低压离子色谱法同时测定水中铜(Ⅱ)、锌(Ⅱ)和铁(Ⅱ)

在低交换容量0．02mol／L的低压阳离子分离柱上选用40mmol／L酒石酸-20mol／L柠檬酸(pH4．30)的洗脱液分离微量Cu^2 、Zn^2 和Fe^2 离子，以吡啶-(2-偶氮-4-)雷琐辛(PAR)作显色剂，在波长520nm处连续检测，得到线性良好的工作曲线，铜、锌和铁最低检测限分别为0．02μg/ml，0、05μg/ml和0．06μg/ml。利用该方法分析了环境水样中的铜、锌和铁，回收率分别为99．0％～102.0％，97．0％～104．0％，98．0％～104、0％。     

基于光谱吸收和谐波检测的瓦斯浓度测量技术

提出了一种基于瓦斯特征光谱吸收特性和二次谐波检测原理的煤矿瓦斯监测方法,从理论上论证了该方法的可行性,并进行了实验验证.以分布反馈(DFB)激光器做光源,使用正弦信号对激光器输出的激光频率进行调制,激光通过瓦斯密闭气室后,由光电探测器探测,对所得到的信号使用二次谐波技术处理后,得到密闭气室中的瓦斯浓度,结果与实际浓度吻合.最后对影响实验检测分辨率的因素进行了分析.结果表明:该技术实现了完全非接触在线自动检测,能够满足煤矿瓦斯安全检测的要求.     

新景矿煤与瓦斯突(喷)出特征及其构造控制

新景矿3号煤层煤与瓦斯突出以小型、频发为特点,严重影响着矿井的安全、有序生产.从矿区地质背景、井田构造特征和突(喷)出点分布状况等方面进行了较系统的分析研究,认为瓦斯突(喷)出易于发生在向斜的轴部附近,次级背、向斜的过渡部位及小断层发育地带.初步总结了矿井瓦斯地质规律,并对未采掘区突(喷)出危险性进行了预测,为矿井瓦斯治理和安全生产提供了依据.     

基于纳米金和辣根过氧化物酶信号放大的 癌胚抗原电化学免疫传感器

以癌胚抗原(CEA)为检测目标构建CEA电化学免疫传感器:壳聚糖为生物活性膜,纳米金和生物素标记的辣根过氧化物酶为放大元,CEA、链霉亲和素标记的癌胚抗体免疫反应形成的复合物为固定的酶标免疫复合物,并对检测条件进行了优化。通过竞争性酶联免疫法检测不同浓度CEA的电化学响应。结果表明,该新型免疫传感器表现出良好的线性范围(4～16 ng/mL,R2=0.992 7),检测限为1 ng/mL。     

表面活性剂对间苯二胺-H_2O_2-HRP伏安酶联免疫分析体系测定HRP的影响

考察了多种表面活性剂对间苯二胺－Ｈ２Ｏ２－ＨＲＰ体系偶合反应伏安法测定辣根过氧化物酶（ＨＲＰ）的影响。结果表明,表面活性剂在一定浓度范围内对反应具有较明显的增敏作用。结合紫外－可见光谱法选择出增敏效果最好的表面活性剂,并对检测范围和检测限进行了考察。结果表明,十四烷基聚氧乙烯（９）醚（ＡＥＯ９）对间苯二胺体系增敏效果最好,浓度达２．０×１０－６ｇ·ｍＬ－１时可使灵敏度提高两个数量级。     

时分复用三轴光纤陀螺信噪比分析

基于信号处理和随机过程理论,研究了基于时分复用(TDM)技术的三轴光纤陀螺(FOG)的整体精度,利用差分方程建立了TDM闭环处理中相位差的衰减模型。将单轴总体噪声分为稳态噪声和调整噪声两部分,推算出了单轴信噪比(SNR)的计算公式,并对各影响参数进行了仿真分析,提出了相应的改进建议。设计了FOG实验,验证了模型分析的合理性及正确性。     

流动注射在线预富集测定环境样品中痕量铅

流动注射在线无过滤沉淀-溶解系统被应用于火焰原子吸收测定环境水样中痕量铅。通过样品溶液和氨溶液的混合已经可以达到痕量铅的在线析出。结果沉淀物无需过滤就被收集在编结反应器的内壁上。引入1mol/L的HNO3溶液来溶解沉淀物并将分析物输送至火焰原子吸收光谱仪(FAAS)进行在线分析。样品载入流速为3.5mol?L-1/m in,富集时间40 s,增强因子37,检测频率60/h。检测限(3σ)为7.5μg/L。50μg/L水平时,精密度(RSD,n=11)为2.9%。采用该方法测定用简单水溶液标准校准后的国家标准材料(GBW 08607,河道水),所得铅浓度0.96±0.04g/g。结果与标准值(1.00±0.02g/g)非常接近。该方法也可以成功应用于多种水样中痕量铅的测定。     

基于光谱吸收和谐波检测的瓦斯浓度测量技术

提出了一种基于瓦斯特征光谱吸收特性和二次谐波检测原理的煤矿瓦斯监测方法,从理论上论证了该方法的可行性,并进行了实验验证，以分布反馈（DFB）激光器做光源,使用正弦信号对激光器输出的激光频率进行调制,激光通过瓦斯密闭气室后,由光电探测器探测,对所得到的信号使用二次谐波技术处理后,得到密闭气室中的瓦斯浓度,结果与实际浓度吻合，最后对影响实验检测分辨率的因素进行了分析，结果表明：该技术实现了完全非接触在线自动检测,能够满足煤矿瓦斯安全检测的要求。     

CDMA与OFDM技术在宽带电力线通信中的应用比较

基于多载波频谱扩展技术，对应用于下行宽带电力线通信(PLC)中的两大热点技术直接序列码分多址复用(DS—CDMA)及正交频分复用(OFDM)进行模拟实验。在存在频率选择多径衰减、通道白噪声干扰的室内电力线环境中，以相同的数据传输速率、占用带宽、传输功率进行比特误码率(BER)的性能比较。结果表明采用位加载算法(BL)的OFDM技术可以实现更高的性能及灵活的资源分配；CDMA技术则可以降低接收端的复杂性，也取得比较令人满意的性能。     

基于空芯光子晶体光纤的F-P干涉式折射率计

提出了一种基于空芯光子晶体光纤(HCPCF)的Fabry-Perot(F-P)干涉式高灵敏度折射率计。利用被测液体进入F-P腔后可改变腔内介质的折射率,从而使得干涉光光程差发生变化这一特点,通过检测光程差的变化就可实现对液体折射率的测量。实验结果表明,对折射率在1.3340～1.3612内变化的不同浓度酒精溶液测量时,光程差变化了9.508μm,其折射率测量灵敏度可达187μm/RI     

差分红外型甲烷浓度光纤网络传感系统的研究

基于甲烷气体在其特征吸收波长下光的吸收程度随浓度变化的机理和差分吸收测量方法,结合空分复用技术和长光程吸收池技术,并考虑煤矿矿井中环境的特点,复用多个气体吸收型光纤传感器.介绍了利用差分红外光谱方法测量矿井中甲烷浓度的光纤网络传感系统的工作原理,给出了系统的结构框图.实验表明,吸收气室光程长为20 cm时,该传感器的检测限为4.278 mg/m3,精确度和稳定性可以满足实际要求,可在不同场合进行多点在线测量.     

基于煤矿瓦斯浓度的窄带光源谐波检测技术研究

在对煤矿瓦斯气体浓度的检测中,由于噪声、气体的吸收峰很窄、光源波长随温度的漂移等原因将引起测量的不稳定,通过采用对激光器的中心波长和气体吸收峰中心波长对准,测量光经过气体时的损耗就可以检测气体的浓度,利用一次谐波作为误差信号,可将光源精确地锁定在气体吸收峰上,并给出了窄带光源谐波检测的理论依据。实验结果表明,该方法可应用于甲烷气体浓度的光谱测量,它具有高精度、强选择性、快速响应等特点。     

Research on fault mode and diagnosis of methane sensor

To improve the reliability of coal mine safety monitoring systems we have analyzed the characteristics of a methane sensor, an important component of the monitoring system of production safety in a coal mine and studied the main type and mode of faults when the sensor was used on-line. We introduced a new method based on artificial neural network to detect faults of me-thane sensors. In addition, using the output information of a single methane sensor, we established a sensor output model of a dy-namic non-linear neural network for on-line fault detection. Finally, the fault of the heating wire of the sensor was simulated, indi-cating that, when the methane sensor had a fault, the predicted output of the neural network clearly deviated from the actual output,exceeding the pre-set threshold and showing that a fault had occurred in the methane sensor. The result shows that the model has good convergence and stability, and is quite capable of meeting the requirements for on-line fault detection of methane sensors.     

Evaluation and intelligent deployment of coal and coalbed methane coupling coordinated exploitation based on Bayesian network and cuckoo search

Coal and coalbed methane (CBM) coordinated exploitation is a key technology for the safe exploitation of both resources. However, existing studies lack the quantification and evaluation of the degree of coordination between coal mining and coalbed methane extraction. In this study, the concept of coal and coalbed methane coupling coordinated exploitation was proposed, and the corresponding evaluation model was established using the Bayesian principle. On this basis, the objective function of coal and coalbed methane coordinated exploitation deployment was established, and the optimal deployment was determined through a cuckoo search. The results show that clarifying the coupling coordinated level of coal and coalbed methane resource exploitation in coal mines is conducive to adjusting the deployment plan in advance. The case study results show that the evaluation and intelligent deployment method proposed in this paper can effectively evaluate the coupling coordinated level of coal and coalbed methane resource exploitation and intelligently optimize the deployment of coal mine operations. The optimization results demonstrate that the safe and efficient exploitation of coal and CBM resources is promoted, and coal mining and coalbed methane extraction processes show greater cooperation. The observations and findings of this study provide a critical reference for coal mine resource exploitation in the future.     

Evaluation of fiber optic methane sensor using a smoke chamber

This report presents the results of experiments to evaluate a prototype fiber optic methane monitor exposed to smoke using a smoke chamber to simulate atmospheric conditions in an underground coal mine after a fire or explosion. The experiments were conducted using test fires of different combustible sources commonly found in mines —douglas-fir wood, SBR belt, and Pittsburgh seam coal. The experiments were designed to assess the response of the fiber optic methane sensor to different contaminants,different contaminant levels and different contaminant durations produced from the test fires. Since the prototype methane monitor detects methane by measuring absorption at a specific wavelength, optical power at the absorption wavelength(1650 nm) was measured as a function of smoke concentration and duration. The other sensor response parameter-methane response times-were measured between smoke tests to assess the impact of soot accumulation on the sensor. Results indicate that the sensor screen effectively prevented smoke from obscuring the optical beam within the sensor head, with minimal impact on the system optical power budget. Methane response times increased with smoke exposure duration, attributed to soot loading on the protective screen.     

Phenomenon of methane driven caused by hydraulic fracturing in methane-bearing coal seams

The methane concentration of the return current will always be enhanced to a certain degree when hydraulic fracturing with bedding drilling is implemented to a gassy coal seam in an underground coal mine. The methane in coal seam is driven out by hydraulic fracturing. Thus, the phenomenon is named as methane driven effect of hydraulic fracturing. After deep-hole hydraulic fracturing at the tunneling face of the gassy coal seam, the coal methane content exhibits a ‘‘low-high-low" distribution along excavation direction in the following advancing process, verifying the existence of methane driven caused by hydraulic fracturing in methane-bearing coal seam. Hydraulic fracturing causes the change of pore-water and methane pressure in surrounding coal. The uneven distribution of the pore pressure forms a pore pressure gradient. The free methane migrates from the position of high pore(methane) pressure to the position of low pore(methane) pressure. The methane pressure gradient is the fundamental driving force for methane-driven coal seam hydraulic fracturing. The uneven hydraulic crack propagation and the effect of time(as some processes need time to complete and are not completed instantaneously) will result in uneven methane driven. Therefore, an even hydraulic fracturing technique should be used to avoid the negative effects of methane driven; on the other hand, by taking fully advantage of methane driven, two technologies are presented.     

应用瓦斯地质图指导安全生产

本文介绍了半罗山矿的地质概况，探讨了低瓦斯矿井瓦斯漏出的一般规律，论述了瓦斯地质编图对煤矿通风安全及生产的指导意义。     

阿刀亥煤矿掘进巷道煤壁瓦斯涌出规律的研究

针对阿刀亥煤矿1203炮掘巷道,通过现场实测掘进巷道煤壁瓦斯涌出量,建立了掘进巷道煤壁瓦斯涌出强度随时间的变化规律方程,确定出掘进巷道煤壁瓦斯涌出量与巷道长度、掘进速度及煤壁暴露时间的关系,给出了煤壁瓦斯涌出枯竭极限时间、掘进巷道煤壁最大瓦斯涌出量以及掘进巷道煤壁达到最大瓦斯涌出量时巷道长度的计算方法.该研究结果,对于指导矿井的通风设计和采掘部署,采取有针对性的防治煤巷掘进瓦斯灾害措施,具有重要的理论意义和实用价值.     

Application of gas wettability alteration to improve methane drainage performance: A case study

Hydraulic fracturing technique is widely used for methane drainage and has achieved good effects in numerous coal mines, but negative effects may occur as the fracturing fluids are absorbed into the coal seam. Gas wettability alteration(GWA) technology can be used as it can enhance the gas and water mobility during dewatering process as a result of capillary pressure change. However, there have been few reported field tests in coal mines using GWA technology. This paper describes a pilot-scale field test in Xinjing coal mine, Yangquan, China. The fluorocarbon surfactants perfluorooctyl methacrylate monomer-containing polymethacrylate(PMP) was used to alter the wettability of coal seam to strong gas-wetness during the hydraulic fracturing process. The study focuses on the comparison of two boreholes(Boreholes #9 and #10) and one other borehole(Borehole #8) with and without using GWA approach. A well-defined monitoring program was established by measuring the dewatering volume of the fracturing fluid and the drainage volume of methane as well as the concentration. The field test results showed that the average methane drainage rates of Boreholes #9(39.28 m~3/d) and #10(51.04 m3/d) with GWA treatment exceeded that of Borehole #8(21.09 m~3/d) without GWA treatment,with an increase of 86.3% and 142.1%, respectively. The average methane concentrations of Boreholes #9(4.05%) and #10(6.18%) were 64.6% and 151.2% higher than that of Borehole #8(2.46%), respectively. On the other hand, the dewatering ratio of Boreholes #9(4.36%) and #10(3.11%) was almost 19 times and 13 times greater than that of Borehole #8(0.22%). These field test results were in agreement with the experimental data. The significant increase in both methane concentration and dewatering ratio demonstrated that GWA technology could be applied for enhanced methane drainage in coal mines. Important lessons learned at Xinjing coal mine might be applied to other coal mines in China and elsewhere.