Search

Objective To evaluate the application of personalized oral care in patients with oral and maxillofacial diseases. Methods Totally 200 patients with oral and maxillofacial diseases were randomly divided into two groups. Patients in the control group(n=100) were given routine oral care during the treatment, and those in the observation group(n=100) were given personalized oral care based on routine management. The therapeutic effect, incidence of complications, patient satisfaction with nursing service and compliance rate of the two groups were evaluated and compared. Results The therapeutic effect in the observation group was higher than that in the control group (98. 00% vs. 89. 00%, P＜0. 05 ). The satisfaction rate, incidence of complications and compliance rate of the observation group were better than those of the control group (P＜0. 05). Conclusion Personalized oral care could effectively improve the treatment effect, satisfaction and compliance rate of patients, facilitate the development of diagnosis and treatment, and then help to reduce the incidence of complications, promote the rehabilitation of patients and improve the quality of life. (目的 探讨个性化口腔护理在口腔颌面疾病中的应用效果。方法 将2019年1月—2021年1月收治的200例口腔颌面疾病患者随机分为观察组和对照组, 各100例。对照组给予常规护理, 观察组在对照组基础上开展个性化护理措施。观察组两组治疗效果、护理满意度、并发症发生情况以及治疗依从性。结果 观察组治疗总有效率98. 00%(98/100), 高于对照组的89. 00%(89/100), 差异有统计学意义(P＜0. 05)。观察组护理满意度91. 00%(91/100), 高于对照组的74. 00%(74/100), 差异有统计学意义(P＜0. 05)。观察组并发症发生情况优于对照组, 差异有统计学意义(P＜0. 05)。观察组依从率92. 00%(92/100), 高于对照组的83. 00%(83/100), 差异有统计学意义(P＜0. 05)。结论 口腔颌面疾病诊疗过程中采用个性化口腔护理干预, 有助于提高患者治疗依从性, 促进口腔功能恢复, 值得临床推广应用。)

Objective To explore the effect of stratified teaching method in teaching newly recruited dental nurses. Methods Newly recruited nurses in Stomatology Department of hospital in the past three years were selected as the teaching objects, the stratified teaching practice was carried out for the newly recruited nurses through various methods such as improving the teaching management system, establishing the teaching faculty, formulating the teaching training plan and comprehensive teaching evaluation. Results Through stratified teaching, the teaching results showed that the daily performance and examination results of nurses in the undergraduate group, the junior college group and the technical secondary school group after practice were better than those before practice, with a statistically significant difference (P＜0. 05). The performance of nurses in the undergraduate group was better than that in the junior college group and the technical secondary school group, with a statistically significant difference (P＜0. 05). Conclusion In accordance with student aptitude, stratified teaching method has achieved good teaching effect and is worth popularizing in clinical teaching of stomatology. (目的 探讨口腔科新入职护士分层临床教学方法和效果。方法 以医院近3年口腔科新入职护士为教学对象, 通过完善教学管理制度, 组建教学师资队伍, 制定教学培训计划及综合教学评价等各种方法, 来对新入职护士进行分层临床教学实践。结果 通过分层教学, 教学结果表明本科组、大专组、中专组三组新护士临床护理工作考核及年终考试培训后的成绩均优于培训前, 差异有统计学意义(P＜0. 05), 本科组的临床护理工作考核成绩优于大专组及中专组, 差异有统计学意义(P＜0. 05)。结论 分层教学能够根据三个层次护士不同情况因材施教, 教学效果良好, 值得在口腔临床教学中推广。)

Beam orbit stability is vital for the synchrotron radiation light source. Hefei Advanced Light Facility (HALF), the fourth generation diffraction limit storage ring now under preliminary research with submicron beam orbit stability, requires a beam position monitor (BPM) system with accuracy better than 100 nm. In this paper, a BPM processor with pilot tone was developed using domestic chips, which is composed of the pilot tone module, the analog frontend module, the digital processing module and the embedded control module. The input signals from BPM detector were adjusted in pilot tone module and analog frontend module, digitalized in digital processing module by bandpass sampling principle, and the digital signals were processed in FPGA (field programmable gata array) to obtain turnbyturn data, fast acquisition data (FA data) at a 10 kHz rate, and slow acquisition data (SA data) at a 10 Hz rate. The embedded control module transmitted the beam position information in real time and communicated with the accelerator control system. Thermal drifts of the channels and variations of the cables frequency response (due to changes in temperature or humidity) could introduce uncontrolled fluctuations in the position calculated. To enhance longterm stability of the BPM processor, a low phasenoise pilot tone was added to the beam signal as a reference to eliminate the effect of gain drifts of the individual channel on position calculation. The analog front end was customized with adjustable gain to increase the dynamic range of the system, and composed of four identical radiofrequency (RF) channels, each with several amplifiers, attenuators and filters to adjust the signals for ADC sampling. All beam position calculations were performed in the digital domain. The bandpass sampling technique was applied to convert narrowband RF signals into intermediatefrequency (IF) digital signals. And then the IF signals were converted to the baseband inphase and quadraturephase (IQ) data through the digital down conversion method. CIC (cascaded integrator comb) and FIR (finite impulse response) decimation filters were used to avoid highcomponent signal aliasing and decimate the IQ data rate. CORDIC (coordinated rotation digital computer) module was implemented in pipeline structure to calculate the signal amplitudes from IQ data. With four BPM signal amplitudes, the beam position could be obtained by the differenceoversum algorithm. These digital signal processing algorithms were integrated on one FPGA. At present, the laboratory offline tests and the beam tests of the designed beam position processor were carried out. The offline tests demonstrate the effectiveness of pilot tone in compensating for external changes and improving the longterm stability. The test results indicate that the resolutions of the FA data and SA data are better than 120 nm and 70 nm respectively with the input amplitudes ranging from -55 dBm to 5 dBm, which meet the design requirements.

Glycosylation is one of the most important post-translational modifications (PTM), mediating physiological processes like cell adhesion, cell proliferation, cell signaling, and immune responses. The special functionality of glycosylation for cancer progression and metastasis were reported in recent researches. Analytical methods based on mass spectrometry (MS), especially liquid chromatography mass spectrometry (LC-MS), are the routine practices for protein glycosylation research. However, due to the high complexity and multiformity of glycan structures, as well as the existence of numerous isomers, in-depth analysis of glycosylation ends up as a major challenge for conventional LC-MS-based method. Ion mobility separation is a promising approach to fill the gap as it provides an additional separation dimension for mass spectrometry analysis based on structures and charges of the gas-phase ions. As a technology with an entirely different separation mechanism from that of liquid chromatography, ion mobility spectrometry (IM) has several properties superior to other separation facilities. First of all, unlike liquid chromatography or capillary electrophoresis which demand minutes of separation time, IM only requires a few milliseconds to finish the separation, and it is well compatible with fast mass spectrometry analysis. Besides, as a separation technique for gas phase ions, IM can be modularized and readily integrated into full-fledged LC-MS system. Most importantly, IM is proved to have great potential in glycan isomer discriminations. Given the aforementioned merits, ion mobility mass spectrometry (IM-MS) is gaining attention from glycomics community. This review summarized the basic principles of IM-MS and its applications in protein glycosylation research for the past five years. The means of enhancing isomeric separation performance of glycans were comprehensively discussed, including derivatization, forming metal and other noncovalent adducts, and utilizing high-resolution ion mobility spectrometry implementation. The various approaches of leveraging collision cross section (CCS) values to assist glycan identification and isomer discrimination were also summarized. Furthermore, as two monosaccharides with great biological and pathological significance, the IM-MS applications on fucoses and sialic acids were given special attention. As for glycopeptides, innovative spectra matching algorithms, novel ion activation techniques to facilitate glycan and peptide elucidations, and brand new quantification strategies for isomers were included, along with various glycoproteomic applications of IM-MS on biological samples. Finally, in terms of IM-MS applications in glycoprotein research, investigations of conformational properties, 3D structures, stabilities, and protein-protein interactions were covered. It was concluded that IM-MS is a promising method for protein glycosylation research with great potential.

Objective To explore the expression of 3-hydroxymethylglutaryl-CoA synthase 2 (HMGCS2) and its correlation with the clinicopathological characteristics of patients with bladder cancer. Methods The GEO database was used to screen genes that were significantly differentially expressed between muscle invasive bladder cancer and non-muscle invasive bladder cancer. The survival analysis of the screened public differentially expressed genes was performed by gene expression profiling interactive analysis (GEPIA). The Metascape database was used for the functional enrichment analysis of HMGCS2 and its related genes. The expression of HMGCS2 was detected with immunohistochemical staining in clinical samples from patients with bladder cancer. Chi-square test was used to analyze the relationship between the expression of HMGCS2 and the clinicopathological characteristics, and Cox regression analysis was adopted to verify the prognostic efficacy of HMGCS2. Results The transcriptome data of the GEO database showed HMGCS2 had significantly lower expression in muscle invasive bladder cancer compared with non-muscle invasive bladder cancer (7.42±2.51 vs 9.38±2.78, P < 0.05). The survival analysis of the GEPIA database showed that patients with high expression of HMGCS2 had better prognosis (overall survival: HR=0.6, P=0.028; disease progression-free survival: HR=0.59, P=0.036); KEGG pathway analysis and GO functional enrichment analysis showed that HMGCS2 might be involved in fat metabolism, cell apoptosis and platinum resistance, and exerted effect on the signal transduction of the mTOR pathway. In addition, the Chi-square test showed the expression of HMGCS2 was significantly related to the T stage (P < 0.001), tissue grade (P=0.006), patients' overall survival status (P < 0.001) and patients' disease-free survival status (P < 0.001); Univariate Cox regression analysis showed that HMGCS2 was related to the patients' overall survival rate and the disease progression-free survival rate (OS: HR=0.104, P < 0.001; DFS: HR=0.155, P < 0.001); multivariate Cox regression analysis indicated that HMGCS2 was an independent predictor of the prognostic risk of patients (OS: HR=0.181, P < 0.001; DFS: HR=0.312, P < 0.001). Conclusion HMGCS2 is lowly expressed in muscle invasive bladder cancer, and its low expression is closely related to the poor prognosis of patients.

Wettable cathodes are a very important part of the non-carbon electrolysis process. This study prepared Fe-TiB2/Al2O3 composite cathode materials by cold pressing and sintering using alumina sol as a binder and metal Fe as a sintering agent for aluminum electrolysis. The electrolytic performance of aluminum electrolysis was studied using a 20 A electrolysis test, and the composite cathode materials before and after the test were analyzed via EDS. The migration behavior of various elements in the electrolysis process was studied by composition analysis. The results show that Fe metal can effectively fill the gap between the aggregates during the sintering process. Hence, the sintering density of the composite cathode material can be significantly improved. In the 20 A electrolysis test, the voltage is stable, the current efficiency is 93.2%, the original aluminum quality is 99.47%, and the impurity in the aluminum liquid is 0.53%. After the electrolysis test, the aluminum liquid can moisten the cathode surface effectively. Therefore, the Fe-TiB2/Al2O3 composite is an ideal wettable cathode material. Based on the EDS analysis of the composite cathode electrolysis, the alkali metal in the liquid electrolyte permeates into the cathode material during the electrolysis process. Subsequently, alkali metals gradually penetrate into the binder phase and fill the voids that are not completely filled by alumina sol or metal sintering additives. As the electrolysis proceeds, the penetration depth of the element K is greater than that of Na. The Al generated at the cathode surface also enters the cathode through the gap of the composite material. However, owing to the gap in the cathode, the Fe metal in the cathode will also be reversely dispersed into the liquid aluminum. This study indicates that the stability of the aluminum liquid layer on the cathode surface is the foundation for efficient and stable operation of the cathode.

Several (Cu-Ni-Fe)-xNiFe2O4(x=50,60,70,80,mass fraction/%) composite inert anodes with different contents of alloy phase were prepared using Cu, Ni, Fe and high-temperature synthetic NiFe2O4 by cold-pressing sintering method. The effect of Fe on the composition and microstructure of the (Cu-Ni-Fe)-xNiFe2O4 composite inert anodes during sintering and electrolysis process was studied. It is found that the redox reaction between Ni/Fe and NiFe2O4 phase occurs, leading to the dissociation and regeneration of NiFe2O4. In addition, the film-forming process and corrosion behavior of the (Cu-Ni-Fe)-xNiFe2O4 anodes were studied through low-temperature aluminium electrolysis test. The results indicate that the cell voltage is stable during electrolysis and the impurities in the produced aluminium are less than 0.7% (mass fraction), which indicates that (Cu-Ni-Fe)-xNiFe2O4 composite inert anode is one of the most promising inert anode materials, and the poor thermal stability of the ceramic anode is expected to be solved.

In view of problems of serious loss and low efficiency of operation existed in induction motor of frequency-conversion speed-regulation system controlled by constant flux, the paper put forward a kind of efficiency optimization control scheme of mine frequency-conversion vector control system. Under two-phase d-q rotating coordinate system, the scheme established loss model of the system including set and rotor copper loss and iron loss, derived corresponding relationship between motor loss and rotor flux under different operating conditions. In order to solve problem of slow dynamic response of the system caused by weak magnetic operation, it optimized proportion of torque current and flux current to get fast response of electromagnetic torque and speed tracking of the motor. It established experimental platform of speed regulation system of 22 kW three-level induction motor based on DSP+FPGA control system, and the experimental results show that the optimized scheme can reduce loss of vector control system of induction motor, improve operation efficiency of the system, and ensure steady-state performance and dynamic response performance of the system.

To improve the achievable traffic load of secondary user(SU) under grade of service (GoS) constraints in cognitive wireless networks with heterogeneous traffic,a novel spectrum sharing scheme was proposed.The key idea of the proposed scheme was to introduce preemptive priority and buffering mechanism for real-time traffic and non-real-time traffic,respectively,according to their different delay characteristics.The proposed scheme could reduce the forced termination probability and the blocking probability for heterogeneous calls simultaneously.Numerical results show that the proposed scheme can effectively improve the achievable traffic load of SUs under GoS constraints.

The paper put forward a new feature matching algorithm to solve the problem that existing feature matching methods are not suitable to underground environment. Firstly, the algorithm uses curvelet algorithm to preprocess image noise, then adopts SIFT algorithm to form and match feature vectors, which removes mismatched points effectively by optimization of RANSAC method and achieves image stitching by building projection transformation model. The experiment showed that the algorithm has better robustness in noise, poor illumination and fuzzy environment, and solves mismatching phenomenon in mine environment, whose stitching result is smoothing and natural.

The paper introduced hardware and software design of a mine-used signal converter based on HART transducer. The converter takes C8051F040 single-chip microcomputer as central processor, which achieves communication with sensors with HART transducer and can display measured signal of sensor through digital tube, and has functions of range set, alarm value set, frequency output and CAN bus output.

The purpose of this experiment was to investigate the effects of different proportions of soft acid in drinking water on the production performance, egg quality, and serum biochemical indexes of Jingfen No.2 laying hens at the late of laying peak. A total of 270 Jingfen No.2 laying hens with normal body condition and similar weight at 556 days old were randomly divided into three groups with six replicates in each group and 15 laying hens in each replicate. The control group (CON group) drank tap water. 500 mg/kg and 800 mg/kg of soft acid were added to tap water in the soft acid 500 group and 800 group, respectively. The pre-test period was seven days, and the formal test period was 42 days. The results showed that compared with the control group, the unqualified egg rate of the soft acid 500 group and the soft acid 800 group decreased significantly (P<0.05), the average egg weight increased significantly (P<0.05), and the feed to egg ratio of the soft acid 800 group decreased significantly (P<0.05). Compared with the control group, the eggshell scores of soft acid 500 group and soft acid 800 group increased significantly (P<0.05), and the egg weight, yolk weight, eggshell strength, yolk ratio and yolk score all showed an increasing trend (P>0.05). Compared with the control group, the total protein content in serum of the soft acid 800 group increased significantly (P<0.05). Compared with the control group, the levels of serum IgA and IgG in the soft acid 500 group and 800 group increased significantly (P<0.05). The study indicates that adding 500 mg/kg and 800 mg/kg soft acid in drinking water has positive effects on improving production performance, egg quality, serum biochemical indexes, and immune function of Jingfen No.2 laying hens, and the effect of adding 800 mg/kg soft acid is better than that of 500 mg/kg soft acid. [ABSTRACT FROM AUTHOR]

Guangdong Province is rich in rural small hydropower station resources, with nearly 10 000 small hydropower stations in Guangdong Province, ranking first in the country in terms of quantity. Small hydropower station has played an important role in solving rural electricity consumption and promoting rural economic development.However, with the advancement of technology, the adjustment of national industrial policies, and the advancement of ecological civilization construction, small hydropower in Guangdong Province is facing needs such as green transformation and strengthened management. Therefore it is necessary to analyze the problems and countermeasures of small hydropower in green total factor intelligent management. This research shows that small hydropower in Guangdong Province has problems such as hidden dangers in production safety, insufficient protection of ecological flow, low degree of automation in operation and management, and difficulty in supervision. Problems mentioned above can be solved by establishing a safety production standard mechanism, implementing ecological flow, promoting the green transformation of small hydropower, and carrying out all-factor Intelligent management and other measures. [ABSTRACT FROM AUTHOR]

【Background and Objective】 Water erosion is a common form of soil degradation, affecting 1.071 4 million km2 of soil in China, accounting for 40.77% of national soil erosion. While the soil surface in most regions in Northeastern China is relatively flat, the black soils are susceptible to water erosion due to their unique environment and unsustainable agricultural practices, threatening food production and ecological security. Tremendous efforts have been made in improving the black soil and water conservation to ameliorate water erosion. This paper reviews the progress made over the past decades. 【Method】 The review was based on literature and data related to water erosion in sloped black soils and their mitigation technologies, with the focus on the influence of rainfall, topography, vegetation, soil condition and human activities. 【Result】 The area of soils affected by water erosion was approximately 133 200 km2, accounting for 63.76% of total eroded black soils in the region. Hillslope and gully erosion are the predominant erosion patterns, forming a hillslope-gully system that is a major source of sediment. Key erosion-control technologies included ridge tillage, straw return, ridge planting, hedgerows, terracing, minimal tillage with residue mulching, no-tillage, and gully control. Critical issues in implementing these technologies include a detailed understanding of their underlying mechanisms, effectiveness, optimal configurations, and selection for different regions. Future research should focus on improving understanding of the mechanisms of these technologies, establishing a comprehensive erosion-control system, and developing strategies for regulating runoff and soil consolidation. 【Conclusion】 Water erosion is a great challenge in sloped black soil farmland in Northeastern China, influenced by both natural factors and human activities. Significant efforts have been made in alleviating water erosion both theoretically and practically. This review serves as a foundation for advancing research and developing strategies to mitigate water erosion in sloped black soils and similar environments.

The experiment was to study the effect of replacing soybean meal with different proportions of whole plant fermentated hybrid tree on growth performance, carcass traits, meat quality and nutrient apparent digestibility of finishing pigs. A total of 48 healthy 'Duroc x Landrace x Yorkshire' crossbred finishing pigs with an initial weight of (60.44±2.51) kg were randomly divided into four groups, with three replicates in each group and four pigs in each replicate. The finishing pigs in group A (control group) were fed with basal diet, and the finishing pigs in group B, group C and group D were fed with experimental diet with 3%, 5% and 7% whole fermented hybrid tree instead of soybean meal, respectively. The pre-test lasted for 10 d, and the formal test lasted for 45 d. The results showed that compared with group A, the average daily gain of finishing pigs in group B was increased by 2.78% (P>0.05), the eye muscle area, intramuscular fat content and protein content of finishing pigs in experimental groups were significantly increased (P<0.05). The apparent digestibility of acid detergent fiber, crude fat, neutral detergent fiber, calcium and phosphorus in diets of finishing pigs in group C and group D were significantly increased (P<0.05). The experiment indicates that using 3% whole plant fermented hybrid tree instead of soybean meal has better effect on growth performance, meat quality and apparent digestibility of finishing pigs. [ABSTRACT FROM AUTHOR]

In response to the inability of centrifugation to accurately detect the residue content of seawater-based on-line mixing polymer fracturing fluid, a vacuum filtration method was proposed. According to the separation range of broken particle size of guanidine gum system fracturing fluid in centrifugation, the filter paper with appropriate pore size was determined. Meanwhile, the effects of filter sample volumes, distilled water cleaning and petroleum ether cleaning on the assay data were also investigated to determine the optimal operating conditions. The results indicated that the detection data with good parallelism and high accuracy could be obtained by using a filter paper with the pore size of 38-45 μm, 100 mL of filter sample, 75 mL of distilled water, and 100 mL of petroleum ether. The residue content was measured as 188 mg/L, and the residue yield was 98.2%. In addition, this method was still applicable to the test of residue content in polymer fracturing fluid 1510 and 7130.

[Objective] Due to the limited development of spatialization technology for socioeconomic data, previous research on the factors that affect urban shrinkage at the physical area scale of cities has mostly remained at the stage of qualitative analysis or quantitative analysis using administrative area data instead of physical area data. Breaking through the limit of spatialization of socioeconomic data within physical urban areas is the primary prerequisite for achieving quantitative analysis of influencing factors at the physical area scale. [Methods] By constructing the VANUI index and setting a comprehensive threshold, the scope of physical urban areas in Central and Southern Liaoning was determined. Based on the superposition of the slopes of univariate linear regression between the DN values of nighttime light and LandScan population grid data in the periods of 2013-2017 and 2018-2022, the physical urban areas were divided into four types: absolute growth type, negative growth type, smart shrinkage type, and absolute shrinkage type, and a spatiotemporal evolution analysis was conducted, based on the historical background of the “New Northeast Phenomenon”. By combining CRITIC and entropy weight method for equal weighting, the spatialization of data on influencing factors such as economic development level, medical service level, educational resource abundance, cultural facility density, livability of the environment, and external transportation convenience was achieved using nighttime light data and point of interest (POI) data. Finally, the GTWR model was used to quantitatively analyze the influencing factors of urban population growth and shrinkage during the two periods of the region. [Results] (1) The shrinking areas within cities from 2013 to 2017 in Central and Southern Liaoning were all transformed into growing areas from 2018 to 2022. (2) From 2018 to 2022, the proportion of negative growing areas within cities reached 55.80%. (3) The level of medical services, abundance of educational resources, density of cultural facilities, and livability of the environment all had a positive effect on the overall population growth in each city, but the positive effect was generally weakened in the second period. The overall negative effects of external transportation convenience and economic development level were observed during the two periods. [Conclusions] (1) The urban population shrinkage of Central and Southern Liaoning has achieved a growing transformation, and at present, all cities are more characterized by the mismatch of population, social, and economic development. (2) The multidimensional shrinkage of population, society, and economy within all cities is not common. There is a possibility of achieving growing transformation in the short term, and there are significant differences by urban hierarchy. (3) The social and economic development pains accompanied by resource depletion and industrial transformation have weakened the positive attraction of medical, educational, and cultural facility provisions and improvement of the living environment, which are highly tied to economic development, on population. (4) The development of the external transportation system currently has played a role in promoting population loss in cities.

Alzheimer's disease(AD), the most common neurodegenerative disease, has shown an increasing incidence among younger people. With the onset of disease, most patients' cognitive function will show a progressive decline, bringing a heavy burden to the society and the family. Studies have shown that fibroblast growth factor (FGF) may be involved in the pathogenesis of AD through multiple mechanisms. This article reviews the mechanism of FGF in AD, with the hope of providing new ideas for elucidating the pathogenesis and early diagnosis of AD.

Huainan mining area is a typical high-gas area, with broken soft coal seam, low permeability, high gas content, and difficulty in extraction. In order to probe into the technical feasibility and gas control effect of the horizontal well for segmental hydraulic fracture in roof of coal seam in mining area, a three-dimensional in-situ stress test of coal seam was carried out using the stress relief method based on the analysis of the characteristics of the 13-1 coal reservoir, which was the main coal seam in the mining area. The results shown that, the three-dimensional stress field was mainly σh,max > σv > σh,min, which had sufficient conditions for the implementation of horizontal well with segmental hydraulic fracture in roof of coal seam. MFrac Suite software was used to simulate the fracture parameters of horizontal section at 1, 3 and 5 m from the coal seam. The maximum half-length of the fracture was 107.33 m and the minimum was 89.47 m, which was ideal for fracturing, indicating that the horizontal well with segmental hydraulic fracture had better geological adaptability and feasibility in Huainan mining area. Taking the CBM01 well, a horizontal well with L-type roof segmental fracturing in the 13-1 coal seam of Panyi coal mine, as the research object, the effect of gas control and management was comprehensively analyzed by means of borehole detection and numerical simulation. The results shown that, CBM01 well significantly reduced the gas pressure and gas content of coal seam after 415 d of extraction. The gas pressure at 50 and 65 m from the horizontal well decreased from 6.4 MPa to 2.6 and 2.7 MPa, respectively, by more than 55%. The gas content decreased from 13.5 m3/t to a maximum of 9.11 m3/t, a minimum of 6.92 m3/t, an average of 7.92 m3/t in an area of about 15-20 m on each side of the horizontal section, and decreased to less than 8 m3/t within about 10 m. Finally, a numerical simulation method was used to predict the gas production effect of CBM 01 well extracting for 10 a and the effect with gas control. The cumulative gas production of gas well was about 272.08×104 m3 in 10 a, and the gas content in the range of about 150 m on one side of the horizontal section was reduced to less than 8 m3/t, and the pressure was reduced to less than 3 MPa. Comprehensive research results shown that the horizontal well technology of segmental hydraulic fracturing in roof of coal seam had greater advantage and application effect in gas control and management in Huainan mining area.

This study improves the roller friction experiment platform for monitoring the temperature of flame-retardant conveyor belt in order to realize the early warning of belt conveyor fire.Mass spectrometry is used to analyze the patterns of temperature rise and smoke composition of steel cord flame-retardant conveyor belt in the early stage of friction accident.Results show that as friction progresses, the flame-retardant conveyor belt exhibits symmetrical distribution of surface temperature, where the highest temperature gradually approaches to the center of the conveyor belt and the composition of smoke changes with temperature.The steel cord flame retardant conveyor belt warming process could be divided into three stages according to their warming rate and smoke composition output: stage of oxidation reaction(ambient temperature to 100 ℃), stage of substitution reaction(100~160.2 ℃), and pyrolysis reaction(after 160.2 ℃).The initial stage features low heat capacity of the conveyor belt with quickly-rising temperature, where the products are mostly alkyl and ester compounds.The second stage exhibits gradual increase of heat capacity, slowly-rising temperature, where the products are mostly nitro, ether, and carboxylic acid compounds.The last stage features stable heat capacity of the conveyor belt, the lowest heating rate, where the chlorine-containing compound is detected for the first time in the smoke composition.

In order to explore the effects of enzyme activities from plant root exudates on rhizosphere soil enzyme activities and nutrients in karst areas, the activities of β-1,4-glucosidase (βG), β-N-acetyl-glucosaminidase (NAG), leucine aminopeptidase (LAP), and acidic phosphatase (ACP) of fine root exudates and rhizosphere soils in four vegetation restoration stages, which are shrub-grassland, shrubland, shrub-arbor forest and arbor forest, were measured. And, their relationships with soil carbon (C), nitrogen (N), phosphorus (P) contents were analyzed. The results were as follows: (1) The four enzyme activities of rhizosphere soils and root exudates were significantly higher in the late stage of vegetation restoration than that in the early stage of vegetation restoration. The enzyme activities C∶P to N∶P ratios of root exudates in arbor forest were significantly higher than those of other three stages, while the two parameters of rhizosphere soils were opposite. (2) Correlation analysis showed that the enzyme activities of root exudates were positively correlated with the corresponding soil enzyme activity. Compared with the enzyme activities of root exudates, the correlation between soil enzyme activity and related nutrients became significantly stronger. In addition, the enzyme activities of βG, NAG and LAP in rhizosphere soils and root exudates were positively correlated with soil organic carbon (SOC) and total nitrogen (TN) in rhizosphere soil, while the enzyme activities of ACP in rhizosphere soils and root exudates were positively correlated with available phosphorus (AP) in rhizosphere soil. The above results indicate that vegetation restoration has positive effects on increasing enzyme activities of root exudates and soils. The enzymes of root exudates are the indispensable supplements for soils, and play an important role in promoting carbon, nitrogen and phosphorus nutrient cycling. To sum up, it will be that the regulation of root exudates and its enzyme activities may provide a new perspective for vegetation restoration in karst ecosystem.

The ecological stoichiometry of fine root carbon (C), nitrogen (N), and phosphorus (P) is considered to reflect the strategies whereby plants adapt to the soil environment. In order to gain an understanding of the seasonal variation in fine root C∶N∶P ratios in different forest types of karst ecosystem, we measured the C, N, and P contents and ratios of living and dead fine roots in shrubland and arbor forest, as well as the influence of abiotic and biotic factors. The results were as follows: (1) C, N, and P contents in the fine roots of arbor forest were higher than those of shrubland, thereby indicating that the fine roots of arbors may by characterized by a stronger absorption and storage of nutrients than those of shrubs. In addition, the contents of C in living fine roots were significantly higher than those in dead fine roots (P

Underground coal mining often leads to surface subsidence and water accumulation, changes in the ecological environment, as well as in the spatial pattern of land and water resources, in high groundwater level mining areas. At present, in coal mining subsidence areas, the utilization of water resources is insufficient, and the potential for development in renewable energy, multi energy complementarity, and pumped storage in abandoned mine is huge. The spatial functions of coal mining subsidence areas need to be reconstructed. Under this background, the concept of resource utilization, energization and functionalization was proposed. The relevant scientific issues and key technologies were systematically elaborated. The former comprises the evolution laws of water resources and water ecological environment as well as the residual deformation laws of the surface in coal mining subsidence areas. The latter includes the technology of monitoring and evaluation together with the technology of treatment and utilization. And specific policy recommendations were proposed from aspects such as industrial integration, fund raising, regional coordination, and technological innovation.

The safety in the coal-producing mines in China is continuously improving, but coal and gas outburst accidents still occur. The prediction of coal and gas outbursts allows the scientific application of outburst prevention measures, which can ensure the safe coal mining to a certain extent. Machine learning is an interdisciplinary field involving probability theory, statistics, and computer science, which can explore the nonlinear relationship between outburst accidents and its associated indicators. The application of machine learning in coal and gas outburst prediction has received relatively widespread attention, and with the rapid progress of artificial intelligence and computer technology, it will play a greater role in the field of outburst prediction. Therefore, this paper provides a comprehensive review of the research on machine learning in coal and gas outburst prediction, analyzes the difficulties in outburst prediction and prospects its development direction. Firstly, the paper provides a brief overview of the research status on the hypothesis, occurrence mechanism, and prediction index selection of coal and gas outbursts. Then, it summarizes the research progress in the field of outburst prediction, including the application of support vector machines, neural networks, extreme learning machines, and ensemble learning algorithms. In addition, it also points out the existing problems in the current research, such as imbalanced samples, missing data indicators, and small sample sizes. Finally, the paper gives an outlook on the developments of coal and gas outburst prediction based on machine learning, including improving algorithm performance, optimizing feature engineering, and increasing sample size. With the continuous improvement of computer performance, more powerful models may be proposed, which can further improve the prediction accuracy of outburst accidents.

ZnO nanocrystals with different Na doping concentrations were prepared on PET flexible substrates sputtered with Au/Ti interdigital electrodes by a simple sol gel method. The relationship between the photoassisted room temperature NO2 gas sensing mechanism and surface photovoltage was explored by characterizing the microstructure and optical properties of the sample. The X-ray diffraction (XRD) results show that all samples have the hexagonal wurtzite structure, and Na doping does not exhibit diffraction peaks of Na and its oxides. The room temperature gas sensitivity test results show that Na doped ZnO nanocrystals have excellent room temperature gas sensitivity performance, and 0.94 mg/m3 NO2 is detected, which significantly improves the gas sensitivity response compared to pure ZnO nanocrystals. The experimental results of surface photovoltage spectroscopy (SPV) and ultraviolet visible spectrophotometer (UV-vis) indicate that the room temperature gas sensitivity of doped ZnO samples may be related to their surface defect content and defect energy levels. Na doping can significantly enhance the separation of photo generated charges, while also introducing more oxygen defects (Vo) and active sites to promote the reaction between NO2 gas and surface adsorbed ionized oxygen defects. In addition, the blue shift of the optical bandgap and the newly generated defect energy levels further enhance the sensitivity of NO2 gas.

ObjectiveTo examine changes in the number of sexual partners among young men who have sex with men (YMSM) and their associations with early negative experiences (including adverse childhood experience [ACE] and the age of having first homosexual behavior). MethodsTotally 423 YMSM at ages of 16 – 24 years were recruited with accidental sampling and respondent-driven sampling during September 2017 – January 2018 with the assistance of gay men′s organizations in three cities (Wuhan, Changsha and Nanchang) and were followed up three times from July 2018 to December 2020. Three subgroups of YMSM with different trajectories of changing in the number of sexual partners were discriminated through latent class trajectory modeling with the R LCTMtools program and the relationship between early negative experiences and the trajectory of changing number of sexual partners among the YMSM was explored using unordered multinomial logistic regression analysis. ResultsThe three types of trajectory of changing in the number of sexual partners discriminated among the YMSM were less fluctuation with small number, slow downward, and rapid upward and the proportion (number) of the YMSM assigned into the three trajectory subgroups were 46.81% (198), 35.70% (151), and 17.49% (74), respectively. Among the YMSM, 29.79% (126) reported the first homosexual behavior at the age of less than 18 years and 56.26% (238) reported ACE. The experiences of abuse, neglect, and family dysfunction were reported by 38.53% (163), 22.46% (95), and 27.66% (117) of the YMSM. Unordered multinomial logistic regression analysis revealed that after adjusting for potential confounders (age, education, occupation and sexual orientation) and compared to the YMSM of the subgroup with the trajectory of less fluctuation of small sexual partner number, the YMSM having first homosexual behavior under age of 18 years were more likely to have a slow downward trajectory (adjusted odds ratio [aOR] = 2.469, 95% confidence interval [95%CI]: 1.468 – 4.151) and a rapid upward trajectory (aOR = 2.565, 95%CI: 1.360 – 4.838) of sexual partner number; the YMSM ever experiencing physical abuse and sexual abuse were more likely to have a slow downward trajectory, with the aORs (95%CI) of 1.943 (1.003 – 3.765) and 1.854 (1.053 – 3.265); and the YMSM ever experiencing physical abuse were more likely to have a rapid upward trajectory (aOR = 2.386, 95%CI: 1.114 – 5.108). ConclusionThe self-reported early negative experience is high among YMSM recruited in three China cities and the trajectory of change in sexual partner number of the YMSM is associated with early negative experiences. The results suggest that attention should be paid to early negative experiences of YMSM for implementing relevant interventions.

In this study, hybrid maize (Zea mays L.) cultivar 'Zhengdan 958' seeds were used as materials to reveal the mechanism of seed aging. After artificial aging treatment (45 °C, 100% relative humidity), the seed vigor, O2- production, ATP content, and ATP synthase activity of seed embryo were investigated, and the integrity of ATP synthase subunit mRNAs in seed embryo and different organs (scutellum, radicle, and plumule) was analyzed by the reverse transcription blocking and double-primer amplification method. The results showed that the germination rate and radicle growth rate of maize seeds decreased, the viability of embryo decreased and the respiration intensity of seeds decreased after artificial aging treatment. The O2- production rate in embryo reached the peak on the 3rd day of aging treatment, and then decreased, the O2- production rate and content in radicle and plumule increased significantly. The ATP content and ATP synthase activity in embryo decreased. The mRNA integrity of ATP synthase ε-subunit and γ-subunit increased first and then decreased. The mRNA integrity of δ-subunit did not change significantly. The mRNA integrity of α-subunit and β-subunit decreased continuously in artificial aging treatment. The damage degree of mRNA integrity of ATP synthase subunits in radicle and plumule was much greater than that in scutellum. These results revealed that the production and accumulation of ROS in radicle and plumule could lead to different degrees of damage to ATP synthase subunit mRNAs and the activity of ATP synthase and the content of ATP in embryo decreased, which resulted in the lack of energy supply during germination, and this maybe one of the major factors causing maize seed aging. [ABSTRACT FROM AUTHOR]

The study was to efficiently remove hemicellulose from corncob and improve the feed value of corncob, to study the extraction of hemicellulose from corncob by ultrasonic microwave synergistic technology. The extraction process was optimized by single factor and response surface methodology. The results showed that NaOH concentration 5.23%, extraction temperature 80.6 °C, extraction time 74.1 min, liquid-material ratio 17.0 mL/g, extraction rate of hemicellulose (76.0±0.18)% . The membrane separation technology was used to recover NaOH, which reduced the production cost and environmental pollution. The experiment indicates that the corncob with hemicellulose removed can use in feed production and hemicellulose can use in xylose production. A new process of high-efficiency and pollution-free comprehensive utilization of corncob is established. [ABSTRACT FROM AUTHOR]

Intelligent substation is an important fulcrum of the smart grid strategy, with the increasing of primary equipment in smart substation, the amount of equipment information and data increases exponentially, traditional data retrieval methods have been unable to adapt to requirement of the massive data processing, how accurate and efficient retrieval substation equipment information become the focus of the research problem. Therefore, a method for the primary information retrieval of smart substation equipment based on knowledge graphs was proposed. First, the primary equipment information of the smart substation was classified to obtain relevant equipment information corpus. then an unstructured equipment information extraction framework was defined to achieve efficient equipment information corpus Extraction. then, hidden Markov model was used to segment equipment information so as to construct a knowledge map of substation primary equipment information, realize the visual display of equipment information, and break through the limitations of two-dimensional semantic tables. Finally, the knowledge map technology was utilized to design the information management system of the smart substation primary equipment. Experiments show that the smart substation primary equipment information record retrieval system based on the knowledge graph can provide accurate equipment information and realize the efficient retrieval of smart substation equipment information. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of residual element As on hot ductility of the steel containing Cu and As, the high temperature hot tensile behavior of C-Mn steel with 0.22%Cu and different content of As in the temperature range of 700-1 100 °C was studied by Gleeble-3800 thermal simulation machine. The results showed that the temperature range of brittleness range of steel became wider and the upper limit temperature of brittleness range moved to the higher temperature direction with the increase of As content in the steel from 0 to 0.09% The analysis of fracture morphology and microstructure indicated that the existence of As inhibited the formation of proeutectoid ferrite in the ferrite and austenite two-phase region in the temperature range of 700-800 °C. It resulted in the formation of the thinner film-like proeutectoid ferrite in the steel and thus worsened the hot ductility of the steel. In the temperature range of 850-1 100 °C, the deterioration of ductility was mainly due to the segregation of As at austenite grain boundary. [ABSTRACT FROM AUTHOR]

Owing to the development issues of the Guangdong-Hong Kong-Macao Greater Bay Area in the new domestic and international situation, the content, challenges, and paths of innovation and development of the Greater Bay Area are explored from multiple dimensions, including economic, social, cultural, and institutional. The innovation and development of the Greater Bay Area should strengthen technological and industrial innovation capabilities, improve regional resilience to cope with external shocks, increase the mobility of intraregional factors, improve the well-being of the people's livelihood, enhance the capacity of spatial governance, promote integrated urban-rural development, and optimize the regional pattern of ecological security. The conclusion is that considering the innovation and development of the Greater Bay Area from a systemic and interconnected perspective is crucial for seeking innovations in various development fields and promoting coupling and coordination among them. Therefore, the region may acquire the agency that can continuously break through bottlenecks, resolve external shocks, and unlock new paths of development. We call for the strengthening of cross-field and cross-disciplinary collaborative research to contribute the power of geography to the realization of the development goals of the Guangdong-Hong Kong-Macao Greater Bay Area.

Coal industry’s low-carbon transformation is both an inherent requirement for achieving high-quality development and a crucial lever for implementing the national “dual-carbon” strategy goals. “Dual-carbon” goals have raised higher requirements for carbon emissions reduction in the coal industry. Accurate control of the current status of emission reduction and carbon reduction in the coal industry is the foundation and prerequisite for achieving the “dual-carbon” goals with high quality. This study aims to investigate the carbon emissions and influencing factors throughout the full life-cycle of the coal industry. This study focuses on the Chinese coal industry, and aims to calculate the carbon emissions from the coal industry across four stages: mining and washing, transportation, processing and conversion, and consumption and utilization. Furthermore, an analysis of coal consumption material flow and carbon circulation throughout the full life-cycle of the coal industry will be conducted. Finally, the MDI model will be used to analyze the driving factors of carbon emissions in China’s coal industry. The results show that: ① The carbon emissions of China’s coal industry increased by 6.39% annually from 2000 to 2020, with the processing and conversion stage being the main contributor to the carbon emissions of the coal industry, whose carbon emissions increased from 1296.23 million tons to 5003.65 million tons, with an average annual growth rate of 6.99%. ② In 2020, the carbon emissions of each sub-industry of the coal industry in descending order were: coal power generation industry (53.41%), ferrous metal smelting and rolling processing industry (17.88%), coal-based heating industry (9.73%), non-metallic mineral products industry (5.86%), raw chemical materials and chemical products manufacture industry (5.86%), coal coking industry (1.35%), etc. ③ The positive driving factors of carbon emissions of the coal industry are economic development (11798.35 million tons), carbon strength (1205.79 million tons) and population size (589.85 million tons), and the negative inhibiting factors of carbon emissions of coal industry are energy efficiency (−5232.72 million tons), energy structure (−1498.07 million tons), and industrial structure (−1411.18 million tons). This study is an important response to the need for the accurate calculation of coal supply and demand. It contributes to the targeted formulation of emission reduction and carbon reduction guidance strategies in the coal industry, and promotes the realization of the “dual-carbon” strategy in the coal industry.

From the perspective of the application of headspace solid-phase microextraction-mass spectrometry coupled with gas chromatography-mass spectrometry （HS-SPME-GC-MS） technology in the detection of volatile substances in fruit products, this paper discusses its important position and significance in fruit flavor detection. This paper briefly outlines the principles and characteristics of headspace solid-phase microextraction-mass spectrometry coupled with gas chromatography-mass spectrometry, and highlights the progress of its research on volatile substances in different kinds of fruit raw materials, stored and preserved fruits as well as fruit processed products such as fruit juice, fruit wine, and fruit tea, and also provides an outlook on the research direction of headspace solid-phase microextraction-mass spectrometry coupled with gas chromatography-mass spectrometry in fruit flavor detection.

In order to develop a fast, efficient and intelligent tool to recognize anti-hypertensive peptides (AHTPs), an identification model based on multi-source characteristics and deep learning was constructed for the recognition of AHTPs. Novel enhanced grouped amino acid composition (NEGAAC), reduced dipeptide composition (RDPC), dipeptide deviation from expected mean (DDE), amino acid physicochemical properties-based distance transformation (AAP-DT) and BLOSUM62 encoding were used for feature extraction of peptide sequences. In addition, bidirectional gated recurrent units (BiGRU) were used for deep learning of protein characteristics, so as to effectively identify AHTPs. Under 10-fold cross-validation, the recognition accuracy of the recognition model based on multi-source features and deep learning reaches 96.78% and 98.72% on the benchmark data set and independent data set.

A numerical simulation procedure and method for underground coal gasification under the action of multi-field coupling has been developed, and the multi-field coupled thermal-force-chemical-displacement calculations are carried out simultaneously based on three subroutines DFLUX, HETVAL and USDFLD in ABAQUS software. Taking the first gasification working face of No.12 coal seam of the Shanjiaoshu coal mine in Panzhou, Guizhou Province as the engineering background, through this numerical simulation method, the simulation of heating the coal body by the ignition device at the initial stage of underground coal gasification is realized. The simulation of chemical heat change triggered by the spontaneous combustion of coal body under the continuous backward movement of the injection point is achieved. Also, the simulation of cavity formation after the coal gasification reaction is accomplished. Finally, the evolution law of temperature field-stress field-displacement field after the gasification reaction of No.12 coal seam of the Shanjiaoshu coal is analyzed. The results show that the overall trend of temperature field evolution increases first and then decreases, reaching the peak temperature in turn with the backward movement of the gasification point. The temperature conduction range of the overlying rock layer gradually expands under the influence of heat conduction. After 120 days of gasification, the overall temperature conduction range is similar to the teardrop shape, and there is a slight delay in the temperature change of the overlying rock layer and a gradual decrease in temperature as the height increases. After 120 days of gasification, the tensile stress area of the overlying rock layer is approximately “concave” in shape while that of the underlying rock layer is approximately “T” in shape. The stress evolution pattern of rock layers at different heights varies greatly, whereby the rock layers at the intersection of the combustion void area and the direct top are affected by the formation of cavity, and the stress concentration phenomenon occurs gradually as the gasification working face progresses. The overlying rock layer sinks as a whole, with the settlement amount increasing and then decreasing before stabilizing. The deformation of the rock layer decreases with the increase of height, while the overlying rock layer is thermally expanded under the influence of high temperature, which generates thermal stress to support the upward movement of the rock layer so that the settlement amount decreases. It can be inferred that the thermal stress generated by the high temperature environment can hinder the sinking of the overlying rock layer to a certain extent in the actual operation of large coal underground gasification projects. The present study aims to be closer to the actual working conditions of coal gasification, and the research results provide a new method to simulate coal underground gasification more practically.

The development of energy storage devices that can withstand large and complex deformation is crucial for emerging wearable electronic devices. At present, hydrogels made of conductive polymers have achieved the fusion of high conductivity and versatility during processing. A simple two-step copolymerization method was used to successfully construct a hydrogel supercapacitor with a rich microporous structure: polyvinyl alcohol(PVA) and polyacrylamide(PAM) form a double cross-linked network hydrogel, which endows rigid polymer aniline with flexibility. In addition, polyacrylamide improves the mechanical strength of polyaniline-based hydrogels, making polyaniline-based(NPP)hydrogels have good mechanical and electrochemical properties, and the tensile strength and specific capacitance are 0.3 MPa and 269.12 F·g-1 under 1 A·g-1, respectively. The addition of polyaniline(PANI) reduces the internal resistance of polyvinyl alcohol and polyacrylamide double cross-linked network hydrogel(PP) electrode, and its modified resistance value is 39.184 Ω, which makes the NPP hydrogel realize higher electron transmission capacity. The flexible development and integration of such hydrogels provide an alternative strategy of energy systems for diverse applications such as supercapacitors.

Objective To study the clinical efficacy of biological ceramics (iRoot BP Plus ) and mineral trioxide aggregate (MTA) in direct pulp capping of mature permanent teeth, to provide referrence for clinical application. Methods Seventy-four patients with pulp exposure due to deep caries or reversible pulpitis in 75 mature permanent teeth were selected and were randomly divided into two groups. iRoot BP Plus were used as pulp capping agents in the treatment group and MTA were used as pulp capping agents in the control group respectively. The clinical efficacy and imaging analysis were performed at 1, 3, 6 and 12 months after operation. Treatment success rate of the two groups were calculated, and the influence of various factors including gender, age, tooth position, cavity, number and size of pulp exposure on the efficacy of direct pulp capping were analyzed. Results Sixty patients with 61 mature permanent teeth were selected. Twelve mouths after treatment, 61 teeth of 60 patents were completely investigated (iRoot group: 31 teeth 30 patients; MTA group: 30 teeth 30 patients). The success rates of the 2 groups were 90.3% (iRoot BP Plus) and 90.0% (MTA), respectively. There was no statistical difference between 2 groups (P>0.05). Statistical analysis also showed that gender, age, tooth position, cavity, number and size of pulp exposure had no significant difference between the two groups (P>0.05). Conclusion Both iRoot BP Plus and MTA are effective in direct pulp capping of mature permanent teeth with carious pulp exposure, while the operation of iRoot is simple and convenient.

In order to obtain a high-quality ultrashort pulse light source, we combine the self-similar pulse with the grating pair, and analyze the evolution and compression process of the self-similar pulse in detail through a numeral simulation method. We first launch the Full Width at Half Maximum (FWHM) of 1 ps, energy of 45 pJ Gaussian pusses into a dispersion decreasing fiber to generate the chirp self-similar pulse with strong linear characteristic. Then we use the grating self-similar pulse chirp compensation compressor to obtained an ultrashort pulse with FWHM of 80 fs and peak power of 507.6 W. The compression quality parameter Q is 0.96, and the compression factor is 12.5. On this basis, we analyze the influence of the third-order dispersion in the declining fiber on the compression quality of the grating, and find that as the third-order dispersion increases, the compressed pulse quality will be significantly reduced. The results show that when the third-order dispersion effect in the system is small, high-power ultrashort pulses can be obtained by using self-similar pulses and grating pairs. This result is helpful for the acquisition of ultrashort pulses. [ABSTRACT FROM AUTHOR]

As shallow coal resources are gradually exhausted in China, the shift of coal mining from shallow to deep will become a new normal condition for ensuring the energy demand of China. Aiming at the problems of coal and gas outbursts, rockburst, and complex dynamic disasters faced by the mining of deep coal resources, the research progress of coal and rock dynamic disaster mechanism in China is analyzed, the key technologies of coal and rock dynamic disaster evaluation, monitoring and early warning are expounded, and the measures and technical means of coal and rock dynamic disaster prevention and risk control are summarized. Based on the trend of deep coal mining, the scientific and technological problems and scientific research prospects for the prevention of coal and rock dynamic disasters are put forward. In terms of research means, the research and development should focus on scientific research instruments that can truly reflect the complex geological conditions, engineering conditions and the process of multi-field coupling. The simulation and reconstruction technology should be developed for the evolution of mine dynamic disasters. Also, the coupling evolution mechanism of coal and rock dynamic disasters should be investigated and revealed. In the aspect of dangerous area detection, it should further develop the advanced acceptable detection theory and technology of dynamic disaster dangerous area of working face based on geophysical means, and develop the drilling and inversion technology of multi-parameter space-time distribution of coal and rock strata under the influence of in-situ conditions and mining. In the aspect of risk assessment, it should carry out research on key indicators and intelligent assessment methods of disaster risk assessment under the coupling conditions of deep complex strata and mining engineering. In the aspect of monitoring and early warning, the coal mine multi-disaster integrated monitoring and early warning platform should be established to realize the coal mine multi-disaster integrated monitoring, intelligent early warning and accurate analysis of safety situation. The remote and accurate regional prevention and control technology of coal and rock dynamic disasters should be developed to realize the advanced regional prevention and control of coal and rock dynamic disasters. The digital emergency decision-making theory and key technology of coal and rock dynamic disasters should be studied in order to realize the intelligent emergency decision-making of coal and rock dynamic disasters. The systematic research on theory, technology, and equipment will guarantee the effective prevention and control of dynamic disasters and safe and efficient mining of coal resources.

Objective To analyze the effect of subchronic exposure of polystyrene nanoplastics (PS-NPs) on reproductive function in adult male mice, and to explore the preliminary molecular mechanism of its impact on testosterone synthesis. Methods Sixty 8-week-old C57BL/6 male mice were fully randomly divided into control group (deionized water) and PS-NPs low (10 mg/kg, 10 PS) and high exposure group (40 mg/kg, 40 PS), with 20 mice in each group. The mice were treated once per day for 60 d by gavage. The weights and organ coefficient of the testes, epididymis, brain, liver, spleen, lung and kidney of each group of mice were weighed and calculated at 24 h after the last exposure. HE staining was used to analyze the histopathological differences of testicular tissue, and transmission electron microscopy was used to observe the ultrastructural changes of testicular cells. The computer assisted sperm assay system was used to analyze semen parameters, the contents of serum testosterone (T), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were detected by enzyme-linked immunosorbent assay (ELISA), and the expression levels of key genes for T synthesis, which had been screened by transcriptome sequencing, were determined in testicular tissues by real-time PCR. Results Compared with the control group, the weight of the epididymis in the 40 PS group was increased significantly (P < 0.05), the testicular organ coefficients of mice in the 10 PS group and the epididymis organs coefficients of mice in the 40 PS group were increased obviously (P < 0.05), and the weight and organ coefficients of the liver and spleen of the mice in the 10 PS and 40 PS groups were decreased remarkably (P < 0.05). The pathological results showed that compared with the testis of the control group, the lumen of the semininogenic tubule in the 10 PS and 40 PS groups were enlarged, the semimatogenic cells were loose, and the vacuoleization was increased. Transmission electron microscopy displayed that mitochondrial swelling and endoplasmic reticulum expansion were observed in the cytoplasm of Leydig cells in 10 PS and 40 PS groups. The sperm motility of mice in the 10 PS group was decreased significantly compared with the control group (P < 0.05). The serum T level of mice in the 10 PS and 40 PS groups was decreased, with that of the 40 PS group more significant (P < 0.05). The serum LH and FSH levels of mice in the 10 PS and 40 PS groups were increased notably. Compared with the control group, the mRNA levels of CYP11A1 in the testes of mice were significantly down-regulated in both 10 PS and 40 PS groups (P < 0.05). Conclusion PS-NPs can cause damage to the testes pathologically and functionally in mice, and may reduce T synthesis by inducing structural abnormalities of Leydig cells and down-regulating CYP11A1 expression.

Objective To investigate the effect of polystyrene microplastic (PS-MPs) on the apoptosis of male germ cells. Methods Genes related to male urogenital disorders caused by polystyrene were searched in the Comparative Toxicogenomics Database (CTD). Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to analyze the involved functions and signaling pathways. A cell model was established based on mouse mesenchymal cells (TM3 cells), and then 0, 10, 20 and 40 μg/mL PS-MPs with a particle size of 5 μm and 80 nm respectively were used to treat TM3 cells respectively for 48 h. Cell morphology was observed, cell viability was detected with CCK-8 assay, apoptosis by flow cytometry, and mRNA and protein expression levels of key molecules in the p53 signaling pathway were detected by RT-qPCR and Western blotting, respectively. Results GO and KEGG enrichment analyses showed that the genes screened from CTD database were found to be significantly enriched in cell apoptosis and p53 signaling pathway (P < 0.05). PS-MPs of 5 μm and 80 nm in size treatment for 48 h resulted in significant inhibition of cell growth while enhancement in cell apoptosis (P < 0.05), up-regulated the mRNA and protein levels of p53 and Bax in the p53 signaling pathway (P < 0.05), enhanced downstream molecules Caspase3 and Caspase9 (P < 0.05), and inhibited Bcl2 at mRNA and protein levels in TM3 cells (P < 0.05). Conclusion PS-MPs exposure may induce apoptosis of testicular mesenchymal TM3 cells via the p53 signaling pathway.

The development of coalbed methane resources in China has broad prospects, and the evolution process of coalbed water and its transportation law has important impacts on coalbed methane production capacity. This paper clarifies the composition, properties, sources and isotopic chronology of coal reservoir water, analyzes the expansion law of the pressure drop funnel and the inter-well interference mechanism during the water transport process, discusses the reservoir damage that may be caused by the water transport during drainage, and puts forward several suggestions for coalbed methane development according to the evolution of coal reservoir water and its transport and migration law during production. The results show that: (1) coal reservoir water is originated from primary sedimentary water, infiltration water, deep-forming water and diagenetic water, and the sodium-chlorine coefficient (rNa+/rCl−), Scholler coefficient (IBE), and mineralization degree of the original sedimentary water is0.129, and >10000 mg/L, respectively; corresponding values of infiltration water are the opposite of these relations; the δD and δ18O of deep-forming water is ranged from −80‰ to+40‰ and +7‰ to +9.5 ‰, respectively; the δD and δ18O of diagenetic water is ranged from −65‰ to −20‰ and +5‰ to+25‰, respectively; (2) the geochemical characteristics of coal reservoir water have important indicative significances for the enrichment and development of coalbed methane, and the high gas-containing areas of coalbed methane usually have the characteristics of low sodium-chlorine coefficient, low desulfurization coefficient, low magnesium-calcium coefficient, and high degree of metamorphism, correspondingly, the low gas-containing areas have the opposite characters; (3) the pressure drop funnel propagation during coal reservoir water transport and migration and the interference between wells are conducive to improve the coalbed methane production, and most of the coalbed methane wells in China are deployed by rectangular or diamond-shaped well networks, and the optimal well space is usually ranged between 250m and 400m; (4) the water transport of coal reservoirs can cause pulverized coal to block the formation, water lock damage, water sensitive damage, and velocity sensitive damage. To reduce reservoir damage, implementing reasonable drainage strength, optimizing the well network, and adding waterproof locking agent and pulverized coal dispersant to the incoming fluid are suggested. The research results can provide a certain theoretical basis for improving the exploration efficiency and coalbed methane yield in China.

Submarine optical fiber composite cables are widely used in cross-ocean information and energy interconnection projects play a key role in the national marine strategy. the environment condition is complex, different types of mechanical damage will directly affect the safety of the submarine cable. The finite element simulation analysis provides a low-cost and high-efficiency theoretical method for the safety monitoring through the simulation of different working conditions. In order to summarize the existing technology and evaluate the future development direction, this paper the finite element simulation analysis of submarine cables under tensile, torsion and bending load summarize the research results of submarine cable mechanical damage from anchor and natural ocean current, which can provide reference for monitoring technology such as optical fiber sensing. Finally, the simulation technology is summarized and prospected.