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The over-exploitation of groundwater and the deterioration of its quality have heightened the importance of non-traditional water resources, such as mine water. The study of the water's chemical characteristics and the formation mechanism of high-salinity mine water in semi-arid regions holds significant importance for zero discharge and the resource utilization of mine water in Northwest China. In this study, a total of 38 groundwater and mine water samples were collected to examine the hydrogeochemical characteristics of high-salinity mine water using Piper diagrams and Gibbs diagrams, as well as isotope analyses and ion ratio coefficients. Additionally, the corresponding mine water treatment recommendations were put forward. The results show that the TDS content of groundwater increases with hydrographic depth. The average TDS concentration of Quaternary, Luohe, and Anding groundwater is 336.87, 308.67, and 556.29 mg/L, respectively. However, the TDS concentration of Zhiluo groundwater and mine water is 2768.57 and 3826.40 mg/L, respectively, which belong to high-salinity water. The Quaternary, Luohe, and Anding groundwater hydrochemical type is predominantly HCO3-Ca type, and the Zhiluo groundwater and mine water hydrochemical type is predominantly the SO4-Na type. Furthermore, there is minimal difference observed in δD and δ18O values among these waters. It can be inferred that the Zhiluo Formation in groundwater serves as the primary source of mine water supply, primarily influenced by the processes of concentration caused by evaporation. The high salinity of mine water is closely related to the high salinity of Zhiluo groundwater. The high salinity of groundwater has evolved gradually under the control of the concentration caused by evaporation and rock-weathering processes. The dissolution of salt rock, gypsum, along with other minerals, serves as the material basis for high-salinity groundwater formation. In addition, the evolution of major ions is also affected by cation exchange. The TDS concentration of mine water ranges from 3435.4 mg/L to 4414.3 mg/L, and the combined treatment process of nanofiltration and reverse osmosis can be selected to remove the salt. After treatment, mine water can be used for productive, domestic, and ecological demands. [ABSTRACT FROM AUTHOR]

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China's need for energy resources is growing every day. Future energy demands will be partly met by low-temperature pyrolysis of oil-rich coal, which is a form of coal-to-oil technology. Under the existing fully-mechanized coal mining technology, oil-rich coal is mechanically broken into different particle sizes by a shearer and used in different industrial utilization directions. However, due to differences in particle size and material composition, the pyrolysis products of oil-rich coal with different natural particle sizes are different, which affect the pyrolysis efficiency of oil-rich coal with different particle sizes. In order to explore the differences and influencing factors of pyrolysis products of oil-rich coal with different particle sizes, and taking Jurassic oil-rich coal in northern Shaanxi as the research object, the differences and causes of pyrolysis production of oil and gas from nine kinds of oil-rich coal with different natural particle sizes under existing coal mining conditions are discussed according to particle size characteristics, pore structure, heat transfer velocity and molecular structure. The findings demonstrate that the pyrolysis characteristics of coal do not show a single trend with change in particle size. With decrease in particle size, the ash and sulfur contents were relatively high, and the tar yield increased first and then decreased. In contrast, the light fraction decreased overall, and the heavy fraction decreased. The tar yield of 0.125–0.25 mm was the highest, and the tar content was 1.996 g. For the gas components produced by pyrolysis, the contents of CH4, CO and H2 first increased and then decreased with decrease in particle size, while the contents of CO2 and CnHm showed the opposite trend. Larger particles (about 30 mm) affect the escape efficiency of pyrolysis products and the amount of carbon deposition due to the difference in porosity (interparticle resistance) of the inner surface and pyrolysis bed, resulting in secondary reactions of the products escaped from a primary reaction, thus affecting the differences in pyrolysis products. The heat transfer process of coal was affected by particle size, and the thermal conductivity increased gradually with decrease in particle size, which is consistent with the change of tar yield with particle size. The maceral components and molecular structure functional groups in coal with different particle sizes were also different, which resulted in the differences in tar yield. Studies have shown that smaller particle sizes have longer alkyl side chains, and pyrolysis accompanied by rising temperature causes different changes in the aliphatic hydrocarbon content in coal coke after pyrolysis. The aliphatic hydrocarbon content decreased the most when the particle size was 0.125 mm, which is more beneficial to the improvement of tar yield. In addition, vitrinite is a good carrier of tar yield, and the granular coal vitrinite after crushing is enriched to smaller particles. [ABSTRACT FROM AUTHOR]

Hydrochemical evolution of groundwater can be related to and affected by mining activity, such as mine drainage. However, it is difficult to systematically and accurately identify and assess the hydrochemical evolution after mine drainage. In this study, we reported the hydrochemical evolution of groundwater in the overburden aquifers (Jurassic Anding and Zhiluo aquifers) under the influence of water drained from the underlying Yan'an aquifer, based on hydrochemistry and groundwater dynamics characteristics using self-organizing map (SOM) and time series analysis. The groundwater components presented significant change after mine drainage. A continuous decline of groundwater level observed at both Anding and Zhiluo aquifers revealed that these two aquifers had a good hydraulic connection and were influenced by mine drainage. Based on those, it is found that the water–rock interaction (minerals precipitation) and inflow of dilute water could be responsible for hydrochemical variations in Anding and Zhiluo groundwater, respectively. The results of this work could improve the understanding of hydrochemical evolution induced by mining activity and could provide an essential information for water resources management in the coalfield. [ABSTRACT FROM AUTHOR]

In heterogeneous wireless networks, random packet loss and high latency lead to conventional TCP variants performing unsatisfactorily in the case of competing communications. Especially on high-latency wireless links, conventional TCP variants are unable to estimate congestion degrees accurately for fine-grained congestion control because of the effects of random packet loss and delay oscillations. This paper proposes a TCP variant at the sender side to identify congestion degrees, namely TCP-WBQ, which quickly responses to the real congestion and effectively shields against random packet loss and oscillations of latency time. The proposed algorithm of congestion control firstly constructs a backlog-queue model based on the dynamics of the congestion window, and deduces the two bounds of the model which delimit oscillations of the backlog queue for non-congestion and random packet loss respectively. TCP-WBQ detects congestion degrees more accurately and thus implements the corresponding schemes of adjusting the congestion window, maintaining a tradeoff between high throughputs and congestion avoidance. The comprehensive simulations show that TCP-WBQ works efficiently in bandwidth utilization with single and multiple bottleneck scenarios, and achieves high performance and competitive fairness in heterogeneous wireless networks. [ABSTRACT FROM AUTHOR]

The threat degree of radiation source detected by fighter in penetration operation is the main reference for fighter to make the next operation plan. The research objective of this project is to evaluate the threat of radiation sources detected by aircraft, based on distributed interactive simulation technology, the system modeling of aircraft flight detection data and ground radar detection warning in distributed system is realized by building a variety of simulation modules such as ground radar model, aircraft radar model, coordinate transformation model and threat level evaluation model, the simulation environment system of airborne emitter warning is completed. In this experimental environment, through simulation, the real-time calculation of the threat factor of the aircraft radiation source can be carried out, and then the dynamic threat assessment of the radiation source target can be realized. [ABSTRACT FROM AUTHOR]

Located in an arid and semi-arid region, the northern Ordos Basin is one of the key coal mining areas of China. The Zhiluo (J2z) sandstone aquifers, which overlay the Yan'an (J2y) coal seam layer, are a major source of drinking water. However, the hydrochemical evolution and possible impacts of coal mining on pollution of J2z groundwater over recent decades, and the water inrush hazard it presents, are not well understood. In this study, we investigate the groundwater's origins and the factors controlling its quality and hydrochemical characteristics in these areas. In the northern and southern areas, J2z groundwater hydrochemistry shows distinct hydrochemical features, being Ca-HCO3 type with lower total dissolved solids (TDS) in the north, and Na + K-SO4 type with higher TDS in the south. Different water–rock interactions and coal mining activities may be the causes of such differences. We suggest that greater attention should be paid to preventing water inrush events during mining, as J2z groundwater has a good hydraulic connection with shallow groundwater in the northern area. Water treatment is also needed, as J2z groundwater in the southern area exceeds the safe limits for drinking and irrigation. In conclusion, the main factors determining local groundwater hydrochemistry and quality are mining activity, ground temperature, groundwater flow velocity, and groundwater circulation. [ABSTRACT FROM AUTHOR]

The determination of changes in hydrogeological properties (e.g., permeability and specific storage) of aquifers disturbed by mining activity is significant to groundwater resource and ecological environment protection in coal mine areas. However, such parameters are difficult to continuously measure in situ using conventional hydrogeological methods, and their temporal changes associated with coal mining are not well understood. The response of well water level to Earth tides provides a unique probe to determine the in situ hydrogeological parameters and their variations. In this study, the tidal responses of well water level were employed to characterize the changes in hydrogeological parameters of the overburden aquifer induced by longwall mining in a coalfield, northwest China. Based on the long-term hourly recorded water level data, two analytical models were used to determine the temporal changes of permeability and specific storage of the overburden aquifer. The results showed that the hydrogeological parameters changed with the longwall coal face advance. When the longwall coal face approached the wells, the aquifer permeability increased several to dozens of times, and the response distance ranged from 80 m to 300 m. The specific storage decreased before the coal face reached wells and recovered after the coal face passed. The results of this study indicate that the hydrogeological parameter changes induced by coal mining are related to the location of the well relative to the coal face and the stress distribution in the overburden aquifer. This study revealed the changes in permeability and specific storage associated with the mining disturbance which could have great significance for quantitative assessment of the impact of mining on overburden aquifer. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the effects of environmental tobacco smoke (ETS) on the inflammatory process of periodontitis by evaluating bone loss and the expression of cyclooxygenase‐2 (COX‐2) and Src homology phosphotyrosine phosphatase 2 (SHP‐2). Materials and Methods: Eighty 6‐month‐old male SD rats were randomized into four groups (10 rats/group/per time point): (a) normal group, (b) ETS group, (c) ligature‐induced periodontitis group, and (d) ligature‐induced periodontitis + ETS group. After treatment with ligature and/or ETS for 8 and 12 weeks, the levels of alveolar bone resorption and the expressions of COX‐2 and SHP‐2 in periodontal tissue were analyzed using histology and immunohistochemistry. Results: The ligature‐induced periodontitis group displayed increased bone resorption and elevated expression of COX‐2 and SHP‐2 in periodontal tissues compared to the normal and ETS groups at 8 and 12 weeks. Furthermore, bone resorption and COX‐2 and SHP‐2 levels in the ligature‐induced periodontitis + ETS group were significantly increased compared to those in the normal and ligature‐induced periodontitis groups at both 8 and 12 weeks. Conclusion: Environmental tobacco smoke increased alveolar bone loss in periodontitis with enhanced expression of COX‐2 and SHP‐2 in periodontal tissues. Further investigation is needed to explore the role of COX‐2 and SHP‐2 in ETS‐associated periodontitis. [ABSTRACT FROM AUTHOR]

Congestion control is an important and difficult point in the computer network course. By introducing NS3 network simulation tool, this paper discusses the methods and steps of constructing complex hybrid network experimental environment and realizes several network experimental scenes based on 4:4 dumbbell network topology. Based on the size of congestion window, the theoretical verification experiments of several common congestion control algorithms are carried out. Based on the throughput, the fairness between the same congestion control algorithms and the friendliness between different congestion control algorithms are compared. The experimental results are consistent with the theoretical analysis, and the algorithm idea and control process of congestion control are visually displayed. [ABSTRACT FROM AUTHOR]

Understanding the sources and mechanisms of groundwater recharge in the Ningtiaota Coalfield, an arid area in northwest China, is important for water resources management and coal mine safety. Hydrochemical and stable hydrogen and oxygen isotopic data were used to study water–rock interactions and groundwater recharge in the area. A total of 45 water samples, including surface water, Quaternary groundwater, and Jurassic Zhiluo Group (J2z) and Yan’an Group (J2y) groundwater, were collected for major ions and stable isotope (δD and δ18O) analyses. Our results showed that the groundwater originated from atmospheric precipitation, and experienced weak evaporation during infiltration. Water in the study area has a low salinity and is dominated by HCO3–Ca type. The dominant water–rock interactions in the Jurassic Zhiluo Group (J2z) groundwater were dissolution of silicate minerals, gypsum, and halite and cation exchange. The results may aid in water resources management and groundwater inrush prevention in the coalfield and at other coal mines. [ABSTRACT FROM AUTHOR]

Metal ions are important for many biological processes and are steadily available in the human body. Metal concentrations can be extremely high in diseased areas of various pathological conditions. Some synthetic and natural drugs need to be activated by metal ions as prodrugs. In this review, we provide a few examples to illustrate how metal ions activate and mediate drug targeting in the body. This knowledge may be helpful for the development of more effective drugs and pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

Triploid carp (100%) with 150 (3n=150) chromosomes were obtained by crossing the females of improved tetraploid hybrids (♀, 4n=200) of red crucian carp (♀)×common carp (♂) with the males of diploid yellow river carp (♂, 2n=100). The crosses yielded transgenic triploid carp (positive triploid fish, 44.2% of the progeny) and non-transgenic triploid carp (negative triploid fish). Histological examination of the gonads of 24-month-old positive triploid fish suggested they were sterile and the fish were not able to produce mature gametes during the breeding season. Morphologically, both the positive and negative triploid fish were similar. They had a spindle-shaped, laterally compressed, steel grey body with two pairs of barbells. Most of the quantifiable traits of the triploid carp were intermediate between those of the two parents. The positive and negative triploid fish were raised in the same pond for 2 years. The mean body weight of the positive triploid fish was 2.3 times higher than the negative triploid fish. The weight of the largest positive triploid fish was 2.91 times higher than that of the largest negative triploid fish. Thus, we produced fast-growing transgenic triploid carp that have a reduced ecological risk because of their inability to mate and produce progeny. [ABSTRACT FROM AUTHOR]

In this review, the author discusses recent advances in anti-HIV inhibitors, targeting CXCR4, including natural and modified chemokines, peptides and organic compounds, their mechanisms of action, and the molecular process of virus invasion of immune cells. Peptides with strong anti-HIV activity exhibit several common features, such as electrostatic charges, cyclization, β-turns and dimerization induced by a sulphide bond. Organic compounds, such as cyclams, display a unique metal-mediated mechanism in the binding process to its target CXCR4. Understanding of their mechanisms of action may be useful for the design of more effective drugs. Consecutive interactions of viral glycoprotein gp120 with CD4 and the co-receptor, CXCR4 or another co-receptor CCR5 on the cell surface leads to virus invasion into host cells. The molecular details of the binding between HIV glycoproteins and the co-receptors also provide a basis for anti-HIV therapy. [ABSTRACT FROM AUTHOR]

The macrocyclic antiviral drug xylyl-bicyclam blocks entry of HIV into cells by targeting the CXCR4 coreceptor, a seven-helix transmembrane G-protein-coupled receptor. Its affinity for CXCR4 is enhanced by binding to Cu2+ Ni2+ or Zn2+. Metallocyclams have a rich configurational chemistry and proteins may bind selectively to specific metallocyclam configurations. Our studies of lysozyme reveal structural details of protein-metallocyclam interactions that are important for receptor recognition. Solution NMR studies show that Cu-cyclam interacts with specific tryptophan residues of lysozyme (Trp-62, Trp-63, and Trp-123). Two major binding sites for both Cu-cyclam and Cu2-xylyl-bicyclam were detected by x-ray crystallography. In the first site, Cu2+ in one cyclam ring of Cu2-xylyl-bicyclam adopts a trans configuration and is coordinated to a carboxylate oxygen of Asp-101, whereas for Cu-cyclam two ring NH groups form H bonds to the carboxylate oxygens of Asp-101, stabilizing an unusual cis (folded) cyclam configuration. For both complexes in this site, a cyclam ring is sandwiched between the indole side chains of two tryptophan residues (Trp-62 and Trp-63). In the second site, a trans cyclam ring is stacked on Trp-123 and H bonded to the backbone carbonyl of Gly-117. We show that there is a pocket in a model of the human CXCR4 coreceptor in which trans and cis configurations of metallobicyclam can bind by direct metal coordination to carboxylate side chains, cyclam-NH…carboxylate H bonding, together with hydrophobic interactions with tryptophan residues. These studies provide a structural basis for the design of macrocycles that bind stereospecifically to G-coupled and other protein receptors. [ABSTRACT FROM AUTHOR]

The Yuheng mining area of the Jurassic coalfield in northern Shaanxi Province is one of the most important coal-producing regions in China. The present study examines the mechanism of a water-rich coal seam in this area, namely, the No. 2 water-rich coal seam of the Balasu coal mine, by using the groundwater aquifers. From pumping and water chemistry tests, a macroscopic study of the aquifers, and a microcosmic analysis of the coal and rock, the hydrogeological conditions of the coal mine, the hydraulic relations between the various aquifers and the water-rich characteristics and the mechanism of the water-rich coal seam were analysed and summarised. According to the spatial distribution order, from shallow to deep, the salinity of the aquifers increases with an increase in the buried depth and the dissolved organic matter content decreases with aquifer depth. The direct water recharge source is the fractured sandstone aquifers of two Jurassic formations. Both aquifers are distributed in fluvial banded facies and their overall water content is relatively weak. The main mechanism for the formation of the water-rich coal seam in this area is that the No. 2 coal seam contains the original fissure and local special water-rich strata assemblage condition. This study is aimed at providing the basis for the hydrogeological characteristics of the Balasu coal mine, as well as a reference for similar mine conditions in the area. [ABSTRACT FROM AUTHOR]