mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Reservoir reconstruction technologies for coalbed methane recovery in deep and multiple seams

Multiple coal seams widely develop in the deep Chinese coal-bearing strata. Ground in situ stress and coal seam gas pressure increase continuously with the increase of the mining depth, and coal and gas outburst disasters become increasingly severe. When the coal is very deep, the gas content and pressure will elevate and thus coal seams tends to outburst-prone seams. The safety and economics of exploited firstmined coal seams are tremendously restricted. Meanwhile, the multiple seams occurrence conditions resulted in different methane pressure systems in the coal-bearing strata, which made the reservoir reconstruction of coal difficult. Given the characteristics of low saturation, low permeability, strong anisotropy and soft coal of Chinese coal seams, a single hydraulic fracturing surface well for reservoir reconstruction to pre-drain the coalbed methane (CBM) of multiple seams concurrently under the different gas pressure systems has not yet gained any breakthroughs. Based on analyses of the main features of deep CBM reservoirs in China, current gas control methods and the existing challenges in deep and multiple seams, we proposed a new technology for deep CBM reservoir reconstruction to realize simultaneous high-efficiency coal mining and gas extraction. In particular, we determined the first-mined seam according to the principles of effectiveness and economics, and used hydraulic fracturing surface well to reconstruct the first-mined seam which enlarges the selection range of the first-mined seam. During the process of mining first-mined seam, adjacent coal seams could be reconstructed under the mining effect which promoted high-efficiency pressure relief gas extraction by using spatial and comprehensive gas drainage methods (combination of underground and ground CBM extraction methods). A typical integrated reservoir reconstruction technology, ‘‘One well for triple use”, was detailed introduced and successfully applied in the Luling coal mine. The application showed that the proposed technology could effectively promote coal mining safety and simultaneously high-efficiency gas extraction.
Ultrasonic vibrations and coal permeability: Laboratory experimental investigations and numerical simulations

Ultrasonic vibrations in coal lead to cavitation bubble oscillation, growth, shrinkage, and collapse, and the strong vibration of cavitation bubbles not only makes coal pores break and cracks propagate, but plays an important role in enhancing the permeability of coal. In this paper, the influence of ultrasonic cavitation on coal and the effects of the sonic waves on crack generation, propagation, connection, as well as the effect of cracks on the coal permeability, are studied. The experimental results show that cracks in coal are generated even connected rapidly after ultrasonic cavitation. Under the effect of ultrasonic cavitation, the permeability increases between 30% and 60%, and the number of cracks in coal also significantly increased. Numerical experiments show that the effective sound pressure is beneficial to fracture propagation and connection, and it is closely related to the permeability. Moreover, the numerical simulations and physical experiments provide a guide for the coal permeability improvement.
Effects of longwall-induced stress and deformation on the stability and mechanical integrity of shale gas wells drilled through a longwall abutment pillar

This paper presents the results of a comprehensive study conducted by CONSOL Energy, Marcellus Shale Coalition, and Pennsylvania Coal Association to evaluate the effects of longwall-induced subsurface deformations on the mechanical integrity of shale gas wells drilled over a longwall abutment pillar. The primary objective is to demonstrate that a properly constructed gas well in a standard longwall abutment pillar can maintain mechanical integrity during and after mining operations. A study site was selected over a southwestern Pennsylvania coal mine, which extracts 457-m-wide longwall faces under about 183 m of cover. Four test wells and four monitoring wells were drilled and installed over a 38-m by 84-m centers abutment pillar. In addition to the test wells and monitoring wells, surface subsidence measurements and underground coal pillar pressure measurements were conducted as the 457-m-wide longwall panels on the south and north sides of the abutment pillar were mined by. To evaluate the resulting coal protection casing profile and lateral displacement, three separate 60-arm caliper surveys were conducted. This research represents a very important step and initiative to utilize the knowledge and science obtained from mining research to improve miner and public safety as well as the safety and health of the oil and gas industries.
Void fill and support techniques to stabilize drift excavated through a transition zone mined by a TBM at the Stillwater mine

Stillwater Mining Company is the only U.S. producer of platinum group metals (PGMs) and the largest producer outside of South Africa and Russia. The company controls a considerable portion of the J-M reef and is currently developing the ‘‘Blitz Project,” which will provide a main haulage level, ore pass systems, backfill plants, and flow-through ventilation to increase production and ensure sustainable extraction of this critical strategic mineral. While driving two sub-parallel footwall laterals 8125 m in length, one of the development drifts experienced a massive fall in a geologically disturbed area created by a mafic dike intrusion. Combinations of a void fill material (Tekseal), polyurethane injection, fore poling coupled with steel arches, and supplemental bolting allow safe and efficient advance through this geologically disturbed zone. This paper presents the details of this project.
Sorption behavior of coal for implication in coal bed methane an overview

CBM has been recognized as a significant natural gas resource for a long time. Recently, CO_2 sequestration in coalbeds for ECBM has been attracting growing attention because of greater concerns about the effects of greenhouse gases and the emerging commercial significance of CBM. Reservoir-simulation technology, as a useful tool of reservoir development, has the capability to provide us with an economic means to solve complex reservoir-engineering problems with efficiency. The pore structure of coal is highly heterogeneous, and the heterogeneity of the pores depends on the coal type and rank.
Guest editorial–Special issue on ground control in mining in 2016

In 1981 a Professor at West Virginia University recognized the need to establish a program for bringing together members of the mining community to share and discuss methods, technology and experiences related to ground control in mining operations [1]. From this initial idea the International Conference on Ground Control in Mining (ICGCM) was established. Professor Syd S. Peng was that individual and 35 years later this event is widely recognized as the premier gathering of ground control researchers, consultants, regulators, manufacturers and mine operators [2–6]. From the initial gathering in 1981, the Conference has grown significantly and has been expanded to include a sister event held annually in China [7]. Both events are focused on advancing the knowledge and science of ground control in mining applications with the overall goal of providing solutions for the mining industry. The range of topics covered at the conferences is extensive and the individuals attending and presenting is truly a who's who of the ground control community. Prior to the first Conference in 1981, ground control failures in underground coal mines accounted for more than 50% of all fatalities and all severe injuries. This number has decreased significantly and for 2014 ground control failures only account for about 14%. Virtually all of the advances in technology, knowledge and operational strategies for ground control have been presented and published at the International Conference on Ground Control in Mining over the last 35 years.
Assessment of potential impacts to surface and subsurface water bodies due to longwall mining

Ground movements due to longwall mining operations have the potential to damage the hydrological balance within as well as outside the mine permit area in the form of increased surface ponding and changes to hydrogeological properties. Recently, the Office of Surface Mining, Reclamation and Enforcement (OSMRE) in the USA, has completed a public comment period on a newly proposed rule for the protection of streams and groundwater from adverse impacts of surface and underground mining operations (80 FR 44435). With increased community and regulatory focus on mining operations and their potential to adversely affect streams and groundwater, now there is a greater need for better prediction of the possible effects mining has on both surface and subsurface bodies of water. With mining induced stress and strain within the overburden correlated to changes in the hydrogeological properties of rock and soil, this paper investigates the evaluation of the hydrogeological system within the vicinity of an underground mining operation based on strain values calculated through a surface deformation prediction model. Through accurate modeling of the preand post-mining hydrogeological system, industry personnel can better depict mining induced effects on surface and subsurface bodies of water aiding in the optimization of underground extraction sequences while maintaining the integrity of water resources.
Green coal mining technique integrating mining-dressing-gas draining-backfilling-mining

Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine: (1) difficulty in implementing auxiliary lifting because of its depth (i.e., beyond 1000 m); (2) highly gassy main coal seam with low permeability; (3) unstable overlying coal seam without suitable conditions for implementing conventional mining techniques for protective coal seam; and (4) predominant reliance on ‘‘under three” coal resources to ensure production output. This study proposes an integrated, closed-cycle mining-dressing-gas draining-backfilling-mining (MDGBM) technique. The proposed approach involves the mining of protective coal seam, underground dressing of coal and gangue (UDCG), pressure relief and gas drainage before extraction, and backfilling and mining of the protected coal seam. A system for draining gas and mining the protective seam in the rock stratum is designed and implemented based on the geological conditions. This system helps in realizing pressure relief and gas drainage from the protective seam before extraction. Accordingly, another system, which is connected to the existing production system, is established for the UDCG based on the dense medium-shallow trough process. The mixed mining workface is designed to accommodate both solid backfill and conventional fully mechanized coal mining, thereby facilitating coal mining, USCG, and backfilling. The results show that: The mixed mining workface length for the Ji 15-31010 protected seam was 220 m with coal production capacity 1.2 million tons per year, while the backfill capacity of gangue was 0.5 million tons per year. The gas pressure decreased from 1.78 to 0.35 MPa, and the total amount of safely mined coal was 1.34 million tons. The process of simultaneously exploiting coal and draining gas was found to be safe, efficient, and green. This process also yielded significant economic benefits.
Numerical Investigation Into a Surface Plasmon Resonance Sensor Based on Optical Fiber Microring

A reflective surface plasmon resonance(SPR)sensor based on optical fiber microring is proposed. In such a sensor, plasmons on the outer surface of the metallized channels containing analyte can be excited by a fundamental mode of a thin-core fiber(TCF). The refractive index(RI)sensing can be achieved as the surface plasmons are sensitive to changes in the refrective index of the analyte. Numerical simulation results show that the resonance spectrum shifts toward the shorter wavelength gradually when the analyte refractive index increases from 1.0 to 1.33, whereas it shifts toward the longer wavelength gradually when the analyte refractive index increases from 1.33 to 1.43, and there is a turning point at the refractive index value of 1.33. The highest sensitivity achieved is up to 2.30×10~3 nm/RIU near the refractive index value of 1.0. Such a compact sensor has potential for gaseous substance monitoring.
Effect of exposure to ambient PM_(2.5) pollution on the risk of respiratory tract diseases: a meta-analysis of cohort studies

The International Agency for Research on Cancer and the World Health Organization have designated airborne particulates, including particulates of median aerodynamic diameter ≤ 2.5 μm (PM_(2.5)),as Group 1 carcinogens. It has not been determined, however, whether exposure to ambient PM_(2.5) is associated with an increase in respiratory related diseases. This meta-analysis assessed the association between exposure to ambient fine particulate matter (PM_(2.5)) and the risk of respiratory tract diseases, using relevant articles extracted from PubMed, Web of Science, and Embase. In results, of the 1,126 articles originally identified, 35 (3.1%) were included in this meta-analysis. PM_(2.5) was found to be associated with respiratory tract diseases. After subdivision by age group, respiratory tract disease, and continent, PM_(2.5) was strongly associated with respiratory tract diseases in children, in persons with cough, lower respiratory illness, and wheezing, and in individuals from North America, Europe, and Asia. The risk of respiratory tract diseases was greater for exposure to traffic-related than non-traffic-related air pollution. In children, the pooled relative risk (RR) represented significant increases in wheezing (8.2%), cough (7.5%), and lower respiratory illness (15.3%). The pooled RRs in children were 1.091 (95%CI: 1.049, 1.135) for exposure to <25 μg/m~3 PM_(2.5), and 1.126 (95%CI: 1.067,1.190) for exposure to > 25 μg/m~3 PM_(2.5). In conclusion, exposure to ambient PM_(2.5) was significantly associated with the development of respiratory tract diseases, especially in children exposed to high concentrations of pm25.
Fast and accurate generation method of PSF-based system matrix for PET reconstruction

This work investigates the positional single photon incidence response(P-SPIR) to provide an accurate point spread function(PSF)-contained system matrix and its incorporation within the image reconstruction framework.Based on the Geant4 Application for Emission Tomography(GATE) simulation,P-SPIR theory takes both incidence angle and incidence position of the gamma photon into account during crystal subdivision,instead of only taking the former into account,as in single photon incidence response(SPIR).The response distribution obtained in this fashion was validated using Monte Carlo simulations.In addition,two-block penetration and normalization of the response probability are introduced to improve the accuracy of the PSF.With the incorporation of the PSF,the homogenization model is then analyzed to calculate the spread distribution of each line-of-response(LOR).A primate PET scanner,Eplus-260,developed by the Institute of High Energy Physics,Chinese Academy of Sciences(IHEP),was employed to evaluate the proposed method.The reconstructed images indicate that the P-SPIR method can effectively mitigate the depth-of-interaction(DOI) effect,especially at the peripheral area of field-of-view(FOV).Furthermore,the method can be applied to PET scanners with any other structures and list-mode data format with high flexibility and efficiency.
Constraints on dark matter annihilation and decay from the isotropic gamma-ray background

We study the constraints on dark matter(DM) annihilation/decay from the Fermi-LAT Isotropic Gamma-Ray Background(IGRB) observation.We consider the contributions from both extragalactic and galactic DM components.For DM annihilation,the evolution of extragalactic DM halos is taken into account.We find that the IGRB annihilation constraints under some DM subhalo models can be comparable to those derived from the observations of dwarf spheroidal galaxies and CMB.We also use the IGRB results to constrain the parameter regions accounting for the latest AMS-02 electron-positron anomaly.We find that the majority of DM annihilation/decay channels are strongly disfavored by the latest Fermi-LAT IGRB observation;only DM decays to μ~+μ~-and 4μ channels may be valid.
A Nonorthogonal Joint Block Diagonalization Algorithm Avoiding Degenerate Solutions

The joint block diagonalization algorithm is instrumental to the convolution blind signal separation. However, the nonorthogonal joint block diagonalization algorithm based on a Weighted least-squares (WLS) criterion sometimes converges to the degenerate or trivial solution. It is simple to avoid the trivial solution by adding some constraint on the de-mixing matrix. But the degenerate solution is hard to be excluded. This paper probes the phenomenon of the degenerate solution. By adding a new penalty function to the WLS criterion, an efficient algorithm which can avoid the degenerate solution is developed. Through the theoretical derivation and numerical simulation, we can make the conclusion that the proposed algorithm is more robust and not sensitive to the square or non-square mixing matrix.
Fast Implementation for the Singular Value and Eigenvalue Decomposition Based on FPGA

A fast and efficient hardware implementation for computing the Singular value decomposition (SVD) and Eigenvalue decomposition (EVD) is presented. Considering that the SVD and EVD are complex and expensive operations, to achieve high performance with low computing complexity, our approach takes full advantage of the combination of parallel and sequential computation, which can increase efficiently the hardware utilization. Besides, regarding to EVD, we propose a hardware solution of a simplified Coordinate rotation digital computer (CORDIC)-like algorithm which can obtain higher speed. The performance analysis and comparison results show that the proposed methods can be realized on Filedprogrammable gate arrays (FPGAs) with less computation time by using systolic array. It will be shown that the proposed implementation could be an efficient alternative for real-time applications.
Pheromone Model Selection in Ant Colony Optimization for the Travelling Salesman Problem

As a meta-heuristic approach, Ant colony optimization (ACO) has many applications. In the algorithm selection of pheromone models is the top priority. Selecting pheromone models that don't suffer negative biases is a natural choice. Specifically for the travelling salesman problem, the first order pheromone is widely recognized. When come across travelling salesman problem, we study the reasons for the success of ant colony optimization from the perspective of pheromone models,and unify different order pheromone models. In tests, we have introduced the concept of sample locations and the similarity coefficient to pheromone models. The first order pheromone model and the second order pheromone model are compared and are further analysed. We illustrate that the second order pheromone model has better global search ability and diversity of population than the former. With appropriate-scale travelling salesman problems, the second order model performs better than the first order pheromone model.
A Novel Sparse Penalty for Singular Value Decomposition

Singular value decomposition (SVD) is a tool widely used in data denoising, matrix approximation, recommendation system, text mining and computer vision. A majority of applications prefer sparse singular vectors to capture inherent structures and patterns of the input data so that the results are interpretable. We present a novel penalty for SVD to achieve sparsity. Comparing with the traditional penalties, the proposed penalty is scale, dimensional insensitive and bounded between 0 and 1, which are in favor of controlling sparsity. Regulated by the penalty, we provide an efficient algorithm to project a vector onto a given sparse level in O(n) expected time. The efficient projection algorithm serve as a drudge for sparse SVD (SSVD). In experiments, SSVD is efficient and could capture the latent structures and patterns of the input data.
高频重复经颅磁刺激治疗精神分裂症强迫症状对照研究

目的探讨高频率10 Hz重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗精神分裂症强迫症状的疗效和安全性。方法选择伴强迫症状的精神分裂症患者共60例,按随机数字表法分为两组,每组30例。在原抗精神病药基础上,研究组予以10 Hz rTMS联合舍曲林治疗,对照组口服舍曲林治疗,观察4周。采用阳性与阴性症状量表(positive and negative syndrome scale,PANSS)和耶鲁—布朗强迫量表(Yale-Brown obsessive compulsive scale,Y-BOCS)评估疗效,并对不良反应发生情况进行记录。结果治疗前两组间PANSS和Y-BOCS评分差异无统计学意义(P>0.05)。治疗4周后,研究组PANSS总分、PANSS阴性因子分较治疗前下降(P<0.05);对照组治疗前后PANSS总分差异有统计学意义(P<0.05);治疗后研究组PANSS阴性因子分较对照组低,差异有统计学意义(P<0.05)。治疗4周后,两组Y-BOCS评分较治疗前均下降(P< 0.05),其中研究组Y-BOCS评分更低于对照组(P<0.05)。研究期间,两组不良反应轻微,不良反应发生率组间无统计学差异(P>0.05)。结论rTMS联合舍曲林治疗精神分裂症强迫症状的疗效优于单用舍曲林治疗, rTMS治疗还可以改善精神分裂患者的阴性症状以及一般精神病理症状,且安全性好。
Hydrogen - A sustainable energy carrier

Hydrogen may play a key role in a future sustainable energy system as a carrier of renewable energy to replace hydrocarbons. This review describes the fundamental physical and chemical properties of hydrogen and basic theories of hydrogen sorption reactions, followed by the emphasis on state-of-the-art of the hydrogen storage properties of selected interstitial metallic hydrides and magnesium hydride, especially for stationary energy storage related utilizations. Finally, new perspectives for utilization of metal hydrides in other applications will be reviewed.
Hydrogen absorption properties of amorphous (Ni_(0.6)Nb_(0.4–y)Tay)_(100–x)Zr_x membranes

Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work the melt spun (Ni_(0.6)Nb_(0.4–y)Tay)_(100–x)Zr_x with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T < 400 °C, even in a hydrogen atmosphere (1–10 bar), the amorphous structure was retained. The crystallization process was characterized by differential thermal analysis and the activation energy of such process was obtained. The hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method, and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear change of the hydrogen solubility was observed with the variation of the Zr content. The values of the hydrogenation enthalpy changed from ~37 kJ/mol for x=30 to ~9 kJ/mol for x=20. The analysis of the volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum of energy levels.
Preparation and catalytic effect of porous Co_3O_4 on the hydrogen storage properties of a Li-B-N-H system

A porous Co_3O_4 with a particle size of 1–3 μm was successfully prepared by heating Co-based metal organic frameworks MOF-74(Co) up to 500 °C in air atmospheric conditions. The as-prepared porous Co_3O_4 significantly reduced the dehydrogenation temperatures of the LiBH_4-2LiNH_2 system and improved the purity of the released hydrogen. The LiBH_4-2LiNH_2-0.05/3Co_3O_4 sample started to release hydrogen at 140 °C and released hydrogen levels of approximately 9.7 wt% at 225 °C. The end temperature for hydrogen release was lowered by 125 °C relative to that of the pristine sample. Structural analyses revealed that the as-prepared porous Co_3O_4 is in-situ reduced to metallic Co, which functions as an active catalyst, reducing the kinetic barriers and lowering the dehydrogenation temperatures of the LiBH_4-2LiNH_2 system. More importantly, the porous Co_3O_4-containing sample exhibited partially improved reversibility for hydrogen storage in the LiBH_4- 2LiNH_2 system.