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基坑降水方案设计及地下水位变化规律研究

江西建材 2024年第2期 206-208页

作者：胡天亮山东莱克工程设计有限公司山东东营257000

文中结合实际基坑工程案例,提出了“前期顶部快速大量排水,后期底部稳定轻量排水”的降水方案,并借助集水井进行降水幅度调节。结合地下水水位变化数据,发现该降水方案与施工强度时间差异性匹配度更高,能保证地下水水位在基坑施工面以下... 详细信息

文中结合实际基坑工程案例,提出了“前期顶部快速大量排水,后期底部稳定轻量排水”的降水方案,并借助集水井进行降水幅度调节。结合地下水水位变化数据,发现该降水方案与施工强度时间差异性匹配度更高,能保证地下水水位在基坑施工面以下,能够控制降水速率,保证基坑边坡安全。

关键词：基坑降水地下水分析抽水降水法排水管降水法集水井降水法

Superconvergence and L^(∞)-Error Estimates of the Lowest Order Mixed Methods for Distributed Optimal Control Problems Governed by Semilinear Elliptic Equations

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Numerical Mathematics(Theory,Methods and Applications) 2013年第3期6卷 479-498页

作者： tianliang Hou School of Mathematical Sciences South China Normal UniversityGuangzhou 510631GuangdongChina

In this paper, we investigate the superconvergence property and the L∞-errorestimates of mixed finite element methods for a semilinear elliptic control problem. Thestate and co-state are approximated by the lowest order Raviart-Thomas mixed finite element spaces and the control variable is approximated by piecewise constant *** derive some superconvergence results for the control variable. Moreover, we derive L^(∞)-error estimates both for the control variable and the state variables. Finally, anumerical example is given to demonstrate the theoretical results.

关键词： Semilinear elliptic equations distributed optimal control problems superconvergence L^(∞)-error estimates mixed finite element methods.

Hydrolysis of cellobiose catalyzed by zeolites—the role of acidity and micropore structure

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Journal of Energy Chemistry 2016年第1期25卷 141-145页

作者： Lipeng Zhou Zhen Liu Yuqi Bai tianliang Lu Xiaomei yang Jie Xu College of Chemistry and Molecular Engineering Zhengzhou University School of Chemical Engineering and Energy Zhengzhou University State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences

The roles of acidity and micropore structure of zeolite were studied in the hydrolysis of the model oligosaccharide of cellulose–cellobiose. HZSM-5, HY, HMOR and Hβ zeolites were selected as model catalysts for the hydrolysis of cellobiose. The effect of acidity of zeolite, including the strength, type and location, on its catalytic activity was investigated. The strong Br？nsted acid sites located in micropores are the active sites for the hydrolysis of cellobiose to glucose. Meanwhile, the catalytic performance of zeolite is also dependent on the micropore size of zeolite.

关键词： Zeolites Biomass Cellulose Hydrolysis Acidity

施工期RC框架结构内力与变形规律现场试验研究与数值模拟分析

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建筑科学 2024年第7期40卷 140-147页

作者：张世杰瞿天亮陈适才北京工业大学土木工程系北京100124 中铁建设集团有限公司北京100095

为研究施工期混凝土结构存在的复杂非线性受力和变形规律,本文通过开展结构施工期现场试验来研究钢筋内部约束和构件外部约束影响的非线性结构反应,首先进行了施工期钢筋混凝土结构的现场试验,测量和分析了结构的应力应变变化发展过程,... 详细信息

为研究施工期混凝土结构存在的复杂非线性受力和变形规律,本文通过开展结构施工期现场试验来研究钢筋内部约束和构件外部约束影响的非线性结构反应,首先进行了施工期钢筋混凝土结构的现场试验,测量和分析了结构的应力应变变化发展过程,其次进行了基于ABAQUS的非线性数值模型的验证与分析,最后通过参数分析研究了施工期混凝土结构的内力和变形规律。研究结果表明:施工期梁截面温度发展趋势相似,由于约束水平不同,边跨梁截面的应变大于中跨梁截面的应变;施工期框架柱的位移分布接近直线分布形状,但其剪力随着跨数的增多呈现明显的非线性分布规律。

关键词：施工期 RC结构变形规律现场试验

Hydraulic Accumulator-Motor-Generator Energy Regeneration System for a Hybrid Hydraulic Excavator

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1121-1129页

作者： LIN tianliang WANG Qingfeng State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China College of Mechanical Engineering and Automation Huaqiao University Xiamen 361021 China

Though the traditional energy regeneration system（ERS） which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.

关键词： hybrid system excavator energy regeneration system energy-saving

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不同海拔猪种血液生理生化指标分析

中兽医医药杂志 2020年第6期39卷 13-17页

作者：柏云心杨天良蔡原权金强顾玲荣杨雅楠赵生国甘肃农业大学动物科学技术学院甘肃兰州730070

为阐明三个不同海拔高度各猪种间血液生理生化指标特征。以分布在甘肃夏河县(海拔约3500 m)的藏猪、青海互助县(海拔约2500 m)的八眉猪和甘肃泾川县(海拔约1000 m)的长白猪为研究对象,前腔静脉采集血液并测定红细胞数(RBC)、血红蛋白浓... 详细信息

为阐明三个不同海拔高度各猪种间血液生理生化指标特征。以分布在甘肃夏河县(海拔约3500 m)的藏猪、青海互助县(海拔约2500 m)的八眉猪和甘肃泾川县(海拔约1000 m)的长白猪为研究对象,前腔静脉采集血液并测定红细胞数(RBC)、血红蛋白浓度(HGB)等22项生理指标和血清中碳酸氢根(HCO3-)、钠离子(Na+)等9项生化指标。结果表明,藏猪血液中性粒细胞百分比(GRA%)、单核细胞百分比(MONO%)、血红蛋白浓度(HGB)、红细胞压积(HCT)、血小板数目(PLT)等指标均极显著高于八眉猪(P<0.01),而八眉猪极显著高于长白猪(P<0.01);藏猪的Na+浓度极显著低于长白猪(P<0.01),而K+浓度则极显著高于长白猪(P<0.01);藏猪的二氧化碳分压(Pco2)极显著低于八眉猪和长白猪(P<0.01),而氧分压(Po2)极显著高于八眉猪和长白猪(P<0.01),长白猪极显著高于八眉猪(P<0.01)。基于血液各项生理生化指标特征认为,藏猪血液有更强的结合和运输氧气能力,以及更强的血液内环境调节能力,同时在免疫及对病原的抵抗力方面也具有明显优势,八眉猪血液在氧气利用和免疫水平等方面虽然不及藏猪,但相比长白猪也存在明显优势,由此说明地方猪种在抗逆性等方面要比高强度选育的长白猪具有一定优势。

关键词：藏猪海拔血液生理生化指标低氧适应性

Synthesis of Mesoporous Anatase TiO2 Sphere with High Surface Area and Enhanced Photocatalytic Activity

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Journal of Materials Science & Technology 2017年第3期33卷 300-304页

作者： tianliang Lu Youqiang Wang Yingli Wang Lipeng Zhou Xiaomei yang Yunlai Su School of Chemical Engineering and Energy Zhengzhou University Zhengzhou 450001 China College of Chemistry and Molecular Engineering Zhengzhou University Zhengzhou 450001 China

Mesoporous anatase TiO2 spheres with high surface area（119 m^2g^（-1）） were successfully synthesized via a facile and green template-free method. The prepared TiO2 was characterized by X-ray diffraction（XRD）,N2 adsorption, scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and UV–vis absorbance spectra. It was found that the prepared TiO2 is characterized by pure anatase phase, which shows uniform spheres and has a typical mesostructure with a high specific surface area and a large pore volume. The effects of complexant（acetylacetone） amount, crystallization temperature and calcination temperature were also investigated. Based on the results, a sketch for the preparation of mesoporous TiO2 was proposed. First, complex formed between tetrabutyl titanate and acetylacetone in ethanol. After introduction of aqueous of ammonia sulfate and urea, hydrolysis of tetrabutyl titanate would occur slowly,and sol of TiO2 was formed. Then, crystallization proceeded under hydrothermal conditions. Calcination process favored the formation of bigger TiO2 crystal through combining of the small crystals in *** led to the formation of bigger mesopores between TiO2 crystals. Photocatalytic activity of the prepared TiO2 was evaluated by decomposition of methyl orange.

关键词： TiO2 Mesoporous Template-free method Photocatalysis

激光清洗2024铝合金氧化膜的数值模拟与技术研究

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机械工程师 2024年第9期 44-46页

作者：梁天亮王蔚沈阳工业大学机械工程学院沈阳110870

通过建立激光清洗2024铝合金氧化膜有限元模型,得到了激光清洗氧化膜过程中铝合金表面温度变化规律;分别探究了不同激光能量密度和激光清洗速度对其表面温度变化的影响,其中,能量密度越大,铝合金表面氧化膜温度上升速率越高,铝合金氧化... 详细信息

通过建立激光清洗2024铝合金氧化膜有限元模型,得到了激光清洗氧化膜过程中铝合金表面温度变化规律;分别探究了不同激光能量密度和激光清洗速度对其表面温度变化的影响,其中,能量密度越大,铝合金表面氧化膜温度上升速率越高,铝合金氧化膜的表面温度随着清洗速度的增加而缓慢下降。随后,进行纳秒脉冲激光清洗2024铝合金氧化膜实验,探究激光功率、脉冲频率及清洗速度对清洗前后表面形貌的影响。研究结果表明,在激光功率为400 W、激光频率为4.5k Hz、清洗速度为5 mm/s时能完全去除表面氧化膜,并且不损伤铝合金基体;在此激光清洗参数下,清洗后铝合金基体微观形貌完好,氧元素质量分数为10.03%。

关键词：激光清洗 2024铝合金铝合金氧化膜有限元模型表面形貌工艺参数

Extreme precipitation events in East China and associated moisture transport pathways

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Science China Earth Sciences 2016年第9期59卷 1854-1872页

作者： ZHAO yang XU XiangDe ZHAO tianliang XU HongXiong MAO Fei SUN Han WANG YuHong State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science & Technology Nanjing 210044 China Institute of Ecological Environment and Agricultural Meteorology Chinese Academy of Meteorological Sciences Beijing 100081 China Guangxi Institute of Meteorological Disaster Mitigation Nanning 530022 China

Interannual variation of summer precipitation in East China, and frequency of rainstorms during the monsoon season from 1961 to 2010, are analyzed in this study. It is found that the two variables show opposite trends on a decadal time scale: frequency of rainstorms increases significantly after the 1990 s, while summer precipitation in East China decreases during the same period. Analysis of the spatial distribution of summer rainstorm frequency from 1961 to 2010 indicates that it decreases from the southeast to the northwest at the east edge of the large-scale topography associated with the plateaus. Spatial distribution of rainstorms with daily rainfall greater than 50 mm is characterized by a "high in the southeast and low in the northwest" pattern, similar to the staircase distribution of the topography. However, the spatial distribution of variation in both summer precipitation and frequency of extreme rainstorms under global warming differs significantly from the three-step staircase topography. It is shown that moisture characteristics of summer precipitation and extreme rainstorms during the monsoon season in East China, including moisture transport pathways, moist flow pattern, and spatial structure of the merging area of moist flows, differ significantly. Areas of frequent rainstorms include the yangtze River Valley and South China. Column-integrated moisture transport and its spatial structure could be summarized as a "merging" of three branches of intense moist flows from low and middle latitude oceans, and "convergence" of column-integrated moisture fluxes. The merging area for moist flow associated with rainstorms in the high frequency region is located slightly to the south of the monsoonal precipitation or non-rainstorm precipitation, with significantly strong moisture convergence. In addition, the summer moist flow pattern in East China has a great influence on the frequency of extreme rainstorms. Moisture flux vectors in the region of frequent rai

关键词： Frequency of rainstorms Moisture transport Synoptic circulation Extreme rainstorms Synchronized variations Vortex structure