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Ceramic Properties of Three Specimens of Alluvial Clays Used in Local Constructions from Mbouda Clay Deposit, West Cameroon
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作者 Philémon Zo’o Zame Sylvain Kouayep Lawou +3 位作者 Philippe Samba Assomo Audrey Erman Moutsou Yannick Lontchi Dzoti Véronique Kamgang Kabeyene Beyala 《Journal of Minerals and Materials Characterization and Engineering》 2024年第5期265-279,共15页
The Mbouda alluvial deposit is located at the foot of the Bamboutos mountains (West Cameroon) where three types of clayey materials are widespread. The populations collect these clays in their natural state in view of... The Mbouda alluvial deposit is located at the foot of the Bamboutos mountains (West Cameroon) where three types of clayey materials are widespread. The populations collect these clays in their natural state in view of constructions using fired bricks or compressed blocks. Unfortunately, these buildings are not strong. This study investigates the causes of the strengthlessness of buildings and suggests solutions to overcome the difficulty. The research content includes field and laboratory studies. The methodology consists of sampling black (AN), white (AB) and red (AR) clays specimens identified in the study area and analysing them simultaneously at MIPROMALO (Cameroon) and at ACME LAB in Vancouver (Canada). The results obtained show a high sand content in the samples AN (64%), AB (55.2%), AR (30.9%). The compressive strength of the built specimens is low at 900˚C considered as the traditional firing temperature AN (0.94 MPa), AB (5.25 MPa), AR (2.18 MPa). The mineralogical series are identically made by kaolinite, chlorite, gibbsite, quartz, muscovite, biotite, goethite, magnetite and hematite. Silica (SiO2) presents higher contents AN (52.87%), AB (48.02%), AR (47.68%) followed by alumina (Al2O3) AN (29.96%), AB (28.13%), AR (24.72%). The other elements are poorly represented. 展开更多
关键词 SAND BRICKS Clays Mechanical Properties Local constructions
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Measurement of the Level of Knowledge of the Sands Used in Constructions in Togo
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作者 Ezoba Nayo Kossi Bollanigni Amey +1 位作者 Essé MawuléEdorh Komla Assogba Kassegne 《Journal of Minerals and Materials Characterization and Engineering》 2024年第4期225-235,共11页
Faced with the proliferation of quarries extracting silty sand and river sand used in the building and public works sector in Togo, recognition of the granular properties of these materials remains a major challenge f... Faced with the proliferation of quarries extracting silty sand and river sand used in the building and public works sector in Togo, recognition of the granular properties of these materials remains a major challenge for builders. This study aims to take stock of the use of sand in construction in Togo. One hundred and eighteen (118) sand quarries in operation, including thirty-eight (38) silty sand quarries and eighty (80) river sand quarries, were identified following surveys carried out among stakeholders involved in the chain of construction on 40% of the national territory. It appears from these surveys that river sands (59.43% to 84.68%) are prioritized over silty sands (15.32% to 40.57%). Three (3) main reasons are behind the choice of sand type;namely, proximity (28%), cleanliness (25%), good appearance (25%). These three (03) reasons partly explain the strong dependence of users on the sands located in their vicinity as well as the related expenses. Thus, making data available on the characteristics of sand, the materials most used in construction in Togo, would contribute to improving the housing conditions of the Togolese population. . 展开更多
关键词 SANDS TOGO Reasons for Use Construction
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The Technique of the Tri-Layer Coating: An Effective Solution for the Protection of Earthen Constructions
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作者 Sinko Banakinao Soviwadan Drovou +1 位作者 Komlan Lolo Kodjo Attipou 《Open Journal of Civil Engineering》 2023年第4期706-722,共17页
The problem with earth constructions is their low resistance to water. Step by step, the water degrades the exterior facings of the structures and ends up creating zones of weakness through the structures, making them... The problem with earth constructions is their low resistance to water. Step by step, the water degrades the exterior facings of the structures and ends up creating zones of weakness through the structures, making them collapse and creating enormous socio-economic problems, especially in rural areas. The solutions proposed to date, like the use of straw, cow dung, boiled skins, banana leaves, tar, cement soil, have shown their limits. Generally, the poor adhesion between the protected material and the protective layer means that the latter always ends up peeling off. This work, which is inspired by the traditional practice where plant tannins are used to brush the earthen walls to waterproof them, proposes a tri-layer coating composed of soil, powder and hydrolysable tannins extracted from the stem bark of Bridelia. This work focuses on the geotechnical characterization of the soil, the extraction of hydrolysable tannin, the manufacture of the micro-coating, the resistance tests carried out on the micro-coating, the technique of implementation and the test of evaluation of the performance of the tri-layer coating. The results obtained show that not only does the tri-layer coating adhere perfectly to the layer to protect, but it also waterproofs it and protects it against shocks. 展开更多
关键词 Tri-Layer TANNIN COATING Soil Earthen constructions
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On the Principal Constructions to Express the Future Time and Their Implications
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作者 朱虹 《海外英语》 2019年第13期256-257,共2页
According to the definition of tense,English has no actual future tense.The ways to express future time in English vary with the specific situation.We should avoid frequently using the same way to express the future.I... According to the definition of tense,English has no actual future tense.The ways to express future time in English vary with the specific situation.We should avoid frequently using the same way to express the future.It is important to study the different construction of the future time in English and its implications in order to make it clear that the appropriate construction to cope with the specific situation should be noticed. 展开更多
关键词 FUTURE constructions IMPLICATION of FUTURE constructions
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Constructions and Preliminary HV Conditioning of a Photocathode Direct-Current Electron Gun at IHEP 被引量:3
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作者 李小平 王九庆 +6 位作者 徐金强 裴士伦 肖欧正 何大勇 吕琨 孔祥成 彭晓华 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第7期56-60,共5页
As one of the most important key technologies for future advanced light source based on the energy recovery linac, a photocathode dc electron gun is supported by Institute of High Energy Physics (IHEP) to address th... As one of the most important key technologies for future advanced light source based on the energy recovery linac, a photocathode dc electron gun is supported by Institute of High Energy Physics (IHEP) to address the technical challenges of producing very low ernittance beams at high average current. Construction of the dc gun is completed and a preliminary high voltage conditioning is carried out up to 440 k V. The design, construction and preliminary HV conditioning results for the dc gun are described. 展开更多
关键词 ERL constructions and Preliminary HV Conditioning of a Photocathode Direct-Current Electron Gun at IHEP HV
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THE ECOLOGICAL FEATURES AND ECOLOGICAL CONSTRUCTIONS OF A MIRE IN CHINA
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作者 黄锡畴 《Chinese Geographical Science》 SCIE CSCD 1991年第1期56-63,共8页
A mire as an ecosystem, usually is considered as an aquatic ecosystem,or a terrestrial ecosystem. The author thinks that mire is a special ecosystem between these two ecosystems, and proposes the new concept that a mi... A mire as an ecosystem, usually is considered as an aquatic ecosystem,or a terrestrial ecosystem. The author thinks that mire is a special ecosystem between these two ecosystems, and proposes the new concept that a mire is a natural ecosystem with transitional nature of semi-water and semi-land formed by water and land interaction. The paper discusses the nature of the mire ecosystem, the exploitation and utilization and ecological construction of a mire. 展开更多
关键词 MIRE ECOSYSTEM nature of semi-water and semi- land ECOLOGICAL constructions
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Some Explicit Constructions of Type-Ⅱ,Ⅲ,Ⅳ,Ⅴ QC-LDPC Codes with Girth 6
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作者 Farzaneh Abedi Mohammad Gholami 《China Communications》 SCIE CSCD 2020年第5期89-109,共21页
Multi-type quasi-cyclic(QC) low-density parity-check(LDPC) codes can be considered as multiple-edge protograph QC-LDPC codes having some advantages in the minimum Hamming distance bound over single-edge protograph cod... Multi-type quasi-cyclic(QC) low-density parity-check(LDPC) codes can be considered as multiple-edge protograph QC-LDPC codes having some advantages in the minimum Hamming distance bound over single-edge protograph codes or type-Ⅰ QC-LDPC codes when the base matrices have the same size. In this paper, we investigate a class of multi-type QC-LDPC codes whose parity-check matrices contain just one blockrow of circulants and we obtain the generator matrix of such codes in general form. Using the permutation arrays and defining injection arrays, we present a new approach to construct a class of high-rate type-Ⅰ QC-LDPC codes with girth 6 from the constructed 4-cycle free multi-type QC-LDPC codes. In continue, for 2 ≤ w≤6, some type-w QC-LDPC codes with girth 6 are constructed explicitly such that the constructed codes are flexible in terms of rate and length. To the best of our knowledge, for w = 5,6, this is the first paper which deals with the explicit construction of type-w QC-LDPC codes with girth 6 and high rates. Moreover, for w = 3, 4, the constructed type-w QC-LDPC codes have better(6,8)-cycle multiplicities than the codes with minimum achievable length recently constructed by cyclic difference families(CDFs). Simulation results show that the binary and non-binary constructed codes outperform the constituent underlying QC-LDPC codes. 展开更多
关键词 QC-LDPC codes permutation arrays GIRTH explicit constructions
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The Dimensions of Graphs and Constructions of Their Bases
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作者 王斌 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第2期71-76,共6页
Let G(V,E) be a connected graph and W{w 1,w 2,…,w k} an ordered set of V. Given v∈V, the representation of v with respect to W is the k-vector r(v|W)(d(v,w 1),d(v,w 2),…,d(v,w k)). The set W is a resolving set of G... Let G(V,E) be a connected graph and W{w 1,w 2,…,w k} an ordered set of V. Given v∈V, the representation of v with respect to W is the k-vector r(v|W)(d(v,w 1),d(v,w 2),…,d(v,w k)). The set W is a resolving set of G if r(u|W)r(v|W) implies that uv for all pairs {u,v} of vertices of G. The resolving set of G with the smallest cardinality is called a basis of G. The dimension of G, dim (G), is the cardinality of a basis for G. The bound of a Cartesian product of a connected graph H and a path P k was reached: dim(H)≤dim(H×P k)≤dim(H)+1. Then, the dimension value of some graphs was given. At last, the constructions of some graphs’ bases were showed. 展开更多
关键词 basis of graph dimension of graph constructions of bases
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Rehabilitation of Semi-mountainous Forest Area Using Bioclimatic Forest Constructions in Greece
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作者 Sarantis-Angelos Liampas Christos Stamatiou +3 位作者 Dimitris Farmakis Christodoulos Daoutis George Tasionas Vasileios Drosos 《Journal of Environmental Science and Engineering(A)》 2018年第2期82-88,共7页
Forest constructions are structures erected for serving the forest exploitation and utilization of its products,including recreation.The construction principals of a standard forest village with wooden lodgings apply ... Forest constructions are structures erected for serving the forest exploitation and utilization of its products,including recreation.The construction principals of a standard forest village with wooden lodgings apply principles of bioclimatic design and use ecological building materials.It highlights the area and helps to maintain the natural beauty of the forest.Accurate analysis of the area of the forest village requires the creation of topographic plan with great precision.Topographical drawing in AutoCAD in coordinate system HGRS’87 with contour interval 2 meters with the help of geodetic GPS was created.The aim of this paper was the rehabilitation of a semi-mountainous area taking into consideration environmental,economic,ergonomic and architectural constrains with the help of Google Earth.The area of the camp outside the village of Dadia of Evros Prefecture was granted by the army to the Forest Office of Soufli and remains unexploited until today.The installations were recorded and shown together with the topographic diagram and an image from Google Earth for the understudy-area.All the proposed facilities are presented in a Google Earth image and in a three-dimensional view.The forest village will be composed of 20 wooden lodges with a capacity of 4 persons each.The lodges will be designed around the bioclimatic design,in order to exercise the least impact on the natural environment and to meet the needs of residents for a comfortable and relaxed living.The landscaping was based on better utilization and lower environmental cost of construction in the landscape. 展开更多
关键词 FOREST constructions FOREST village GEODETIC GPS landscape Google Earth AutoCAD
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Free State Constructions
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作者 Thamir A1 Barrag Mohammad A1 Zahrani 《Sino-US English Teaching》 2017年第2期104-115,共12页
This paper attempts to investigate Free State (FS) in Hijazi Arabic. This structure is not used in Modem Standard Arabic. It was introduced into the Arabic dialects later on as a competing structure to the Construct... This paper attempts to investigate Free State (FS) in Hijazi Arabic. This structure is not used in Modem Standard Arabic. It was introduced into the Arabic dialects later on as a competing structure to the Construct State (CS). First, we discuss the characteristics of this structure in comparison to its counterpart: the CS. we show that semantically FS can express only three semantic relations out of the five semantic relations CS can convey. Furthermore, the paper shows that the FS genitive exponent in HA "hagg" agrees with the head noun of the matrix DP in phi-features. The discussion then shifts to the origin of the genitive exponent hagg. The paper argues that it is originally a noun that has acquired a new meaning: an anaphor that means something like "one of". Hence, we gloss hagg as ANAPH. Contrary to previous analyses for the FS genitive exponent, the paper proposes that hagg, the noun, heads its own CS and it is linked to the preceding DP by a binding relationship, which involves feature agreement in gender and number. Consequently, we propose that hagg-headed CS has the same structure of the nominal CS. Finally, we investigate the occurrence of both FS and CS structures in HA and show when one structure is preferred to the other. 展开更多
关键词 syntax ARABIC constructions ANNEXATION STATE ANAPHOR MINIMALISM
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Special Marking of 3D Networks' Points for the Monitoring of Modern Constructions
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作者 Evangelia Lambrou George Pantazis Konstantinos Nikolitsas 《Journal of Civil Engineering and Architecture》 2011年第7期643-649,共7页
In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncert... In order to monitor the deformations of modern constructions a local 3D network was usually being established at the surrounding area. The centering error, of both the instrument and targets, causes significant uncertainties in the determination of the x, y, z coordinates of the network's points. In order to assure precise centering for both the instrument and targets, not only for the accessible but also for the inaccessible network's points, a prototype way of marking is being implied. A special semi-permanent portable metallic stand (Photo 1) was manufactured for marking the accessible points. The stand provides forced instrument centering of the order of_+0, lmm. It is light enough to carry, it accelerates and facilitates the centering and leveling of the instrument as well as it eliminates the time needed for the measurements. The applied laboratory checks in order to certify the suitability of its use and the provided accuracy are being described. For the inaccessible points special targets were used. The targets were put in permanent attachments (Photos 7-8), which were also manufactured. Useful conclusions were drawn when these special accessories were used in to a 3D network, which was established for the monitoring of a new football stadium. Two measurement phases were carried out. The first one is with the stadium empty and the second one is when it was crowded (about 32000 people) during a significant football match. 展开更多
关键词 Precise centering point marking geodetic control networks monitoring modern constructions.
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TWO NEW CONSTRUCTIONS OF CARTESIAN AUTHENTICATION CODES FROM SYMPLECTIC GEOMETRY 被引量:4
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作者 GAO YOU AND ZOU ZENGJIA (Department of Basic Science, Northeast Institute of Electric Power, Jinn 132012). 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第3期345-356,共12页
In this paper, two new constructions of Cartesian authentication codes from symplectic geometry are presented and their size parameters are computed.
关键词 Cartesian authentication code construction symplectic geometry
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Chinese Liandong(Serial Verb) Constructions from the Perspective of Figure-Ground Relation
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作者 刘鹏 《海外英语》 2011年第1X期253-254,256,共3页
Empty categories,which lack phonological form and hence are not visible in the phonetic representation of the sentence,have both syntactic and semantic properties.Null subjects PRO and pro are base-generated empty cat... Empty categories,which lack phonological form and hence are not visible in the phonetic representation of the sentence,have both syntactic and semantic properties.Null subjects PRO and pro are base-generated empty categories.This thesis,based on Chomsky's theory about empty categories and research achievements made by Chinese scholars,attempts to analyze the liandong(Serial Verb) construction from Figure and Ground perspective. 展开更多
关键词 PRO Liandong(Serial) VERB construction FIGURE-GROUND
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Traffic organization during urban road constructions
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作者 宋丽英 《Journal of Beijing Institute of Technology》 EI CAS 2012年第2期216-221,共6页
This research presented a bi-level programming approach to optimize the schedule of ur- ban road construction activities based on a hypothetical transport network, with an objective of mini- mizing the overall traffic... This research presented a bi-level programming approach to optimize the schedule of ur- ban road construction activities based on a hypothetical transport network, with an objective of mini- mizing the overall traffic delays. A heuristic algorithm was utilized to identify a set of road construction schedules, while PARAMICS was adopted to estimate the total travel time in the network under each road construction scenario. To test the performance of proposed heuristics-simulation methodology, a numerical test was implemented. The overall results suggested that the proposed methodol- ogy could quickly find the optimum solution with good convergence. 展开更多
关键词 artificial intelligence microscopic traffic simulation road construction road network
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Study on destructions and reinforcement measures of mined constructions
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作者 成枢 崔冬梅 《Journal of Coal Science & Engineering(China)》 2007年第3期373-376,共4页
Ground movement and deformation caused by underground mining would destroy the constructions located within subsidence area. Constructions would suffer different destructions with different location. The effect of gro... Ground movement and deformation caused by underground mining would destroy the constructions located within subsidence area. Constructions would suffer different destructions with different location. The effect of ground deformation caused by underground mining to constructions was analyzed. Analyzed the destructive types of constructions in different ground movement and deformation. Taking a two-storey building for example, the walls were reinforced by computation before mining. To protect the construction the reinforcement measures to the construction before mining were studied. 展开更多
关键词 mining subsidence CONSTRUCTION DESTRUCTION REINFORCEMENT
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CONSTRUCTIONS OF THE GENERAL SOLUTION FOR A SYSTEM OF PARTIAL DIFFERENTIAL EQUATIONS WITH VARIABLE COEFFICIENTS
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作者 张鸿庆 杨光 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1991年第2期149-153,共5页
Solving partial differential equations Has not only theoretical significance, but also practical value. In this paper, by the property of conjugate operator, we give a method to construct the general solutions of a sy... Solving partial differential equations Has not only theoretical significance, but also practical value. In this paper, by the property of conjugate operator, we give a method to construct the general solutions of a system of partial differential equations. 展开更多
关键词 general solution noncommutative ring construction of solution conjugate operator
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Cyclic Shear Tests on Key Connection Joints of Modularized Constructions
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作者 Deshen Chen Xiaofei Jin +3 位作者 Huajie Wang Hongliang Qian Deci Chang Feng Fan 《Journal of Harbin Institute of Technology(New Series)》 CAS 2022年第3期13-20,共8页
Modularized construction is a new type of prefabricated building system with green environmental protection and excellent performance. There are few studies on the seismic performance of its key connection joint. This... Modularized construction is a new type of prefabricated building system with green environmental protection and excellent performance. There are few studies on the seismic performance of its key connection joint. This paper presents a new type of assembled connection joint for the high-rise modularized construction. Cyclic shear tests of full-scale joints were carried out, and the key indexes of their seismic performances including the hysteretic performance, ductility, and energy dissipation capacity were analyzed and obtained. The results show that the hysteresis loops of longitudinal and lateral cyclic shear tests were both plump in shapes. The ductility coefficients were 4.54 and 4.98, and the energy dissipation coefficients were 1.83 and 1.43, respectively. The test joint had good ductility and energy dissipation capacity. The positions of yield failure of specimens were mainly concentrated in the connection areas between the column and short beam or end-plate. The research can provide the technical reference for the seismic design and engineering application of related modularized constructions. 展开更多
关键词 modularized construction assembled connection joint cyclic shear test seismic performance
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Evaluation of Inverse Modeling Techniques for Pinpointing Water Leakages at Building Constructions
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作者 A. W. M. van Schijndel 《Modeling and Numerical Simulation of Material Science》 2015年第1期15-25,共11页
The location and nature of the moisture leakages are sometimes difficult to detect. Moreover, the relation between observed inside surface moisture patterns and where the moisture enters the construction is often not ... The location and nature of the moisture leakages are sometimes difficult to detect. Moreover, the relation between observed inside surface moisture patterns and where the moisture enters the construction is often not clear. The objective of this paper is to investigate inverse modeling techniques as a tool for the detection of moisture leakage locations in building constructions from inside surface moisture patterns. It is concluded that although the presented methodology is promising, more research is needed to confirm its usability. 展开更多
关键词 INVERSE Modeling BUILDING CONSTRUCTION MOISTURE LEAKAGE
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The Effect of Micro Air Movement on the Heat and Moisture Characteristics of Building Constructions
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作者 A.W.M. (Jos) van Schijndel 《Journal of Civil Engineering and Architecture》 2010年第10期9-15,共7页
The research focuses on the effect of air movement through building constructions. Although the typical air movement inside building constructions is quite small (velocity is of order -10-5 m/s), this research shows... The research focuses on the effect of air movement through building constructions. Although the typical air movement inside building constructions is quite small (velocity is of order -10-5 m/s), this research shows the impact on the heat and moisture characteristics. The paper presents a case study on the modeling and simulation of 2D heat and moisture transport with and without air movement for a building construction using a state-of-art multiphysics FEM software tool. Most other heat and moisture related models don't include airflow or use a steady airflow through the construction during the simulation period. However, in this model, the wind induced pressure is dynamic and thus also the airflow through the construction is dynamic. For this particular case study, the results indicate that at the intemal surface, the vapor pressure is almost not influenced by both the 2D effect and the wind speed. The temperatures at the inner surface are mostly influenced by the 2D effect. Only at wind pressure differences above 30 Pa, the airflow has a significant effect. At the extemal surface, the temperatttres are not influenced by both the 2D effect and the wind speed. However, the vapor pressure seems to be quite dependent on the wind induced pressure. Overall it is concluded that air movement through building materials seems to have a significant impact on the heat and moisture characteristics. In order to verify this statement and validate the models, new in-depth experiments including air flow through materials are recommended. 展开更多
关键词 CONSTRUCTION HEAT MOISTURE TRANSFER air movement modeling.
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The Structure of Classifier Constructions and Some Related Theoretical Issues
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作者 Yang Yongzhong 《宏观语言学》 2021年第2期1-24,共24页
Some questions regarding the analysis of classifiers and classifier constructions are raised in this paper.The classifier,as a mere adjunct adjoining to the head,cannot serve as the head of the noun phrase containing ... Some questions regarding the analysis of classifiers and classifier constructions are raised in this paper.The classifier,as a mere adjunct adjoining to the head,cannot serve as the head of the noun phrase containing it,and as a result,it cannot project as ClP or nP.Under this approach,the DP analysis and the classifier construction theory are further refined.The constituents which precede and follow the classifier are analyzed in terms of their syntactic functions,semantic relations,linear features,feature assignment and syntactic occurrence in order to represent the classifier construction with the X-bar phrase structure theory appropriately and correctly and present a universal approach to classifier constructions in various languages. 展开更多
关键词 CLASSIFIER classifier construction HEAD phrase structure functional category
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