A method of improving the accuracy of laser pulse range finding from ±10 m to ±1 m inexpensively by means of time scale up is described. Time scale up can stretch the entire flight time by a factor of 1 00...A method of improving the accuracy of laser pulse range finding from ±10 m to ±1 m inexpensively by means of time scale up is described. Time scale up can stretch the entire flight time by a factor of 1 000 and then the stretched result is counted to calculate the distance. The use of this technique decreases the resolution of counting from nanosecond to microsecond, therefore a separate counting oscillator followed by an interpolation operation is unnecessary. This technique can improve the accuracy of laser pulse range finding inexpensively and effectively.展开更多
The long-term stability of large-span soft rock tunnel is influenced greatly by the creep effect of surrounding rock.The development of a new type of foam concrete which has the property of high compressibility and lo...The long-term stability of large-span soft rock tunnel is influenced greatly by the creep effect of surrounding rock.The development of a new type of foam concrete which has the property of high compressibility and low ductility was introduced.And it was made as filling material of reserved deformation layer between the first lining and the second lining used in large-span soft rock tunnel.The effect of the new type of foam concrete was simulated as filling material of reserved deformation layer using numerical simulation.Through the comparison with the common large-span soft rock tunnel,the vault settlement and surrounding convergence are reduced by about 61% and 45%,respectively,after creep of 100 a.And in the second lining,the plastic zone reduces apparently and the maximum equivalent plastic strain decreases relatively.So,it can be found that the application of the new type of foam concrete as the filling material of reserved deformation layer can relieve the excessive force in second lining induced by rock creep,reduce its deformation and improve the stability of tunnel.展开更多
In solid backfill mining without gangue removal, the gangue is separated directly underground and backfilled into goaf. This necessitates the underground construction of an extra-large section chamber for separation e...In solid backfill mining without gangue removal, the gangue is separated directly underground and backfilled into goaf. This necessitates the underground construction of an extra-large section chamber for separation equipments. For the construction of an extra-large section chamber in the Tangshan mine, we proposed an active support through a combination of bolting, anchor cables, lining, and a reinforced chamber floor by inverted arch pouring. ABAQUS software was used to analyze the surrounding rock deformation and the plastic zone development of the chamber under different excavation schemes.The best excavation scheme was determined, and the effectiveness of the combined supports was verified. In practice, the engineering installation showed good overall control of the movement of the surrounding rock, with roof-to-floor and side-to-side convergences of 154.6 and 77.5 mm, respectively,which meets the requirements for underground coal gangue separation.展开更多
Nitrogen-controlled atmosphere has been internationally recognized as a green grain storage technology.This study used Jiangsu ordinary late japonica rice as the test material and investigated the effects of different...Nitrogen-controlled atmosphere has been internationally recognized as a green grain storage technology.This study used Jiangsu ordinary late japonica rice as the test material and investigated the effects of different nitrogen concentrations(88%,93%,and 98%)and different storage temperatures(10,20,and 30℃)on the rice quality indexes during nitrogen-controlled atmosphere storage.The results showed that the water content of rice in different nitrogen-controlled atmosphere groups fluctuated between 12.85%~13.15%at 20℃,which was significantly lower than that in the control group.High-concentration nitrogen-controlled atmosphere treatment(93%and 98%)effectively slowed down the fatty acid value,malondialdehyde(MDA)content,and electrical conductivity of rice,and also significantly inhibited the rapid increase in the final viscosity and water absorption of rice starch,while the changes in the peak viscosity and attenuation value of rice were not significantly different from those of the control group.Meanwhile,the impacts of controlled atmosphere storage with 98%nitrogen concentration on the water content,fatty acid value,MDA content,electrical conductivity,gelatinization characteristics,and water absorption of rice at 10,20,and 30℃were studied.It was found that all quality parameters,except the MDA content,changed most gently at 10℃.In conclusion,the combined treatment of nitrogen-controlled atmosphere storage(98%)and low temperature(10℃)can effectively delay the quality deterioration of ordinary late japonica rice.展开更多
It is critical for the material to be of active supporting capacity before initial collapse ot mare root wltn supermgn water material backfill mining, and the maximum bending moment should be first calculated in order...It is critical for the material to be of active supporting capacity before initial collapse ot mare root wltn supermgn water material backfill mining, and the maximum bending moment should be first calculated in order to determine the initial collapse span. In the light of principal of virtual work, the simple expression of deflection, bending moment of elastic clamped plate were deduced under the condition of vertical uniform distributed load, horizontal pressure and supporting by elastic foundation, and then, the maximal bending moment expression was derived too. At the same time, the influence degree on square clamped plate by adding horizontal pressure and elastic foundation were analyzed. The results show that the effect of horizontal pressure on maximal bending moment can be ignored when the value of horizontal pressure is two orders of magni- tude less than that of coeificient of elastic stiffness existing elastic foundation.展开更多
Usually landslide studying investigates the facts such as gender land, atmospheric rainfall, gradients＇ change, earthquake, volcanic eruption, subterranean water vibration, and human causes in the form of different m...Usually landslide studying investigates the facts such as gender land, atmospheric rainfall, gradients＇ change, earthquake, volcanic eruption, subterranean water vibration, and human causes in the form of different models. However, the facts can have main share in appearing this phenomenon but correlative and sufficient condition for genesis and such a phenomenon is historical base of lands＇ bed that has experienced specific formative process. In the case of distribution and dispersion of slides and their reasons of occurring in lsfahan, general studying has also been carried out. And this article has investigated this phenomenon on the other aspects and has tried to reveal this phenomenon＇s effect on instigating instabilities, so that it can conclude distribution of this phenomenon references to climate on one side and historical formative process on the other side. It aims to study this effect by using IDW （Inverse Distance Weighting）, Kiriging method in ArcGIS 9.3 software dispersal map of Isfahan＇s main landslides and formative systems on the other side and by local analyzing these two collections evaluated their vicinity relation using local-statistical ways. Results of this research will show that in the past the main part of this landslide has occurred in cold hole and seldom occurred in hot hole.展开更多
This research is showing the effect of increasing an Fe extracting from the compression strength, tension and bending moment. The variations in this experiment are the increasing of Fe extracting 0.5%, 1% and 1.5% of ...This research is showing the effect of increasing an Fe extracting from the compression strength, tension and bending moment. The variations in this experiment are the increasing of Fe extracting 0.5%, 1% and 1.5% of concrete volume. Water Cement Ratio （WCR） variation of 0.48, 0.56 and 0.60. The result of increasing 1.5% Fe extracting causes the increasing of tension strength 44.028 kN/cm2, the increasing of slit tension strength 2.226 kN/cm2, the increasing of bending moment 14.81 kN/cm2 from normal concrete. 0.48 WCR produces tension strength, slit tension strength and bending moment more than 0.56 and 0.60 WCR. The increasing of Fe extracting with the distribution variation area and the spread concrete in the tension concrete area produce 3.705 kN/cm2 bending moment higher than the spread fiber in all of concrete area. The 4 cm fiber length produces the higher bending moment than the 2 cm fiber length. The difference is equally 5.185 kN/cm2. The combination result of the examined acting varieties by continuation statistic test gives the result to get the maximum tension and split tensile. It is a concrete combination of increasing 1.5% fiber percentage, 0.48 WCR, full spreading area and the 4 cm fiber length. The maximum bending moment is the increasing of 0.5% fiber percentage, 0.48 WCR, full spreading area and the 4 cm fiber length.展开更多
This paper designs a mechanical swing of placementing mobile phone, which is inspired by the mechanical watch automatic winding process. The use of the kinetic energy generated by human body motion drives the wheel sw...This paper designs a mechanical swing of placementing mobile phone, which is inspired by the mechanical watch automatic winding process. The use of the kinetic energy generated by human body motion drives the wheel swing and the generator, it can carry out mobile phone additional charge through the electronic components rectifier and DC/DC converter regulator, the use of human motion and light energy can extend a fixed charge mobile phone standby time. The human motion power uses electromagnetic coupling technique and collects energy by using foot swing, solar power generation uses DSP chip in TMS320F28927 control a plurality of charging circuit, inverter circuit and solar maximum power point tracking by sampling and multiple output PWM wave. Finally, charging process has the basic constant current process discovered by device testing, the design of human motion and light energy mobile phone charger can satisfy the need of mobile phone rechargeable lithium batteries.展开更多
The Neoproterozoic Kangdian Rift Basin is a continental rift basin in the western Yangtze Continent.Determining its time of opening and subsequent filling pattern is an important aspect of understanding the formation ...The Neoproterozoic Kangdian Rift Basin is a continental rift basin in the western Yangtze Continent.Determining its time of opening and subsequent filling pattern is an important aspect of understanding the formation and evolution of the Yangtze Continent,South China.The Luliang Formation is the early filling in the eastern part of this rift basin,and its deposition age and filling sequence are significant for studies of the regional stratigraphic correlation,opening time,and filling pattern of this basin.Having been correlated to the upper part of the Mesoproterozoic Kunyang Group or to the Neoproterozoic Chengjiang Formation,the age and regional stratigraphic correlation of the Luliang Formation have long been uncertain.This is due to a lack of reliable absolute age constraints.To address this issue,the first zircon SHRIMP U-Pb geochronology has been established for this formation,yielding two high-precision isotopic ages of 818.6±9.2 and 805±14 Ma for the tuff layers at the bottoms of the lower and upper members of the Luliang Formation,respectively.Given the error factor,the bottom age of the lower member of the Luliang Formation can be interpreted as ca.820 Ma,corresponding to the bottom age of the lower part of the Banxi Group,which is the early filling of the Neoproterozoic Xianggui Rift Basin,a representative basin of the Neoproterozoic rift basins in the Yangtze Continent,South China.The bottom age of the upper member of the Luliang Formation can be interpreted as ca.800±5 Ma,corresponding to the bottom age of the Chengjiang Formation in the western part of the Neoproterozoic Kangdian Rift Basin and also corresponding to the bottom age of the upper part of the Banxi Group in the Neoproterozoic Xianggui Rift Basin.These ages indicate that the Neoproterozoic Kangdian Rift Basin shares the same opening time and filling sequences as those of the other Neoproterozoic rift basins in South China.Basin analysis shows that the Neoproterozoic Kangdian Rift Basin is a typical half-graben basin,with its main boundary fault in the west and basin center in the east.This basin consisted of mini unidirectional half-graben basins in its juvenile stage and simplified to become a large united half-graben basin in its mature stage,i.e.,a supradetachment basin.展开更多
文摘A method of improving the accuracy of laser pulse range finding from ±10 m to ±1 m inexpensively by means of time scale up is described. Time scale up can stretch the entire flight time by a factor of 1 000 and then the stretched result is counted to calculate the distance. The use of this technique decreases the resolution of counting from nanosecond to microsecond, therefore a separate counting oscillator followed by an interpolation operation is unnecessary. This technique can improve the accuracy of laser pulse range finding inexpensively and effectively.
基金Projects(41072238,51009133)supported by the National Natural Science Foundation of China
文摘The long-term stability of large-span soft rock tunnel is influenced greatly by the creep effect of surrounding rock.The development of a new type of foam concrete which has the property of high compressibility and low ductility was introduced.And it was made as filling material of reserved deformation layer between the first lining and the second lining used in large-span soft rock tunnel.The effect of the new type of foam concrete was simulated as filling material of reserved deformation layer using numerical simulation.Through the comparison with the common large-span soft rock tunnel,the vault settlement and surrounding convergence are reduced by about 61% and 45%,respectively,after creep of 100 a.And in the second lining,the plastic zone reduces apparently and the maximum equivalent plastic strain decreases relatively.So,it can be found that the application of the new type of foam concrete as the filling material of reserved deformation layer can relieve the excessive force in second lining induced by rock creep,reduce its deformation and improve the stability of tunnel.
基金supported by the National Natural Science Foundation of China (No. 51304206)the Project of National Scientific and Technical Supporting Programs Foundation of China (No. 2012BAB13B03)the Program for New Century Excellent Talents in University of Ministry of Education of China (No. NCET-11-0728)
文摘In solid backfill mining without gangue removal, the gangue is separated directly underground and backfilled into goaf. This necessitates the underground construction of an extra-large section chamber for separation equipments. For the construction of an extra-large section chamber in the Tangshan mine, we proposed an active support through a combination of bolting, anchor cables, lining, and a reinforced chamber floor by inverted arch pouring. ABAQUS software was used to analyze the surrounding rock deformation and the plastic zone development of the chamber under different excavation schemes.The best excavation scheme was determined, and the effectiveness of the combined supports was verified. In practice, the engineering installation showed good overall control of the movement of the surrounding rock, with roof-to-floor and side-to-side convergences of 154.6 and 77.5 mm, respectively,which meets the requirements for underground coal gangue separation.
文摘Nitrogen-controlled atmosphere has been internationally recognized as a green grain storage technology.This study used Jiangsu ordinary late japonica rice as the test material and investigated the effects of different nitrogen concentrations(88%,93%,and 98%)and different storage temperatures(10,20,and 30℃)on the rice quality indexes during nitrogen-controlled atmosphere storage.The results showed that the water content of rice in different nitrogen-controlled atmosphere groups fluctuated between 12.85%~13.15%at 20℃,which was significantly lower than that in the control group.High-concentration nitrogen-controlled atmosphere treatment(93%and 98%)effectively slowed down the fatty acid value,malondialdehyde(MDA)content,and electrical conductivity of rice,and also significantly inhibited the rapid increase in the final viscosity and water absorption of rice starch,while the changes in the peak viscosity and attenuation value of rice were not significantly different from those of the control group.Meanwhile,the impacts of controlled atmosphere storage with 98%nitrogen concentration on the water content,fatty acid value,MDA content,electrical conductivity,gelatinization characteristics,and water absorption of rice at 10,20,and 30℃were studied.It was found that all quality parameters,except the MDA content,changed most gently at 10℃.In conclusion,the combined treatment of nitrogen-controlled atmosphere storage(98%)and low temperature(10℃)can effectively delay the quality deterioration of ordinary late japonica rice.
基金Supported by the National Natural Science Foundation of China （41071273） the Special Research Fund for the Doctoral Program of Higher Education of China （200090095110002）
文摘It is critical for the material to be of active supporting capacity before initial collapse ot mare root wltn supermgn water material backfill mining, and the maximum bending moment should be first calculated in order to determine the initial collapse span. In the light of principal of virtual work, the simple expression of deflection, bending moment of elastic clamped plate were deduced under the condition of vertical uniform distributed load, horizontal pressure and supporting by elastic foundation, and then, the maximal bending moment expression was derived too. At the same time, the influence degree on square clamped plate by adding horizontal pressure and elastic foundation were analyzed. The results show that the effect of horizontal pressure on maximal bending moment can be ignored when the value of horizontal pressure is two orders of magni- tude less than that of coeificient of elastic stiffness existing elastic foundation.
文摘Usually landslide studying investigates the facts such as gender land, atmospheric rainfall, gradients＇ change, earthquake, volcanic eruption, subterranean water vibration, and human causes in the form of different models. However, the facts can have main share in appearing this phenomenon but correlative and sufficient condition for genesis and such a phenomenon is historical base of lands＇ bed that has experienced specific formative process. In the case of distribution and dispersion of slides and their reasons of occurring in lsfahan, general studying has also been carried out. And this article has investigated this phenomenon on the other aspects and has tried to reveal this phenomenon＇s effect on instigating instabilities, so that it can conclude distribution of this phenomenon references to climate on one side and historical formative process on the other side. It aims to study this effect by using IDW （Inverse Distance Weighting）, Kiriging method in ArcGIS 9.3 software dispersal map of Isfahan＇s main landslides and formative systems on the other side and by local analyzing these two collections evaluated their vicinity relation using local-statistical ways. Results of this research will show that in the past the main part of this landslide has occurred in cold hole and seldom occurred in hot hole.
文摘This research is showing the effect of increasing an Fe extracting from the compression strength, tension and bending moment. The variations in this experiment are the increasing of Fe extracting 0.5%, 1% and 1.5% of concrete volume. Water Cement Ratio （WCR） variation of 0.48, 0.56 and 0.60. The result of increasing 1.5% Fe extracting causes the increasing of tension strength 44.028 kN/cm2, the increasing of slit tension strength 2.226 kN/cm2, the increasing of bending moment 14.81 kN/cm2 from normal concrete. 0.48 WCR produces tension strength, slit tension strength and bending moment more than 0.56 and 0.60 WCR. The increasing of Fe extracting with the distribution variation area and the spread concrete in the tension concrete area produce 3.705 kN/cm2 bending moment higher than the spread fiber in all of concrete area. The 4 cm fiber length produces the higher bending moment than the 2 cm fiber length. The difference is equally 5.185 kN/cm2. The combination result of the examined acting varieties by continuation statistic test gives the result to get the maximum tension and split tensile. It is a concrete combination of increasing 1.5% fiber percentage, 0.48 WCR, full spreading area and the 4 cm fiber length. The maximum bending moment is the increasing of 0.5% fiber percentage, 0.48 WCR, full spreading area and the 4 cm fiber length.
文摘This paper designs a mechanical swing of placementing mobile phone, which is inspired by the mechanical watch automatic winding process. The use of the kinetic energy generated by human body motion drives the wheel swing and the generator, it can carry out mobile phone additional charge through the electronic components rectifier and DC/DC converter regulator, the use of human motion and light energy can extend a fixed charge mobile phone standby time. The human motion power uses electromagnetic coupling technique and collects energy by using foot swing, solar power generation uses DSP chip in TMS320F28927 control a plurality of charging circuit, inverter circuit and solar maximum power point tracking by sampling and multiple output PWM wave. Finally, charging process has the basic constant current process discovered by device testing, the design of human motion and light energy mobile phone charger can satisfy the need of mobile phone rechargeable lithium batteries.
基金supported by National Natural Science Foundation of China(Grant Nos.4103031541072088)China Geological Survey(Grant No.1212011121105)
文摘The Neoproterozoic Kangdian Rift Basin is a continental rift basin in the western Yangtze Continent.Determining its time of opening and subsequent filling pattern is an important aspect of understanding the formation and evolution of the Yangtze Continent,South China.The Luliang Formation is the early filling in the eastern part of this rift basin,and its deposition age and filling sequence are significant for studies of the regional stratigraphic correlation,opening time,and filling pattern of this basin.Having been correlated to the upper part of the Mesoproterozoic Kunyang Group or to the Neoproterozoic Chengjiang Formation,the age and regional stratigraphic correlation of the Luliang Formation have long been uncertain.This is due to a lack of reliable absolute age constraints.To address this issue,the first zircon SHRIMP U-Pb geochronology has been established for this formation,yielding two high-precision isotopic ages of 818.6±9.2 and 805±14 Ma for the tuff layers at the bottoms of the lower and upper members of the Luliang Formation,respectively.Given the error factor,the bottom age of the lower member of the Luliang Formation can be interpreted as ca.820 Ma,corresponding to the bottom age of the lower part of the Banxi Group,which is the early filling of the Neoproterozoic Xianggui Rift Basin,a representative basin of the Neoproterozoic rift basins in the Yangtze Continent,South China.The bottom age of the upper member of the Luliang Formation can be interpreted as ca.800±5 Ma,corresponding to the bottom age of the Chengjiang Formation in the western part of the Neoproterozoic Kangdian Rift Basin and also corresponding to the bottom age of the upper part of the Banxi Group in the Neoproterozoic Xianggui Rift Basin.These ages indicate that the Neoproterozoic Kangdian Rift Basin shares the same opening time and filling sequences as those of the other Neoproterozoic rift basins in South China.Basin analysis shows that the Neoproterozoic Kangdian Rift Basin is a typical half-graben basin,with its main boundary fault in the west and basin center in the east.This basin consisted of mini unidirectional half-graben basins in its juvenile stage and simplified to become a large united half-graben basin in its mature stage,i.e.,a supradetachment basin.
