地质构造及局部大倾角条件下综放工作面安全回采关键技术研究与应用

断层等地质构造是制约矿井安全生产的重要因素,尤其是在大倾角、大落差断层等条件下,片帮、漏冒顶等将会严重影响安全生产.针对大平矿3111工作面在最大倾角达30°条件下,通过三机防滑、注浆、爆破、调斜等措施,采取"硬过"的方式在大倾角条件下工作面顺利通过了大落差断层,取得了较好的实践效果,为矿井积累了宝贵的回采经验.     

N,N-bis(sulfopropyl)aminyl-4-phenyl polysulfone and O,O′-bis(sulfopropyl)resorcinol-5-yl-4-phenyl polysulfone composite membrane for proton exchange membrane fuel cells

Novel functionalized polysulfone with high local density of sulfonic acid groups, N,N-bis(sulfopropyl)aminyl-4-phenyl polysulfone or O,O′-bis(sulfopropyl)resorcinol-5-yl-4-phenyl polysulfone (PSF-X-C₃H₆SO₃H, X = N or O) are synthesized. These polymers are synthesized by bromination of polysulfone followed by Suzuki cross-coupling reaction to graft the aminophenyl groups and the dimethoxyphenyl groups onto the polymeric backbone, followed by introduction of the sulfopropyl groups via sultone ring-opening reaction. In addition, the composite membrane of PSF-O-C₃H₆SO₃H and PSF-N-C₃H₆SO₃H is also synthesized for comparison. The maximum proton conductivity of composite PSF-O-C₃H₆SO₃H and PSF-N-C₃H₆SO₃H reaches 46.66 mS cm⁻¹ at 95 °C and 90% RH, higher than PSF-O-C₃H₆SO₃H (42.06 mS cm⁻¹) and PSF-N-C₃H₆SO₃H (38.76 mS cm⁻¹). Meanwhile, the composite exhibits compromised water uptake and swelling ratio, and low methanol permeability. The excellent overall performance of the composite is attributed to phase-separation between the hydrophilic and the hydrophobic subphases, and the hydrogen-bonding network developed in the hydrophilic subphases.     

Just-in-time learning for the prediction of oil sands ore characteristics using GPS data in mining applications

For the mining based oilsands industry, it is desirable to determine the quality of the ore delivered to the extraction processes in real-time to make optimal operational decisions such as optimal ore blending to achieve maximal bitumen recovery. Currently, the industry determines the real-time ore characteristics for any given shovel Global Positioning System (GPS) location by first determining the shovel elevation from the topological mine map and then using the determined geological coordinates in the 3D geological block model. It should be noted that the block model is built based on the widely spaced core hole samples, and it is updated only on a yearly basis due to high cost of narrower core hole sampling. Thus, the block model predictions are often inaccurate in between the core hole spacing. On the other hand, mining operations data are available that contain accurate ore characteristics information in the already mined area. Therefore, in this work, we present a just-in-time based data-driven modelling strategy that utilizes the recently available mining operations data to obtain reliable ore characteristics given the GPS data. The prediction capability of ore characteristics using the proposed modelling strategy is validated at core hole locations. Further, the prediction of ore characteristics at non-core hole points demonstrate promising results.     

惰气技术在防治尾巷局部火灾中的应用

在惰气防灭火技术中,N2和CO2在煤矿防灭火领域被广泛应用。基于内蒙古某矿现场先注N2、后注液态CO2的尾巷局部火灾治理措施,对采取联合惰气防灭火技术后发火区域内气体浓度的变化情况进行分析,对比N2和液态CO2对尾巷局部火灾的防灭火性能。结果表明:向发火区域内注入大量N2可有效稀释O2浓度,但在此次煤火防治中没有排除复燃隐患;由液态转化为气态的低温CO2通过稀释O2浓度和更有效地减小外部漏风,将发火区域氧浓度快速降低至3%;CO2比N2具有更好的扩散性和稀释作用,对O2、C2H4和C2H6的稀释效果较为明显,从侧面体现出CO2能更好地降低煤的氧化反应活性。经实践证明液态CO2对局部煤火的防治效果优于N2。     

Comparative analysis of inbreeding parameters and runs of homozygosity islands in 2 Italian autochthonous cattle breeds mainly raised in the Parmigiano-Reggiano cheese production region

Reggiana and Modenese are autochthonous cattle breeds, reared in the North of Italy, that can be mainly distinguished for their standard coat color (Reggiana is red, whereas Modenese is white with some pale gray shades). Almost all milk produced by these breeds is transformed into 2 mono-breed branded Parmigiano-Reggiano cheeses, from which farmers receive the economic incomes needed for the sustainable conservation of these animal genetic resources. After the setting up of their herd books in 1960s, these breeds experienced a strong reduction in the population size that was subsequently reverted starting in the 1990s (Reggiana) or more recently (Modenese) reaching at present a total of about 2,800 and 500 registered cows, respectively. Due to the small population size of these breeds, inbreeding is a very important cause of concern for their conservation programs. Inbreeding is traditionally estimated using pedigree data, which are summarized in an inbreeding coefficient calculated at the individual level (F_PED). However, incompleteness of pedigree information and registration errors can affect the effectiveness of conservation strategies. High-throughput SNP genotyping platforms allow investigation of inbreeding using genome information that can overcome the limits of pedigree data. Several approaches have been proposed to estimate genomic inbreeding, with the use of runs of homozygosity (ROH) considered to be the more appropriate. In this study, several pedigree and genomic inbreeding parameters, calculated using the whole herd book populations or considering genotyping information (GeneSeek GGP Bovine 150K) from 1,684 Reggiana cattle and 323 Modenese cattle, were compared. Average inbreeding values per year were used to calculate effective population size. Reggiana breed had generally lower genomic inbreeding values than Modenese breed. The low correlation between pedigree-based and genomic-based parameters (ranging from 0.187 to 0.195 and 0.319 to 0.323 in the Reggiana and Modenese breeds, respectively) reflected the common problems of local populations in which pedigree records are not complete. The high proportion of short ROH over the total number of ROH indicates no major recent inbreeding events in both breeds. ROH islands spread over the genome of the 2 breeds (15 in Reggiana and 14 in Modenese) identified several signatures of selection. Some of these included genes affecting milk production traits, stature, body conformation traits (with a main ROH island in both breeds on BTA6 containing the ABCG2, NCAPG, and LCORL genes) and coat color (on BTA13 in Modenese containing the ASIP gene). In conclusion, this work provides an extensive comparative analysis of pedigree and genomic inbreeding parameters and relevant genomic information that will be useful in the conservation strategies of these 2 iconic local cattle breeds.     

基于WinForm的航天电磁继电器动态特性测试系统软件设计与实现

动态特性是航天电磁继电器的重要特征之一，在继电器的生产与研究过程中需要进行测试与分析。现有条件下，动态特性测试系统测得的结果以文本和图像形式保存在本地计算机中，研究人员需采用人工作业的方式对文本文件和图像文件进行分析。针对上述问题，本文设计了一套基于WinForm的动态特性测试系统软件，具体分为客户端软件与服务器软件，双方基于Socket多线程通信实现文本文件和图像文件传输的及时性与可靠性，突破了研究人员本地作业的空间局限性；基于双缓冲技术绘制文本文件的曲线图，加强对测试结果的直观性分析；基于图像调用与局部放大技术，实现对图像的有效处理与显示。测试结果表明，所设计的系统软件运行稳定，分析与显示结果直观准确，具有较高的使用价值。     

Local body cooling to improve sleep quality and thermal comfort in a hot environment

The effects of local body cooling on thermal comfort and sleep quality in a hot environment were investigated in an experiment with 16 male subjects. Sleep quality was evaluated subjectively, using questionnaires completed in the morning, and objectively, by analysis of electroencephalogram (EEG) signals that were continuously monitored during the sleeping period. Compared with no cooling, the largest improvement in thermal comfort and sleep quality was observed when the back and head (neck) were both cooled at a room temperature of 32°C. Back cooling alone also improved thermal comfort and sleep quality, although the effects were less than when cooling both back and head (neck). Mean sleep efficiency was improved from 84.6% in the no cooling condition to 95.3% and 92.8%, respectively, in these conditions, indicating good sleep quality. Head (neck) cooling alone slightly improved thermal comfort and subjective sleep quality and increased Stage N3 sleep, but did not otherwise improve sleep quality. The results show that local cooling applied to large body sections (back and head) could effectively maintain good sleep and improve thermal comfort in a hot environment.     

无线传感器网络中广播通信的安全协议设计

摘 要：广播通信安全是无线传感器网络设计中的重要问题。本文首先分析了无线传感器网络中广播通信的特点、所需要解决的关键安全问题和以及安全协议设计原则,随后提出了基于公钥算法的全局广播通信安全协议和基于单向密钥链的局部广播通信安全协议,较好地实现了广播通信的可靠性认证、完整性和时效性。同时从性能分析看,本文方案只为传感节点引入了少量的通信负荷、能量消耗和存储空间。     

矿井多级机站可控式通风系统的研究与实践

本文对矿井多级机站可控式通风系统研究工作作总结，并列举了工业应用情况，说明多级机站可控式通风技术是一种节能、易于风量痫节等特点的新技术。