基于径向基函数网络的溢油预测模型

为了提高溢油预测的准确性,建立和优化溢油预测模型,提出了基于径向基函数网络模型的溢油预测方法,实现溢油预测功能.径向基函数网络模型解决了模拟预测过程中样本库巨大、函数模型收敛速度慢的问题.通过选择有效的输入参数和样本数据,建立局部逼近网络;通过径向基函数训练样本数据,利用输出值与实际值之间的误差作为约束条件调整权重因子、径向基中心和宽度,加快函数模型的收敛速度.该模型模拟了溢油的漂移、扩散过程,达到预测的目的.利用该模型,建立了溢油预测模块,并针对一次溢油事故进行预测模拟,验证了该模型的可行性,能够为应急决策提供一定的支持.     

地质封存中CO_2水溶液密度研究进展

CO2地下盐水层封存是减排CO2、缓解气候变化的可行方案之一。CO2盐水溶液密度影响CO2在储层中的扩散和运移,从而影响封存的安全性;因此,对于CO2盐水层封存十分重要。文章从实验测量和数学模型两个角度总结了对CO2水溶液密度的研究进展,认为现有实验数据的工况范围能够覆盖封存条件范围,但在数量和准确性方面都无法满足CO2地下盐水层封存需要。现有溶液密度模型大多数是经验公式,适用范围较窄、预测精度不高。理论模型正处于研究阶段,基于SAFT状态方程的理论模型是目前的研究热点。因此,需要系统研究封存条件下的CO2水溶液密度与温度、压力、CO2质量分数、盐度等因素之间的关系,建立适用范围广、预测精度高的理论模型,为CO2地下盐水层封存提供必要的支持。     

极地船舶冰载荷研究方法综述

梳理了船冰相互作用时冰载荷的研究方法,从理论分析法、试验方法和仿真模拟方法三个方向进行了分类综述。首先,阐述了理论分析法中直接计算法和概率法的原理和适用性,着重论述了直接计算法分别在总体冰载荷与局部冰载荷的应用。其次,重点介绍了试验方法中的室内模型试验和实尺度实测的研究成果和进展,并指出试验方法在海冰制备、设备环境等方面的研究难点。然后,比较分析了仿真模拟方法中的有限元法和离散元法,简述了各自的优缺点与适用范围,认为有限元法在分析结构失效、断裂等过程中有一定的优势,但对冰的破碎过程的模拟则不如离散元法。最后,讨论总结了船冰相互作用时冰载荷研究方法发展趋势和存在的问题,为领域学者提供一定的参考。     

套箍加固RC轴压中长柱的承载力理论研究∗

为研究套箍加固RC轴压中长柱的承载力理论计算分析方法,采用切线模量理论,根据材料本构关系和内外力平衡条件,推导了套箍加固RC轴压中长柱的弹塑性稳定承载力计算方法。将理论计算结果与试验结果进行了对比分析,结果表明:理论计算值均低于实测值,且二者的偏差在15%以内。根据所推导的计算分析方法,研究了核心柱初始荷载水平β、柱子长细比l0/b、套箍层混凝土强度、套箍层配筋量四种参数对加固柱承载力Nu的影响规律,结果表明:Nu总体上随β增大而减小,当β<0.7时,减小趋势不够明显,β>0.7后,减小趋势变得明显;l0/b对Nu有明显影响,Nu随l0/b的增大而减小,但二者不是线性关系;Nu随套箍层混凝土强度提高而增大,随套箍层配筋量增大而增大。     

Impact of fertilization on chestnut growth, N and P concentrations in runo water on degraded slope land in South China

Growing fruit trees on the slopes of rolling hills in South China was causing serious environmental problems because of heavy application of chemical fertilizers and soil erosion. Suitable sources of fertilizers and proper rates of applications were of key importance to both crop yields and environmental protection. In this article, the impact of four fertilizers, i.e., inorganic compound fertilizer, organic compound fertilizer, pig manure compost, and peanut cake （peanut oil pressing residue）, on chestnut （Castanea mollissima Blume） growth on a slope in South China, and on the total N and total P concentrations in runoff waters have been investigated during two years of study, with an orthogonal experimental design. Results show that the organic compound fertilizer and peanut cake promote the heights of young chestnut trees compared to the control. In addition, peanut cake increases single-fruit weights and organic compound fertilizer raises single-seed weights. All the fertilizers increased the concentrations of total N and total P in runoff waters, except for organic compound fertilizer, in the first year experiment. The observed mean concentrations of total N varied from 1.6 mg/L to 3.2 mg/L and P from 0.12 mg/L to 0.22 mg/L, which were increased with the amount of fertilizer applications, with no pattern of direct proportion. On the basis of these experiment results, organic compound fertilizer at 2 kg/tree and peanut cake at 1 kg/tree are recommended to maximize chestnut growth and minimize water pollution.     

如何克服锅炉安装施工设计编制中意识上的误区

阐明了锅炉安装施工组织设计的作用、重要性、编制依据及质量控制与管理体制的建立中存在意识上的误区,拾遗补缺,明确编制要领。     

·OH自由基介导2,4-二氯酚光降解机理及产物毒性变化特征的理论研究

由于2,4-二氯酚(2,4-dichlorophenol,简称2,4-DCP)具有"三致"作用及潜在的生态风险,其光化学降解机理及产物的生态毒理效应目前成为人们关注的焦点。本研究采用理论化学计算手段,系统阐明了2,4-DCP在水环境中·OH介导的间接光化学转化机理、动力学和转化产物的生态毒性变化特征。结果表明2,4-DCP很容易被·OH氧化降解,其降解主要通过·OH-加成和H-迁移路径进行。在低温条件下·OH-加成路径将占主导,主要形成4,6-二氯苯-1,3-二酚;而当温度超过313 K时,·OH提取酚羟基上的氢原子为主要降解途径,主要形成2-氯苯-对苯醌。尤其在活性物种浓度较低的高温环境中,H-迁移路径有可能生成二噁英。计算毒理学结果表明:H-迁移产物的水生毒性超过·OH-加成产物,甚至超出母体2,4-DCP一个毒性等级。因此,我们建议在以后的环境监测以及风险评估过程中,关注2,4-DCP及其转化产物特别是H-迁移路径的转化产物的生态毒理学问题。     

Anoxic biodegradation of dimethyl phthalate （DMP） by activated sludge cultures under nitrate-reducing conditions

Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and wastewaters. Dimethyl phthalate (DMP) biodegradation by activated sludge cultures under nitrate-reducing conditions was investigated. Under one optimized condition, DMP was biodegraded from 102.20 mg/L to undetectable level in 56 h under anoxic conditions and its reaction fitted well with the first-order kinetics. Using the high-performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC-MS) analysis, mono-methyl phthalate (MMP) and phthalic acid (PA) were detected as the major intermediates of DMP biodegradation. When combined with the determination of chemical oxygen demand (CODCr) removal capacity and pH, DMP was found to be mineralized completely under anoxic conditions. The biodegradation pathway was proposed as DMP → MMP → PA → … → CO2 H2O.The molar ratio of DMP to nitrate consumed was found to be 9.0:1, which agrees well with the theoretical stoichiometric values of DMP biodegradation by nitrate-reducing bacteria. The results of the non-linear simulation showed that the optimum pH and temperature for the degradation were 7.56 and 31.4℃, respectively.     

基于FMEA与RBF神经网络的LPG汽车罐车储罐系统故障诊断

为了对液化石油气(LPG)公路运输罐车储罐系统故障进行准确、全面的诊断,通过利用故障模式影响分析方法(FMEA)构建储罐系统故障模式及故障特征指标,根据日常检测数据构造训练样本,运用径向基函数(RBF)神经网络对网络进行训练建立诊断模型并利用诊断模型对罐车故障进行诊断。经验证:诊断结果与实际情况相符合。因此,基于FMEA与RBF神经网络所构建的模型可以用于危险化学品汽车罐车储罐系统的故障诊断。     

地下水曝气技术（AS）的国内外研究进展

地下水曝气法（Air Sparging,AS）凭借其高效、原位的优势已经成为治理土壤、地下水有机污染的重要技术,其修复机理是将加压空气注入到饱和含水层以下,有机污染物通过相间传质作用（溶解、挥发、解吸、生物降解等）转化为挥发性污染物,并随气流迁移至包气带,再由其他抽气装置收集到地表气体处理设备。本文总结了AS技术在理论模型、曝气性能影响因素（气体流型、曝气影响半径）等方面的研究现状,归纳了气体流型的发展过程以及测量曝气影响半径的常见方法。地下水曝气法在国外地下水、土壤有机污染修复中的应用越来越广泛,理论研究方面也比较成熟。文章比较了AS技术在国内外的研究和应用情况,认为目前该技术应朝着综合的方向发展,以提高污染物修复效率。