基于质量守恒方程导出了冬季空调系统不加湿时房间内的含湿量计算式,综合考虑影响室内含湿量的主要因素,得出冬季空调可以不加湿时应满足的条件,考察了中国典型气候区代表性空调房间冬季空调不加湿时室内相对湿度能否满足设计要求.研究表明:中国各地区的商场,夏热冬冷地区的餐厅及三星级及以下酒店多功能厅,夏热冬暖地区的影剧院、办公室、酒店客房及多功能厅、餐厅,温和地区的办公室、三星级及以下酒店客房、酒店多功能厅及餐厅空调系统不加湿即可达到设计湿度要求;严寒地区及寒冷地区的影剧院、办公室、酒店客房、酒店多功能厅及餐厅,夏热冬冷地区的影剧院、办公室、酒店客房、四星级及以上酒店多功能厅以及温和地区的影剧院、四星级及以上酒店客房等房间的空调系统必须加湿才能达到设计要求.
Six rectangle steel tube confined concrete columns were investigated experimentally under axial compression.The experimental results show that:The rectangle steel tube can effectively confine internal concrete and obviously improve the peak stress.In addition,the descending branch of confined concrete stress-strain curve is gentler and the ultimate deformation ability of concrete is improved effectively.On the basis of experiments,a method to calculate the effective transverse confined stress provided by the rectangle steel tube was proposed through analyzing the strain of steel tubes and the stress state of core zone concrete.Furthermore,a model to determinate the stress-strain relationship of rectangle steel tube confined concrete under axial compression was put forward reference to the Mander's model.Computation results of the stress-strain curve of rectangle steel tube confined concrete were in good agreement with the experimental results.
A new hyperbolic p-y curve was derived to generally simulate then onlinearity of piles in layered soils,and the new p-y curve was presented containing parameters such as the initial ratio of elastic foundation coefficient,the initial elastic foundation coefficient,characteristic value of lateral displacementfor soils,and etc..Model test of six timber piles and two steel piles in two groups settled in layer soils with upper clay and lower sand were done.The calculated lateral displacements of model piles both at the top and at the ground are consistent with the test values by p-y curve method,and the new hyperbolic p-y curve is verified.While the characteristic value of lateral displacement for layered soils increases,the displacement and the maximum bending moment of the pile decrease,the maximum shear and the maximum soil pressure around the pile increase.The variety of characteristic value of lateral displacement for the lower sand has extremely small effect on mechanical property of the pile,then the characteristic value of lateral displacement for lower soils can be defined as the same as that of the top soil during engineering application.
A series of factors,such as dosage of tobacco scrap,the solution pH of solution,the time of adsorption,the original concentration and temperature,influencing adsorption of tobacco scrap to U are investigated by means of static experiment.It takes the tobacco scrap produced during the production of cigarette as ingredient.Besides,this thesis has also adopted the FTIR,SEM and EDS to represent the tobacco scrap and has discussed the mechanism of adsorbing U (Ⅵ).The result has shown that the tobacco scrap has the best adsorption of U (Ⅵ) on condition that the temperature is 30 ℃,the dosage is 4g/L,the? pH of the solution is 5,the concentration of U (Ⅵ) is 25 mg/L and the adsorption time is 100 minutes.The process of adsorption fits the Level 2 Dynamic Model (R2≈ 1) and Langmuir Isotherm Model (R2≈1) better.The results of X-ray diffraction,FTIR,and SEM have shown that the tobacco scrap has a great capability of adsorption to U (Ⅵ),whose adsorption makes the form of its surface change.The groups that interact with U (Ⅵ) are mainly hydroxyl and carboxyl groups.
针对实际工程监测时损伤识别误差大的问题,提出一种基于改进粒子群算法的两阶段识别方案.第1阶段利用D-S证据理论融合算法进行损伤定位;第2阶段利用改进的粒子群算法,对定位结果进行修正,同时准确定量损伤.仿真算例和实验分析结果表明:由于第1阶段损伤定位减少了可能损伤单元的数量,第2阶段基于改进粒子群算法的搜索范围减小,能更准确地识别多损伤和小损伤的位置和程度,且抗噪性能良好.
Temperature and humidity were measured in two typical Huizhou dwellings in winter in order to compare the indoor thermal and humidity conditions in the Huizhou traditional vernacular dwelling with that in the modern dwelling.The indoor humidity environment and thermal comfort in different zones were also studied.The results show that the level of the humidity environment is at'wet'and'very wet'in the Huizhou traditional vernacular dwelling in which the relative humidity is higher than that in the modern dwelling.The daily amplitude of humidity is smaller in the traditional vernacular dwelling than that in the modern dwelling,which is considered that the indoor humidity environment is stable well.There is a strong correlation between the outdoor humidity ratio and the indoor humidity ratio with a correlation coefficient over 0.8 both in the traditional vernacular dwelling and the modern dwelling.However,only 7.36％ time in the hall and 8.77％ time in the wing-room are comfortable with natural ventilation in the traditional vernacular dwelling,that means that the thermal comfort is unsatisfied.To improve the indoor thermal comfort,it is supposed to apply local heating equipment.
Under the condition of different cement content and curing time of NaCl,grease,Pb(NO3)2 pollution in Wenzhou soft soil cement solidification processing,the strength of the soil have been improved.In order to further obtain the treatment effect of different contaminated soil during cement solidification process,unconfined compressive strength tests and microstructure studies were conducted on different cement solidified contaminated soil.The effect of pollution type,pollution content,cement content,curing time on the cement solidified soil strength characteristics was analyzed.Furthermore,the difference of the microstructure of cement solidified soil with different pollutants concentration was also analyzed.The results show that within a certain range,the NaCl concentration promotes cement solidification of the early strength;grease content makes the cement solidification soil strength reduce obviously and compressibility increase;after Pb(NO3)2was dropped into the soil,the strength of the cement solidification is reduced in general.A linear relationship appears between the strength and admixing amount.The cement solidification soil strength enhances with the increase of cement content and curing time.Scanning electron microscopy(SEM)results indicate that the increase of contaminate leads to the rise of porosity and loose structure of the solidified soils.
The study of human body's radiation heat loss and thermal comfort need to calculate the angle factor between the human body and the envelope surfaces.Firstly,the paper derived the mathematical equation to revise the result of numerical calculation of angle factor based on the discrete formula of the angle factor and the effective radiation area,and established the standard three-dimensional body model of Chinese human in sitting posture.Then,the paper calculated the angle factor between the human body and roof,wall,floor,respectively,and found that the angle factor between the human body and the front surface is greater than the rear surface.Compared numerical calculation of angle factor with semi-analytical calculation,it is found that there are good agreements between semi-analytical calculation and numerical calculation for the roof and vertical wall,but there is a larger error for the floor,and the paper has modified these errors.
构建了由碎石、陶粒、玻璃轻石、HDPE和PVC排水板5种排水材料组成的佛甲草轻型种植屋面模拟试验平台(室内自然状态),测定了各材料处理土壤以及土壤底部空气的温、湿度.结果表明:土壤湿度在少雨季节受到不同排水材料的显著影响,而在雨量充沛的季节差异不显著.在干旱月份,与碎石处理相比,具有蓄水性能的4种排水材料(陶粒、玻璃轻石、HDPE和PVC排水板)有明显的抗旱优势,平均土壤湿度提高了约35％;然而,这4种材料的蓄水量大小对处理之间的土壤湿度没有显著影响;另外,材料的排水性能对土壤湿度有显著影响,通水量大的HDPE排水板在雨后初期土壤湿度显著小于其他材料.土壤(空气)温度没有受到材料蓄水性能的影响.轻型种植屋面土壤热湿环境的变化不完全由材料蓄水性能所决定;同时,其具有明显的保温(冬季夜间)隔热(全年白天)作用,且热工性能存在季节性和日内差异.
The in-situ test was carried out for the environmental vibration response of the surrounding buildings and the ground caused by high speed railway trains,the spectrum analysis method was used to study vibration characteristics of the surrounding buildings and ground.The environmental vibration levels of high speed railway was analyzed and evaluated in combination with the vibration control standard of urban railway.The results of study show that the environmental vibration frequency caused by the 270 km/h high-speed trains is mainly concentrated on the range of 25~60 Hz.The vertical vibration of building is larger than the horizontal vibration,the maximum of Z-level of vertical vibration is 70.62 dB.The second vibration in the building has a obvious height amplification effect,the maximum Z-level of vertical vibration on the top floor of the building is about 1.094 times of that on the first layer.The ground vibration is obviously larger than that of the surrounding buildings,but the similar changing law is shown between the ground and the building,the maximum of vibration level of division frequency on the ground can up to 92 dB,but the maximum of vibration level of division frequency on the buildings can only up to 80 dB.The environmental noise of high speed railway is up to 92.8 dB,more than the severe pollution standards of city environmental noise.Environmental noise pollution caused by high speed railway is greater than the impact of environmental vibration,the corresponding noise reduction and sound insulation measures should be adopted to effectively control the level of environmental noise.
In terms of the common green buildings techniques obtained from statistics and climate features of hot-summer and cold-winter zone in China,a case study has been done.The effects of techniques,such as the enhancement of the performance of building envelope,energy comprehensive utilization,have been analyzed.The results show that the energy-saving benefit from total heat recovery of exhaust air which reaches 35％ is the biggest in those common green buildings techniques;the utilization of fresh air in interim can save 10％ energy;it could save as much as 7％ energy by the means of setting adjustable exterior shading or improving the thermal performance of building envelop;the energy-saving rate of light control is 12.3％,etc.The study indicates that the energy efficiency of green buildings techniques interact with each other.Therefore,a comprehensive consideration of an energy conservation scheme of green buildings must be taken.The results show comparing with the requirements of current energy-saving standards,the whole energy efficiency of green buildings can achieve 46.9％,which can save energy by 75 ％ compared with the reference building in the current energy-saving standards.
Architectural external shading is an important measure for building energy saving,but single and improper shading may hinder the heat insulation,lighting,ventilation and vision of the room,and reduce the comfort of indoor environment.With the aim of comprehensive energy saving,this paper put forward the optimal design method of architectural external shading.Taking Chongqing as an example,based on the analysis of climate characteristics,the exterior shading forms of south and west orientation with good comprehensive performance were studied.Simulating the general office space to build an experimental platform of composite external shading,its insulation,shading,lighting and ventilation effects were tested and inspected.The results show that the optimized external shading devices have good lighting,ventilation and vision effects as well as obvious cooling effect.
Based on elastic mechanics and soil mechanics theory and radial deformation coordination conditions between the anchor body outer and the surrounding rock,the distribution formulas of stress along the bonded length of pressure type recoverable anchor were derived.Compared with existing theoretical results,the formulas were proved to be more practical.The peak value and range of shear stress were analyzed with various of the ratio of the anchor body's elastic modulus to the rock-soil body's E1/E2 and the poisson's ratio of rock-soil bodyμ and anchor body's outer radius R,Results show that E1 /E2 and R are opposite to the value of peak shear stress but positive to shear stress range while μ is on the contrary.
针对太阳能通风井道蓄热单元的技术需求,制备了复合相变蓄热材料,并将其应用于通风井壁,建立了基于复合相变蓄热材料的太阳能通风井测试系统,并测试了其运行性能.结果表明:添加5％碳纳米管制备的复合相变材料,其导热系数为0.65 W/m·K,是添加前的2.03倍,相变潜热为107 J/g,是添加前的0.718倍.应用上述材料的太阳能通风井测试系统在10:00-21:00时段通风量为55.0～103.9 m3/h,其中在17:00风速和风量达到最大,为良好的自然通风提供了保障.
Existing energy-saving potential evaluation methods for building occupant behavior improvement do not take occupants' diversity into consideration.This significantly decreases the accuracy of evaluation results.To address this issue,a new energy-saving potential evaluation method has been established.First,principal component analysis is used to reduce the number of influencing factors of occupant behavior.Then,a data mining technique,clustering analysis is used to classify sample occupants into different groups.At last,energy-saving potentials are evaluated in terms of different groups characteristics.This method takes both the impact of various influencing factors and the diversity of occupants into account,and thus could improve the evaluation accuracy significantly.The method was applied to evaluate the energy-saving potential of 100 graduate students' computer standby usage behavior in 3 universities in Hunan province.The results demonstrate its effectiveness and feasibility.
应用地质雷达进行混凝土构件缺陷检测时,浅埋钢筋会对层下钢筋及目标物的探测造成干扰,对其原因进行分析并采取有效的手段去除干扰具有重要意义.通过理论计算设计了检测试验方案,在沙槽中埋设不同埋深钢筋模拟混凝土中钢筋的检测,运用多种偏移手段对检测信号进行处理.结果表明:浅层钢筋对深层钢筋检测的干扰,与地质雷达探测区域覆盖的浅层钢筋的长度有关;相较于绕射叠加偏移、Kirchoff偏移、F-K域偏移等方法,Tau-p域偏移能够更好地对钢筋检测信号进行偏移处理,钢筋的位置被更为准确地识别,偏移后的地质雷达三维图像变得平坦、干净.结合工程实例,对地质雷达数据进行了偏移分析,取得了良好的效果.
Most of the analysis and calculation of soil stability is based on the formula from the two-dimensional theory,in order to solve the problem that it cannot take into account the effect of the pile hole circular arch in the space project Based on B.Γ.theory and the principle of retaining wall,considering the soil arch effect on the stability of the hole wall,a calculation model for calculating the maximum hole depth of self-supporting hole wall was put forward.According to different formula solutions and the MATLAB numerical analysis software,the correlation coefficient in the model was adjusted several times.Finally a simplified calculation formula was proposed,the calculation formula and B.Γ.formula solution were contrasted and analyzed.The result shows that this formula can calculate B.Γ.theoretical solution for better approximation,which is more concise than the B.Γ.formula,beneficial to the popularization and application,and more convenient for application in practical engineering.
The main control building of the substation is not only to meet the operational requirements of precision equipment,but also to meet the working requirements of personnel.The design of external shading should take into account the requirements of energy saving and daylight.In this study,a typical substation building as an example in the hot-summer and warm-winter area was chosen.The change of indoor light environment and energy consumption of this building in different shading facilities were simulated and analyzed by using energy and lighting simulation software.And the suitable range of size of the shading facilities were obtained by taking the building energy efficiency and lighting coefficient standard value as evaluation index.Finally,it is clear that the size design of the external shading of this kind of building should adopt the method of double goals optimization of energy saving and natural lighting,to change the way that outside shading coefficient as a single evaluation parameter.
基于性能的抗震设计特点是使结构抗震设计从宏观定性目标转化为具体量化指标的多重结构性能目标.《建筑抗震设计规范》 (GB 50011)给出的是针对整体结构弹性及弹塑性变形的变形指标量,对构件没有量化的损伤指标,为此,进行了5片配置HRB600级钢筋T型截面剪力墙试件的低周反复加载抗震抗剪性能试验,研究配置高强钢筋与普通钢筋剪力墙之间的抗震性能差异;收集剪力墙抗剪试验数据对Park-Ang双参数地震损伤模型进行参数修正,得到适用于剪切破坏下剪力墙构件的损伤模型.利用修正的损伤模型来评估发生剪切破坏的剪力墙各个受力阶段的损伤程度,结合剪力墙的变形状态进行损伤评估,给出不同性能状态下与剪力墙构件位移角的量化关系限值.
为研究Q460高强角钢轴压构件的受力性能,采用静力试验对试件破坏状态和稳定承载力进行分析,两端设置球铰、单刀口铰和双刀口铰支座,分析了不同铰接方式对构件受力性能的影响.结果表明,采用不同支座均能很好地反映杆件的受力性能;短构件的极限承载力由钢材强度控制,长细比变化对其影响很小,长细比等于30和45的试件以局部破坏为主,长细比等于60和80的杆件以整体弯曲失稳为主.比较试验和各规范理论计算结果发现,试验值显著高于中国DL/T5154-2002杆塔技术规定计算值,与美国ASCE 10-97导则计算值吻合较好.
