High resolution temperature measurement technique is one of the key techniques for measuring marine heat flow. Basing on Pt1000 platinum resistance which has the characteristics of high accuracy and good stability, we...High resolution temperature measurement technique is one of the key techniques for measuring marine heat flow. Basing on Pt1000 platinum resistance which has the characteristics of high accuracy and good stability, we designed a bridge reversal excitation circuit for high resolution temperature measurement. And the deep ocean floor in-situ test results show that: (1) temperature deviation and peak-to-peak resolution of the first version circuit board (V1) are 1.960-1.990 mK and 0.980-0.995 m Kat 1.2-2.7°C, respectively; and temperature deviation and peak-to-peak resolution of the second circuit board (V2) are 2.260mK and 1.130 mK at 1.2-1.3°C, respectively; (2) During the 2012NSFC-IndOcean cruise, seafloor geothermal gradient at Ind2012HF03,-07 and-12 stations (water depth ranges from 3841 to 4541 m) were successfully measured, the values are 59.1,75.1 and 71.6°C/km, respectively. And the measurement errors of geothermal gradient at these three stations are less than 3.0% in terms of the peak-to-peak resolution. These indicate that the high resolution temperature measurement technique based on Pt1000 platinum resistance in this paper can be applied to marine heat flow measurement to obtain high precision geothermal parameters.展开更多
By carbothermal reduction of Mg O with black carbon as reduction agent at a high temperature,Mg O was deposited on the surface of Mg O- Ca O clinker（ as coating） to improve the clinker ＇s hydration resistance. In t...By carbothermal reduction of Mg O with black carbon as reduction agent at a high temperature,Mg O was deposited on the surface of Mg O- Ca O clinker（ as coating） to improve the clinker ＇s hydration resistance. In the paper,effect of deposition temperature and holding time on the hydration resistance of the treated Mg O-Ca O,the deposition mechanism and Mg O coating kinetics were investigated with hydration resistance test,X-ray diffractometry（ XRD） and scanning electronic microscope（ SEM）. Results showed Mg O coating grew in a2D mode on the surface of Mg O- Ca O particles; the Mg O coating improved the hydration resistance of the coated Mg O- Ca O clinker,and the coated clinker would become stronger when coated at higher deposition temperature and longer holding time. The measurements also found that Mg O deposition process varied with the deposition temperature： it was mainly a chemical-controlled process at temperatures between 1 400- 1 500 ℃,with an apparent activation energy（ AAE） of 97. 8kJ·mol^（-1）; it would change into a diffusion-controlled process when the temperature rising to 1 500- 1 600 ℃,with apparent activation energy of 19. 2kJ·mol^（-1）.展开更多
Ni-doped phenol resin was prepared with 1∶100 mass ratio of Ni（ NO_3）_2·6H_2O to thermosetting phenol resin to optimize the structure and properties of pyrolytic carbon derived from phenol resin and increase i...Ni-doped phenol resin was prepared with 1∶100 mass ratio of Ni（ NO_3）_2·6H_2O to thermosetting phenol resin to optimize the structure and properties of pyrolytic carbon derived from phenol resin and increase its carbon yield. The specimens were cured at 200 ℃ and carbonized under different atmospheres（ carbon-embedded atmosphere and Ar atmosphere） and at different temperatures（ 600,800,1000 and 1200 ℃） for3 h,respectively. The carbon yield was measured. Thermal decomposition characteristics of Ni-doped phenol resin,and the oxidation resistance,phase composition and microstructure of pyrolytic carbon were characterized by differential scanning calorimetry,X-ray diffraction,energy dispersive spectroscopy, scanning electron microscopy and transmission electron microscopy. The results show that the carbon yield of Ni-doped phenol resin carbonized at800 or 1 000 ℃ is increased significantly,compared with that without any dopants. The graphitization degree of pyrolytic carbon structure derived from Ni-doped phenol resin increases with the increase of carbonization temperature. The massive multi-wall carbon nanotubes of 50-100 nm in diameter and of micrometre scale in length are generated at 1000 ℃. Compared with the carbonembedded atmosphere,carbon nanotubes can be more easily generated in Ar atmosphere,resulting in higher carbon yield and degree of crystallinity of the pyrolyticcarbon derived from Ni-doped phenol resin. The oxidation resistance of the pyrolytic carbon derived from Ni-doped phenol resin at 1200 ℃ is improved significantly and its highest oxidation temperature is increased by about 84℃,compared with that from Ni free phenol resin.展开更多
基金supported jointly by the Instrument Developing Project of the Chinese Academy of Sciences(Grant No.YZ201136)the National Natural Science Foundation of China(Grant No.41106086)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.SQ201007) the Key Laboratory of Marginal Sea Geology,Chinese Academy of Sciences(Grant No.MSGL09-08)
文摘High resolution temperature measurement technique is one of the key techniques for measuring marine heat flow. Basing on Pt1000 platinum resistance which has the characteristics of high accuracy and good stability, we designed a bridge reversal excitation circuit for high resolution temperature measurement. And the deep ocean floor in-situ test results show that: (1) temperature deviation and peak-to-peak resolution of the first version circuit board (V1) are 1.960-1.990 mK and 0.980-0.995 m Kat 1.2-2.7°C, respectively; and temperature deviation and peak-to-peak resolution of the second circuit board (V2) are 2.260mK and 1.130 mK at 1.2-1.3°C, respectively; (2) During the 2012NSFC-IndOcean cruise, seafloor geothermal gradient at Ind2012HF03,-07 and-12 stations (water depth ranges from 3841 to 4541 m) were successfully measured, the values are 59.1,75.1 and 71.6°C/km, respectively. And the measurement errors of geothermal gradient at these three stations are less than 3.0% in terms of the peak-to-peak resolution. These indicate that the high resolution temperature measurement technique based on Pt1000 platinum resistance in this paper can be applied to marine heat flow measurement to obtain high precision geothermal parameters.
基金supported by The Industrial Research Project of Shaanxi Province , China under Grant No. 2012k07-07
文摘By carbothermal reduction of Mg O with black carbon as reduction agent at a high temperature,Mg O was deposited on the surface of Mg O- Ca O clinker（ as coating） to improve the clinker ＇s hydration resistance. In the paper,effect of deposition temperature and holding time on the hydration resistance of the treated Mg O-Ca O,the deposition mechanism and Mg O coating kinetics were investigated with hydration resistance test,X-ray diffractometry（ XRD） and scanning electronic microscope（ SEM）. Results showed Mg O coating grew in a2D mode on the surface of Mg O- Ca O particles; the Mg O coating improved the hydration resistance of the coated Mg O- Ca O clinker,and the coated clinker would become stronger when coated at higher deposition temperature and longer holding time. The measurements also found that Mg O deposition process varied with the deposition temperature： it was mainly a chemical-controlled process at temperatures between 1 400- 1 500 ℃,with an apparent activation energy（ AAE） of 97. 8kJ·mol^（-1）; it would change into a diffusion-controlled process when the temperature rising to 1 500- 1 600 ℃,with apparent activation energy of 19. 2kJ·mol^（-1）.
基金financial supports from the National Natural Science Foundation of China(51174152)National Basic Research Program of China(973 Program)(2012CB722702)
文摘Ni-doped phenol resin was prepared with 1∶100 mass ratio of Ni（ NO_3）_2·6H_2O to thermosetting phenol resin to optimize the structure and properties of pyrolytic carbon derived from phenol resin and increase its carbon yield. The specimens were cured at 200 ℃ and carbonized under different atmospheres（ carbon-embedded atmosphere and Ar atmosphere） and at different temperatures（ 600,800,1000 and 1200 ℃） for3 h,respectively. The carbon yield was measured. Thermal decomposition characteristics of Ni-doped phenol resin,and the oxidation resistance,phase composition and microstructure of pyrolytic carbon were characterized by differential scanning calorimetry,X-ray diffraction,energy dispersive spectroscopy, scanning electron microscopy and transmission electron microscopy. The results show that the carbon yield of Ni-doped phenol resin carbonized at800 or 1 000 ℃ is increased significantly,compared with that without any dopants. The graphitization degree of pyrolytic carbon structure derived from Ni-doped phenol resin increases with the increase of carbonization temperature. The massive multi-wall carbon nanotubes of 50-100 nm in diameter and of micrometre scale in length are generated at 1000 ℃. Compared with the carbonembedded atmosphere,carbon nanotubes can be more easily generated in Ar atmosphere,resulting in higher carbon yield and degree of crystallinity of the pyrolyticcarbon derived from Ni-doped phenol resin. The oxidation resistance of the pyrolytic carbon derived from Ni-doped phenol resin at 1200 ℃ is improved significantly and its highest oxidation temperature is increased by about 84℃,compared with that from Ni free phenol resin.
