蠕变条件下完整岩石的起裂和扩展准则

The mechanism and criterion of crack initiation and propagation of rocks were investigated by many researchers,And the creep behaviour of rocks was also theoretically and experimentally studied by some scientists and engineers.The characteristics of crack initation and propagation of rocks under creep condition.however,are very improtant for rock engineering and still not paid enough attention by researchers,In this paper,the criterion and mechanism of crack initiation and propagation under creep condition were investigated using specimens collected from sandstone rock formations outcropping in the Emei Mountain,the Sichuan Province of China.Cuboid specimens under three point bending were used in this investigation.All specimens were classified into four sorts and used for Mode-I fracutre of creep frcture tests.The experimental result shows that due to creep deformation.rock crack will inevitably initialt and propagate under a load of KI,which is less than fracture toughness KIC but not less than a constant(marked as KIC2),KIC2 indicates the ability of rock to resist crack initiation and propagation under creep conditions and is less than fracture tough ness KIC.defined as creep fracture toughness in this paper,KIC2 should be considered as an importnat parameter on design and computation of rock engineering.The microstructureal mechanism for crack initiation and propagation of rock materials under creep condition was introduced based on competitive model between softening effect and hardening effect,and the validity of test result was explained.The test result was also verified in rheological theory.When KI is more than KIC2 but less than KIC,rock crack will initiate and propagate after a time interval of sustained loading under creep condition.In order to find the relation between duration of sustained lading.which can lead to crack initiation and propagation,and the initial stress intensity factor KI,an unequal0interval time sequence forecasting and predicting model was introduced,and the relation was obtained for homogeneous and isotropic fine-grained red sandstone.Finally a modified fracture toughness formula was given,in which the influence of fracture process zone(FPZ) was fully considered.     

改进深度置信网络在城市用水量预测中的应用

城市用水量的准确预测可以为供水管网智能调度、异常报警提供支持,便于及时发现漏损、排查及检修,具有极大的现实意义与经济利益。针对现有用水量预测方法忽视用水量数据自身特征及不能模拟更复杂的数学运算的问题,提出一种改进深度置信网络（DBN）的用水量预测方法。对有高斯分布的连续受限玻尔兹曼机（CRBM）引入稀疏正则项,解决特征同质化现象的同时也适用于用水量数据输入。实验结果表明,在实际用水量预测中,改进DBN模型相比传统神经网络和传统DBN预测模型,预测准确率得到了较大的提高。     

改进的灰色模型在基础沉降预测中的应用

一般的灰色残差修正GM(1,1)模型只是单纯利用差分来代替微分,而且用原始沉降数据第一点的值作为时间响应函数的初始值,导致了一定的误差。提出一种多项式逼近法改进后的残差修正GM(1,1)模型,该模型利用多项式在离散观测点上的导数代替常用的差分,同时添加一个初值参数C_0做出调整。实验验证,改进模型具有较好的准确性和工程应用价值。     

云南省产业结构现状分析及发展趋势预测

本文通过调查我国云南省及云南省各地州建国以来产业结构的变动情况，利用三次产业分类法对云南省产业结构的发展和现状进行了分析，并对云南省未来25年产业结构的发展作出预测。     

Generalized Nonlinear Irreducible Auto-Correlation and Its Applications in Nonlinear Prediction Models Identification

There is still an obstacle to prevent neural network from wider and more effective applications, i.e. , the lack of effective theories of models identification. Based on information theory and its generalization, this paper introduces a universal method to achieve nonlinear models identification. Two key quantities, which are called nonlinear irreducible auto-correlation (NIAC) and generalized nonlinear irreducible auto-correlation (GNIAC), are defined and discussed. NIAC and GNIAC correspond with intrinstic irreducible auto-dependency (IAD) and generalized irreducible autodependency (GLAD) of time series respectively. By investigating the evolving trend of NIAL; and GNIAC, the optimal auto-regressive order of nonlinear auto-regressive models could be determined naturally, Subsequently, an efficient algorithm computing NIAC and GNIAC is discussed. Experiments on simulating data sets and typical nonlinear prediction models indicate remarkable correlation between optimal auto-regressive order and the highest order that NIAC-GNIAC have a remarkable non-zero value, therefore demonstrate the validity of the proposal in this paper.     

河西地区内陆河流域地表水资源及动态趋势分析

河西地区是甘肃省主要经济地区之一，是国家下世纪初大规模开发大西北的纽带与依托。河西地区未来的经济发展规模，在很大的程度上取决于本地区水资源的承载能力。本文对河西地区内陆河流域天然地表水资源进行了计算和评价；对天然地表径流的变化特征进行了分析；并对河西地区>河西地区、内陆河流域、地表水资源、变化特征、动态过程、趋势预测     

现代设备管理趋势初探

本文通过对目前设备管理的新要求的总结,阐述了现代设备管理加入了更多的服务理念,更切近企业业务的发展趋势。现代设备服务管理将在整合服务资源和企业业务,提高企业设备管理和运营的能力和水平,引导组织高效和有效地使用技术,让既有的设备资源发挥更大的效能。     

“创新一号”卫星研制实践及微小卫星发展趋势

中国科学院研制的"创新一号"小卫星于2003年10月21日发射升空,卫星运行及其应用系统均获圆满成功.文章介绍了"创新一号"卫星的研制实践并阐述了微小卫星的发展趋势.     

我国CIO现状及发展研究

作为推进企业信息化的一把手，CIO已经成为不可或缺的人才。本篇论文总结了中国CIO的发展现状并对其发展趋势进行预测。最后，论文还对CIO的发展提出若干建议。     

太阳黑子数的时-频域模型

讨论了将小波变换用于非平稳信号建模的原理,分析了１７００年～１９９３年的太阳黑子数的年均值,提出一种用于非线性非平稳时间序列建模的新方法,与传统方法相比具有独到之处,它适用于需要进行长期预测的情形