Healing Project (GEHP) uses a network of several hundred physical noise generators to amplify the combined intentions of their users in order to infuse positive affirmations into the global consciousness. As mentioned in the original study design, it was intended to use the GCP as a reference for the effectiveness of its activities. The data of the GEHP consisting of 21 events from 2013 to 2020 is analyzed and statistically compared to the data of the GCP. An astonishing synchronicity was observed, which suggests an interaction between the brain states of the observers and the physical noise generators of the GCP. 展开更多
关键词 Global Consciousness project Global Consciousness Information Field Coherence PEAR Lab Quantum Entanglement Decline effect
下载PDF
Effectiveness Evaluation of the Construction of the Natural Forest Resources Protection Project in Haikou Forest Farm of Kunming
18
作者 ZHANG Zhihong WANG Yating +1 位作者 CHEN Jinlong YAN Yi 《Journal of Landscape Research》 2018年第2期42-44,共3页
The current situation about the natural forest resources protection project in Haikou Forest Farm of Kunming on the protection of forest resources, forest fire prevention, forest administration resource management, fo... The current situation about the natural forest resources protection project in Haikou Forest Farm of Kunming on the protection of forest resources, forest fire prevention, forest administration resource management, forest pests, and money management was briefed. Achievements made in the implementation of natural forest protection project in Haikou Forest Farm were analyzed, and problems existing in the project as well as corresponding countermeasures were expounded. 展开更多
关键词 林场 天然林 资源保护工程 景观设计
下载PDF
考虑质量传导的项目调度与人员配置集成优化 被引量:1
19
作者 陶莎 刘洋 周晶 《系统管理学报》 CSCD 北大核心 2024年第2期356-367,共12页
研究表明,质量问题是项目返工的主要原因之一,而人员技能水平是影响项目活动完成质量的关键因素。基于一般性的多技能资源受限项目调度问题,综合考虑人员技能水平以及活动间质量传导作用对活动完成质量的影响,进一步数学表达级联作用下... 研究表明,质量问题是项目返工的主要原因之一,而人员技能水平是影响项目活动完成质量的关键因素。基于一般性的多技能资源受限项目调度问题,综合考虑人员技能水平以及活动间质量传导作用对活动完成质量的影响,进一步数学表达级联作用下的返工子网以及重构的项目网络,并结合一个大型船舶制造项目案例进行实验分析。对比实验结果表明:所提出的模型可有效平衡有限人力资源在不同活动间的分配,有利于减少返工风险的级联,缩短项目总工期。进一步,通过质量评估区间和人员技能水平参数波动的随机实验,验证模型对两类参数波动具有一定的鲁棒性。 展开更多
关键词 项目调度 多技能 质量传导 返工子网 级联效应
下载PDF
自然对流下蒸汽凝结表面传热系数测定实验装置研制
20
作者 幸文婷 朱赤 +1 位作者 叶晓明 吴杰俊 《实验技术与管理》 CAS 北大核心 2024年第6期172-176,共5页
自然对流下蒸汽凝结表面传热系数测定实验是将蒸汽通过一组表面状态各不相同的管道,测定管道在大空间空气介质中自然冷却过程中的蒸汽凝结表面传热系数。由于管道的材质、几何形状、接触方式及管外空气流动状况都会不同程度地影响换热效... 自然对流下蒸汽凝结表面传热系数测定实验是将蒸汽通过一组表面状态各不相同的管道,测定管道在大空间空气介质中自然冷却过程中的蒸汽凝结表面传热系数。由于管道的材质、几何形状、接触方式及管外空气流动状况都会不同程度地影响换热效果,因此测定每根管道的表面传热系数值,可条理性和系统性地分析影响传热过程的各因素。该文设计了自然对流下蒸汽凝结表面传热系数测定实验装置,可开展管道材质、肋片结构、管道横截面几何形状、管道保温材料对传热系数的影响实验研究。应用实践表明,实验项目内容全面,提高了学生的课堂积极性,具有良好的教学效果。 展开更多
关键词 蒸汽凝结 表面传热系数 实验项目 教学效果
下载PDF
上一页 1 2 117 下一页 到第
使用帮助 返回顶部