基于TW-SVM预测模型的某堆石坝变形预测分析

为提高监测资料有缺失的大坝变形预测模型精度,采用支持向量机方法建立一种具有小样本、高维、非线性的预测模型,并结合对其重要组成部分核函数的分析应用,提出一种根据结构风险最小化的TW-SVM预测模型。以某堆石坝为例进行研究,利用坝坡垂直位移和水平位移的监测数据,分别采用TW-SVM方法和BP神经网络(NET)方法建立相应预测模型进行比较分析。结果表明:采用TW-SVM方法和NET方法预测的垂直位移最大绝对误差分别为0.58 mm和6.18 mm,最大相对误差分别为270.00%和1 286.22%;采用TW-SVM方法和NET方法预测的水平位移最大绝对误差分别为0.25 mm和14.91 mm,最大相对误差分别为31.25%和1 189.85%;TW-SVM预测模型比NET预测模型更适合于影响因素为时间、水位的小样本预测分析。研究结果为堆石坝变形预测与分析提供参考。     

Water Bloom Precursor Analysis Based on Two Direction S-Rough Set

In the field of water quality management, it is vital to determine the main precursory anomalies from the precursor of intricate water bloom in the context of a given area. In this paper, a water bloom precursor analysis method, based on two direction singular rough set, was proposed. This approach was produced on the basis of the different sections and pre-water bloom of water bloom precursor anomalies and characteristic of elements transferred in singular rough set. For testing the validity of two direction singular rough set application in water bloom precursor analysis, Xiangxi River, which is one of the typical tributaries of Three Gorges Reservoir in China, was selected as study area. The result showed that compared with other indexes, pH and dissolved oxygen (DO) are the most valuable indicators of water bloom in the precursory anomalies. Furthermore, regarding with water bloom precursory anomalies in Xiangxi River, most of the nutrient loading and biological community are the key indicators. Hence, this method can determine the main precursory anomaly for water bloom in the study area, which provides powerful knowledge support to water quality specialists for them to comprehensively analyze precursory anomaly so as to find out its relationship with occurrence law of water bloom.     

Analysis of the Spatial Characteristics of the Water Usage Patterns Based on ESDA-GIS: An Example of Hubei Province,China

The spatial characteristics and the high-duty water regions of the Water Usage Patterns (WUP) are very important for the allocation and management of water resources. Taken Hubei province, China as an example, we adopted the exploratory spatial data analysis (ESDA) method to investigate the spatial dependence and local patterns of the WUP from 2003 to 2012. Subsequently, the spatial variation mechanisms were analyzed through the gravity center model. The results indicated that the overall spatial dependence of the agricultural WUP was detected (more significant after 2008). Moreover, the global spatial autocorrelation analysis results on the domestic WUP showed statistical significance (Moran’s I?>?0.1, P?<?0.05). These indicated that the local patterns were presented. The high values clustering areas of the agricultural and domestic WUP were mainly distributed in the central province and in the western province respectively. However, the approximate random distribution was identified for the industrial WUP because the industrial development had been conducted widely in the whole province during these years. Furthermore, the governmental policies and natural environment contributed to the spatial evolution tendency of the WUP. An increasing trend of the spatial association of the agricultural WUP and a significant decreasing trend of that of the domestic WUP, which suggested that the natural circumstance superiority and the industrial structure adjustment related to water utilization has been utilized and implemented effectively. This study can provide a useful reference and guidance for scientific planning of water resource systems.     

Modeling of Water Resources Allocation and Water Quality Management for Supporting Regional Sustainability under Uncertainty in an Arid Region

In this study, a scenario-based interval-stochastic fraticle optimization with Laplace criterion (SISFL) method is developed for sustainable water resources allocation and water quality management (WAQM) under multiple uncertainties. SISFL can tackle uncertainties presented as interval parameters and probability distributions; meanwhile, it can also quantify artificial fuzziness such as risk-averse attitude in a decision-making issue. Besides, it can reflect random scenario occurrence under the supposition of no data available. The developed method is applied to a real case of water resources allocation and water quality management in the Kaidu-kongque River Basin, where encounter serve water deficit and water quality degradation simultaneously in Northwest China. Results of water allocation pattern, pollution mitigation scheme, and system benefit under various scenarios are analyzed. The tradeoff between economic activity and water-environment protection with interval necessity levels and Laplace criterions can support policymakers generating an effective and robust manner associated with risk control for WAQM under multiple uncertainties. These discoveries avail local policymakers gain insight into the capacity planning of water-environment to satisfy the basin’s integrity of socio-economic development and eco-environmental sustainability.     

ABS／PVC合金的研究

研究了ＡＢＳ／ＰＶＣ合金的相结构和ＡＢＳ含量对合金力学性能、加工性能的影响，借助ＴＧＡ、ＩＲ等方法研究了ＡＢＳ／ＰＶＣ合金的热稳定性，结果表明，ＡＢＳ／ＰＶＣ合金具有良好的综合性能。     

拱肋间距对喷混凝土拱肋加固效应的影响研究

喷混凝土拱肋是加固软弱围岩的一种有效支护形式,其间距主要根据经验确定,可能偏大或偏小。为了揭示拱肋间距对加筋拱肋加固效应的影响,采用基于有限差分法的FLAC3D软件对施工期某地下厂房交通洞软弱围岩在拱肋间距分别在1.0―5.0m之间变化情况下变形、应力和屈服区等分布规律进行了对比仿真模拟。仿真结果表明:拱肋间距越大,围岩变形、顶拱最大主压应力和塑性屈服区越大,拱肋承受荷载越大;且拱肋间距介于2.0―3.0m时,能充分发挥围岩自承作用和拱肋支护潜力,围岩变形稳定满足要求,支护成本最低。本文的研究成果为确定喷混凝土拱肋合理间距提供了重要参考。     

大分子相容剂在填充聚烯烃中的应用

综述了国内外大分子相容剂在填充聚烯烃塑料中的应用，以及大分子相容剂改性填充聚烯烃塑料的物理与力学性能；指出大分子相容剂用于填充塑料，能改善高分子基体与填料间界面粘结，提高填充塑料复合材料的物理与力学性能，比传统有机偶联剂更具特点。     

多孔碳酸钙陶瓷--人造珊瑚的研究

天然珊瑚有三维贯通的多孔网络结构，它的主要成分碳酸钙(CaC03)在人体环境可降解。模拟珊瑚的组成与结构，研制新型的组织工程支架材料有着良好的应用前景。本文探索了多孔碳酸钙陶瓷的制备方法，并通过盐析法制备了一种多孔的碳酸钙陶瓷，有望获得高的孔隙率和孔连通性。     

MAH接枝EPDM增韧PA66的研究

研究了MAH(马来酸酐)接枝三元乙丙橡胶(EPDM—g-MAH)对尼龙66(PA66)的增韧作用。利用SEM(扫描电镜)观察了共混体系的微观形貌(形态结构)，并运用小角激光散射(SALS)方法研究了EPDM的加入对PA66结晶性能的影响。结果表明，未接枝的EPDM与PA66的相容性很差，而EPDM—g—MAH与PA66相容性明显增加，EPDM-g—MAH粒子均匀分散在PA66中，共混体系力学性能有很大提高。随着EPDM—g—MAH用量的增加，PA66球晶尺寸变小，共混体系界面结合更加紧密。     

BaTiO_3粉体中Ti/Ba比分析方法的比较

提出了用ＫＯＨ熔融分解ＢａＴｉＯ３粉体〔１〕，再用浓ＨＣｌ酸化后，用感应耦合等离子体发射光谱法（ＩＣＰ—ＡＥＳ法）测定试样中的Ｔｉ／Ｂａ比，并与化学分析法的结果作了比较，显示出ＩＣＰ—ＡＥＳ法简便，快速，结果更好。