In this paper we deduce the analytic solutions of the first- and second-order vertical derivative zero points for gravity anomalies in simple regular models with single, double, and multiple edges and analyze their sp...In this paper we deduce the analytic solutions of the first- and second-order vertical derivative zero points for gravity anomalies in simple regular models with single, double, and multiple edges and analyze their spatial variation. For another simple regular models where it is difficult to obtain the analytic expression of the zero point, we try to use the profile zero points to analyze the spatial variation. The test results show that the spatial variation laws of both first- and second-order vertical derivative zero points are almost the same but the second-order derivative zero point position is closer to the top surface edge of the geological bodies than the first-order vertical derivative and has a relatively high resolution. Moreover, with an increase in buried depth, for a single boundary model, the vertical derivative zero point location tends to move from the top surface edge to the outside of the buried body but finally converges to a fixed value. For a double boundary model, the vertical derivative zero point location tends to migrate from the top surface edge to the outside of the buried body. For multiple boundary models, the vertical derivative zero point location converges from the top surface edge to the outside of the buried body where some zero points coincide and finally vanish. Finally, the effectiveness and reliability of the proposed method is verified using real field data.展开更多
To investigate the variation law of pericarp tenderness in growth progress of super sweet corn kernel, the values of pericarp tenderness of 10 super sweet corn inbreeds were measured during kernel growth, and the vari...To investigate the variation law of pericarp tenderness in growth progress of super sweet corn kernel, the values of pericarp tenderness of 10 super sweet corn inbreeds were measured during kernel growth, and the variations under differ- ent conditions were analyzed. The results showed that there existed gradient differ- ences in pericarp tenderness among the 10 materials, of which PE10 had the best pericarp tenderness, T105 took medial place, and $33205 performed worst in peri- carp tenderness. Pericarp tenderness values of these 3 inbreeds increased curvedly from 12 to 24 days after pollination, in the spring （Wuhan, Hubei） and winter （Ling- shui, Hainan） of 2014. Moreover, the average pericarp tenderness at different time points presented the same decreasing order of $33205, T105, PE10, which was not altered by enviroment. With the growth of kernel, for one material, the difference of pericarp tenderness under different environments presented a law of increment, re- duction, uniformity. As for optimum-picking time, there was four days difference be- tween the spring in Wuhan and winter in Lingshui. However, there was no obvious difference in pericarp tenderness on the optimum picking time, which indicated that growing environment could affect the variation ratio of pericarp tenderness, but it still depended on the nature of materials.展开更多
In seasonal frozen soil region,the engineering geological properties of loess-like soil will be deteriorated after freeze-thaw cycles.Through the freeze-thaw cycle experiment of remolded loess-like soil,under differen...In seasonal frozen soil region,the engineering geological properties of loess-like soil will be deteriorated after freeze-thaw cycles.Through the freeze-thaw cycle experiment of remolded loess-like soil,under different freezing temperatures,the authors carried out freeze-thaw cycle tests for 3 times and 20 times,respectively.With mercury intrusion porosimetry and granulometric analysis,from the micro-structure,the authors studied the law that freeze-thaw cycle times and frozen temperature effect on the variation of microscopic pore of loesslike soil.This result can provide theoretical basis for comprehensive treatment of problems in the construction of the project in seasonal frozen loess-like soil region.展开更多
Based on the air temperature (1.0 m and 1.5 m) every 10 minutes, ground temperature (0 cm, 10 cm and 20 cm) and air relative humidity (1.5 m) from the stations in the greenhouse, and the air temperature (1.5 m) every ...Based on the air temperature (1.0 m and 1.5 m) every 10 minutes, ground temperature (0 cm, 10 cm and 20 cm) and air relative humidity (1.5 m) from the stations in the greenhouse, and the air temperature (1.5 m) every 10 minutes and air relative humidity (1.5 m) from the regional stations in Chutouling Town, Jizhou district of Tianjin from April 2019 to November 2020, the changes of the microclimate in the greenhouse of Pleurotus nebrodensis were studied. The results explained that 1) the heat preservation effect of the greenhouse was the best in spring, the effective accumulative temperature and active accumulated temperature in the greenhouse had increased by 203.7°C and 233.7°C, respectively, compared with that outside the greenhouse. In the sunny or cloudy days of summer, the range of temperature difference (TD) between inside and outside the greenhouse was wider, more than 90% of the TD ranged from -6.0°C to 2.9°C;2) the minimum temperature occurred later because of heat preservation effect of the greenhouse, the delay time can reach about 30 minutes in spring, it was about 20 minutes in summer and autumn, and 10 minutes in winter, however, the maximum temperature appeared earlier, it occurred 50 minutes ahead of time in spring, and it has been advanced by 20 minutes in summer and 10 minutes in autumn and winter;3) the greenhouse mainly played a role of increasing humidity, the humidity in the greenhouse basically was larger than that outside the greenhouse, except the periods of 03:10-07:20 in spring, 0:00-08:50 and 23:10-23:50 in winter;4) the temperature in the greenhouse significantly positively correlated with the temperature outside the greenhouse, the stronger correlation also appeared between the ground temperature (at the depth of 0 cm and 10 cm) in the greenhouse and the temperature inside and outside the greenhouse, however, there was a weak correlation between the ground temperature (20 cm) and the temperature inside and outside the greenhouse, this implies that the change of temperature had less impact on the ground temperature at deeper soil layers. This paper is of significance in identifying the microclimate in the Pleurotus nebrodensis greenhouse.展开更多
There was little research on the changes and interconversion of organic compounds in the intermediate liquid-phase productsin the hydrogen production by anaerobic fermentation of coal.The types and concentrations of t...There was little research on the changes and interconversion of organic compounds in the intermediate liquid-phase productsin the hydrogen production by anaerobic fermentation of coal.The types and concentrations of the intermediate liquid-phase products are not only related to the efficiency of coal conversion into biohydrogen,but one of the important contents of study on the generation mechanism of biohydrogen from coal.In order to study the change of key liquid phase products in the process of bio-hydrogen production from coal,the simulation experiments of bio-hydrogen production were conducted under suitable environmental conditions using lignite from Daliuta,Shaanxi province.The hydrogen concentration and key liquid phase products were measured using gas chromatography and GC-MS,respectively,to reveal its change.The results show that:(1)there is correspondence between the key liquid phase products and hydrogen yield.The saturated alkanes and cyclic hydrocarbons show a trend of first increasing,then decreasing,and finally increasing,but the changes of proteinaceous materials are just the opposite,which is correspondent to the initial stage,peak stage and terminal stage of hydrogen production,respectively.(2)The short-chain volatile fatty acids are accumulated gradually in the process of hydrogen production,and the short-chain acids of aromatic show a trend of first increasing,then decreasing,increase again and finally decreasing,which is correspondent to the different biochemical reactions,such as the release of small molecules,the utilization of microorganisms,hydrocarbon oxidation and the redegradation of macromolecule.(3)The lipids,aldehydes and ketones are the parent substances of acid production,and the changes are related to the increased acids to a certain extent.This research not only reveals the biochemical effects between gas and liquid phases,but further enriches the theory of bio-hydrogen production from coal.展开更多
The Tibetan Plateau(TP),known as the“Third Pole”of the Earth and“Asian Water Tower”,is the magnifier of global climate change and birthplace of many large rivers in Asia.There are unique alpine wetlands on the TP,...The Tibetan Plateau(TP),known as the“Third Pole”of the Earth and“Asian Water Tower”,is the magnifier of global climate change and birthplace of many large rivers in Asia.There are unique alpine wetlands on the TP,accounting for 20%of Chinese wetlands area,and the lakes alone constitute half of the national lake area.Wetlands are critical to human survival and development as one of the three major ecosystems[1].展开更多
基金jointly supported by the National Major Science and Technology Program (No. 2008ZX05025)the National 973 Program (Grant No. 2009CB219400)
文摘In this paper we deduce the analytic solutions of the first- and second-order vertical derivative zero points for gravity anomalies in simple regular models with single, double, and multiple edges and analyze their spatial variation. For another simple regular models where it is difficult to obtain the analytic expression of the zero point, we try to use the profile zero points to analyze the spatial variation. The test results show that the spatial variation laws of both first- and second-order vertical derivative zero points are almost the same but the second-order derivative zero point position is closer to the top surface edge of the geological bodies than the first-order vertical derivative and has a relatively high resolution. Moreover, with an increase in buried depth, for a single boundary model, the vertical derivative zero point location tends to move from the top surface edge to the outside of the buried body but finally converges to a fixed value. For a double boundary model, the vertical derivative zero point location tends to migrate from the top surface edge to the outside of the buried body. For multiple boundary models, the vertical derivative zero point location converges from the top surface edge to the outside of the buried body where some zero points coincide and finally vanish. Finally, the effectiveness and reliability of the proposed method is verified using real field data.
基金Supported by the Open Project of the State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources(SKL-CUSAb-2013-03)
文摘To investigate the variation law of pericarp tenderness in growth progress of super sweet corn kernel, the values of pericarp tenderness of 10 super sweet corn inbreeds were measured during kernel growth, and the variations under differ- ent conditions were analyzed. The results showed that there existed gradient differ- ences in pericarp tenderness among the 10 materials, of which PE10 had the best pericarp tenderness, T105 took medial place, and $33205 performed worst in peri- carp tenderness. Pericarp tenderness values of these 3 inbreeds increased curvedly from 12 to 24 days after pollination, in the spring （Wuhan, Hubei） and winter （Ling- shui, Hainan） of 2014. Moreover, the average pericarp tenderness at different time points presented the same decreasing order of $33205, T105, PE10, which was not altered by enviroment. With the growth of kernel, for one material, the difference of pericarp tenderness under different environments presented a law of increment, re- duction, uniformity. As for optimum-picking time, there was four days difference be- tween the spring in Wuhan and winter in Lingshui. However, there was no obvious difference in pericarp tenderness on the optimum picking time, which indicated that growing environment could affect the variation ratio of pericarp tenderness, but it still depended on the nature of materials.
文摘In seasonal frozen soil region,the engineering geological properties of loess-like soil will be deteriorated after freeze-thaw cycles.Through the freeze-thaw cycle experiment of remolded loess-like soil,under different freezing temperatures,the authors carried out freeze-thaw cycle tests for 3 times and 20 times,respectively.With mercury intrusion porosimetry and granulometric analysis,from the micro-structure,the authors studied the law that freeze-thaw cycle times and frozen temperature effect on the variation of microscopic pore of loesslike soil.This result can provide theoretical basis for comprehensive treatment of problems in the construction of the project in seasonal frozen loess-like soil region.
文摘Based on the air temperature (1.0 m and 1.5 m) every 10 minutes, ground temperature (0 cm, 10 cm and 20 cm) and air relative humidity (1.5 m) from the stations in the greenhouse, and the air temperature (1.5 m) every 10 minutes and air relative humidity (1.5 m) from the regional stations in Chutouling Town, Jizhou district of Tianjin from April 2019 to November 2020, the changes of the microclimate in the greenhouse of Pleurotus nebrodensis were studied. The results explained that 1) the heat preservation effect of the greenhouse was the best in spring, the effective accumulative temperature and active accumulated temperature in the greenhouse had increased by 203.7°C and 233.7°C, respectively, compared with that outside the greenhouse. In the sunny or cloudy days of summer, the range of temperature difference (TD) between inside and outside the greenhouse was wider, more than 90% of the TD ranged from -6.0°C to 2.9°C;2) the minimum temperature occurred later because of heat preservation effect of the greenhouse, the delay time can reach about 30 minutes in spring, it was about 20 minutes in summer and autumn, and 10 minutes in winter, however, the maximum temperature appeared earlier, it occurred 50 minutes ahead of time in spring, and it has been advanced by 20 minutes in summer and 10 minutes in autumn and winter;3) the greenhouse mainly played a role of increasing humidity, the humidity in the greenhouse basically was larger than that outside the greenhouse, except the periods of 03:10-07:20 in spring, 0:00-08:50 and 23:10-23:50 in winter;4) the temperature in the greenhouse significantly positively correlated with the temperature outside the greenhouse, the stronger correlation also appeared between the ground temperature (at the depth of 0 cm and 10 cm) in the greenhouse and the temperature inside and outside the greenhouse, however, there was a weak correlation between the ground temperature (20 cm) and the temperature inside and outside the greenhouse, this implies that the change of temperature had less impact on the ground temperature at deeper soil layers. This paper is of significance in identifying the microclimate in the Pleurotus nebrodensis greenhouse.
基金Project supported by the National Natural Science Foundation of China“Response Mechanism of Trace Elements to Coal Methane Generation”(No.41502158)Henan Science and Technology Key Project“Key Technologies and Applications of Coal and Straw Synergistic Conversion of Biomethane”(No.:182102310845).
文摘There was little research on the changes and interconversion of organic compounds in the intermediate liquid-phase productsin the hydrogen production by anaerobic fermentation of coal.The types and concentrations of the intermediate liquid-phase products are not only related to the efficiency of coal conversion into biohydrogen,but one of the important contents of study on the generation mechanism of biohydrogen from coal.In order to study the change of key liquid phase products in the process of bio-hydrogen production from coal,the simulation experiments of bio-hydrogen production were conducted under suitable environmental conditions using lignite from Daliuta,Shaanxi province.The hydrogen concentration and key liquid phase products were measured using gas chromatography and GC-MS,respectively,to reveal its change.The results show that:(1)there is correspondence between the key liquid phase products and hydrogen yield.The saturated alkanes and cyclic hydrocarbons show a trend of first increasing,then decreasing,and finally increasing,but the changes of proteinaceous materials are just the opposite,which is correspondent to the initial stage,peak stage and terminal stage of hydrogen production,respectively.(2)The short-chain volatile fatty acids are accumulated gradually in the process of hydrogen production,and the short-chain acids of aromatic show a trend of first increasing,then decreasing,increase again and finally decreasing,which is correspondent to the different biochemical reactions,such as the release of small molecules,the utilization of microorganisms,hydrocarbon oxidation and the redegradation of macromolecule.(3)The lipids,aldehydes and ketones are the parent substances of acid production,and the changes are related to the increased acids to a certain extent.This research not only reveals the biochemical effects between gas and liquid phases,but further enriches the theory of bio-hydrogen production from coal.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0608 and 2019QZKK0604)。
文摘The Tibetan Plateau(TP),known as the“Third Pole”of the Earth and“Asian Water Tower”,is the magnifier of global climate change and birthplace of many large rivers in Asia.There are unique alpine wetlands on the TP,accounting for 20%of Chinese wetlands area,and the lakes alone constitute half of the national lake area.Wetlands are critical to human survival and development as one of the three major ecosystems[1].
