Mining-induced variation in water levels in unconsolidated aquifers and mechanisms of water preservation in mines

Phreatic water resources are widely found in thick unconsolidated surface layers in western China, where water levels respond sensitively and quickly to large-scale underground mining in conjunction with shallow coal seams. Longwall face #32201 of the Bulianta Coal Mine, in the Shendong coalfield was selected as an industrial trail base, where field observations on ground-water levels were conducted when the working face was below a water-rich area. The space-time variation in the behavior of un-consolidated water levels in response to underground mining and its relation with of advance were observed through the field trials. The basic conditions for water preservation in mines are presented and the mechanisms of water preservation in mining analyzed, given the geological condition of two key strata and a severely weathered layer buried in the overburden. The field trails show that water preservation in mining shallow coal seams can be successful under suitable conditions, providing new technology for envi-ronmental protection in the desert coalfields of northwestern China.

Research on in-situ condition preserved coring and testing systems

As shallow resources are increasingly depleted,the mechanics'theory and testing technology of deep insitu rock has become urgent.Traditional coring technologies obtain rock samples without retaining the in-situ environmental conditions,leading to distortion of the measured parameters.Herein,a coring and testing systems retaining in-situ geological conditions is presented:the coring system that obtains in-situ rock samples,and the transfer and testing system that stores and analyzes the rocks under a reconstructed environment.The ICP-Coring system mainly consists of the pressure controller,active insulated core reactor and insulation layer and sealing film.The ultimate bearing strength of 100 MPa for pressurepreservation,temperature control accuracy of 0.97%for temperature-retained are realized.CH_(4)and CO permeability of the optimized sealing film are as low as 3.85 and 0.33 ppm/min.The average tensile elongation of the film is 152.4%and the light transmittance is reduced to 0%.Additionally,the pressure and steady-state temperature accuracy for reconstructing the in-situ environment of transfer and storage system up to 1%and±0.2 is achieved.The error recorded of the noncontact sensor ring made of lowdensity polymer is less than 6%than that of the contact test.The system can provide technical support for the deep in-situ rock mechanics research,improving deep resource acquisition capabilities and further clarifying deep-earth processes.

Attacks on Anonymization-Based Privacy-Preserving: A Survey for Data Mining and Data Publishing

Data mining is the extraction of vast interesting patterns or knowledge from huge amount of data. The initial idea of privacy-preserving data mining PPDM was to extend traditional data mining techniques to work with the data modified to mask sensitive information. The key issues were how to modify the data and how to recover the data mining result from the modified data. Privacy-preserving data mining considers the problem of running data mining algorithms on confidential data that is not supposed to be revealed even to the party running the algorithm. In contrast, privacy-preserving data publishing (PPDP) may not necessarily be tied to a specific data mining task, and the data mining task may be unknown at the time of data publishing. PPDP studies how to transform raw data into a version that is immunized against privacy attacks but that still supports effective data mining tasks. Privacy-preserving for both data mining (PPDM) and data publishing (PPDP) has become increasingly popular because it allows sharing of privacy sensitive data for analysis purposes. One well studied approach is the k-anonymity model [1] which in turn led to other models such as confidence bounding, l-diversity, t-closeness, (α,k)-anonymity, etc. In particular, all known mechanisms try to minimize information loss and such an attempt provides a loophole for attacks. The aim of this paper is to present a survey for most of the common attacks techniques for anonymization-based PPDM & PPDP and explain their effects on Data Privacy.

Research on Privacy Preserving Data Mining

In recent years,with the explosive development in Internet,data storage and data processing technologies,privacy preservation has been one of the greater concerns in data mining.A number of methods and techniques have been developed for privacy preserving data mining.This paper provided a wide survey of different privacy preserving data mining algorithms and analyzed the representative techniques for privacy preservation.The existing problems and directions for future research are also discussed.

Discrimination conditions and process of water-resistant key strata

Water-preservation mining is one of the most important parts of the ‘Green Mining' technology system,which can realize the effective regulation of groundwater resources by controlling strata movement,changing passive prevention and governance of water disasters to active conservation and utilization of groundwater resources and thus obtaining coal and water simultaneously in mining.The concept of water-resistant key strata further enriches the content of the key stratum theory and provides a theoretical basis for water-preservation mining.In order to realize the idea of water-resistant key strata as a guideline in the design of water-preservation mining and engineering applications,the conditions for discrimination in the process of water-resistant key strata,we have presented a mechanical model,as well as its corresponding computer program,based on a large number of theoretical analyses and field measurements,as well as on a comprehensive consideration of the position,structural stability and seepage stability of key strata.Practical engineering applications indicate that this discrimination method and its corresponding computer program on water-resistant key strata are accurate and reliable and can satisfy the actual design needs of water-preservation mining and thus have instructional importance for water-preservation mining in mining areas lacking water.

Data Mining with Privacy Protection Using Precise Elliptical Curve Cryptography

Protecting the privacy of data in the multi-cloud is a crucial task.Data mining is a technique that protects the privacy of individual data while mining those data.The most significant task entails obtaining data from numerous remote databases.Mining algorithms can obtain sensitive information once the data is in the data warehouse.Many traditional algorithms/techniques promise to provide safe data transfer,storing,and retrieving over the cloud platform.These strategies are primarily concerned with protecting the privacy of user data.This study aims to present data mining with privacy protection(DMPP)using precise elliptic curve cryptography(PECC),which builds upon that algebraic elliptic curve infinitefields.This approach enables safe data exchange by utilizing a reliable data consolidation approach entirely reliant on rewritable data concealing techniques.Also,it outperforms data mining in terms of solid privacy procedures while maintaining the quality of the data.Average approximation error,computational cost,anonymizing time,and data loss are considered performance measures.The suggested approach is practical and applicable in real-world situations according to the experimentalfindings.

Novel Privacy Preserving Method of Countering the Threats from Priori Knowledge

Recently,many data anonymization methods have been proposed to protect privacy in the applications of data mining.But few of them have considered the threats from user's priori knowledge of data patterns.To solve this problem,a flexible method was proposed to randomize the dataset,so that the user could hardly obtain the sensitive data even knowing data relationships in advance.The method also achieves a high level of accuracy in the mining process as demonstrated in the experiments.

深部煤层原位保压保瓦斯取心技术装备及初步应用

深部煤层瓦斯含量精准测定是矿井瓦斯灾害防治和煤层气高效开发利用的基本前提。煤层传统取心技术普遍采用开放式取心,需利用估算方法获得煤层取心过程中的瓦斯损失量,难以保证煤层瓦斯原位参数的准确性和有效性。基于“原位保真取心”学术思想,开发了深部煤层原位保压保瓦斯取心技术,研制了深部煤矿原位保压保瓦斯取心器,并基于三维数值仿真对取心器外管、保压舱体结构与关键薄弱部件进行了强度校核。同时,依托自主研发的保压取心实验室模拟测试平台,测定并分析了保压控制器的保压能力,通过煤矿现场试验验证了取心器的可靠性。研究结果表明:自主研制的取心器具有保压能力强、保压时间长、防扰动性能稳定等优势;取心器在内部流体压力20 MPa和1000 N m扭矩作用下等效应力为121.1 MPa,远小于材料屈服强度,满足强度设计要求;取心器在20 MPa荷载作用下等效应力为63.9 MPa,满足强度设计要求;取心器整体在19.4 MPa压力条件内可持续稳定运行,可以满足大部分深部煤矿瓦斯测试需求;现场测试表明保压保瓦斯取心器的保压控制器闭合情况良好,现场取心率达100%。研究成果可为深部煤层瓦斯含量精准测定奠定理论、技术和装备基础,对于煤矿瓦斯灾害防治和煤层气勘探开发具有重要意义。

基于数据挖掘探讨高血压合并射血分数保留型心力衰竭的用药规律

目的/意义运用数据挖掘方法探讨中医药治疗高血压合并射血分数保留型心力衰竭的用药规律和组方特点。方法/过程基于黑龙江中医药大学附属第一医院心血管病一科2019年1月-2022年7月收治的高血压合并射血分数保留型心力衰竭患者中药处方信息建立数据库。采用SPSS Statistics、Moderler软件进行频数、性味归经、功效、关联规则及聚类分析,挖掘组方用药规律。结果/结论中医药治疗高血压合并射血分数保留型心力衰竭多以益气健脾、养心安神为主,辅以化痰止咳平喘,同时注重活血化瘀、利水渗湿,标本兼顾,可为临床用药提供参考。

韧性视角下华北型煤田底板承压灰岩水原位保护技术研究

目的为推进保水开采技术高质量发展,有效解决华北型煤田底板承压灰岩水原位保护问题,方法根据扰动下系统韧性演化特征,从韧性抵抗力、恢复力和适应力出发,分析煤层底板在采动和承压水影响下由抵抗到恢复及再适应的全过程。基于“精准、高效、全面”的核心内涵,构建以“治理靶区精准确定、多分支井高效注浆、保水效果全面评价”为主体的华北型煤田底板承压灰岩水原位保护技术框架。结果结果表明:治理靶区精准确定包括垂向层位确定和横向靶位确定;多分支井高效注浆包括定、钻、注3个步骤;保水效果全面评价包括底板岩层注浆效果评价和水资源承载力恢复评价。根据底板破坏深度和临界隔水层厚度计算,确定底板注浆垂向层位,根据关键指标参数探测和脆弱性指数模型计算确定底板注浆横向靶位,形成底板注浆靶区的量化确定方法并开发相应的软件系统。多分支井注浆结合随钻定向技术,对相关裂隙等进行注浆封堵,减少直井段数量,提高钻井效率。针对保水开采中“安全开采”和“水资源保护”理念,提出基于底板岩层注浆效果探测和水资源承载力恢复监测的原位保水效果评价方法。结论在安徽某矿进行工程应用,保障底板承压灰岩水上开采煤层安全性的同时,兼顾矿区经济效益与生态环境发展。研究结果完善了承压水上保水开采技术体系,为后续研究及现场应用提供借鉴。

一种共生保序模式挖掘算法

作为数据挖掘的一个新兴方向,研究人员在时间序列领域提出了用于挖掘相对次序相同的保序模式.尽管现有的保序模式挖掘算法可以有效地找出全部的频繁模式,但在当用户仅对某个特定的模式及其为前缀的模式较为感兴趣时,现有的挖掘算法效率过于低下.为了解决上述问题,本文提出了一种共生保序模式挖掘算法,用于挖掘出以给定模式为前缀的共生保序模式.该算法包括融合准备和计算超模式的支持度两个主要部分,其中,融合准备分为4个步骤:获取模式p的后缀保序模式,计算后缀保序模式的出现,前向验证模式p的出现,后向查找所有可融合模式的出现;在计算超模式的支持度时,提出一种剪枝策略,使得候选模式的个数进一步减少.在真实数据集上,实验结果验证了本文算法的高效性.

中医药治疗射血分数保留心力衰竭的核心处方及类方分析

目的分析中医药治疗射血分数保留心力衰竭(HFpEF)的核心处方及类方的用药规律,为HFpEF临床遣药组方提供参考。方法检索中国知识资源总库(CNKI)、中国学术期刊数据库(Wanfang Data)、中文科技期刊数据库(VIP)、中国生物医学文献数据库(CBM)、PubMed、Web of Science、Embase、Cochrane Library建库至2023年11月1日收录的中医药治疗HFpEF临床研究文献,采用复杂网络、处方相似性网络、社团划分等数据挖掘方法,探讨HFpEF的处方用药规律。结果共纳入中医药治疗HFpEF临床研究文献142篇,包含146首处方,涉及中药162味;使用频次较高的中药以黄芪、丹参、茯苓为代表;利用复杂网络分析得到治疗HFpEF的核心处方及常用药物配伍,核心处方由黄芪、茯苓、丹参、甘草、川芎、桂枝、葶苈子、白术、赤芍、麦冬、当归组成;进一步基于处方相似性网络和社团划分方法,得到对应于HFpEF分期及证型的3个主要社团类方集合基础方,发现HFpEF病程发展的分期诊疗用药规律。结论益气活血、温阳利水为HFpEF的治疗大法;采用数据挖掘技术分析HFpEF核心处方及类方,可为HFpEF中医诊疗规律及用药经验总结提供依据。

A Data Mining-Based Study on Medication Rules of Chinese Herbs to Treat Heart Failure with Preserved Ejection Fraction

Objective:To summarize the medication rules of Chinese herbs to treat heart failure with preserved ejection fraction(HFPEF)based on data mining and to provide references for clinical utilization.Methods:The China National Knowledge Infrastructure(CNKI),Wanfang database(Wanfang),VIP database(VIP),Chinese Biomedical Literature(CBM),PubMed,Embase,and Cochrane Library databases were searched from inception to October 2021 to identify relevant literature on treating HFPEF with Chinese herbs.Microsoft Excel 2019 was used to set up a database,and then,association rule analysis and hierarchical cluster analysis were performed by using apriori algorithm and hclust function respectively in R-Studio(Version 4.0.3).Results:A total of 182 qualified papers were included,involving a total of 92 prescriptions,130 Chinese herbs,and 872 individual herbs prescribed,with an average of 9.5 herbs per prescription.The six most frequently prescribed herbs were Astragali Radix(Huangqi),Salviae Miltiorrhizae Radix Et Rhizoma(Danshen),Poria(Fuling),Glycyrrhizae Radix Et Rhizoma(Gancao),Cinnamomi Ramulus(Guizhi),and Ginseng Radix Et Rhizoma(Renshen).There were 35 herbs used more than 5 times,involving 11 efficacy categories.The top three categories were deficiency-tonifying herbs,blood-activating and stasis-removing herbs,and dampnessdraining diuretic herbs.The most commonly used herbs were mainly warm and sweet.The primary meridian tropisms were Lung Meridian,Heart Meridian and Spleen Meridian.Association rule analysis yielded 26 association rules,such as Astragali Radix(Huangqi)&Salviae Miltiorrhizae Radix Et Rhizoma(Danshen),Poria(Fuling),Cinnamomi Ramulus(Guizhi)&Atractylodis Macrocephalae Rhizoma(Baizhu).Hierarchical cluster analysis yielded four herb classes,and their functions were mainly qi-replenishing and yang-warming,bloodactivating and diuresis-inducing.Conclusions:HFPEF is the syndrome of root vacuity and tip repletion,and its core pathogenesis is"deficiency","stasis",and"wafer",with"deficiency"being the most principal,which is closely related to Xin(heart),Fei(Lung),and Pi(Spleen).The treatment of this disease occurs by improving qi,warming yang,activating blood and inducing diuresis.Astragali Radix(Huangqi)with Salviae Miltiorrhizae Radix Et Rhizoma(Danshen)is the basic combination of herbs applied.

矿区规划环评在协调地下水资源保护和矿区有序开发中的作用

针对矿区规划环评如何协调地下水资源保护和矿区有序开发的问题,以神东煤炭基地新街台格庙矿区总体规划环评为例,在对矿区总体规划方案布局、周边地下水资源环境特点进行充分调查识别清楚的基础上,客观分析了矿区规划布局与地下水水源地的空间冲突,以及矿区南部矿井开发对红碱淖地下水流系统水资源影响,提出了较为全面的矿区开发布局、规模及时序优化等优化建议,较好地协调了矿区煤炭开发与地下水环境保护关系,实现矿区有序开发与环境保护相协调。

浅埋煤层综放开采导水裂隙发育特征及隔水层稳定性研究

针对我国西北浅埋煤层保水开采关键隔水层N2红土稳定性不足及水资源保护等问题,研究了陕北榆神矿区薄基岩厚土层典型工作面综放开采导水裂隙发育特征及其对N2红土隔水层稳定性的影响程度。结果表明:理论计算得到导水裂隙带发育高度为57.9~113.9 m,现场实测所得结果121.10~139.79 m;数值模拟分析不同工作面推进距离下导水裂隙带发育规律,当工作面走向长度达到170 m后,导水裂隙高度增长缓慢,最大值为96.5 m,煤层开采导水裂隙带贯穿基岩后基本发育至N2红土层底部;基于层次分析方法(AHP)构建N2红土层采动损害评价模型,明确了影响N2红土关键隔水层稳定性的主要因素,基于导水裂隙带发育高度、红土层厚度、红土层与主采煤层间距因素评价结果,并考虑红土层残余厚度进行保水开采结果评价,确定隔水层稳定判据,提出基于裂隙发育特征的隔水层稳定性评价方法。研究结果对于陕北煤田类似条件煤炭绿色开采及保水采煤具有重要参考意义。

同宝煤矿15号煤层首采面采空区积水下安全开采评价

为保证同宝煤矿15105首采面安全回采,使用不同的计算方法,对导水裂隙带高度、保护层厚度和3号煤层开采底板破坏深度进行分析,并结合数值模拟方法,分析评价15105首采面上覆采空区积水对首采面回采的安全性影响。结果表明:15105工作面范围内,煤间距与防水煤岩柱高度差值均大于0,即煤间距均大于防水煤岩柱高度。依据FLAC^(3D)数值模拟结果,在无构造等其他导水通道情况下,15105首采面第一阶段回采形成的导水裂缝带基本未沟通上覆3号煤层采空区积水。

我国水体下保水采煤技术研究进展

针对我国水体下保水采煤的理论与实践,就采动覆岩导水裂隙演化规律,以及在此基础上形成的保水采煤技术研究进展进行了综述和展望。结果表明:导水裂隙作为地层含水层破坏与地下水漏失的主要根源,其动态发育与发展直接受控于覆岩关键层的破断运动;因而,可按具体开采条件下覆岩关键层的赋存情况进行导水裂隙带高度的确定,从而科学指导水体下保水采煤对策的制定。依据水体下保水采煤所包括的4个层次的内涵,分别从顶板突水灾害防治、含水层原位保护、采动破坏含水层的再恢复、采动漏失水资源的转移储存与利用等4个方面,进行了相关保水采煤技术研究进展的论述,在此基础上提出了今后的研究方向。

干旱半干旱矿区水资源保护性采煤基础与应用研究

干旱半干旱矿区水资源保护性采煤既是一项重要的国家发展战略,也是重要的基础和应用科学研究内容之一。结合神东矿区具体地质采矿条件,从矿区水文地质结构分析、采动覆岩导水裂隙通道发育规律与隔水关键层稳定性、有隔水层区上覆含水层保水采煤方法、无隔水层区上覆含水层预疏放转移存贮等多个方面,系统地展开了对干旱半干旱矿区水资源保护性采煤的基础与应用研究工作。通过水文地质分析,将浅层含水区域分为4种水文地质结构类型,又把有隔水层区结构细分为5种隔水层结构,进而提出了5种保水采煤分区。通过现场实测、数值模拟和理论分析等,揭示了采动覆岩裂隙演化、渗流通道发育与渗流规律,并给出了隔水关键层稳定性判别条件。根据不同的地质采矿条件,提出了针对有隔水层区上覆含水层的控制隔水关键层结构稳定保水开采方法、控制采动导水裂隙闭合保水开采方法、局部支撑区域充填保水开采方法,提出了针对无隔水层区上覆含水层预疏放向采空区转移存贮水方法,并在实践中取得了良好的应用效果。

保水开采隔水关键层的基本概念及力学分析

提出了在控制采场顶底板水运移中隔水关键层的概念,建立了复合隔水关键层的基本力学模型,进而对具有5层岩层组成的复合隔水关键层进行了相关的强度和刚度分析,给出了不同组合的阻隔水能力判定.从岩层运动与水体运移的视角提出了保水开采的矿压控制思路,为开发水资源保护性的煤矿绿色开采技术提供了相关的技术途径.

典型高强度开采矿区保水采煤关键技术与实践

神东矿区是我国重要的煤炭生产基地和典型的高强度开采矿区,同时也是我国典型的干旱半干旱生态环境脆弱区,矿区高强度煤炭生产与生态环境的协调发展是该区的重要研究课题。针对神东矿区干旱半干旱地区水资源贫乏、生态环境脆弱等特点,通过研究矿区水文地质结构特征、煤层覆岩结构类型等,提出了矿区的水文地质结构分区和保水采煤分区;以此为基础,针对不同的水文地质结构类型,提出了神东矿区的保水采煤的基本原则,以及矿区重要水源地、厚基岩含水层、烧变岩含水层、水资源转移存贮、矿井水资源化利用等保水采煤的关键技术;最后,结合典型矿井,开展了上述关键技术的现场工程实践,并取得了良好的应用效果。