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| 1 | Effects of clay and calcium ions on coal flotation显示文摘The microflotation of three single minerals,mixed coal–kaolinite and mixed coal–montmorillonite were examined to study the effects of clay and calcium ions on coal flotation.The results show that the ash content of flotation concentrate increases by 3%in the presence of clay minerals,and the ash content would further increase by 3%in co-presence of clay minerals and high concentration of Ca2+.Scanning electron microscope(SEM)images and elemental spectrum analysis indicate that fne clay particles that coat on the coal surface,which is called slime coating,can affect the coal flotation.The slime coating would be induced much more easily in the presence of Ca2+. | Zhang Zhijun Liu Jiongtian Xu Zhiqiang Ma Liqiang | 2013 | International Journal of Mining Science and Technology2013,23,5: | 24 |
| 2 | Seasonal variations and size distributions of water-soluble ions in atmospheric aerosols in Beijing, 2012显示文摘The characteristics of water-soluble ions in airborne particulate matter in Beijing were investigated using ion chromatography. The results showed that the total concentrations of ions were 83.7 ± 48.9 μg/m3 in spring, 54.0 ± 17.0 μg/m3 in summer, 54.1 ± 42.9 μg/m3 in autumn, and 88.8 ± 47.7 μg/m3 in winter, respectively. Furthermore, out of all the ions, NO3-,SO42-and NH4+accounted for 81.2% in spring, 78.5% in summer, 74.6% in autumn, and 76.3%in winter. Mg2+and Ca2+were mainly associated with coarse particles, with a peak that ranged from 5.8 to 9.0 μm. Na+, NH4+and Cl-had a multi-mode distribution with peaks that ranged from 0.43 to 1.1 μm and 4.7 to 9.0 μm. K+, NO3-, and SO42-were mainly associated with fine particles, with a peak that ranged from 0.65 to 2.1 μm. The concentrations of Na+, K+,Mg2+, Ca2+, NH4+, Cl-, NO3-and SO42-were 2.69, 2.32, 1.01, 4.84, 16.9, 11.8, 42.0, and 44.1 μg/m3 in particulate matter(PM) on foggy days, respectively, which were 1.4 to 7.3 times higher than those on clear days. The concentrations of these ions were 2.40, 1.66, 0.92, 4.95, 17.5,7.00, 32.6, and 34.7 μg/m3 in PM on hazy days, respectively, which were 1.2–5.7 times higher than those on clear days. | Yongjie Yang Rui Zhou Jianjun Wu Yue Yu Zhiqiang Ma Lejian Zhang Yi'an Di | 2015 | Journal of Environmental Sciences2015,27,8: | 19 |
| 3 | Arabidopsis AtBECLIN 1/AtAtg6/AtVps30 is essential for pollen germination and plant development显示文摘兼容丑恶纸巾的表面上的花粉萌芽是为植物授精的必要的步。这里,我们报导 Arabidopsis 变异的 bcl1 是由于花粉萌芽的失败不育的男性。我们证明 bcl1 异种等位基因不能被男配偶体播送,没有同型结合的 bcl1 异种被获得。花粉发育阶段的分析显示 bcl1 变化影响花粉萌芽然而并非花粉成熟。分子的分析证明花粉萌芽的失败被 AtBECLIN 1 的混乱引起。AtBECLIN 1 在成熟花粉主要被表示并且与重要相同编码蛋白质到在酵母为 autophagyand vacuolar 蛋白质排序的过程(VPS ) 要求的 Beclin1/Atg6/Vps30。我们也证明 AtBECLIN 1 为正常被要求植物开发,和那与 autophagy, VPS 和 glycosylphosphatidylinositolanchor 系统有关的基因,被 AtBECLIN 1 的缺乏影响。 | Genji Qin Zhiqiang Ma Li Zhang Shufan Xing Xianhui Hou Jie Deng Jingjing Liu Zhangliang Chen Li-Jia Qu Hongya Gu | 2007 | Cell Research2007,17,3: | 17 |
| 4 | Characteristics and recent trends of sulfur dioxide at urban,rural,and background sites in North China:Effectiveness of control measures显示文摘SO 2 measurements made in recent years at sites in Beijing and its surrounding areas are performed to study the variations and trends of surface SO 2 at different types of sites in Northern China.The overall average concentrations of SO 2 are (16.8±13.1) ppb,(14.8±9.4) ppb,and (7.5±4.0) ppb at China Meteorological Administration (CMA,Beijing urban area),Gucheng (GCH,relatively polluted rural area,110 km to the southwest of Beijing urban area),and Shangdianzi (SDZ,clean background area,100 km to the northeast of Beijing urban area),respectively.The SO 2 levels in winter (heating season) are 4-6 folds higher than those in summer.There are highly significant correlations among the daily means of SO 2 at different sites,indicating regional characteristics of SO 2 pollution.Diurnal patterns of surface SO 2 at all sites have a common feature with a daytime peak,which is probably caused by the downward mixing and/or the advection transport of SO 2 -richer air over the North China Plain.The concentrations of SO 2 at CMA and GCH show highly significant downward trends (-4.4 ppb/yr for CMA and -2.4 ppb/yr for GCH),while a less significant trend (-0.3 ppb/yr) is identified in the data from SDZ,reflecting the character of SDZ as a regional atmospheric background site in North China.The SO 2 concentrations of all three sites show a significant decrease from period before to after the control measures for the 2008 Olympic Games,suggesting that the SO 2 pollution control has long-term effectiveness and benefits.In the post-Olympics period,the mean concentrations of SO 2 at CMA,GCH,and SDZ are (14.3±11.0) ppb,(12.1±7.7) ppb,and (7.5±4.0) ppb,respectively,with reductions of 26%,36%,and 13%,respectively,compared to the levels before.Detailed analysis shows that the differences of temperature,relative humidity,wind speed,and wind direction were not the dominant factors for the significant differences of SO 2 between the pre-Olympics and post-Olympics periods.By extracting the data being more representative of local or regional characteristics,a reduction of up to 40% for SO 2 in polluted areas and a reduction of 20% for regional SO 2 are obtained for the effect of control measures implemented for the Olympic Games. | Weili Lin Xiaobin XU Zhiqiang Ma Huarong Zhao Xiwen Liu Ying Wang | 2012 | Journal of Environmental Sciences2012,24,1: | 15 |
| 5 | Chromosome-scale genome assembly provides insights into the evolution and flavor synthesis of passion fruit (Passiflora edulis Sims)显示文摘Passion fruit(Passiflora edulis Sims)is an economically valuable fruit that is cultivated in tropical and subtropical regions of the world.Here,we report an~1341.7Mb chromosome-scale genome assembly of passion fruit,with 98.91%(~1327.18Mb)of the assembly assigned to nine pseudochromosomes.The genome includes 23,171 protein-coding genes,and most of the assembled sequences are repetitive sequences,with long-terminal repeats(LTRs)being the most abundant.Phylogenetic analysis revealed that passion fruit diverged after Brassicaceae and before Euphorbiaceae.Ks analysis showed that two whole-genome duplication events occurred in passion fruit at 65 MYA and 12 MYA,which may have contributed to its large genome size.An integrated analysis of genomic,transcriptomic,and metabolomic data showed that‘alpha-linolenic acid metabolism’,‘metabolic pathways’,and‘secondary metabolic pathways’were the main pathways involved in the synthesis of important volatile organic compounds(VOCs)in passion fruit,and this analysis identified some candidate genes,including GDP-fucose Transporter 1-like,Tetratricopeptide repeat protein 33,protein NETWORKED 4B isoform X1,and Golgin Subfamily A member 6-like protein 22.In addition,we identified 13 important gene families in fatty acid pathways and eight important gene families in terpene pathways.Gene family analysis showed that the ACX,ADH,ALDH,and HPL gene families,especially ACX13/14/15/20,ADH13/26/33,ALDH1/4/21,and HPL4/6,were the key genes for ester synthesis,while the TPS gene family,especially PeTPS2/3/4/24,was the key gene family for terpene synthesis.This work provides insights into genome evolution and flavor trait biology and offers valuable resources for the improved cultivation of passion fruit. | Zhiqiang Xia Dongmei Huang Shengkui Zhang Wenquan Wang Funing Ma Bin Wu Yi Xu Bingqiang Xu Di Chen Meiling Zou Huanyu Xu Xincheng Zhou Rulin Zhan Shun Song | 2021 | Horticulture Research2021,8,1: | 15 |
| 6 | The Deep-Time Digital Earth program:data-driven discovery in geosciences显示文摘Current barriers hindering data-driven discoveries in deep-time Earth(DE)include:substantial volumes of DE data are not digitized;many DE databases do not adhere to FAIR(findable,accessible,interoperable and reusable)principles;we lack a systematic knowledge graph for DE;existing DE databases are geographically heterogeneous;a significant fraction of DE data is not in open-access formats;tailored tools are needed.These challenges motivate the Deep-Time Digital Earth(DDE)program initiated by the International Union of Geological Sciences and developed in cooperation with national geological surveys,professional associations,academic institutions and scientists around the world.DDE’s mission is to build on previous research to develop a systematic DE knowledge graph,a FAIR data infrastructure that links existing databases and makes dark data visible,and tailored tools for DE data,which are universally accessible.DDE aims to harmonize DE data,share global geoscience knowledge and facilitate data-driven discovery in the understanding of Earth’s evolution. | Chengshan Wang Robert MHazen Qiuming Cheng Michael HStephenson Chenghu Zhou Peter Fox Shu-zhong Shen Roland Oberhansli Zengqian Hou Xiaogang Ma Zhiqiang Feng Junxuan Fan Chao Ma Xiumian Hu Bin Luo Juanle Wang Craig M.Schiffries | 2021 | National Science Review2021,8,9: | 14 |
| 7 | Long Distance Transmission of SARS-CoV-2 from Contaminated Cold Chain Products to Humans——Qingdao City,Shandong Province,China,September 2020显示文摘Summary What is already known about this topic?Though coronavirus disease 2019(COVID-19)has largely been controlled in China,several outbreaks of COVID-19 have occurred from importation of cases or of suspected virus-contaminated products.Though several outbreaks have been traced to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)isolated on the outer packaging of cold chain products,live virus has not been obtained. | Huilai Ma Zhaoguo Wang Xiang Zhao Jun Han Yong Zhang Hong Wang Cao Chen Ji Wang Fachun Jiang Jie Lei Jingdong Song Shaofeng Jiang Shuangli Zhu Huihui Liu Dongyan Wang Yao Meng Naiying Mao Yanhai Wang Zhen Zhu Zhixiao Chen Bingling Wang Qinqin Song Haijun Du Qun Yuan Dong Xia Zhiqiang Xia Peipei Liu Yuchao Wu Zijian Feng Ruqin Gao George F.Gao Wenbo Xu | 2021 | China CDC weekly2021,3,30: | 13 |
| 8 | Marine Yeasts and Their Applications in Mariculture显示文摘The terrestrial yeasts have been receiving great attention in science and industry for over one hundred years because they can produce many kinds of bioactive substances. However, little is known about the bioactive substances of marine yeasts. In recent years, it has been found that marine yeasts have wide applications in mariculture and other fields. Therefore,marine yeasts, the bioactive substances from them and the applications of marine yeasts themselves and the bioactive substances they produced are reviewed in this paper. | CHI Zhenming LIU Zhiqiang GAO Lingmei GONG Fang MA Chunling WANG Xianghong LI Haifeng | 2006 | Journal of Ocean University of China2006,5,3: | 12 |
| 9 | Effects of sulfur fertilization and short-term high temperature on wheat grain production and wheat flour proteins显示文摘The content of wheat flour proteins affects the quality of wheat flour. Sulfur nutrition in wheat can change the protein content of the flour. The inconsistency and instability of wheat grain quality during grain filling under high temperature stress(HTS) are a major challenge to the production of high-quality wheat. The effects of sulfur fertilization and HTS on wheat flour protein and its components are unknown. In this study, treatments varying two factors: sulfur fertilization and exposure to short-term HTS, at 20 days postanthesis, were applied to two wheat cultivars with differing gluten types. Plants of a stronggluten wheat(Gaoyou 2018) and a medium-gluten wheat(Zhongmai 8) were grown in pots in Beijing in 2015–2017. HTS significantly increased the contents of total protein, albumin,gliadin, glutenin, Cys, and Met in wheat kernels, but reduced grain yield, grain weight,protein yield, globulin content, and total starch accumulation. The HTS-induced increase in total protein amount was closely associated with nitrate reductase(NR) and glutamine synthetase(GS) activities in flag leaves. Sulfur fertilization increased grain and protein yields; grain weight; total protein, albumin, gliadin, glutenin, and globulin contents; protein yield; total starch; Cys, Met; and NR and GS activities. HTS and sulfur fertilization had larger effects on the strong-than on the medium-gluten cultivar. Sulfur fertilization also alleviated the negative effects of HTS on grain yield, protein yield, and starch content.Thus, growing wheat with additional soil sulfur can improve the quality of the flour. | Zhiqiang Tao Xuhong Chang Demei Wang Yanjie Wang Shaokang Ma Yushuang Yang Guangcai Zhao | 2018 | The Crop Journal2018,6,4: | 11 |
| 10 | Characteristics of ozone vertical profile observed in the boundary layer around Beijing in autumn显示文摘In the autumn of 2008,the vertical profiles of ozone and meteorological parameters in the low troposphere (0-1000 m) were observed at two sites around Beijing,specifically urban Nanjiao and rural Shangdianzi.At night and early morning,the lower troposphere divided into two stratified layers due to temperature inversion.Ozone in the lower layer showed a large gradient due to the titration of NO.Air flow from the southwest brought ozone-rich air to Beijing,and the ozone profiles were marked by a continuous increase in the residual layer at night.The accumulated ozone in the upper layer played an important role in the next day's surface peak ozone concentration,and caused a rapid increase in surface ozone in the morning.Wind direction shear and wind speed shear exhibited different influences on ozone profiles and resulted in different surface ozone concentrations in Beijing. | Zhiqiang Ma Xiaoling Zhang Jing Xu xiujuan Zhao Wei Meng | 2011 | Journal of Environmental Sciences2011,23,8: | 11 |
| 11 | Nonlinear Dynamic Characteristic Analysis of the Shaft System in Water Turbine Generator Set显示文摘A 3D finite element vibration model of water turbine generator set is constructed considering the coupling with hydropower house foundation.The method of determining guide bearing dynamic characteristic coefficients according to the swing of the shaft is proposed, which can be used for studying the self-vibration characteristic and stability of the water turbine generator set.The method fully considers the complex supporting boundary and loading conditions;especially the nonlinear variation of guide bearing dynamic characteristic coefficients and the coupling effect of the whole power-house foundation.The swing and critical rotating speed of an actual generator set shaft system are calculated.The simulated results of the generator set indicate that the coupling vibration model and calculation method presented in this paper are suitable for stability analysis of the water turbine generator set. | MA Zhenyue SONG Zhiqiang | 2009 | Chinese Journal of Mechanical Engineering2009,22,1: | 10 |
| 12 | Analytical solutions for characteristic radii of circular roadway surrounding rock plastic zone and their application显示文摘In the non-uniform stress field, the surrounding rock plastic zone of the circular roadway shows different shapes under the different confining pressure conditions. Based on the boundary shape characteristics of the plastic zone, the characteristic radii of the plastic zone were proposed, namely the horizontal,longitudinal and medial axis radii, which could reflect the plastic zone shapes characteristics and classify the sizes of the key parts. On the theoretical basis of elastic-plastic mechanics, analytical solutions for the characteristic radii were obtained by theoretical deduction, and the relationships between the characteristic radii and key influencing factors were analyzed. Finally, the evaluation criterion of the circular roadway surrounding rock plastic zone shapes, evaluation criterion of the location of potential hazards caused by the roadway surrounding rock and evaluation critical points of roadway dynamic disasters based on characteristic radii were proposed. This work could provide a theoretical basis for stability analysis of the surrounding rock, support design, and guide the prevention and control of dynamic roadway disasters. | Xiaofei Guo Zhiqiang Zhao Xu Gao Xiangye Wu Nianjie Ma | 2019 | International Journal of Mining Science and Technology2019,29,2: | 9 |
| 13 | Zebrafish model for assessing induced organ toxicity by Strychnos nux-vomica显示文摘OBJECTIVE:To assess the acute organ toxicity of Strychnos nux-vomica with zebrafish model visually.METHODS:To assess acute toxicity,we initially determined the lethal concentration after Strychnos nux-vomica treatment for 24 h.Zebrafish was treated with five concentrations Strychnos nux-≦vo LC10 for 24 h,and the effects ofmica on morphology,function of heart,central nervous system,liver,kidney and organ-specific cell death were assessed.Next,we assessed the reversibility of toxic effect.RESULTS:Strychnos nux-vomica has an effect on the different organs of zebrafish,including heart,central nervous system,liver,and kidney,and cadiotoxicity induced by Strychnos nux-vomica was reversible to some extent.CONCLUSION:Zebrafish model is suitable for confirming the toxic target organs for Chinese traditional medicine. | Zhao Chongjun Tian Jinghuan Wang Jinfeng Feng Yaru Ni Yuanyuan Fan Jiaojiao Wang Chunmei Cao Dan Zou Qinwen Ma Zhiqiang Lin Ruichao | 2016 | Journal of Traditional Chinese Medicine2016,36,4: | 9 |
| 14 | Olmutinib(HM61713) reversed multidrug resistance by inhibiting the activity of ATPbinding cassette subfamily G member 2 in vitro and in vivo显示文摘Overexpressing of ATP-binding cassette(ABC) transporters is the essential cause of multidrug resistance(MDR), which is a significant hurdle to the success of chemotherapy in many cancers.Therefore, inhibiting the activity of ABC transporters may be a logical approach to circumvent MDR.Olmutinib is an epidermal growth factor receptor(EGFR) tyrosine kinase inhibitor(TKI), which has been approved in South Korea for advanced EGFR T790 M-positive non-small cell lung cancer(NSCLC). Here,we found that olmutinib significantly increased the sensitivity of chemotherapy drug in ABCG2-overexpressing cells. Furthermore, olmutinib could also increase the retention of doxorubicin(DOX) and rhodamine 123(Rho 123) in ABC transporter subfamily G member 2(ABCG2)-overexpressing cells. In addition, olmutinib was found to stimulate ATPase activity and inhibit photolabeling of ABCG2 with [^(125) I]-iodoarylazidoprazosin(IAAP). However, olmutinib neither altered ABCG2 expression at protein and m RNA levels nor blocked EGFR, Her-2 downstream signaling of AKT and ERK. Importantly,olmutinib enhanced the efficacy of topotecan on the inhibition of S1-MI-80 cell xenograft growth. All the results suggest that olmutinib reverses ABCG2-mediated MDR by binding to ATP bind site of ABCG2 and increasing intracellular chemotherapeutic drug accumulation. Our findings encouraged to further clinical investigation on combination therapy of olmutinib with conventional chemotherapeutic drugs in ABCG2-overexpressing cancer patients. | Zhiqiang Zhang Xiaoran Guo Kenneth K.W.To Zhen Chen Xiaona Fang Min Luo Chunling Ma Jianhua Xu Shirong Yan Liwu Fu | 2018 | Acta Pharmaceutica Sinica B2018,8,4: | 9 |
| 15 | Effects of tridimensional uniform sowing on water consumption, nitrogen use, and yield in winter wheat显示文摘Wheat is a staple crop worldwide, but yields may diminish as climate change causes increasingly unpredictable patterns of precipitation and soil nutrient availability. Farmers are thus challenged to maximize planting efficiency to increase yield, while also improving their resource use efficiency. In this study the effectiveness of tridimensional uniform sowing was tested across a range of planting densities for winter wheat crops on the North China Plain. Tridimensional uniform sowing was tested against conventional drilling at three planting densities (180 × 104, 270 × 104, and 360 × 104 plants ha 1) and assessed for water consumption, biomass, nitrogen uptake and allocation, and aspects of yield. The tridimensional uniform sowing treatment outperformed the conventional drilling treatment in most metrics and at most planting densities, while performing markedly better at higher planting densities. Water consumption decreased and nitrogen efficiency increased. Tiller number and percentage of productive tillers, leaf area index, dry weight, and yield increased without a significant decline in grain protein. Nitrogen allocation was more efficient under tridimensional uniform sowing than with conventional drilling, and also varied according to annual precipitation and planting density. Both yield and grain protein contents were significantly correlated with the amount of pre-anthesis accumu- lated nitrogen translocated from vegetative organs to kernels after anthesis. Overall, a density of 270 × 104 plants ha 1 provided the highest water use efficiency and grain yield. Tridimensional uniform sowing will benefit farmers by forming stronger overall crops, promoting the coordinated improvement of yield, nitrogen uptake and efficiency, and increasing grain protein content at higher planting densities. | Zhiqiang Tao Shaokang Ma Xuhong Chang Demei Wang Yanjie Wang Yushuang Yang Guangcai Zhao Jiancang Yang | 2019 | The Crop Journal2019,7,4: | 8 |
| 16 | Differences between onset times of bursty bulk flows (BBFs) of two Cluster satellites in the magnetotail显示文摘This paper using the dataset of BBFs (bursty bulk flows) observed by two Cluster satellites C1 and C4 studies the difference between onset times of BBFs observed by C1 and C4. It is found that the onset time differences of most of BBFs observed by C1 and C4 are smaller than 60 s. The average onset time difference of BBFs of C1 and C4 is 68.5 s. The probabilities of onset time difference of BBFs of C1 and C4 larger than 30 60 90 and 120 s are respectively 55% 35% 27% and 23%. The largest onset time difference of BBFs of C1 and C4 decreases with the increase of earthward component of maximum velocities of BBFs. The onset time difference of BBFs of C1 and C4 results from the velocity inhomogeneity inside the flow channel of BBF which may be produced in propagation path and/or in source region of BBFs. Such a wide range of onset time difference of BBFs suggests that the velocity inhomogeneity inside the flow channel of BBF is various. These results are very important to the current study of substorm research based on THEMIS data because they indicate that it is impossible to determine the onset time of BBF with a single satellite. | CAO JinBin WANG ZhiQiang MA YuDuan CAI CunLin | 2012 | Science China(Technological Sciences)2012,55,5: | 8 |
| 17 | Long-term variations of solar activity显示文摘Using the Lomb-Scargle periodogram we analyzed two sunspot series: the one over the past 11000 years at the 10-year interval based upon the survey data of 14C concentration in tree-rings, recon- structed by Solanki et al.; and the sunspot number over the past 7000 years, derived from geomagnetic variations by Usoskin et al. We found the periods and quasi-periods in solar activity, such as about 225, 352, 441, 522 and 561 a, and near 1000 and 2000 a. An approach of wavelet transform was applied to check the two sunspot time series, with emphasis on investigating time-varying characteristics in the long-term fluctuations of solar activity. The results show that the lengths and amplitudes of the periods have changed with time, and large variations have taken place during some periods. | YIN ZhiQiang MA LiHua HAN YanBen HAN YongGang | 2007 | Chinese Science Bulletin2007,52,20: | 8 |
| 18 | Cancer nanotechnology: Enhancing tumor cell response to chemotherapy for hepatocellular carcinoma therapy显示文摘Hepatocellular carcinoma(HCC)is one of the deadliest cancers due to its complexities,reoccurrence after surgical resection,metastasis and heterogeneity.In addition to sorafenib and lenvatinib for the treatment of HCC approved by FDA,various strategies including transarterial chemoembolization,radiotherapy,locoregional therapy and chemotherapy have been investigated in clinics.Recently,cancer nanotechnology has got great attention for the treatment of various cancers including HCC.Both passive and active targetings are progressing at a steady rate.Herein,we describe the lessons learned from pathogenesis of HCC and the understanding of targeted and non-targeted nanoparticles used for the delivery of small molecules,monoclonal antibodies,miRNAs and peptides.Exploring current efficacy is to enhance tumor cell response of chemotherapy.It highlights the opportunities and challenges faced by nanotechnologies in contemporary hepatocellular carcinoma therapy,where personalized medicine is increasingly becoming the mainstay.Overall objective of this review is to enhance our understanding in the design and development of nanotechnology for treatment of HCC. | Yongbing Sun Wen Ma Yuanyuan Yang Mengxue He Aimin Li Lei Bai Bin Yu Zhiqiang Yu | 2019 | Asian Journal of Pharmaceutical Sciences2019,14,6: | 8 |
| 19 | Partitioning characteristics of gas channel of coal-rock mass in mining space and gas orientation method显示文摘In order to research the influence of coal-rock mass morphology of mining space on the flow law of gas,the laboratory physical model and numerical computation methods were adopted to simulate coal mining activities.The simulation results indicate that,after coal seam mining,the loose rock accumulation body of free caving,ordered rock arrangement body of plate damage rich in longitudinal and transverse fractures and horizontal fissure body formed by rock mass deformation imbalance are formed from bottom to top in the mining space.For these three types of accumulation bodies,there are essential differences in the accumulation state,rock size and gas breakover characteristics.According to this,the coal-rock mass in the mining space is classified into gas turbulence channel area,gas transitional flow channel area and gas seepage channel area.In the turbulence channel area,the gas is distributed transversely and longitudinally and gas diffuses in the form of convection with Reynolds number R_e more than100;in the transitional flow channel area,one-way or two-way gas channels are crisscross and gas is of transitional flow regime with R,.between 10 and 100.In the seepage channel area,there are a few vertical gas channels with R,.less than 10.In this paper,the researches on the gas orientation method in different partitions were further carried out,gas orientation methods of low-level pipe burying,middle-level interception and high-level extraction were determined and an on-site industrial test was conducted,achieving the effective diversion of gas and verifying the reasonableness of gas channel partition. | Zhao Zhiqiang Ma Nianjie Jia Housheng Cheng Yuanping | 2013 | International Journal of Mining Science and Technology2013,23,6: | 8 |
| 20 | Crack behavior in Mg/Al alloy thin sheet during hot compound extrusion显示文摘A novel and effective method to co-extrude metallic alloys is described which named Direct Extrusion and Bending-Shear Deformation.The compound extrusion plates have cracked at 290℃ and 3 mm/s.According to this phenomenon,a model was built to investigate the crack generation and development between the 6061 Al and AZ31 Mg alloy during the compound extrusion process by DEFORM-3D.The cracking behavior of the Mg/Al composite rod with a soft Mg AZ31 core and a hard Al 6061 sleeve were systematically studied to disclose the influence of microstructure on crack in the different regions.The simulation results show that the distribution of strain and velocity has significant differences due to the influence of dies structure and material properties at different locations in the same region.The experimental results show that in the same conditions,there are differences in recrystallization and texture weakening of AZ31 Mg alloys and 6061 Al alloy,which are important factors for the formation of crack.Both the Mg layer and the Al layer have a homogeneous microstructure in the region d. | Kun Sheng Liwei Lu Yao Xiang Min Ma Zhiqiang Wu | 2019 | Journal of Magnesium and Alloys2019,7,4: | 8 |