基于改进Gordon算法的内陆水体大气校正研究

内陆水体大气校正是水质参数定量估算的基础.本文针对浑浊Ⅱ类水体,在Gordon大气校正的基础上,引入MODIS气溶胶散射分区计算方法,实现GOCI和HJ-1 CCD影像的水体大气校正,并将该算法应用于不同时期的影像中.与地面准同步实测数据进行对比分析,结果表明:不同时期的GOCI和HJ-1 CCD影像大气校正结果均与准...     

绝缘子电气试验中的湿度校正方法

认为美国标准ANSI C29.1—1982“电力绝缘子试验方法”第4.2.4.2条中计算蒸汽压P_h的一个公式有误,并作了校正。指出了按美标正确地进行绝缘子电气试验中湿度校正的方法。     

基于区域增长的海岸带黑暗像元自动提取算法研究

针对海岸带区域独特的地表状况设计了一个近海岸的黑暗像元自动提取算法。首先利用修订型归一化水体指数(RNDWI)和归一化植被指数(NDVI)对黑暗像元备选区域进行确定,然后从备选区域中找到初始黑暗像元,最后利用多阈值的区域增长法对黑暗像元的选取进行优化,最终计算得到黑暗像元值。应用此算法对Landsat-5 TM影像遥感数据进行处理,结果表明,大气校正之后的典型地物光谱曲线更接近于真实的光谱曲线,说明此算法设计合理,其大气校正结果与用ENVI软件进行FLAASH大气校正和黑暗像元法大气校正的结果相比,此算法更接近于FLAASH模型法,校正效果较好。同时利用黑暗像元自动提取算法得到大气校正后的结果大大减少了反射率值为负的情况,提高了数据的利用率。     

氧弹量热仪测定物质燃烧热值的误差分析

从两方面研究了环境恒温式氧弹量热仪在测定物质燃烧热值过程中可能出现的误差,讨论了误差的产生机理和校正方式,给出了计算方法,并进行了试验分析.     

氧弹量热仪测定物质燃烧热值的误差分析

从两方面研究了环境恒温式氧弹量热仪在测定物质燃烧热值过程中可能出现的误差，讨论了误差的产生机理和校正方式，给出了计算方法，并进行了试验分析。     

外绝缘放电电压校正方法的分析与比较

针对电力设备在不同大气条件、不同海拔高度下外绝缘的放电电压,现行国内外标准以及一些研究群体提出了多种校正方法.从校正方法的理论依据、使用条件、校正数值三方面比较了各种方法存在的差异,提出了各自的适宜范围.在工程应用时,应根据电力设备的参数以及安装地的气候特点、海拔条件、安全可靠性要求等,选择一种适宜的校正方法对外绝缘放...     

河南WR-1地热井降压试验水位校正的应用研究

一般的单井稳定流抽水试验,可直接利用从孔口测得的水位降深与对应的流量关系,求取含水层的水文地质参数。但对地热井而言,由于在抽水过程中,井筒内水温的变化可对井中水位产生较大影响,故不宜直接利用降压试验前测得的静水位埋深和孔口所测的水位降深值,而应该进行静水位和动水位的校正(刘永贵,2016),才能与观测的水位埋深、水量、水温相匹配进行参数计算(高新智,2015)。文章以尉氏县WR-1地热井馆陶组降压试验静水位、动水位校正实例,阐述地热井降压试验水位校正的有效性和必要性。     

一种基于状态观测器的SISO系统校正方法

分析了由状态观测器构成的反馈系统与经典控制理论中的串联、反馈校正构成的闭环系统之间的等价关系，提出了一种以极点配置为原则的、基于观测器的单输入－单输出系统的校正方法，该方法与经典控制中常用的校正方法相比，具有数学关系明确，计算简单等优点。最后通过一个例子说明了该方法的有效性。     

装载机臂架扭曲变形的简易校正法

轮式装载机臂架严重扭曲变形的一般校正方法是:从焊接部位分割后,逐一进行校正,然后再照原样重新焊接成整体,吊装。这种方法的割、焊工作量大,变形部位很难校正复原,且需要专用设备。1993年我厂接收一台臂架严重撞坏变形的ZL40轮式装载机。经分析、计算,我们决定在不拆下臂架的情况下,利用动臂举升缸自身的推、拉力和材料的热变形性,对臂架进行整体校正,仅用了一天时间,便将变形臂架恢复到原状。     

地下水流有限差分模型开采井内水位的校正试验

许多地下水流数值模拟的初学者往往将有限差分法求得的格点(结点)水位当作相同位置开采井的水位,这是一种错误做法。本文根据前人研究,系统阐明了由有限差分法计算出的格点(结点)水位只能代表该格点(结点)所在均衡区域的某种平均水位,必须减去用普勒凯特(Prickett)公式计算出的校正降深和井损之后,才能得出井内水位的合理模拟值。针对这个问题,设计了室内沙箱阶梯流量抽水试验,采用均匀正方形网格有限差分法进行模拟,并做出井中水位校正。试验结果表明,用有限差分法得到的开采井降深明显偏小,相对误差可达60%,而经校正之后精度显著提高,相对误差一般小于3%。     

Simulation of air flow in the IEA Annex 20 test room—validation of a simplified model for the nozzle diffuser in isothermal test cases

The modeling of air supply devices has been identified from the International Energy Agency (IEA) Annex 20 project as one of the most important problems in applying computational fluid dynamics (CFD) to predict air flow pattern and air distribution in buildings, and the complicated HESCO nozzle diffuser used in the IEA Annex 20 test room has been proved to be particularly difficult to model. In a previous study, a simplified model for this diffuser was developed and validated against experimental data. It has been shown that this model can yield good prediction for the wall jet flow issued from the diffuser, but whether this model is capable of correctly predicting the global flow pattern in the whole test room was not known. In this paper, the benchmark data of the IEA Annex 20 Test Cases B2 and B3 were used to evaluate the performance of the model for the prediction of the global air flow pattern in the test room. It was demonstrated that this model can predict the air flow pattern in the whole test room for both the Test Cases B2 and B3 with reasonable accuracy. The significance of a velocity correction when comparing the numerical prediction with experimental data obtained using omni-directional anemometers was also discussed.     

水泥改性聚乙烯醇固化轻质土的强度特性

为改善水泥固化轻质土存在的不足,采用水泥-改性聚乙烯醇(SH)对轻质土进行固化.分析探讨了水泥-SH固化轻质土的受压破坏方式、应力-应变曲线类型以及龄期、养护环境、SH掺量、土质成分对水泥-SH固化轻质土无侧限抗压强度的影响.结果表明:水泥-SH固化轻质土受压破坏没有出现明显的破裂面,且破坏应变较大,有较高的残余强度;室温养护下水泥-SH固化轻质土的无侧限抗压强度显著高于恒温恒湿养护;SH固化剂显著提高水泥固化轻质土无侧限抗压强度的最低掺量为4.5%(质量比);SH固化剂可以减小土质成分对水泥固化轻质土无侧限抗压强度的影响.     

Compost and vermicompost of olive cake to bioremediate triazines-contaminated soil

The use of organic amendments to bioremediate potential organic pollutants of soil and water has become an increasingly relevant issue in the last years. This strategy has been applied to four triazine herbicides in a typical calcareous agricultural soil of the Mediterranean area. The soil was amended with olive cake, compost and vermicompost of olive cake at rates four times higher than the agronomic dose in order to stimulate biodegradation of simazine, terbuthylazine, cyanazine and prometryn, added in a mixture to the soils. Degradation studies were carried out in sterile and microbially active soil to evaluate the effect of the chemical and biological degradation of triazines. The residual herbicide concentrations at the end of the degradation assay showed no significant differences between non amended and amended soil. However, the addition of compost and vermicompost enhanced the biological degradation rate of triazines during the first week of incubation, with half-lives ranging form 5 to 18 days for the amended soils, whilst negligible degradation occurred in non-amended soil during this period. In contrast, olive cake did not significantly modify the degradation of triazines in spite that the addition of this amendment to soil resulted in the highest dehidrogenase activity values. In all the substrates, degradation of cyanazine and prometryn was faster (between 1.5 and two times higher) than those of terbuthylazine and simazine, without significant relationship with sorption parameters. The first order kinetic equation satisfactorily explained the experimental data for all triazines. A biphasic model, such as that proposed by Hoerl, was better to predict the very rapid triazines decay during the first week of incubation in soil amended with compost and vermicompost.     

Identification and correction of water velocity measurement errors associated with ultrasonic Doppler flow monitoring

Ultrasonic Doppler flow monitoring (UDFM) is used to measure water flow in pipes and channels. However, a lack of scattering particles and signal noise can cause velocity errors, particularly for smaller discharges and surface water ('clean') flows. A postprocessing methodology is presented that identifies and corrects these errors, maximising the value of existing data. Test criteria are used to identify errors. The error correction procedure defines depth–velocity relationships from cleaned 'training data' representing the range of flow conditions (including backed up) and uses these relationships to replace erroneous velocities automatically. UDFM velocity errors have been successfully identified and corrected in example applications. Routine use allows early identification of changes in instrument or site behaviour. The methodology is practical, consistent and updateable. This is a significant advancement over previous methods for correcting velocity errors, improving the applicability of UDFM.     

Osterberg静载荷试桩法10年的发展

简要介绍了Ｊ．Ｏｓｔｅｒｂｅｒｇ 撰写的关于静载荷试桩法在１０ 余个国家应用１０ 年的总结，其中已完成的约３００ 项试验，包括钻孔灌注桩、打入式钢管桩、预制混凝土桩及矩形（或条形） 壁板桩。试桩最大荷载已达１３３ＭＮ。介绍了应用中获得的主要成果及新的装置方法等。     

深圳市会展中心建筑设计方案简介

回顾了深圳会展中心数次规划选址的原因，介绍了会展中心建筑设计方案国际竞标的情况以及中标方案的构思和特点，特别是该建筑设计方案与中心区城市设计的紧密结合，使其功能和形象都成为中心区中轴线的有机组成部分。     

Effect of acidity on attenuation performance of sandy soil amended with granular calcium-magnesium composite

Utilising naturally contaminated soils and rocks is essential for significantly reducing geo-waste. However, there are no well-established concepts regarding the methods or countermeasures for utilising these soils and rocks, which would realise cost-effectiveness and environmental safety. Therefore, several researches focusing on the attenuation layer method have recently been undertaken. This method involves installing an attenuation layer between the contaminated materials and the ground to prevent ground contamination due to the attenuation capacity. A critical issue in the attenuation layer’s design is to evaluate the attenuation performance of the layer material against target chemicals. Several important concerns and questions need to be solved when evaluating the attenuation performance. One is how the acidic leachate might diminish the layer material’s attenuation performance. This paper presents the attenuation performance of a soil amended with a granular calcium-magnesium composite against acidic leachate. Batch and column tests, employing arsenic solutions of pH 2, 4 and 6, were applied to evaluate its attenuation performance. Using Freundlich parameter K as an index, the soil’s attenuation performance was determined to have improved by at least 40% after the addition of the agent, even when the agent content was 5%. The amended soil’s attenuation performance should be similar if the leachate pH is pH 6–4, although it might reduce by up to ~30% for pH < 4. Moreover, the amended soil can buffer the acid to pH > 6. If the attenuation layer buffers the acid and provides the leachate with pH > 6, it will assure that the original ground’s attenuation capacity is utilised. Considering this work’s findings, amended soil can be employed as material for the attenuation layer.     

框架结构拟动力试验方法研究

清华大学拟动力实验室开发了一套拟动力试验控制软件TUT,用于一维、二维、扭转及子结构拟动力试验,并在国内得到一定的应用。本文针对框架结构,在TUT基础上采用杆单元模型,编制了框架结构拟动力试验的建模软件TUTKJ,是对TUT的完善;同时讨论了框架子结构拟动力试验边界条件近似模拟的方法并对其进行了验证。     

采暖热负荷朝向修正率的计算

采暖设计热负荷计算中,对朝向修正率βch的取值问题提出新看法,指出βch 应根据建筑物遮挡情况给予适当修正,并给出了计算方法。     

Linear alkylbenzene sulfonates (LAS) in the terrestrial environment

The occurrence of linear alkylbenzene sulfonates (LAS) in a series of soil samples originating from the municipality of Roskilde has been studied. The study includes soil samples from eight different locations with different histories: a preserved natural area that has not been cultured for 50-100 years, a soil that has been ecologically cultured for 40 years, a soil sustainably manured in ecologically culture for 5 years (formerly conventionally cultured) and a soil that has been conventionally cultured using artificial fertilizer. In addition, a soil was studied that had been sludge amended by applying medium amounts of sludge as well as a soil that has been amended with high amounts of sludge for a 25-year period. In the latter case, the sludge amendment was abandoned 6 years before the first sampling, followed by the application of artificial fertilizers. Finally, a meadow in the run-off zone from a sludge storage area was included in the investigations. In addition to the soil samples, selected samples of the applied sludge and other fertilizers were analyzed for their possible content of LAS. Apart from the location where the soil had been heavily sludge-amended and the location situated in the run-off zone of the sludge storage, concentrations of LAS in all soil samples were found to be below approximately 1 mg/kg, which is well below the proposed preliminary soil quality criteria for LAS of 5 mg/kg. On the other hand, the study unambiguously disclosed that in the case of heavy sludge amendment, the proposed soil quality criteria might well be exceeded.