三峡水库蓄水前后植被覆盖对气候的响应

为揭示三峡水库蓄水前后区域植被覆盖对气候变化的响应规律,基于SPOT NDVI和实际观测气象数据,采用偏相关系数法分析了三峡水库蓄水前后长江上游干流区间寸滩至宜昌段及外围100 km的气象因子与植被覆盖的相关性,同时对其非线性映射关系进行了研究.结果 表明:在长江上游干流区间寸滩至宜昌段及外围100 km区域内,植被覆...     

基于双向LSTM卷积网络与注意力机制的自动睡眠分期模型

针对现阶段深度睡眠分期模型存在的梯度消失、对时序信息学习能力较弱等问题,提出一种基于双向长短时记忆卷积网络与注意力机制的自动睡眠分期模型。将少样本类别的睡眠脑电数据通过过采样方式进行数据增强后,利用带残差块的卷积神经网络学习数据特征表示,再通过带注意力层的双向长短时记忆网络挖掘深层时序信息,使用Softmax层实现睡眠分期的自动判别。实验使用Sleep-EDF数据集中19晚单通道脑电信号对模型进行交叉验证,取得了较高的分类准确率和宏平均F₁值,优于对比方法。该方法能够有效缓解睡眠分期判别中少数类分类性能较低的问题,并提高了深度睡眠分期模型的整体分类性能。     

18FDG-PET在直肠、结肠癌诊断中的价值

对24例经肠镜检查初步诊断为直肠、结肠癌的患者进行18FDG-PET显像研究，评价18FDG-PET对大肠癌诊断、分期及治疗计划的价值。结果表明：24例病理证实为大肠癌，23例局部18FDG摄取增高（SUVmax＝7.09±3.26，2.98～12.2）。18FDG-PET对于肿瘤原发病灶诊断准确率为95%（23/24），假阴性1例，8例远处转移全部检出；对于单纯局部（主要为第1站）淋巴结转移灵敏度为50%（8/16），特异性为100%；改变了33%（8/24）患者的治疗方案。因此，18FDG-PET对大肠癌原发病灶诊断其灵敏度高，假阴性率低，但鉴别原发病灶早期局部侵犯程度作用有限；18FDG-PET对于淋巴结、肝、骨骼等远处转移探测效率高；18FDG-PET对大肠癌的分期和治疗计划制定有一定的价值     

基于WebService与数据库中间表相结合的中间件接口技术

随着工业自动化、信息化的发展,多系统间对接技术的发展具有十分重要的意义。分别对WebService和数据库中间表进行分析,叙述了两种技术的优缺点,并将两种技术进行插件化结合,提出一种基于WebService与数据库中间表相结合的中间件接口技术。该技术分为WebService模块和数据库中间表模块,以物流仓储的数据传输为例,详细介绍了WebService与数据库中间表结合的过程,并分别对两种方法的功能进行了阐述。     

大坝蓄水初期事故分析

在蓄水初期，大坝处于一个不稳定的、复杂敏感的工作阶段。随着蓄水加荷，坝基、坝体、近坝库岸边坡等部位的运行性态不断调整变化，有可能向事故方向转化，尤其是在激烈加荷条件下，再加上设计和施工中的重要失误，这种转化很可能被触发而酿成重大事故。因此，在大坝整个生命周期中，蓄水初期是事故风险相对较大的阶段。统计了13座典型大坝蓄水初期事故，对事故原因进行了深入分析，并提出了相应的处理措施。     

基于滑带土强度特性的水库蓄水诱发滑坡研究综述

针对滑带土强度特性及对库岸滑坡的影响,通过回顾国内外一些代表性的成果,归纳和总结滑带土残余强度、强度的应变软化规律、边坡涉水后强度的水软化规律、边坡渐进性破坏等方面的研究现状,并对水位变动条件下库岸滑坡的研究手段和技术路径进行探讨。     

Investigations of the distribution of residence times of river impoundments using naturally occurring tracers

A mathematical model for the determination of the detention characteristics of river impoundments is presented. The time dependent concentration of a naturally occurring, long-lived substance (chloride) was measured at the inlet and the outlet of an impoundment and used as a tracer. No extraneous tracer is necessary, in this case, so none of the possible problems with such procedures occurs. The method was successfully applied to the Baldeneysee impoundment on the Ruhr, giving results which helped the interpretation of observed water quality processes.     

A Stich in Time: The Needlework of Aging Women in Antebellum America

Abstract

Through the auspices of the international biennial, contemporary practices in textiles have reached a maturity of critical reference. Drawing on anthropological theory (Alfred Gell) and contemporary critical theory from art and performance (Amelia Jones), this article supports and frames a relationship between exchange, conversation, and enactment as manifested through textile practice in the context of Textile 07: Kaunas Textile Art Biennial.     

Numerical analysis and geophysical monitoring for stability assessment of the Northwest tailings dam at Westwood Mine

The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling along with geophysical monitoring for assessing the Northwest dike stability during the restoration phase. The impact of waste rock deposition in the upstream TSF #1 is considered. The geophysical monitoring is based on electrical resistivity methods and was used to investigate the internal structure of the dike embankment in different deposition stages. The numerical simulations were performed with SLOPE/W code. The results show a factor of safety well above the minimum recommended value of 1.5. Geophysical monitoring revealed a vertical variation in the electrical resistivity across the dike, which indicates a multilayer structure of the embankment. Without any current in situ data, the geophysical monitoring helped estimating the nature of the materials used and the internal structure of the embankment. These interpretations were validated by geological observation of geotechnical log of the embankment. Based on this study, it is recommended that the water polishing pond be partly filled before waste rock is deposited in TSF #1. In addition, to ensure the stability of the dike, the piezometric head monitoring prior to and during waste rock deposition is recommended.     

Optimal Design of a Gas‐to‐Liquids Process with a Staged Fischer‐Tropsch Reactor

The optimal design of a natural gas‐to‐liquid hydrocarbons (GTL) process with a multistage cobalt‐based Fischer‐Tropsch reactor and interstage product separation is considered. The objective function is to maximize the wax (C₂₁₊) production rate at the end of the reactor path. Sectioning of the Fischer‐Tropsch reactor increases the chain growth probability inside the reactor which results in a higher production of wax. The carbon efficiency of the two‐stage reactor is distinctly higher than that of the single‐stage reactor.