Nanopipette based scanning probe technique is a versatile tool in non-contact imaging in biology.In addition to the topographic imaging,its capability of localized delivery of bio-active molecules is emerging.In this ...Nanopipette based scanning probe technique is a versatile tool in non-contact imaging in biology.In addition to the topographic imaging,its capability of localized delivery of bio-active molecules is emerging.In this mini review,we introduce the applications of nanopipette in single-cell researches with a focus on localized delivery.The working principles of three delivery modes including resistive pulse,pressure-driven flow,and electroosmotic flow-driven delivery are summarized and compared.Their applications in single-cell researches are reviewed.The current technical challenges in scanning ion conductance microscopy-based delivery,and their growing influence in medicine and pharmacologic researches are also discussed.展开更多
Based on the helix rotating screen and the digital micro-mirror device （DMD）, the former proto of volumetric-swept display system is improved. The 3-D display system adopting a helix rotating screen to construct an ...Based on the helix rotating screen and the digital micro-mirror device （DMD）, the former proto of volumetric-swept display system is improved. The 3-D display system adopting a helix rotating screen to construct an imaging space meliorate the defects, such as the smaller image space, the fewer voxels and the severer voxel overlap dead zone caused by planar rotating screen. DMD with spatial light modular （SLM） technology increases the transmission bandwidth of 3-D data in the voxel activation subsystem and activate multi-voxel once time. The volumetric-swept system based on helix rotating screen and DMD is developed. The experimental results show that the image space, the vision dead zone, the voxels on slice, and the voxel activation capacity of the designed proto are superior to the plane rotating screen system.展开更多
The 2,5-bis（ethyldisulfanyl）-l,3,4-thiadiazole （T561）, benzotriazole （BTA）,1-N, N-bis （2-ethylhexyl） aminomethyl-4-methyl-lh-benzotriazole （IRGAMET39） and I-IN, N-bis （2-ethylhexyl） aminomethyl] methyl ben...The 2,5-bis（ethyldisulfanyl）-l,3,4-thiadiazole （T561）, benzotriazole （BTA）,1-N, N-bis （2-ethylhexyl） aminomethyl-4-methyl-lh-benzotriazole （IRGAMET39） and I-IN, N-bis （2-ethylhexyl） aminomethyl] methyl benzotriazole （TT- LX） have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefficient of friction increased by 35.6% and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy （SEM） and energy dispersive spectrometry （EDS） analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confocal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.展开更多
Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy dem...Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy demands of modern civilization. However, due to ItS high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combus- tion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid （HF） concentration （10-20% by vo!ume ）,. temper- ature （60-100 ~C）, and time （90-180 min）, for ash reduction from the low-grade coal was Investigated.. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design （CC.D）method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temper- ature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy （FTIR） analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray （FESEM- EDX） analysis for confirmation of the ash reduction.展开更多
Objective To assese the healing of stoma after magnetic anastomosis for the reconstruction of biliary-enteric continuity under severe inflammation. Methods Acute bile duct injury was constructed as a bile peritonitis ...Objective To assese the healing of stoma after magnetic anastomosis for the reconstruction of biliary-enteric continuity under severe inflammation. Methods Acute bile duct injury was constructed as a bile peritonitis model in mongrel dogs(n=32). Magnetic anastomosis(group A, n=16) and traditional suture anastomosis(group B, n=16) were performed to reconstruct the biliary-enteric continuity in one stage. Half of the dogs in each group were euthanized on the 30 th postoperative day, and the other half on the 90 th postoperative day to harvest the stoma region. The healing conditions of the stoma after the 2 anastomotic approaches were observed with naked eyes, under light microscope and scanning electron microscope. Results The stoma leakage rate(50% versus 0% on the 30 th postoperative day, 37.5% versus 12.5% on the 90 th postoperative day, both P<0.05) and stenosis degree(13.9%±0.3% versus 7.1%±0.3% on the 30 th postoperative day, 17.2%±0.4% versus 9.4%±0.4% on the 90 th postoperative day, both P<0.01) were significantly higher in group B than in group A. Compared with traditional manual anastomoses, the histological analysis under light and electron microscope showed a more continuous stoma with more regular epithelium proliferation and collagen arrangement, less inflammation in group A. Conclusions Magnetic anastomosis stent ensures better healing of the stoma even under the circumstance of severe inflammation.展开更多
Anthracite in Jincheng is a highly metamorphic coal and its system of fissures and pores is differentfrom that of low and medium ranked coal.In order to discover their characteristics,69 samples were collected from 18...Anthracite in Jincheng is a highly metamorphic coal and its system of fissures and pores is differentfrom that of low and medium ranked coal.In order to discover their characteristics,69 samples were collected from 18 CBM wells in Zhengzhuang in Jincheng and their fissures and pores were observed by a Scanning Electron Microscope(SEM).To the naked eyes and by SEM,the pores in the Jincheng anthracite are seen to have abundant mold pores with isolated,shallow and poor connectivity(diameters between 1～50 μm) and few plant tissue pores,gas pores,and solution pores.Most of the fissures are filled with clay minerals or closed;while open fissures are not often visible in the Jincheng coal(aperture between 3～10 μm).These characteristics are determined by the high rank and high vitrinite content of the coal.The existence of too many mold pores and filled fissures does not allow the migration of methane,hence hydraulic fracture stimulation will be required and is an effective method of adding and connecting fissures to enhance CBM production.展开更多
Biodiesel soot （BDS） was collected from the combustion of biodiesel using a self-made soot trap. The effect of BDS on the txibological behavior of liquid paraffin （LP） was investigated using a four-ball txibometer...Biodiesel soot （BDS） was collected from the combustion of biodiesel using a self-made soot trap. The effect of BDS on the txibological behavior of liquid paraffin （LP） was investigated using a four-ball txibometer. A rotating viscometer was used to investigate the effect of BDS on the viscosity of LE The morphology, composition, and tribological mechanism of BDS were studied by means of FETEM, XRD, XPS, SEM/EDS, and the 3D laser scanning microscopy. Test results showed that the BDS aggregates were chain-like, and the average diameter of BDS was 35 nm. The BDS existed in the form of graphitic layers and amorphous carbon. The oxygen-containing functional groups in BDS consisted of the （C-O-C） and （C-O-H）. With an increasing BDS content, the dynamic viscosity of LP increased and the maximum non-seizure load increased initially and became stable later. In addition, the average wear scar diameter （AWSD） of LP increased and the average friction coefficient of LP decreased at first and then increased later. The tribological mechanisms could be ascribed to the variation in content of BDS： BDS could act as a friction modifier for a lower friction coefficient in case of low BDS content. However, the BDS aggregates could lead to increase of abrasive wear to influence the lubricating oil film at higher content of BDS, which would reduce the friction reduction ability and wear resistance of LP.展开更多
In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatm...In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.展开更多
For deep mining engineering, heat transfer of coal mass is a vital factor in the thermal environment of coal mines. In order to study the thermal conduction mechanism, we obtained gray images of coal mass microstructu...For deep mining engineering, heat transfer of coal mass is a vital factor in the thermal environment of coal mines. In order to study the thermal conduction mechanism, we obtained gray images of coal mass microstructure by scanning samples with a digital microscope. With the use of Matlab, these gray images were transformed into binary images, which were then transformed into a corresponding matrix consisting only of the values 0 and 1. According to the calculation method of box-counting dimension, we calculated the fractal dimension of the loose coal to be approximately 1.86. The thermal conductivity expressions of loose coal were derived based on the simulation method of thermal resistance. We calculated the thermal conductivity of loose coal by using a fractal model and compared the calculated values with our experimental data. The results show that the test data show an encourag-ing agreement with the calculated values. Hence fractal theory is a feasible method for studying thermal conductivity of loose coal.展开更多
Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits wi...Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.展开更多
Potassium humate was extracted from brown coal. A novel super absorbent composite, poly （acrylic acid-co-acryla- mide）/potassium humate （PAA-AM/KHA）, was prepared by graft polymerization of acrylic acid, acrylamid...Potassium humate was extracted from brown coal. A novel super absorbent composite, poly （acrylic acid-co-acryla- mide）/potassium humate （PAA-AM/KHA）, was prepared by graft polymerization of acrylic acid, acrylamide and coal based potassium humate using N, N＇-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator. The effects of reaction temperature, degree of neutralization of the poly （acrylic acid） and the amounts of crosslinker, initiator and potassium humate were investigated. Salt resistance tests were also carded out. The composite prepared under optimal conditions had a potassium bumate content of 10% and exhibited a water absorption of 770 g/g in distilled water, and 349, 286 and 41 gig in 0.5 mol/L KC1, MgC12 and A1CI3 solutions respectively. The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly （acrylic acid-co-acrylamide） because of the collaborative effect of functional groups of the coal based potassium humate. The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy. Introduction of potassium humate into the poly （acrylic acid-co-acrylamide） structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments. The salt resisting property of the composite is improved, production costs are reduced and the growth stimulant effect is still present.展开更多
In our study we investigated a refractory copper-nickel sulfide ore separation by using a cyclonic-static micro-bubble flotation column (FCSMC). The process mineralogy of the main products was studied. Using a scannin...In our study we investigated a refractory copper-nickel sulfide ore separation by using a cyclonic-static micro-bubble flotation column (FCSMC). The process mineralogy of the main products was studied. Using a scanning electron microscope-energy dispersive system (SEM-EDS) and an X-ray spectrometer the mineral category and content of samples were analyzed. By using a mineral liberation analyzer (MLA) the mineral liberation characteristics were revealed. It is shown that in roughing feed the monomers liberation degree of nickel pyrite and chalcopyrite take up 84.11% and 88.82%, respectively. In tailings, the lost nickel pyrite and chalcopyrite are mainly monomers. Therefore, strengthening the micro-fine particle recovery capacity is the key to increase recovery.展开更多
In order to investigate the characteristics of re-oxidation of residual coal in goafs in close coal seam mining,scanning electron microscope and infrared spectrometer are used to study the changes of coal microstructu...In order to investigate the characteristics of re-oxidation of residual coal in goafs in close coal seam mining,scanning electron microscope and infrared spectrometer are used to study the changes of coal microstructure and chemical reaction of functional groups of eight coal samples at different ranks.Result shows that after initial oxidation,the surface morphology of pore are different,and the porosity of coal is increased and the oxygen adsorption capacity of coal is improved.The change of coal molecular structure and presence of a large amount of active oxygen-containing functional groups lead to increasing tendency of coal to further oxidation.In addition,the higher lever of the initial oxidation is,the easier the re-oxidation occurs.展开更多
The mesoporous materials supported zirconium （Zr-MCM-48） and magnesium （Mg-MCM-48） with three-dimen- sional pore structures and different Zr or Mg contents were prepared via the hydrothermal method, respectively. ...The mesoporous materials supported zirconium （Zr-MCM-48） and magnesium （Mg-MCM-48） with three-dimen- sional pore structures and different Zr or Mg contents were prepared via the hydrothermal method, respectively. The prepared samples were characterized by means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, Fourier transform infrared spectroscopy （FT-IR）, NH3 temperature programmed desorption （NH3-TPD） and N2 adsorption-desorption. The XRD, TEM and N2 adsorption-desorption results suggested that M-MCM-48 （where M = Zr, Mg） samples still maintained typical cubic mesoporous framework of MCM-48, with slight decrease of specific surface areas and mesopore orders. The isomerization of n-heptane was carried out as a probe reaction at various factors including the zirconium or magnesium content, reaction time, reaction temperature and weight hourly space veloc- ity （WHSV）. Preliminary results demonstrated that the Mg-MCM-48 catalyst exhibited a higher catalytic activity with a maximum heptane conversion of 91.5% and a corresponding isomerization selectivity of 72.3% as compared to that of Zr- MCM-48. However, for catalytic stability of Mg-MCM-48 for n-heptane isomerization was poorer than Zr-MCM-48, because the Mg-MCM-48 catalyst could maintain a relatively high catalytic activity for only 130 rain, while the Zr-MCM-48 catalyst could maintain a relatively high catalytic activity for more than 190 min without any obvious decrease in performance.展开更多
Tungsten film(W film) is deposited by using the ion beam assisted deposition(IBAD) on the 316 L substrate surface in this experiment. The micro structure and nano-hardness of the film are investigated by scanning elec...Tungsten film(W film) is deposited by using the ion beam assisted deposition(IBAD) on the 316 L substrate surface in this experiment. The micro structure and nano-hardness of the film are investigated by scanning electron microscopy(SEM) and nano-indentation tester. The tribological behavior of W film under lubrication by oil with ZDDP and MoDTC is evaluated by a SRV test machine. The tribo-film formed on the worn surfaces is investigated by X-ray photoelectron spectroscopy(XPS) to find out the tribological mechanisms between the W film and the two additional additives. The result shows that the W film lubricated by ZDDP and MoDTC-blended base oil has synergistic effects on the friction reduction property, while the anti-wear property is mainly caused by the hard surface of W film.展开更多
The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 1...The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 100 ℃ for 120 h,respectively,and then the thermal and hydrothermal stability of Al-SBA-15 sample was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and nitrogen adsorption and desorption techniques.The Al-SBA-15 sample was also studied by 27 Al nuclear magnetic resonance (27 Al NMR) and ammonia temperature programmed desorption (NH 3-TPD) techniques.In addition,the catalytic activity of Al-SBA-15 zeolite was investigated by the Friedel-Crafts reactions of 2,4-di-tert-butylphenol with cinnamyl alcohol.The test results showed that the thermal and hydrothermal stability of Al-SBA-15 zeolite was better than that of SBA-15 zeo-lite.The Al-SBA-15 zeolite sample prepared by impregnation method exhibits more framework aluminum species and Al-O-Si units.Therefore,the number of the surface hydroxyl groups was reduced,resulting in the stabilization of framework structure ofAl-SBA-15 zeolite.The aluminum species can form weak and medium-strong acid sites with catalytic activity.展开更多
基金support from the National Institute of General Medical Sciences(1R35G M147172-01).
文摘Nanopipette based scanning probe technique is a versatile tool in non-contact imaging in biology.In addition to the topographic imaging,its capability of localized delivery of bio-active molecules is emerging.In this mini review,we introduce the applications of nanopipette in single-cell researches with a focus on localized delivery.The working principles of three delivery modes including resistive pulse,pressure-driven flow,and electroosmotic flow-driven delivery are summarized and compared.Their applications in single-cell researches are reviewed.The current technical challenges in scanning ion conductance microscopy-based delivery,and their growing influence in medicine and pharmacologic researches are also discussed.
基金Supported by the National High Technology Research and Development Program of China(″863″Program)(2007AA01Z338)the National Science Foundation for Post-doctoral Scientists of China(20080441051)the Jiangsu Province Science Foundation for Post-doctoral Scientists(0802014c)~~
文摘Based on the helix rotating screen and the digital micro-mirror device （DMD）, the former proto of volumetric-swept display system is improved. The 3-D display system adopting a helix rotating screen to construct an imaging space meliorate the defects, such as the smaller image space, the fewer voxels and the severer voxel overlap dead zone caused by planar rotating screen. DMD with spatial light modular （SLM） technology increases the transmission bandwidth of 3-D data in the voxel activation subsystem and activate multi-voxel once time. The volumetric-swept system based on helix rotating screen and DMD is developed. The experimental results show that the image space, the vision dead zone, the voxels on slice, and the voxel activation capacity of the designed proto are superior to the plane rotating screen system.
基金financially supported by the National Natural Science Foundation of China (No.51274037)the Key Science and Technology Project of China (No.2011BAE23B00)the Cooperation Program between USTB and SINOPEC (No.112116)
文摘The 2,5-bis（ethyldisulfanyl）-l,3,4-thiadiazole （T561）, benzotriazole （BTA）,1-N, N-bis （2-ethylhexyl） aminomethyl-4-methyl-lh-benzotriazole （IRGAMET39） and I-IN, N-bis （2-ethylhexyl） aminomethyl] methyl benzotriazole （TT- LX） have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefficient of friction increased by 35.6% and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy （SEM） and energy dispersive spectrometry （EDS） analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confocal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.
文摘Coal is the world＇s most abundant energy source because of its abundance and relatively low cost. Due to the scarcity in the supply of high-grade coal, it is necessary to use low-.grade coal for fulfilling energy demands of modern civilization. However, due to ItS high ash and moisture content, low-grade coal exerts the substantial impact on their consumption like pyrolysis, liquefaction, gasification and combus- tion process. The present research aimed to develop the efficient technique for the production of clean coal by optimizing the operating parameters with the help of response surface methodology. The effect of three independent variables such as hydrofluoric acid （HF） concentration （10-20% by vo!ume ）,. temper- ature （60-100 ~C）, and time （90-180 min）, for ash reduction from the low-grade coal was Investigated.. A quadratic model was proposed to correlate the independent variables for maximum ash reduction at the optimum process condition by using central composite design （CC.D）method. The study reveals that HF concentration was the most effective parameter for ash reduction in comparison with time and temper- ature. It may be due to the higher F-statistics value for HF concentration, which effects to large extent of ash reduction. The characterization of coal was evaluated by Fourier transform infrared spectroscopy （FTIR） analysis and Field-emission scanning electron microscopy with energy-dispersive X-ray （FESEM- EDX） analysis for confirmation of the ash reduction.
基金Supported by the National Natural Science Foundation of China(30830099)China Postdoctoral Science Foundation(20100481341)Scienceand Technology Research and Development Project of Shaanxi Province(2009K14-01)
文摘Objective To assese the healing of stoma after magnetic anastomosis for the reconstruction of biliary-enteric continuity under severe inflammation. Methods Acute bile duct injury was constructed as a bile peritonitis model in mongrel dogs(n=32). Magnetic anastomosis(group A, n=16) and traditional suture anastomosis(group B, n=16) were performed to reconstruct the biliary-enteric continuity in one stage. Half of the dogs in each group were euthanized on the 30 th postoperative day, and the other half on the 90 th postoperative day to harvest the stoma region. The healing conditions of the stoma after the 2 anastomotic approaches were observed with naked eyes, under light microscope and scanning electron microscope. Results The stoma leakage rate(50% versus 0% on the 30 th postoperative day, 37.5% versus 12.5% on the 90 th postoperative day, both P<0.05) and stenosis degree(13.9%±0.3% versus 7.1%±0.3% on the 30 th postoperative day, 17.2%±0.4% versus 9.4%±0.4% on the 90 th postoperative day, both P<0.01) were significantly higher in group B than in group A. Compared with traditional manual anastomoses, the histological analysis under light and electron microscope showed a more continuous stoma with more regular epithelium proliferation and collagen arrangement, less inflammation in group A. Conclusions Magnetic anastomosis stent ensures better healing of the stoma even under the circumstance of severe inflammation.
基金supported by the National Basic Research Program of China (No.2006CB202200)
文摘Anthracite in Jincheng is a highly metamorphic coal and its system of fissures and pores is differentfrom that of low and medium ranked coal.In order to discover their characteristics,69 samples were collected from 18 CBM wells in Zhengzhuang in Jincheng and their fissures and pores were observed by a Scanning Electron Microscope(SEM).To the naked eyes and by SEM,the pores in the Jincheng anthracite are seen to have abundant mold pores with isolated,shallow and poor connectivity(diameters between 1～50 μm) and few plant tissue pores,gas pores,and solution pores.Most of the fissures are filled with clay minerals or closed;while open fissures are not often visible in the Jincheng coal(aperture between 3～10 μm).These characteristics are determined by the high rank and high vitrinite content of the coal.The existence of too many mold pores and filled fissures does not allow the migration of methane,hence hydraulic fracture stimulation will be required and is an effective method of adding and connecting fissures to enhance CBM production.
基金supported by the National Natural Science Foundation of China (Grant No. 51675153)the Major Science and Technology Special Project in Anhui (Grant No.17030901084)
文摘Biodiesel soot （BDS） was collected from the combustion of biodiesel using a self-made soot trap. The effect of BDS on the txibological behavior of liquid paraffin （LP） was investigated using a four-ball txibometer. A rotating viscometer was used to investigate the effect of BDS on the viscosity of LE The morphology, composition, and tribological mechanism of BDS were studied by means of FETEM, XRD, XPS, SEM/EDS, and the 3D laser scanning microscopy. Test results showed that the BDS aggregates were chain-like, and the average diameter of BDS was 35 nm. The BDS existed in the form of graphitic layers and amorphous carbon. The oxygen-containing functional groups in BDS consisted of the （C-O-C） and （C-O-H）. With an increasing BDS content, the dynamic viscosity of LP increased and the maximum non-seizure load increased initially and became stable later. In addition, the average wear scar diameter （AWSD） of LP increased and the average friction coefficient of LP decreased at first and then increased later. The tribological mechanisms could be ascribed to the variation in content of BDS： BDS could act as a friction modifier for a lower friction coefficient in case of low BDS content. However, the BDS aggregates could lead to increase of abrasive wear to influence the lubricating oil film at higher content of BDS, which would reduce the friction reduction ability and wear resistance of LP.
基金the state on behalf of the Ministry of Education and Science of the Russian Federation of the Agreement (No. 14.577.21.0111 (22 September 2014))The unique identifier of the applied research (No. RFMEFI57714X0111)
文摘In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.
基金support for this study, provided by the National Natural Science Foundation of China (Nos50534040 and 50974117)the Research Fund of the State Key Laboratory of Coal Resources & Mine Safety, CUMT (No07KF10)
文摘For deep mining engineering, heat transfer of coal mass is a vital factor in the thermal environment of coal mines. In order to study the thermal conduction mechanism, we obtained gray images of coal mass microstructure by scanning samples with a digital microscope. With the use of Matlab, these gray images were transformed into binary images, which were then transformed into a corresponding matrix consisting only of the values 0 and 1. According to the calculation method of box-counting dimension, we calculated the fractal dimension of the loose coal to be approximately 1.86. The thermal conductivity expressions of loose coal were derived based on the simulation method of thermal resistance. We calculated the thermal conductivity of loose coal by using a fractal model and compared the calculated values with our experimental data. The results show that the test data show an encourag-ing agreement with the calculated values. Hence fractal theory is a feasible method for studying thermal conductivity of loose coal.
基金This project was supported by the National Scientific Committee(969202011), the Natural Science Foundation of Hubei Province(99J
文摘Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.
基金supports from the fundamental research funds for central universities and the National Nature Science Foundation of China (No2010-2012)
文摘Potassium humate was extracted from brown coal. A novel super absorbent composite, poly （acrylic acid-co-acryla- mide）/potassium humate （PAA-AM/KHA）, was prepared by graft polymerization of acrylic acid, acrylamide and coal based potassium humate using N, N＇-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator. The effects of reaction temperature, degree of neutralization of the poly （acrylic acid） and the amounts of crosslinker, initiator and potassium humate were investigated. Salt resistance tests were also carded out. The composite prepared under optimal conditions had a potassium bumate content of 10% and exhibited a water absorption of 770 g/g in distilled water, and 349, 286 and 41 gig in 0.5 mol/L KC1, MgC12 and A1CI3 solutions respectively. The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly （acrylic acid-co-acrylamide） because of the collaborative effect of functional groups of the coal based potassium humate. The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy. Introduction of potassium humate into the poly （acrylic acid-co-acrylamide） structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments. The salt resisting property of the composite is improved, production costs are reduced and the growth stimulant effect is still present.
基金Projects 2008BAB31B01 supported by the National Key Technology R&D Program in the 11th Five-Year Plan of China50834006 by the National Natural Science Foundation of China
文摘In our study we investigated a refractory copper-nickel sulfide ore separation by using a cyclonic-static micro-bubble flotation column (FCSMC). The process mineralogy of the main products was studied. Using a scanning electron microscope-energy dispersive system (SEM-EDS) and an X-ray spectrometer the mineral category and content of samples were analyzed. By using a mineral liberation analyzer (MLA) the mineral liberation characteristics were revealed. It is shown that in roughing feed the monomers liberation degree of nickel pyrite and chalcopyrite take up 84.11% and 88.82%, respectively. In tailings, the lost nickel pyrite and chalcopyrite are mainly monomers. Therefore, strengthening the micro-fine particle recovery capacity is the key to increase recovery.
基金the National Key Foundation for Exploring Scientific Instruments of China(No.2012YQ24012705)the National Natural Science Foundation of China(No.51174113)+2 种基金the special fund for Scientific Research Institutes of China(Nos.2013EG122192 and 2014EG122293)CCTEG Innovation Foundation of China(No. 2014MS030)Shenhua Innovation Foundation of China(No. SHGF-13-07)
文摘In order to investigate the characteristics of re-oxidation of residual coal in goafs in close coal seam mining,scanning electron microscope and infrared spectrometer are used to study the changes of coal microstructure and chemical reaction of functional groups of eight coal samples at different ranks.Result shows that after initial oxidation,the surface morphology of pore are different,and the porosity of coal is increased and the oxygen adsorption capacity of coal is improved.The change of coal molecular structure and presence of a large amount of active oxygen-containing functional groups lead to increasing tendency of coal to further oxidation.In addition,the higher lever of the initial oxidation is,the easier the re-oxidation occurs.
基金supported by the postdoctoral programme for chemical engineering and technology of Northeast Petroleum Universitythe Youth Fund of Northeast Petroleum University(grant number NEPUQN2015-1-08)+2 种基金the Cultivation Fund of Northeast Petroleum University [grant number 2017PYYL-03]the Daqing Science and Technology Plan Projects [grant number szdfy-2015-04]the College Students’ Innovative Entrepreneurial Training Plan Projects of Heilongjiang Province [grant number 201710220030]
文摘The mesoporous materials supported zirconium （Zr-MCM-48） and magnesium （Mg-MCM-48） with three-dimen- sional pore structures and different Zr or Mg contents were prepared via the hydrothermal method, respectively. The prepared samples were characterized by means of X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, Fourier transform infrared spectroscopy （FT-IR）, NH3 temperature programmed desorption （NH3-TPD） and N2 adsorption-desorption. The XRD, TEM and N2 adsorption-desorption results suggested that M-MCM-48 （where M = Zr, Mg） samples still maintained typical cubic mesoporous framework of MCM-48, with slight decrease of specific surface areas and mesopore orders. The isomerization of n-heptane was carried out as a probe reaction at various factors including the zirconium or magnesium content, reaction time, reaction temperature and weight hourly space veloc- ity （WHSV）. Preliminary results demonstrated that the Mg-MCM-48 catalyst exhibited a higher catalytic activity with a maximum heptane conversion of 91.5% and a corresponding isomerization selectivity of 72.3% as compared to that of Zr- MCM-48. However, for catalytic stability of Mg-MCM-48 for n-heptane isomerization was poorer than Zr-MCM-48, because the Mg-MCM-48 catalyst could maintain a relatively high catalytic activity for only 130 rain, while the Zr-MCM-48 catalyst could maintain a relatively high catalytic activity for more than 190 min without any obvious decrease in performance.
基金the Beijing Natural Science Foundation (3132023)the National Natural Science Foundation of China (51275494 and 51005218)+1 种基金the Fundamental Research Funds for the Central Universities (2652012115 and 2652013081)the Tribology Science Fund of State Key Laboratory of Tribology (SKLTKF13B10) for their financial support to this research
文摘Tungsten film(W film) is deposited by using the ion beam assisted deposition(IBAD) on the 316 L substrate surface in this experiment. The micro structure and nano-hardness of the film are investigated by scanning electron microscopy(SEM) and nano-indentation tester. The tribological behavior of W film under lubrication by oil with ZDDP and MoDTC is evaluated by a SRV test machine. The tribo-film formed on the worn surfaces is investigated by X-ray photoelectron spectroscopy(XPS) to find out the tribological mechanisms between the W film and the two additional additives. The result shows that the W film lubricated by ZDDP and MoDTC-blended base oil has synergistic effects on the friction reduction property, while the anti-wear property is mainly caused by the hard surface of W film.
文摘The mesoporous Al-SBA-15 zeolite was obtained via impregnation of pure silica-based SBA-15 zeolite with aluminum nitrate.The Al-SBA-15 sample was calcined in air at 800 ℃ for 6 h and hydrothermally treated at near 100 ℃ for 120 h,respectively,and then the thermal and hydrothermal stability of Al-SBA-15 sample was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and nitrogen adsorption and desorption techniques.The Al-SBA-15 sample was also studied by 27 Al nuclear magnetic resonance (27 Al NMR) and ammonia temperature programmed desorption (NH 3-TPD) techniques.In addition,the catalytic activity of Al-SBA-15 zeolite was investigated by the Friedel-Crafts reactions of 2,4-di-tert-butylphenol with cinnamyl alcohol.The test results showed that the thermal and hydrothermal stability of Al-SBA-15 zeolite was better than that of SBA-15 zeo-lite.The Al-SBA-15 zeolite sample prepared by impregnation method exhibits more framework aluminum species and Al-O-Si units.Therefore,the number of the surface hydroxyl groups was reduced,resulting in the stabilization of framework structure ofAl-SBA-15 zeolite.The aluminum species can form weak and medium-strong acid sites with catalytic activity.
