LUO Gu_yuan , LIU Guo_tao , WANG Wen_biao
1999, 21(3):1-4. DOI: 10.11835/j.issn.1674-4764.1999.03.001
Abstract:Three Gorge reservoir will become a lake like water body which will be faced with the menace from entrophication pollution . Entrophication pollution will cause alga propagation in excess, so that fish and water plant will die largely and may cause the enteron cancer for people. The quiddity of entrophication is the pollution from plant nutriment (N and P etc.). The endure capacity of the water environment to plant nutriment and the development of interrelated technology for water pollution control are the key confining factors for the sustainable development of economy in Chongqing Area.
JIANG Shi_yong , GONG Chong_bing , BAI Shao_liang , ZHANG Ming_sheng , MU Feng
1999, 21(3):5-8. DOI: 10.11835/j.issn.1674-4764.1999.03.002
Abstract:Based on experimental study of 2 reinforced concrete columns with consolidated reinforced cover under cyclic loading action,this paper describes the influence of initial stress state and construction measure at binding surface on loading capacity of the column and puts forward a few consturction measures to ensure integral operation of both old and new parts.
1999, 21(3):9-14. DOI: 10.11835/j.issn.1674-4764.1999.03.003
Abstract:Various cost simulation software packages are extensively used in the construction industry today. There are some differences in the problems to which they are applied,but it is essential that users select suitable known distributions and estimate the parameter values for cost elements before starting any simulation. The accuracy and reliability of the simulation results depend on such selections. This paper proposes a practical and accurate selection method based upon the least differences of expected values and standard deviations between a known distribution and an estimated cost probability histogram.
1999, 21(3):15-22. DOI: 10.11835/j.issn.1674-4764.1999.03.004
Abstract:This paper reviews some major opinions on the avoidance of real estate financial risks. The author puts forward a new idea on this object from the view points of externality and systematic risk.
CHEN Shi_jiao , HONG Chang_yin , LIU Chen
1999, 21(3):23-28. DOI: 10.11835/j.issn.1674-4764.1999.03.005
Abstract:This paper,taking the model KMX15R multi_way valve for an example,analyses some special function demands for multi_way valve raised by modern hydraulic excavator,the structure principle of new multi_way valve to accomplisch these fouctions.
SUN Chun_wu , HUANG Zhong , DONG Xing_jie , FU Xiang_zhao , LIU Xian_ying
1999, 21(3):29-35. DOI: 10.11835/j.issn.1674-4764.1999.03.006
Abstract:This paper uses the one-dimensional resistance network theory for simulating calculation of the dynamic performance during heat storing and heat releasing of the cubic capsule ice thermal storage component. The calculation results have a good correlativity with the experimental values,which makes it clear that the model will be suitable for developing products and use in engineering.
ZHONG Lie_xian , WU De_lun , YAN Zhengping
1999, 21(3):36-40. DOI: 10.11835/j.issn.1674-4764.1999.03.007
Abstract:The dynamic behaviour of a new reinforced concerte hollow plate using the medium strength(800 MPa yield strength)ribbed bar as prestressed wire has been studied experimentaly under various concentrated impact loads.The test results on the inherent characteristics,frequency,damping,dynamic rigidity etc.are presented.Meanwhile the important points in respect to the strength,deformation,cracking under impact loads and earthquake response of plate have discussed.
FENG Ya , CHENG Qi_gao , WANG Er_qi
1999, 21(3):41-44. DOI: 10.11835/j.issn.1674-4764.1999.03.008
Abstract:A coupled heat and moisture transfer model on reinforced concrete under high temperature was provided,then the heat and moisture transfer theory on reinforced concrete under fire disaster was analysed in this paper.The numerical simulation and field measurement data show that the model can roughly explain the actual heat and moisture transfer progress of reinforced concrete under fire disaster.
HE Xue_bing , LIU Xian_ying , Chen Xian_zhang
1999, 21(3):45-49. DOI: 10.11835/j.issn.1674-4764.1999.03.009
Abstract:This paper describes the technological process in producing twisting thermal insulated pipe and compares it with the traditional method in China.In the paper,a technological economic analysis is made as well to compare the twisting thermal insulated direct-buried pipes with underground tunnel laying ones.
HUANG Zhong , SUN Chun_wu , WU Le_song , LIU Xian_ying
1999, 21(3):50-55. DOI: 10.11835/j.issn.1674-4764.1999.03.010
Abstract:以PR状态方程为依据,分别对CFC12和二甲醚(DME)进行了电冰箱理论制冷循环模拟计算和对比试验。试验结果表明,在不改变原冰箱结构条件下,用DME替代CFC12是可行的;在DME最佳充灌量(80g)下,耗电量为1.435kW·h/24h,较原机铭牌额定耗电量(1.45kW·h24/h)降低1.03%;为开发无氟绿色冰箱提供了一个新途径。
1999, 21(3):56-60. DOI: 10.11835/j.issn.1674-4764.1999.03.011
Abstract:中心是人类文化行为的出发点与归宿点,是人类的立足点。通过对中国古代城市空间中心的研究,归纳出聚、居、事、思、逸、礼、市七个方面的特点,由此分析出中国古代城市空间文化的深层内涵,对于我们思考城市空间的历史承传不无益处。
1999, 21(3):61-64. DOI: 10.11835/j.issn.1674-4764.1999.03.012
Abstract:This paper proposes a new way to reduce the drag of the fluid flow past a external fins pipe. If a little rectangular leaf is suitably installed upstream of the base pipe of the external fins pipe, not only the drag will be reduced, but also the heat transfer will be enhanced in a suitable range of Reynolds number. An experimental investigation showed that compared with a general external fins pipe, the new way can reduce the drag more than 40% and enhance the heat transfer about 10% meanwhile.
FU Bin , ZHANG Qin , ZHANG Zhi
1999, 21(3):65-69. DOI: 10.11835/j.issn.1674-4764.1999.03.013
Abstract:A reasonable selection of the method for evaluating the urban drainage system was discussed in this paper.Weighted average method and fuzzy synthetic evaluation were used to evaluate a modern urban drainage system,and a reasonable conclusion was obtained.
1999, 21(3):70-73. DOI: 10.11835/j.issn.1674-4764.1999.03.014
Abstract:BADMP was synthesized with one step method from HCHO,HCL,PCL3 and C6H5CH2NH2,It is estimated that the purity of BADMP is suitable for corrosion-inhibition study by melting point measurement,element analysis and IR spectrogram, The properties of BADMP was also studied.
1999, 21(3):74-77. DOI: 10.11835/j.issn.1674-4764.1999.03.015
Abstract:In this paper the high-performance concretes with 56-day compressive strengths of 60 to 100 MPa (with or without silica fume) have been studied experimentally in order to develop information about the mechanical properties of high-performance concrete. Results and discussions are presented regarding compressive strength gain with time,effect of drying. A linear equation of static modulus of elasticity has been derived.The static modulus of elasticity and Poisson's ratio are calculated by regression with testing data of 20 specimens.
1999, 21(3):78-81. DOI: 10.11835/j.issn.1674-4764.1999.03.016
Abstract:The quantity of alloys and the quality of weld layers are main factors influencing the chemical ingredient,microstructure and durability of hardfacing deposits,they also directly affect components' service life and alloys' utilization ratio.In this paper,these factors and control measures are analyzed.
WU Shu_guang , HU Dai_wen , XU Si_nong
1999, 21(3):82. DOI: 10.11835/j.issn.1674-4764.1999.03.017
Abstract:This paper presents a method of tamping for improving unconsolidated sand and gravel foundation backfilled on the flood land,and introduces the principles of soil improvement with some engineering cases. Results from the field tests show that this method is reliable,economical and feasible.It provides reliable basis for applying this method on other similar engineering projects hereafter.
1999, 21(3):86-90. DOI: 10.11835/j.issn.1674-4764.1999.03.018
Abstract:研究硝酸钯-硝酸镁基体改进剂对测定痕量铅的基体改进效应,建立了石黯炉平台技术测定痕量铅的实用分析方法。其特征量为8.4Pg(Pg/0.0044A),RSD为1.4%~5%,铅回收率为90%~110%。
1999, 21(3):91-96. DOI: 10.11835/j.issn.1674-4764.1999.03.019
Abstract:The relationship between tangent derivative and generalized corvex of set_valued mapping is dealt with in this paper.Then these properties and concepts are applied to optimization problems.Generalized convex properties of perturbation mapping is proved under certain conditims.
1999, 21(3):97-99. DOI: 10.11835/j.issn.1674-4764.1999.03.020
Abstract:Based on ASHRAE's BIN(temperature frequency) method,corresponding Chinese original climate data, the BIN were adjusted, the precision of bin data from standard year by Lagrange_interpolation, was tested the method for transform of regression BIN data to curve was discussed..
HAI Shan , SHEN Li_yin , REN Hong
1999, 21(3):100-105. DOI: 10.11835/j.issn.1674-4764.1999.03.021
Abstract:Since the implementation of the new construction system in 1988 in China, this system has gone through three phases: trial phase(1988-1993),development phase(1993-1995),and comprehensive application phase from 1996.Construction supervision as a new management system has profound effects to the whole process of a construction project, in particular, to the three conventional objectives, that is quality, cost and construction time. The new management system has to a large extent brought the traditional problems of extended construction time, uncontrollable cost and unsecured quality to a normal practice. Construction supervision is a management activity with request of high intelligence. The performance of this activity is closely related to the quality of project general supervision engineer. This paper identifies the basic elements that a proper project general supervision must have. By applying the fuzzy analysis principle, this paper presents a quantitative model for evaluating the quality of project general supervision engineer.It provides an applicable approach for project clients when general supervision engineers are to be chosen.
1999, 21(3):106-109121. DOI: 10.11835/j.issn.1674-4764.1999.03.022
Abstract:Based on neural network,this paper presents a method of damage assessment of frame structures,which provides a new approach for damage assessment of structures under dynamic conditions.The adaptability and efficiency of this method are discussed through computation simulation,The numerical results show that this method is promising.
ZHOU Zuo_hua , YAN Ping , YANG Bo
1999, 21(3):110-113. DOI: 10.11835/j.issn.1674-4764.1999.03.023
Abstract:The Earliness/Tardiness problem in job_shop is discussed in this paper.Based on the analysis of practical situations and lot transfer between stages,an integer programming mode is proposed,The solution is obtained by the application of Lagrangian relaxation technique.
1999, 21(3):114-118. DOI: 10.11835/j.issn.1674-4764.1999.03.024
Abstract:Based on analysis of contest and content of time elements in network schedule,the author has set up a set of standard models for time elements'calculation,which will improve traditional manual calculation method,the accuracy will therefore be increased and time saved.
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