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This study takes the mining of B1+2 and B3-6 coal seams in the southern mining area of a steep and thick coal seam mine as the engineering background, and combines theoretical analysis and numerical simulation methods to compare and study the effects of horizontal and inclined segmented mining of steep and thick coal seams on the prevention and control of rock burst. The results show that: before mining the B3-6 seam at the same level, the stress concentration area of horizontal sectional mining is mainly located in the surrounding rock above and below the roadway and the coal body below the gob, while the stress concentration area of inclined sectional mining is shifted to the coal body at the sharp corner area below the gob and the surrounding rock above and below the roadway at the low level side; compared with horizontal sectional mining, the peak stress in the surrounding rock above and below the high level side roadway of inclined sectional mining is reduced by 10-20 MPa, and the stress concentration roadway is reduced from 4 to 2; mining the B3-6 coal seam first at the same level can weaken the horizontal stress transfer, and it has the function of pressure relief protection for the B1+2 coal seam mined later. In addition, under the condition of inclined sectional mining, the inclined gob can further weaken the horizontal stress transfer, and it has the function of pressure relief protection for the high level side roadway; based on comprehensive comparison, it is believed that the stress level of the surrounding rock above and below the roadway is lower and the degree of deformation of the roadway is the lowest, which is more conducive to the prevention and control of rock burst.

To study the effects of radio frequency-assisted hot air drying (RFHAD) on the quality of South American white shrimp (Penaeus vannamei), the RFHAD process based on the dielectric properties of the shrimp was optimized. The effects of radio frequency drying (RFD) and RFHAD on the flavor nucleotide contents and equivalent umami levels in dried shrimp were compared with those of hot-air drying (HAD). The results showed that as the temperature and moisture content increased, the dielectric constant and loss factor of the shrimp also increased, facilitating moisture migration and enhancing the drying rate. The penetration depth of the RFD was negatively correlated with moisture content, temperature, and frequency. Additionally, increasing the number of stacked layers and reducing the plate spacing significantly increased the drying rate of the shrimp (P

In order to realize the effective prevention and control of coal dust, the magnetic-electric coupling spray dust reduction technology is proposed. First, by measuring the surface tension and contact angle of magnetized water under different magnetization intensities and magnetization times, its wetting and atomization properties are analyzed. Secondly, the magnetized water was magnetized with optimal parameters to increase the applied electric field to explore the effects of electrode voltage, electrode ring parameters, and electrode spacing on the charging characteristics and atomization performance of magneto-electrically coupled water. Then, the dust reduction effects of ordinary water, magnetized water and magneto-electrically coupled water were compared by the self-built dust removal experimental platform. Finally, COMSOL software is used to simulate the changes of collision patterns between the above three liquids and coal dust particles. The experimental results show that: the best dust reduction parameters of magnetized water solution are magnetization intensity of 350 mT and magnetization time of 30 min; the best parameters of magneto-electrically coupled water are electrode voltage of 9 kV, electrode ring parameter of 8 cm and electrode spacing of 3.5 cm; the dust reduction efficiency of magneto-electrically coupled solution is higher than that of other two kinds of liquids, and the dust capturing efficiency of magneto-electrically coupled spray is increased by 38.84% compared with that of ordinary water at the time of total dust, and the dust reduction efficiency reaches 91.2%; the dust capture efficiency of the magneto-electrically coupled spray is 38.59% higher than that of ordinary water in respirable dust, and the dust reduction efficiency reaches 82.3%. The droplets are more easily adhered to the surface of coal dust particles under the three working conditions of ordinary water, magnetized water and magneto-electrically coupled solution.

The occurrence of coal mine rock burst disasters is closely related to the spatial structure, especially in the complex spatial structure area. It is of great significance to master the law of coal and rock catastrophe and reveal its mechanism in the complex spatial structure area of coal seam mining for the prevention and control of rock burst. Taking the Wudong Coal Mine as the research background, using numerical simulation, micro-seismic monitoring, theoretical analysis and other methods, the abnormal size effect of rock pillar stress is studied, the temporal and spatial evolution law of microseisms in the complex spatial structure area is analyzed, the mechanism of rock burst under the complex spatial structure is revealed, and the impact risk in the different areas of coal mining is evaluated. The research results show that: ① The steeply inclined rock pillar with narrower thickness and higher exposed height has stronger prying effect, and the abnormal stress of rock thickness variation forms five divisions. ② The area with narrower rock pillar thickness has more micro-seismic frequency, higher energy, stronger spatio-temporal activity and higher dispersion. The high stress region, the stress gradient region and the stress plateau region show the micro-seismic response characteristics of “low frequency-high energy”, “high frequency-high energy” and “low frequency-low energy” in turn. ③ The micro-seismic events in special spatial structure area are clustered and the energy level increases, and the temporal and spatial activity and dispersion increase sharply. This feature is more obvious especially at the edge of the structure, the energy accumulation and release rate increases, and the probability and intensity of rock burst are higher. The micro-seismic activity of special spatial structures located in the narrower area of rock pillars is more acute. ④ The narrower the thickness of rock pillar (the greater the height of coal pillar), the faster the growth rate of bending moment and energy in the depth of rock pillar, and the higher the impact risk. According to the strength effect of structural plane, it is inferred that the fault zone has slip and dislocation, and fault zone is the dominant area for energy accumulation and release. It is revealed that the mechanism of rock burst is the joint action of high static load and low critical load. The impact risk in the different areas of coal mining is evaluated based on stress concentration characteristics.

With the gradual coal mining of deep rock burst mine, the impact accompanying roadway excavation becomes more and more intense. Aiming at the problem of effective prevention and control of rock burst in roadway excavation, taking the steep seam mine in the Wudong Coal Mine as an example, the temporal and spatial precursor characteristics of rock burst in roadway excavation were analyzed by microseismic monitoring. Combined with the numerical simulation analysis of stress and energy changes in roadway excavation, the mechanism of rock burst in roadway excavation was revealed, and the prevention and control strategy of rock burst in steeply inclined extra-thick coal seam roadway was put forward, which was verified by field engineering practice. The results show that the total energy of microseisms is extremely low for 2−5 days or there is an energy latency of at least 4 days before the rock burst occurs due to roadway excavation in steeply inclined extra-thick coal seam. Within 5 days before rock burst occurs, there is a high-frequency fluctuation period of maximum energy ratio for more than 3 days. There is an obvious lack of earthquake before the rock burst occurs, and the occurrence position is concentrated in the range of minimum value of microseismic energy near the heading face, or in the range of minimum value of microseismic frequency near the extreme value of microseismic energy, and the rock burst event is located in the area with high impact deformation energy index. The hard overburden structure of horizontal sublevel fully mechanized caving mining in steeply inclined extra-thick coal seam is not easy to break, which makes the stress concentration on both sides of upper horizontal goaf exist in roadway excavation. The stress between the front of the heading face and the bottom of the roadway squeezed by the roof and floor strata is concentrated and the energy accumulation is remarkable. With the increase of the heading depth of the roadway, the stress concentration and energy accumulation are further enhanced, which is easy to induce dynamic disasters such as rock burst. The prevention and control strategies of rock burst was established through comprehensive analysis, which consist of face blasting pressure relief, roadway drilling pressure relief and reinforcement support, and scaffolding in complex areas. Combined with the temporal and spatial precursory anomalies of rock burst, it provides an opportunity to strengthen the unloading pressure in time. Through the pressure relief of working face and roadway, the accumulated microseismic energy of more than 1×105 J per day did not occur during the excavation. After the support was optimized and the complex area was protected, the daily average microseismic energy of roadway excavation decreased to 2.2 kJ, and the proportion of microseismic events above 1 kJ decreased, and the overall section of roadway was flat.

In order to investigate the effects of different storage temperatures on the storage quality and enzyme activities of Fritillaria thunbergii Miq from the soil, which were stored at 0, 5, 10 and 20 ℃ for 90 d. The changes in weight loss, sensory quality, color, hardness, total polysaccharides, alkaloids, malondialdehyde (MDA) contents, polyphenol oxidase (PPO), peroxidase (POD) and superoxide dismutase (SOD) activities of Fritillaria thunbergii Miq were explored at different storage temperatures. The results showed that the weight loss rate of Fritillaria thunbergii Miq at 0 ℃ for 90 d was only 7.17%, which was significantly lower than that at 5, 10 and 20 ℃ (9.92%, 19.77% and 30.28%) (P

In order to scientifically evaluate the impact risk of steeply inclined extra-thick coal seam in folded area and provide theoretical guidance for the prevention and control of rock burst, a numerical model including folds is established in this paper based on the prevention and control of rock burst in south mining area of Wudong Coal Mine. With the help of multiple linear regression and CASRock engineering software, the back analysis of ground stress field of steeply-inclined extra-thick coal seam in folded area of Wudong Mine is carried out. Taking B1+2 coal seam as the research object, the stress data in coal seam, roof and floor are extracted, the stress-cover depth variation curve is plotted, the distribution characteristics of pre-mining stress field are explored, and the risk assessment index related to pre-mining stress is determined. According to the back analysis data of in-situ stress and previous research results, the evaluation indexes of burst risk are determined from the aspects of geological factors and mining conditions. The static weights of 7 geological factors and 5 mining conditions are obtained by Analytic Hierarchy Process. By substituting the static weight into the dynamic weight calculation formula and combining with the traditional comprehensive index method, the risk assessment of B1+2 panel at +500 m level in the south area of Wudong Mine is carried out. According to the rockburst risk classification table, the burst risk of this panel is medium, which is consistent with the conclusion of the geological report, and the rationality of the method was verified. This method is used to estimate the burst risk of coal seam with different depths. Control group is chosen, using the traditional comprehensive risk index method to evaluate the burst of the same area, the results show that the method to obtain the risk ratings were higher than the traditional methods, approach of this paper highlights the risk factors in the evaluation index, overcoming the other indicators evaluation error caused by the interference factors.

This study analyzed the differential composition between from concentrate (FC) and not from concentrate (NFC) bayberry juices by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). NFC and FC bayberry juice were distinguished from each other by orthogonal partial least squares discriminant analysis, and 9 compounds that significantly differed in abundance between them were selected and identified according to the variable importance in the projection and the fold-change. By comparison, the content of antioxidant active components such as 4-sulfobenzoate, 5-methyltetrahydrofolic acid, cyanidin, daphnoretin, xanthotoxol and isoxanthopterin in FC bayberry juice were relatively low, whereas the bitter substances (neohesperidin, hesperidin and quercetin-3-O-neohesperidin) were relatively high. Metabolic pathways were analyzed on account of differential metabolites and five metabolic pathways with great differences were identified, among which phenylalanine metabolism, biosynthesis of flavonoids and flavonols were the key metabolic pathways of different metabolites in NFC and FC bayberry juice. This study revealed the difference of metabolites between NFC and FC bayberry juice, which provided theoretical reference for the processing and identification of NFC bayberry juice.

In the process of CO2-ECBM, the tectonic fractures developed in the coal may become the preferential channels of gas-water seepage under the impact of injection pressure, and then influence the recovery of coalbed methane (CBM) and CO2 storage. Based on the theoretical analysis, the displacing profile of CO2-ECBM is established. A numerical model is constructed referring to the TS-634 field trial, and the influence of the tectonic fractures on CH4 recovery and CO2 storage is investigated. The CBM recovery and CO2 storage in the TS-634 trial are evaluated, the mechanism of the rapid breakthrough of CO2 is revealed, the enlightenment of the rapid breakthrough on the optimization of the injection-drainage process is dissected, and the proposals for the injection-drainage process in reservoirs with tectonic fractures are put forward. The results show that CO2 enriched zone, CH4-CO2 mixed zone, CH4 enriched zone, and water enriched zone can be formed among injection-production wells successively. With an injection, the zones affect the producers after their formation and evolution. The difficulty of water seepage determines the level of CH4 output inhibition and then controls the CBM recovery and CO2 storage. The producer along tectonic fracture can achieve an efficient recovery of CH4, but a high permeability often leads to apparent CO2 channeling which causes the loss of cumulative CH4 production and CO2 storage. During the trial period, the strong-breakthrough producer attains a remarkable increase in gas output, with the actual cumulative gas production increasing by 10.4% and bottomhole-pressure-equivalent cumulative gas output increasing by 92.3%. Tectonic fractures provide potential preferential channels for the CO2 rapid breakthrough and become real preferential channels mainly induced by injection pressure. The existence of fracturing affected areas and liquid CO2 phase transformation-induced expansion and energization accelerate the CO2 breakthrough, but the coal matrix expansion-induced permeability decrease is expected to delay the breakthrough. To achieve a better displacement, enhancement, and sequestration, it is necessary to boost the bottomhole pressure in the early injection stage, fine-tune the pressure of the injector or increase the bottomhole pressure drop of producers in the inhibition stage, and maintain the pressure lower than the minimum principal stress of the reservoir in the whole stage. After the breakthrough, the exposure time between CO2 and coal matrix can be increased by irregularly shutting down/restarting the producers or reducing the pressure of the injector, which is expected to further improve the CH4 recovery.

Based on datasets from Shanghai Qingpu dual-polarized radar, Wuhan Doppler weather radar, new generation weather radar network mosaic, ground encrypted automatic weather station, and ERA5 reanalysis, a comparative analysis was conducted on the severe tornado weather processes that occurred in Suzhou and Wuhan on the night of 14 May 2021 from the aspects of weather background, ground triggering mechanism, radar detection characteristics, and environmental parameters. Results are as follows. (1) Both tornadoes in Suzhou and Wuhan occurred under the forced background of southwest warm and humid airflow, with low temperature and high humidity in the lower layer being affected by low-level and ultra-low-level jet streams. However, the location of the tornado in each of the two places was different from the corresponding jet stream location. The western side of the Suzhou tornado corresponded to the exit area of the eastern jet stream, while the Wuhan tornado corresponded to the exit area of the western jet stream. (2) The Suzhou tornado was triggered by the convergence line caused by gust fronts and a weak cold pool with appropriate intensity. Nevertheless, there was a mesoscale convergence center and a weak cold pool on the ground. (3) Tornadoes in both places occurred when the isolated rightward-moving supercells were accompanied by a suddenly strengthened low-level mesocyclone. And tornadic vortex signature (TVS) appeared 2 min and 3 min before the Suzhou tornado and Wuhan tornado, respectively. (4) Different from the environmental conditions of tornadoes occurring in the United States, the Suzhou tornado appeared under the conditions of high convective available potential energy, low lifting condensation height, convective inhibition energy, and medium to weak storm-relative helicity and vertical wind shear. Wuhan tornado occurred under the conditions of weak convective available potential energy, low lifting condensation height, high convective inhibition energy, and strong storm-relative helicity and vertical wind shear. By comparison, before and during the occurrence of tornadoes in the two regions, the thermal condition of the Suzhou tornado was favorable and the dynamic conditions were standard or even unfavorable. However, for the Wuhan tornado, the thermal condition was relatively weak, while the dynamic conditions were favorable. It is indicated that both tornadoes occurred in environments with complementary thermal and dynamic conditions.

CO2 geological sequestration-enhanced coalbed methane (CO2-ECBM) strengthens the development of coalbed methane (CBM) and realizes the stimulation of coalbed methane wells. At the same time, CO2 is stored in deep coal seams. This technology has some great development prospects. Relying on the demonstration project, numerical simulation based on geological modeling is still an important path for its technological development. Based on the analysis of the characteristics for the corner grid geological model and the geological modeling ability of COMSOL Multiphysics, a geological model that can clearly display the three-dimensional spatial morphology and heterogeneity distribution of gas content, adsorption time, porosity, permeability, elastic modulus and Poisson’s ratio of the No. 3 coal in the Shizhuang South Block of Qinshui Basin was established in COMSOL Multiphysics using the split-reconstruction method. On this basis, the numerical simulation of CO2-ECBM for controlling gas injection pressure was carried out in combination with the adsorption-hydraulic-thermal-mechanical-chemical (AHTMC) multi-field coupling mathematical model, and the impact of CO2 injection pressure on CH4 stimulation, CO2 storage and the geochemical environment of coal reservoir were analyzed. Moreover, two kinds of shut-in modes, namely, simultaneous shut-in and sequential shut-in, and four CO2-ECBM engineering objectives, namely, time saving, CH4 stimulation, CO2 storage and comprehensive consideration of the three, were proposed. In addition, the CO2 injection pressures were optimized according to the two shut-in modes with the four objectives. The results show that: ① Under the limit of 15-year and the injection pressure of 5.50−9.50 MPa for the CO2-ECBM project, with the increase of CO2 injection pressure, the CH4 production rate of CBM wells and the CO2 storage capacity of coal reservoir increase, with the maximum of 14.39% and 8.31×107 m3 respectively, the area of coal reservoir containing acid fissure water expands. The CO2 storage rate decreases due to the large output of CO2 from CBM wells with the increase of gas injection pressure, but remains above 95%. ② The heterogeneity of coal reservoirs has a great impact on the production of CBM wells. The higher the CH4 content and the greater the porosity and permeability of the coal reservoirs around the CBM wells, the more significant the CH4 stimulation effect. The stronger the CO2 adsorption capacity of the coal reservoirs surrounding CBM wells, the lower their CO2 production rate. ③ Under the simultaneous and sequential shut-in, CO2 injection pressure has a significant impact on the CO2 concentration and CH4 production rate of gas produced by well group, and the CH4 recovery of coal reservoir decreases with the increase of injection pressure at the end of CO2-ECBM project with 33.28% and 41.63% for 3.50 MPa, 18.90% and 28.03% for 6.50 MPa and 12.81% and 23.01% for 9.50 MPa, respectively. ④ The optimal injection pressure of CO2 for the engineering objectives of time saving, CH4 stimulation, CO2 storage and comprehensive consideration of above three are 8.05, 3.50, 6.35 and 6.25 MPa for the simultaneous shut-in, respectively, and 9.50, 9.50, 3.50 and 9.50 MPa for the sequential shut-in, respectively. ⑤ Compared with simultaneous shut-in, the sequential shut-in can achieve better CH4 stimulation and CO2 storage effects by extending the engineering time when using the optimal CO2 injection pressure.

The aim of this study was to obtain polysaccharides from Hovenia dulcis fruit pedicels, and further evaluate its ability to scavenge free radicals and inhibit the oxidation of biological macromolecules (proteins, lipids, DNA). On the basis of a single-factor experiment, the hot water extraction process of polysaccharides from Hovenia dulcis fruit pedicels was optimized using orthogonal test combined with an analysis of variance. The ability of the extracted polysaccharides to scavenge DPPH and ABTS+ free radicals was determined. In addition, Cu2+/H2O2, FeSO4 and APPH were used to induce the oxidation of bovine serum albumin, linoleic acid and herring sperm DNA, respectively, to construct in vitro protein, lipid and DNA oxidation models and the ability of the extracted polysaccharides to inhibit biological macromolecule oxidation in vitro was evaluated. The results showed that the volume fraction of ethanol precipitation had a significant effect on the yield of polysaccharides from Hovenia dulcis fruit pedicels (P

A new program-controlled initial trajectory allowing an anti-torpedo torpedo(ATT) to find the incoming torpedo quickly and achieve rapid occupation was investigated in this study. A virtual target was introduced according to the target motion characteristics, and a bias proportional guidance law considering the terminal angle constraint was designed. The virtual target led the ATT to the real target according to the designed guidance law. Simulation results indicated that in a typical situation of an ATT intercepting incoming torpedoes, the introduced virtual target and the bias proportional guidance law designed for the ATT can help the ATT quickly detect incoming torpedoes. They can significantly increase the interception probability of ATTs and thus enhance the battlefield survivability of submarines.

BackgroundLipid metabolism in liver shows circadian-dependent profiles. The hepatotoxicity of environmental chemicals is dependent on circadian time. ObjectiveTo observe the effects of bisphenol A (BPA) exposure at different zeitgeber time (ZT) on hepatic and blood lipid metabolism and decipher the underlying mechanisms related to circadian rhythm in mice. MethodsThirty-five female C57BL/6J mice were sacrificed every 4 h in a light-dark cycle (12 h/12 h). The liver tissues were collected to describe the circadian profiles of hepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels within 24 h. Thirty female mice were divided into 6 groups by the timing (ZT3 represents the 3 h after light on, ZT15 represents the 3 h after light off) and dose (50 or 500 μg·kg−1·d−1) of BPA exposure to observe hepatotoxicity. Mice were gavaged with designed doses of BPA once per day for 4 weeks. Mice were maintained with ad libitum access to food and water and measured body weight weekly. After the experiment, mice were euthanatized and liver tissues were separated to determine the biochemical indicators of lipid metabolism and lipid metabolism- and circadian-related gene mRNA expressions. ResultsHepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels were rhythmic during a 24 h period in mice. At ZT3 and ZT15, BPA did not alter body weight, plasma glucose, plasma total cholesterol, plasma low density lipoprotein cholesterol, and plasma triglycerides (P>0.05). The plasma high density lipoprotein cholesterol decreased in the 50 μg·kg−1·d−1 BPA group at ZT3 by 14.56% compared with the control group (P

In order to determine the effect of high pressure homogenization (HPH) on the stability and quality of not-from-concentrate (NFC) cloudy honey peach juice, the samples were subjected to HPH processing with 20~40 MPa for 1~2 successive passes. The changes in turbidity, centrifugation precipitating rate, particle size distribution, Zeta potential, water soluble pectin content, pectin methylesterase (PME) activity, pH, total soluble solids (TSS), total acidity (TA), TSS/TA, reducing sugar content, color, total phenol and VC content were evaluated. The results showed that HPH could effectively improve the stability of NFC cloudy honey peach juice. With the treatment of 30~40 MPa/1 and 20~40 MPa/2, the centrifugation precipitating rates significantly decreased by 13.49%~24.22% (P0.05). HPH decreased the pH, TSS, TA, total phenol and VC content with increasing pass number (P

In order to study the effect of high pressure processing on water bamboo (Zizania caduciflora L.) juice, this study compared the effects of high pressure processing (HPP, 400~500 MPa/5~10 min) and conventional heat treatment (TP, 80 ℃/10 min) on the physicochemical quality, nutritional components, antioxidant properties and volatile flavor components of non-concentrated reduced (NFC) water bamboo juice. The results showed that the sensory quality of heat-treated water bamboo juice was reduced and significant stratification occurred, while HPP treatment had no significant effect on pH, soluble solids and titratable acid content in water bamboo juice (P>0.05), and reduced stratification and improved the sensory quality of water bamboo juice. Meanwhile, compared with TP treatment, HPP treatment could better maintain the total phenols, flavonoids and DPPH free radical scavenging rate in water bamboo juice. In addition, gas chromatography-ion mobility chromatography (GC-IMS) flavor analysis showed that HPP increased the fruit and herbaceous aromas in water bamboo juice, which enhanced the flavor of water bamboo juice. In conclusion, compared with the traditional TP treatment, the HPP treatment had significant advantages in maintaining the quality characteristics, antioxidant and flavor of water bamboo juice.

A new method to obtain multiple scale wind retrievals is proposed by using the Multi-scale Integrating Velocity Azimuth Process (MIVAP) method with different scale analysis sectors for nowcasting. The retrieved winds from the IVAP method with the large-scale analysis sectors are considered as the steering winds involving the systematic movement, while the small-scale internal motion vectors are estimated by the IVAP method with small scale analysis sectors. Then the retrieved winds with different scales are synthesized as the motion vectors for extrapolation nowcasting. Compared to the traditional Multi-scale Tracking Radar Echoes by Correlation (MTREC) methods, which rely on tracking radar echoes of a few time slices, the MIVAP method only needs the radar echo and radial velocity observations at the latest time. Comparison experiments based on a series of convective rainfall cases demonstrate that it is practical to apply the retrieved winds from the MIVAP method for nowcasting. The statistical verification tests show that extrapolated motion from the MIVAP method appears at the right of that from the MTREC method, and the speed of the former is faster than the latter. Nowcasting using the MTREC method performs better than that applying the MIVAP method in the few periods of the first 30 minutes, while the MIVAP method achieves better evaluation scores than the MTREC method after 30 minutes of forecasting periods, so the MIVAP method has a better performance than the MTREC on the whole.

In order to improve the ability of fuzzy C-means (FCM) clustering algorithm to suppress noise, an improved fuzzy clustering image segmentation algorithm was proposed. First, multi-dimensional image information was set up using non-local spatial information and local spatial information. Secondly, a priori probability was introduced to ensure that the membership degree before each iteration takes into account the spatial information of the image. Finally, the membership penalty item was added to improve the clustering segmentation effect. Experimental results show that compared with fuzzy local information C-means (FLICM)clustering algorithm, fuzzy C-means with local information and kernel metric(KWFLICM)clustering algorithm, fuzzy C-means with non-local spatial information(FCM_NLS)clustering algorithm, and non-local fuzzy C-means clustering image segmentation algorithm based on particle swarm optimization(PSO-WMNLFCM), the improved algorithm has greatly improved partition coefficient and partition entropy, the partition coefficient increased to 0.957 3, and the partition entropy is reduced to 0.059 6.

With the development of the national major project of space-integrated-ground information network including space-based access network and LEO constellation system,it is urgently to be solved how to deal with the routing problem of LEO constellation with inter-satellite communication.One of the research ideas is to study the high dynamic characteristics of LEO constellations and analyze the adaptability of ground-based IP routing technology.The correlation analysis process and conclusion were given,which could provide important basis and support for the routing solution of LEO constellation system with inter-satellite communication.

With the development of the national major project of space-integrated-ground information network including space-based access network and LEO constellation system,it is urgently to be solved how to deal with the routing problem of LEO constellation with inter-satellite communication.One of the research ideas is to study the high dynamic characteristics of LEO constellations and analyze the adaptability of ground-based IP routing technology.The correlation analysis process and conclusion were given,which could provide important basis and support for the routing solution of LEO constellation system with inter-satellite communication.

Mining big software data and utilizing the knowledge contained in it to explore intelligent methods for software development is an active research topic. However, existing researches on software developer and crowd collaboration have not yet formed systematic methods. Therefore, the key technologies for intelligent collaboration through in-depth analysis of developer behavior were studied. Besides, the corresponding support environment was also developed on the basis of the key technologies to improve the efficiency and quality of software development. Firstly, a large amount of data related to developers were collected and analyzed. Secondly, a systematic approach of analyzing developers and their collaboration which is called developer knowledge graph was proposed. Thirdly, supported by the developer knowledge graph, the collaborative development method based on intelligent recommendation was introduced thoroughly. Depending on the above technologies, the corresponding supporting tools were developed, and a system of intelligent collaborative development environment was provided. Finally, the future work was prospected.

Cloud computing security issue is one of the most important and difficult problems encountered in today’s cloud computing technology to promote 1anding.From the cloud computing security in the information security section，the basic content of information security in cloud computing and the current cloud computing were described；information security issues were analyzed；some of the solutions and the prospects of cloud computing were given. Fina11y，a brief discussion of GMCC private cloud platform cloud computing security practice was presented.

Cloud computing security issue is one of the most important and difficult problems encountered in today’s cloud computing technology to promote 1anding.From the cloud computing security in the information security section，the basic content of information security in cloud computing and the current cloud computing were described；information security issues were analyzed；some of the solutions and the prospects of cloud computing were given. Fina11y，a brief discussion of GMCC private cloud platform cloud computing security practice was presented.