The spatial distribution of plant populations is an important feature of population structure and it de- termines the population＇s ecological preferences, biological characteristics and relationships with environment...The spatial distribution of plant populations is an important feature of population structure and it de- termines the population＇s ecological preferences, biological characteristics and relationships with environmental factors. The point pattern analysis method was adopted to study the distribution pattern of Picea schrenkiana indi- viduals of different size classes and the correlations between two size classes as well as the impact of topog- raphical attributes on the population distribution. With increasing diameter at breast height, the plant density of the P. schrenkiana population showed a declining trend. Old trees showed a random distribution at a small spatial scale （0-12 m）, whereas saplings, small trees and big trees all had an aggregated distribution at all scales. With the increase of tree age, the scales at which maximal aggregation occurred gradually increased and the aggregation strength decreased. At a small scale （0-16 m）, all size classes showed a negative correlation and the larger the difference between tree size, the more significant the negative correlation. The number of medium, big and old trees had a significantly positive correlation with elevations, whereas the number of saplings and small trees was not significantly correlated with elevations. The numbers of saplings, small and medium trees showed a significant positive correlation with slope gradient, whereas the number of big trees was not significantly correlated, and the number of old trees was negatively correlated with gradient. With the exception of old trees, saplings, small, me- dium and big trees showed negative correlations with convexity index. The study provides a theoretical basis for the conservation, rehabilitation and sustainable management of forest ecosystems in the Tianshan Mountains.展开更多
Stress corrosion cracking （SCC） of stainless steels and Ni-based alloys in high temperature water coolant is one of the key problems affecting the safe operation of nuclear power plants （NPPs）. The nitrogen-added ...Stress corrosion cracking （SCC） of stainless steels and Ni-based alloys in high temperature water coolant is one of the key problems affecting the safe operation of nuclear power plants （NPPs）. The nitrogen-added stainless steel is a kind of possible candidate materials for mitigating SCC since reducing the carbon content and adding nitrogen to offset the loss in strength caused by the decrease in carbon content can mitigate the problem of sensitization. However, the reports of SCC of nitrogen-added stainless steels in high temperature water are few available. The effects of applied potential and sensitization treatment on the SCC of a newly developed nitrogen-containing stainless steel （SS） 316LN in high temperature water doped with chloride at 250 ℃ were studied by using slow strain rate tests （SSRTs）. The SSRT results are compared with our data previously published for 316 SS without nitrogen and 304NG SS with nitrogen, and the possible mechanism affecting the SCC behaviors of the studied steels is also discussed based on SSRT and microstucture analysis results. The susceptibility to cracking of 316LN SS normally increases with increasing potential. The susceptibility to SCC of 316LN SS was less than that of 316 SS and 304NG SS. Sensitization treatment at 700℃ for 30 h showed little effect on the S CC of 316LN S S and significant effect on the S CC of 316 S S. The predominant cracking mode for the 316LN S S in both annealed state and the state after the sensitization treatment was transgranular. The presented conditions of mitigating stress corrosion cracking are some useful information for the safe use of 316LN SS in NPPs.展开更多
Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure wi...Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure without appropriate treatment(Terziroli Beretta-Piccoli et al.,2019).展开更多
This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields ...This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields in four areas(Anjihai,Shihezi suburbs,Mosuowan and Xiayedi)were selected for residual film collection.The average content of residual film in the Eighth Division was 104 kg/ha.The residual film content in the four areas decreased in the order Anjihai>Shihezi suburbs>Mosuowan>Xiayedi.The average amount of residual film collected from cotton fields was greater than that from corn fields.Residual film content in the cotton field at soil depths of 0~10 and 10~30 cm was higher than that in the corn field,whereas the residual film content at a 30–50 cm soil depth in the corn field was higher than that in the cotton field.The results showed that farmers do not consider the long-term benefits,the high cost and short time of recycling,and the easy recycling of surface residual film.The shallow that the higher content of residual film,the less water in the soil of cotton.The same time,the results showed that the quantity of residual film in cotton field had greater influence on cotton quality.展开更多
Graphdiyne(GDY),as a new carbon material with two-dimensional structure composed by sp2 and sp carbon atoms,has exhibited excellent properties in various fields due to its conjugated pore structure,high specific surfa...Graphdiyne(GDY),as a new carbon material with two-dimensional structure composed by sp2 and sp carbon atoms,has exhibited excellent properties in various fields due to its conjugated pore structure,high specific surface area and stable structure.Various properties can also be tuned through the adjustability of the electronic structure by chemical methods.This article systematically discusses the preparation methods and strategies of GDY and GDY based materials.These preparation methods provide the way for us to obtain various GDY materials targeting specific research and application.展开更多
As a window of insight into the lower crust, high pressure granulite has received much attention since last decade. Yushugou high pressure granulite-peridotite Complex was located in the northeast margin of Southern T...As a window of insight into the lower crust, high pressure granulite has received much attention since last decade. Yushugou high pressure granulite-peridotite Complex was located in the northeast margin of Southern Tianshan, NW China. Previous ideas agreed that the peridotite unit in Yushugou, combined with the ultramafic rocks in Tonghuashan and Liuhuangshan, represent an ophiolite belt. However, the metamorphic evolution and tectonic mechanism of the Yushugou high pressure （HP） granulite remain controversial. Petrological investigations and phase equilibrium modelling for two representative fclsic granulitc samples suggest two stages metamorphism of the rocks in Yushugou Complex. Granulite facies metamorphism （Stage I） with P-T conditions of 9.8-10.4 kbar at 895-920℃ was recorded by the porphyroblastic garnet core; HP granulite facies metamorphism （Stage II） shows P-T conditions of 13.2-13.5 kbar at 845-860℃, based on the increasing grossular and decreasing pyrope contents of garnet rims. The Yushugou HP felsic granulites have recorded an anti- clockwise P-T path, characterized by the temperature decreasing and pressure increasing simultaneously. The LA-ICP-MS isotopic investigations on zircons from the felsic granulite show that the protolith ages of the granlulites are -430 Ma, with two age groups of-390 Ma and 340-350 Ma from the metamorphic rims of zircon, indicating the Stage I and II metamorphic events, respectively. A tectonic model was proposed to interpret the processes. The investigated felsic granulite was derived from deep rooted hanging wall, with Stage I granulite facies metamorphism of -390 Ma, which may he related to the Devonian arc magmatic intrusion; Stage II HP granulite facies metamorphism （340-350 Ma） may due to the involvement of being captured into the subducting slab and experienced the high pressure metamorphism.展开更多
This work proposed to use the ionic liquid [EMIM][BF_4] as absorbent for the absorption of gaseous acetic acid. The feasibility of this technology was investigated from molecular level to industrial scale. The acetic ...This work proposed to use the ionic liquid [EMIM][BF_4] as absorbent for the absorption of gaseous acetic acid. The feasibility of this technology was investigated from molecular level to industrial scale. The acetic acid absorption experiment was carried out using [EMIM][BF_4],and the removal ratio of acetic acid in the gas product can achieve 88.6% at 20C under atmospheric pressure at the laboratory scale. Based on the experimental results, a reliable strict equilibrium phase model embedding the parameters of the UNIFAC model was established. On this basis, the conceptual process design and optimization of acetic acid removal by [EMIM][BF_4] at an industrial scale was done, and the most suitable design and operation parameters were obtained. For a further step, the binding energy between [EMIM][BF_4] and acetic acid was calculated to give some insights into the separation mechanism, and the results indicate that the interaction between acetic acid and IL is much stronger than that between nitrogen and IL. Moreover, hydrogen bond can be formed between the cation-acetic acid as well as the anion-acetic acid.展开更多
基金funded by the 12th Five-year Science and Technology Support Program(2011BAD38B0505)the Forestry Industry Research Special Funds for Public Welfare Projects (200804022C)the CFERN & GENE Award Funds on Ecological Papers
文摘The spatial distribution of plant populations is an important feature of population structure and it de- termines the population＇s ecological preferences, biological characteristics and relationships with environmental factors. The point pattern analysis method was adopted to study the distribution pattern of Picea schrenkiana indi- viduals of different size classes and the correlations between two size classes as well as the impact of topog- raphical attributes on the population distribution. With increasing diameter at breast height, the plant density of the P. schrenkiana population showed a declining trend. Old trees showed a random distribution at a small spatial scale （0-12 m）, whereas saplings, small trees and big trees all had an aggregated distribution at all scales. With the increase of tree age, the scales at which maximal aggregation occurred gradually increased and the aggregation strength decreased. At a small scale （0-16 m）, all size classes showed a negative correlation and the larger the difference between tree size, the more significant the negative correlation. The number of medium, big and old trees had a significantly positive correlation with elevations, whereas the number of saplings and small trees was not significantly correlated with elevations. The numbers of saplings, small and medium trees showed a significant positive correlation with slope gradient, whereas the number of big trees was not significantly correlated, and the number of old trees was negatively correlated with gradient. With the exception of old trees, saplings, small, me- dium and big trees showed negative correlations with convexity index. The study provides a theoretical basis for the conservation, rehabilitation and sustainable management of forest ecosystems in the Tianshan Mountains.
基金supported by National Basic Research Program of China (973 Program, Grant No. 2006CB605005)Shanghai Municipal Committee of Science and Technology of china(Grant No. 005207019,Grant No. 08520708000)
文摘Stress corrosion cracking （SCC） of stainless steels and Ni-based alloys in high temperature water coolant is one of the key problems affecting the safe operation of nuclear power plants （NPPs）. The nitrogen-added stainless steel is a kind of possible candidate materials for mitigating SCC since reducing the carbon content and adding nitrogen to offset the loss in strength caused by the decrease in carbon content can mitigate the problem of sensitization. However, the reports of SCC of nitrogen-added stainless steels in high temperature water are few available. The effects of applied potential and sensitization treatment on the SCC of a newly developed nitrogen-containing stainless steel （SS） 316LN in high temperature water doped with chloride at 250 ℃ were studied by using slow strain rate tests （SSRTs）. The SSRT results are compared with our data previously published for 316 SS without nitrogen and 304NG SS with nitrogen, and the possible mechanism affecting the SCC behaviors of the studied steels is also discussed based on SSRT and microstucture analysis results. The susceptibility to cracking of 316LN SS normally increases with increasing potential. The susceptibility to SCC of 316LN SS was less than that of 316 SS and 304NG SS. Sensitization treatment at 700℃ for 30 h showed little effect on the S CC of 316LN S S and significant effect on the S CC of 316 S S. The predominant cracking mode for the 316LN S S in both annealed state and the state after the sensitization treatment was transgranular. The presented conditions of mitigating stress corrosion cracking are some useful information for the safe use of 316LN SS in NPPs.
基金supported by grants from the National Natural Science Foundation of China,China(Nos.81870397,82000534,and 82073156)Shenzhen Kangzhe Pharmaceutical Co.Ltd,China(URC-126/PBC)+1 种基金The Fifth Suzhou Health Talent Project(GSWS201903)The Suzhou Radiotherapy Clinical Medical Center Project,Suzhou,Jiangsu,China(Szlcyxzx202103).
文摘Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure without appropriate treatment(Terziroli Beretta-Piccoli et al.,2019).
基金This study was funded by“Strong youth”key talents of scientific and technological innovation of the Xinjiang Construction Crops(No.2021CB040)“Science and Technology Project of the Eighth Division(No.2022NY03)”.
文摘This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields in four areas(Anjihai,Shihezi suburbs,Mosuowan and Xiayedi)were selected for residual film collection.The average content of residual film in the Eighth Division was 104 kg/ha.The residual film content in the four areas decreased in the order Anjihai>Shihezi suburbs>Mosuowan>Xiayedi.The average amount of residual film collected from cotton fields was greater than that from corn fields.Residual film content in the cotton field at soil depths of 0~10 and 10~30 cm was higher than that in the corn field,whereas the residual film content at a 30–50 cm soil depth in the corn field was higher than that in the cotton field.The results showed that farmers do not consider the long-term benefits,the high cost and short time of recycling,and the easy recycling of surface residual film.The shallow that the higher content of residual film,the less water in the soil of cotton.The same time,the results showed that the quantity of residual film in cotton field had greater influence on cotton quality.
基金supported by the National Natural Science Foundation of China(Nos 51822208,21771187,2179005021790051,21905290)the Youth innovation Promotion Association CAS(No.2020215)+2 种基金the Frontier Science Research Project(QYZDB-SSW-JSCO52)the Chinese Academy of Sciences,the Taishan Scholars Program of Shandong Province(tsqn201812111)the Institute Research Project(QIBEBT ZZBS 201809)。
文摘Graphdiyne(GDY),as a new carbon material with two-dimensional structure composed by sp2 and sp carbon atoms,has exhibited excellent properties in various fields due to its conjugated pore structure,high specific surface area and stable structure.Various properties can also be tuned through the adjustability of the electronic structure by chemical methods.This article systematically discusses the preparation methods and strategies of GDY and GDY based materials.These preparation methods provide the way for us to obtain various GDY materials targeting specific research and application.
基金financially supported by the National Natural Science Foundation of China(Grants 41330210,41520104004)
文摘As a window of insight into the lower crust, high pressure granulite has received much attention since last decade. Yushugou high pressure granulite-peridotite Complex was located in the northeast margin of Southern Tianshan, NW China. Previous ideas agreed that the peridotite unit in Yushugou, combined with the ultramafic rocks in Tonghuashan and Liuhuangshan, represent an ophiolite belt. However, the metamorphic evolution and tectonic mechanism of the Yushugou high pressure （HP） granulite remain controversial. Petrological investigations and phase equilibrium modelling for two representative fclsic granulitc samples suggest two stages metamorphism of the rocks in Yushugou Complex. Granulite facies metamorphism （Stage I） with P-T conditions of 9.8-10.4 kbar at 895-920℃ was recorded by the porphyroblastic garnet core; HP granulite facies metamorphism （Stage II） shows P-T conditions of 13.2-13.5 kbar at 845-860℃, based on the increasing grossular and decreasing pyrope contents of garnet rims. The Yushugou HP felsic granulites have recorded an anti- clockwise P-T path, characterized by the temperature decreasing and pressure increasing simultaneously. The LA-ICP-MS isotopic investigations on zircons from the felsic granulite show that the protolith ages of the granlulites are -430 Ma, with two age groups of-390 Ma and 340-350 Ma from the metamorphic rims of zircon, indicating the Stage I and II metamorphic events, respectively. A tectonic model was proposed to interpret the processes. The investigated felsic granulite was derived from deep rooted hanging wall, with Stage I granulite facies metamorphism of -390 Ma, which may he related to the Devonian arc magmatic intrusion; Stage II HP granulite facies metamorphism （340-350 Ma） may due to the involvement of being captured into the subducting slab and experienced the high pressure metamorphism.
基金financially supported by the National Natural Science Foundation of China(No.U1862103)
文摘This work proposed to use the ionic liquid [EMIM][BF_4] as absorbent for the absorption of gaseous acetic acid. The feasibility of this technology was investigated from molecular level to industrial scale. The acetic acid absorption experiment was carried out using [EMIM][BF_4],and the removal ratio of acetic acid in the gas product can achieve 88.6% at 20C under atmospheric pressure at the laboratory scale. Based on the experimental results, a reliable strict equilibrium phase model embedding the parameters of the UNIFAC model was established. On this basis, the conceptual process design and optimization of acetic acid removal by [EMIM][BF_4] at an industrial scale was done, and the most suitable design and operation parameters were obtained. For a further step, the binding energy between [EMIM][BF_4] and acetic acid was calculated to give some insights into the separation mechanism, and the results indicate that the interaction between acetic acid and IL is much stronger than that between nitrogen and IL. Moreover, hydrogen bond can be formed between the cation-acetic acid as well as the anion-acetic acid.
