The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmi...The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min<sup>-1</sup> at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.展开更多
As of the end of 2009, the total installed capacity of Huaneng Group Corporation broke through 100 GW, thus, Huaneng Group became the largest power generation enterprise in the world.
It is well known that methane hydrate has been identified as an alternative resource due to its massive reserves and clean property. However, hydrate dissociation during oil and gas development(OGD) process in deep wa...It is well known that methane hydrate has been identified as an alternative resource due to its massive reserves and clean property. However, hydrate dissociation during oil and gas development(OGD) process in deep water can affect the stability of subsea equipment and formation. Currently, there is a serious lack of studies over quantitative assessment on the effects of hydrate dissociation on wellhead stability. In order to solve this problem, ABAQUS finite element software was used to develop a model and to evaluate the behavior of wellhead caused by hydrate dissociation. The factors that affect the wellhead stability include dissociation range, depth of hydrate formation and mechanical properties of dissociated hydrate region. Based on these, series of simulations were carried out to determine the wellhead displacement. The results revealed that, continuous dissociation of hydrate in homogeneous and isotropic formations can causes the non-linear increment in vertical displacement of wellhead. The displacement of wellhead showed good agreement with the settlement of overlying formations under the same conditions. In addition, the shallower and thicker hydrate formation can aggravate the influence of hydrate dissociation on the wellhead stability. Further, it was observed that with the declining elastic modulus and Poisson's ratio, the wellhead displacement increases. Hence, these findings not only confirm the effect of hydrate dissociation on the wellhead stability, but also lend support to the actions, such as cooling the drilling fluid, which can reduce the hydrate dissociation range and further make deepwater operations safer and more efficient.展开更多
Since its founding in 2000, the Forum on China-Africa Cooper ation （FOCAC） has without doubt become a world-class international platform with a track record of solid delivery results. China Africa traditional friend...Since its founding in 2000, the Forum on China-Africa Cooper ation （FOCAC） has without doubt become a world-class international platform with a track record of solid delivery results. China Africa traditional friendship and cooperation had had long trajectories before the establishment of the platform; but FOCAC not only re-engineered these ties in a more result-oriented fashion.展开更多
Although China's agricultural subsidies have played a certain positive role,they also have some negative effects. This paper analyzes the relationship between agricultural green development and agricultural subsid...Although China's agricultural subsidies have played a certain positive role,they also have some negative effects. This paper analyzes the relationship between agricultural green development and agricultural subsidies,points out the incompatibility between agricultural subsidies and agricultural green development at this stage. Finally,aimed at adjusting agricultural subsidy policy to promote agricultural green development,the article puts forward the corresponding measures and recommendations.展开更多
This paper attempts to study the interactive relationship among financial development,industrial structure adjustment and urbanization in China.Based on the data from 1978 to 2018,this paper establishes a VAR model fo...This paper attempts to study the interactive relationship among financial development,industrial structure adjustment and urbanization in China.Based on the data from 1978 to 2018,this paper establishes a VAR model for empirical analysis.The results show that after the impulse response analysis and variance decomposition of the model,industrial structure adjustment and urbanization have a positive impact on financial development in the long run.Financial development and industrial structure adjustment do not play a positive role in the process of urbanization,and there is still room for further development.It is suggested that the state should strengthen the financial support for urbanization so that the two can develop in coordination.At the same time,we should adhere to the simultaneous development of industrial structure adjustment and urbanization to ensure the simultaneous development of financial scale and efficiency.展开更多
As a part of certain region,agricultural development has inevitable connection with regional urbanization,and they are highly heterogeneous and complementary in space. Their internal relationship is manifested as agri...As a part of certain region,agricultural development has inevitable connection with regional urbanization,and they are highly heterogeneous and complementary in space. Their internal relationship is manifested as agricultural structure suits demand of urbanization development through adjustment in the process of urbanization,while urbanization is based on development of regional agriculture. From history of world agriculture and urbanization development,agriculture firstly provides primitive accumulation for urbanization development,and drives regional urbanization through promoting agricultural development. When urbanization develops to certain stage,urbanization accumulation increases and reaches the goal of " boosting urbanization through agriculture". If urbanization develops slowly,agricultural adjustment will lack motive force. On the contrary,weak agricultural development will lead to stagnation of urbanization. Therefore,adjustment of agricultural structure and urbanization development are interconnected,mutually promoted and restricted,and interdependent.展开更多
The 2025 Two Sessions,comprising the National People’s Congress(NPC)and the Chinese People’s Political Consultative Conference(CPPCC),are among the most significant political events in China.These annual gatherings ...The 2025 Two Sessions,comprising the National People’s Congress(NPC)and the Chinese People’s Political Consultative Conference(CPPCC),are among the most significant political events in China.These annual gatherings not only shape China’s domestic policies but also influence its foreign relations,particularly with neighboring countries like Myanmar.As a journalist based in Beijing with extensive experience in Myanmar’s socio-political landscape,I explore how the outcomes of the 2025 Two Sessions could positively impact Myanmar,focusing on economic cooperation,infrastructure development,cultural exchange,and regional stability.展开更多
Pentatricopepetide repeat （PPR） proteins are a large family of RNA-binding proteins involved in RNA meta- bolism in plant organelles. Although many PPR proteins have been functionally studied, few of them are identi...Pentatricopepetide repeat （PPR） proteins are a large family of RNA-binding proteins involved in RNA meta- bolism in plant organelles. Although many PPR proteins have been functionally studied, few of them are identified with a function in mitochondrial RNA stability. By using a reverse genetic approach, we characterized the role of the mitochondrion-targeted PPR78 protein in nad5 mature mRNA stability and maize （Zea mays） seed development. Loss of PPR78 function leads to a dramatic reduction in the steady-state level of mitochondrial nad5 mature mRNA, blocks the assembly of complex I in the electron transport chain, and causes an arrest in embryogenesis and endosperm development. Characterization of a second strong allele confirms the function of PPR78 in nad5 mRNA accumulation and maize seed development. The generation of mature nad5 requires the assembly of three distinct precursor RNAs via transsplicing reactions, and the accumulation ofnad5T1 precursor is reduced in the ppr78 mutants. However, it is the instability of mature nad5 rather than nad5T1 causing loss of the full-length nad5 transcript, and degradation of nad5 losing both translation start and stop codons is enriched in the mutant. Our data imply the assembly of mature nad5 mRNA precedes the protection of PPR78.展开更多
Selective laser melting was used to produce an aluminum alloy Al-8.5Fe-1.3V-1.7Si（wt%）. The effects of heat treatment on microstructure evolution and phase stability during long-term thermal exposure of the deposits...Selective laser melting was used to produce an aluminum alloy Al-8.5Fe-1.3V-1.7Si（wt%）. The effects of heat treatment on microstructure evolution and phase stability during long-term thermal exposure of the deposits were investigated. Results show that the microquasi-crystalline phase, Al12（Fe,V）3Si and AlmF e metastable phases coexisted with α-Al in the as-produced alloy. Annealing at 400 ℃ resulted in decomposition of microquasi-crystalline phase and supersaturated α-Al into Al12（Fe, V）3Si phase in the fusion zone, accompanied by the decrease in alloy hardness. The activation energy of this decomposition process was 115 k J/mol. A more homogenous microstructure was obtained after annealing at 400 °C for 60 min,which was resistant to coarsening exposed at 425 °C up to 500 h. The Al12（Fe,V）3Si and AlmF e phases were coarsened at 475 and 525℃ with increasing the exposure time. Coarsening of Al12（Fe,V）3Si phase was attributed to a combination of volume diffusion and grain boundary diffusion mechanism of Fe. Heat treatment at 600℃ resulted in accelerated microstructure coarsening and formation of large-sized equilibrium phases, which signi？cantly degraded the room temperature microhardness.展开更多
The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of signi...The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.展开更多
This study's primary purpose was to explore the role of tourism development in enhancing well-being in a highly populated developing economy by focusing on the case study of Pakistan Several econometric techniques...This study's primary purpose was to explore the role of tourism development in enhancing well-being in a highly populated developing economy by focusing on the case study of Pakistan Several econometric techniques and approaches were used on annual time series data covering the 1990-2016 period to investigate the causal relationship of well-being with tourism development,political stability,economics,and population growth.The findings suggested that tourism development enhances economic growth and well-being,hence providing support for the tourism-led growth hypothesis However,population growth and political instability exhibited a negative relationship with well-being;in addition,the level of political stability determined tourism activities.Hence,this study is unique due to its specific focus on the role of political stability and tourism development in the enhancement of wellbeing in a highly populated developing economy Moreover,the practical implications of the study have been provided in light of the main findings.展开更多
Green development is an important concept based on China's needs and the international situation.Green development will greatly help China choose its path for economic growth.In the newly ratified Paris Agreement,...Green development is an important concept based on China's needs and the international situation.Green development will greatly help China choose its path for economic growth.In the newly ratified Paris Agreement,the carbon emission reduction target willingly and determinedly proposed by China is very challenging.It will increase China's cost per unit of carbon dioxide emissions,slow China's economy growth,and set the upper limit for China's carbon emissions in the future.Facing these challenges,China needs to properly conduct carbon allocations under restrictions and promote green and low carbon development of the Chinese economy primarily by reinforcing structural adjustments and optimizing energy structures,upgrading industrial structures,being actively involved in international cooperation on carbon emission reduction and using other positive strategies.展开更多
For an atomic gravimeter,the measured value of the Earth’s gravity acceleration g is the projection of the local gravity on the direction of Raman laser beams.To accurately measure the g,the Raman laser beams should ...For an atomic gravimeter,the measured value of the Earth’s gravity acceleration g is the projection of the local gravity on the direction of Raman laser beams.To accurately measure the g,the Raman laser beams should be parallel to the g direction.We analyze the tilt effect of the Raman beams on g measurement and present a general method for the tilt adjustment.The systematic error caused by the tilt angle is evaluated as 0(+0,0.8)µGal(1µGal=10 nm/s^2)and the drift is also compensated in real time.Our method is especially suitable for the portable atomic gravimeter which focuses on the mobility and field applications.展开更多
The purpose of this paper is to use cross country regression analysis on a large set of countries from around the world for the year 2007 to test the hypothesis that greater instability, political or economic leads to...The purpose of this paper is to use cross country regression analysis on a large set of countries from around the world for the year 2007 to test the hypothesis that greater instability, political or economic leads to reduced levels of human rights. The results of the paper＇s econometric analysis tend to support the hypothesis that increased levels of either political instability or economic instability are detrimental to human rights within countries.展开更多
This case study of the Hexi Corridor, Northwestern China, utilizes statistical methods to estimate quantitatively the interaction at a regional level between climate change, ancient social developments, and political ...This case study of the Hexi Corridor, Northwestern China, utilizes statistical methods to estimate quantitatively the interaction at a regional level between climate change, ancient social developments, and political coping strategies over the past 2000 years. The data is sourced from high-resolution reconstructions of climate series(temperature and precipitation), and historical records of cultivated land, war, population, and changes in regional administrative systems. The results show that moisture conditions played a more significant role than temperature in driving land reclamation in the Hexi Corridor. Analysis also showed a negative correlation between war frequency and the area of cultivated land in the Corridor over 20-year time intervals. Population growth was found to have a significant positive correlation with the cultivated land area during the study period. The results indicate that a climate-induced decline in agricultural production and the subsequent fluctuations in population could act as a trigger for social unrest, which is especially true at the mutual decadal time-scales. However, the interaction with administrative reform also suggests that, in the face of social and economic turmoil, a reasonable administrative hierarchy could strengthen the social governance of regional government, and promote social stability and economic development at a regional level. The study substantiates this notion with empirical quantitative evidence.展开更多
Mealybugs, such as Phenacoccus solenopsis, are highly sexually dimorphic. Winged adult males present such remarkable morphological differences from females that, to the untrained eye, conspecific adults of both sexes ...Mealybugs, such as Phenacoccus solenopsis, are highly sexually dimorphic. Winged adult males present such remarkable morphological differences from females that, to the untrained eye, conspecific adults of both sexes of P. solenopsis may be considered as two different insect species. A method to investigate sex-dimorphic mechanisms is by evaluating gene expression using RT-qPCR. However, the accuracy and consistency of this technique depend on the reference gene(s) selected. In this study, we analyzed the expression of 10 candidate reference genes in male and female P. solenopsis at different development stages, using common algorithms including the ?Ct method, NormFinder, geNorm, BestKeeper, and a web-based analysis tool, RefFinder. The results showed that EF1-β, RP-L32 and RP-18 S were selected as the most stable genes by both the ?Ct method and NormFinder; TUB-α was the most stable gene identified by BestKeeper; and RP-L40 and RP-L32 were the most stable genes ranked by geNorm. RefFinder, a comprehensive analysis software, ranked the ten genes and determined EF1-β and RP-L32 as the most suitable reference genes for the various developmental stages in male and female P. solenopsis. Furthermore, the two most suitable reference genes were validated by examining expression of the juvenile hormone acid O-methytransferase(JHAMT) gene. Results of the validation portion of the study showed that JHAMT expression was sex-biased towards males and exhibited a dynamic and classic expression pattern among the P. solenopsis developmental stages. The results can help further our knowledge on the molecular mechanisms underlying sexual dimorphic development in P. solenopsis.展开更多
Based on impact of human activities on regional information system, this paper focuses on sedating, adjusting and testing methodology adopted for the regional sustainable development. The case study of Jiangxi Provinc...Based on impact of human activities on regional information system, this paper focuses on sedating, adjusting and testing methodology adopted for the regional sustainable development. The case study of Jiangxi Province aims to show how to simulate, adjust and test regional sustainable development in all provinces.展开更多
A numerical simulation platform that analyzes the variation of the slope factor of safety with time instantaneously is proposed based on heat conduction theory to study the law of stability development of permafrost s...A numerical simulation platform that analyzes the variation of the slope factor of safety with time instantaneously is proposed based on heat conduction theory to study the law of stability development of permafrost slopes during thawing.This platform considers ice-water phase change,elastoplastic constitutive behavior and strength reduction in thawing permafrost and can evaluate the factor of safety of permafrost slopes with different slope angles and water contents.Results indicate that under different slope angles and water contents,the evolution of the factor of safety with time displays two stages:nonlinearly decreasing at first and then essentially remaining constant.During the decreasing stage,the plastic slip line overlaps with the thawing front.In this stage,the selfweight of the post-thawed permafrost layer increases continuously while the shear strength of the frozen-thaw interface keeps unchanged.This is the main reason leading to the decrease in the factor of safety.In the second stage,the thawing depth increases continuously while the position of the plastic slip line remains unchanged,resulting in a constant safety factor stage.展开更多
文摘The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min<sup>-1</sup> at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.
文摘As of the end of 2009, the total installed capacity of Huaneng Group Corporation broke through 100 GW, thus, Huaneng Group became the largest power generation enterprise in the world.
基金supported by the Program for the Changjiang Scholars and Innovative Research Team in University (No. IRT_14R58)the National Natural Science Foundation of China (No. 51704311)+3 种基金the Fundamental Research Funds for the Central Universities (No. 16CX06 033A)the National Key Research and Development Program (No. 2016YFC0304005)the National Basic Research Program of China (973 Program) (No. 2015CB251 201)the Qingdao Science and Technology Project (No. 15-9-1-55-jch)
文摘It is well known that methane hydrate has been identified as an alternative resource due to its massive reserves and clean property. However, hydrate dissociation during oil and gas development(OGD) process in deep water can affect the stability of subsea equipment and formation. Currently, there is a serious lack of studies over quantitative assessment on the effects of hydrate dissociation on wellhead stability. In order to solve this problem, ABAQUS finite element software was used to develop a model and to evaluate the behavior of wellhead caused by hydrate dissociation. The factors that affect the wellhead stability include dissociation range, depth of hydrate formation and mechanical properties of dissociated hydrate region. Based on these, series of simulations were carried out to determine the wellhead displacement. The results revealed that, continuous dissociation of hydrate in homogeneous and isotropic formations can causes the non-linear increment in vertical displacement of wellhead. The displacement of wellhead showed good agreement with the settlement of overlying formations under the same conditions. In addition, the shallower and thicker hydrate formation can aggravate the influence of hydrate dissociation on the wellhead stability. Further, it was observed that with the declining elastic modulus and Poisson's ratio, the wellhead displacement increases. Hence, these findings not only confirm the effect of hydrate dissociation on the wellhead stability, but also lend support to the actions, such as cooling the drilling fluid, which can reduce the hydrate dissociation range and further make deepwater operations safer and more efficient.
文摘Since its founding in 2000, the Forum on China-Africa Cooper ation （FOCAC） has without doubt become a world-class international platform with a track record of solid delivery results. China Africa traditional friendship and cooperation had had long trajectories before the establishment of the platform; but FOCAC not only re-engineered these ties in a more result-oriented fashion.
文摘Although China's agricultural subsidies have played a certain positive role,they also have some negative effects. This paper analyzes the relationship between agricultural green development and agricultural subsidies,points out the incompatibility between agricultural subsidies and agricultural green development at this stage. Finally,aimed at adjusting agricultural subsidy policy to promote agricultural green development,the article puts forward the corresponding measures and recommendations.
基金National Natural Science Foundation of China(71934001)Provincial Teaching and Research Project(2018jyxm1305).
文摘This paper attempts to study the interactive relationship among financial development,industrial structure adjustment and urbanization in China.Based on the data from 1978 to 2018,this paper establishes a VAR model for empirical analysis.The results show that after the impulse response analysis and variance decomposition of the model,industrial structure adjustment and urbanization have a positive impact on financial development in the long run.Financial development and industrial structure adjustment do not play a positive role in the process of urbanization,and there is still room for further development.It is suggested that the state should strengthen the financial support for urbanization so that the two can develop in coordination.At the same time,we should adhere to the simultaneous development of industrial structure adjustment and urbanization to ensure the simultaneous development of financial scale and efficiency.
基金Supported by Scientific Research Foundation of Hunan Provincial Department of Education(13B143)
文摘As a part of certain region,agricultural development has inevitable connection with regional urbanization,and they are highly heterogeneous and complementary in space. Their internal relationship is manifested as agricultural structure suits demand of urbanization development through adjustment in the process of urbanization,while urbanization is based on development of regional agriculture. From history of world agriculture and urbanization development,agriculture firstly provides primitive accumulation for urbanization development,and drives regional urbanization through promoting agricultural development. When urbanization develops to certain stage,urbanization accumulation increases and reaches the goal of " boosting urbanization through agriculture". If urbanization develops slowly,agricultural adjustment will lack motive force. On the contrary,weak agricultural development will lead to stagnation of urbanization. Therefore,adjustment of agricultural structure and urbanization development are interconnected,mutually promoted and restricted,and interdependent.
文摘The 2025 Two Sessions,comprising the National People’s Congress(NPC)and the Chinese People’s Political Consultative Conference(CPPCC),are among the most significant political events in China.These annual gatherings not only shape China’s domestic policies but also influence its foreign relations,particularly with neighboring countries like Myanmar.As a journalist based in Beijing with extensive experience in Myanmar’s socio-political landscape,I explore how the outcomes of the 2025 Two Sessions could positively impact Myanmar,focusing on economic cooperation,infrastructure development,cultural exchange,and regional stability.
文摘Pentatricopepetide repeat （PPR） proteins are a large family of RNA-binding proteins involved in RNA meta- bolism in plant organelles. Although many PPR proteins have been functionally studied, few of them are identified with a function in mitochondrial RNA stability. By using a reverse genetic approach, we characterized the role of the mitochondrion-targeted PPR78 protein in nad5 mature mRNA stability and maize （Zea mays） seed development. Loss of PPR78 function leads to a dramatic reduction in the steady-state level of mitochondrial nad5 mature mRNA, blocks the assembly of complex I in the electron transport chain, and causes an arrest in embryogenesis and endosperm development. Characterization of a second strong allele confirms the function of PPR78 in nad5 mRNA accumulation and maize seed development. The generation of mature nad5 requires the assembly of three distinct precursor RNAs via transsplicing reactions, and the accumulation ofnad5T1 precursor is reduced in the ppr78 mutants. However, it is the instability of mature nad5 rather than nad5T1 causing loss of the full-length nad5 transcript, and degradation of nad5 losing both translation start and stop codons is enriched in the mutant. Our data imply the assembly of mature nad5 mRNA precedes the protection of PPR78.
基金support of the National High Technology Research and Development Program of China("863 Program",Grant No.21100002013101006)
文摘Selective laser melting was used to produce an aluminum alloy Al-8.5Fe-1.3V-1.7Si（wt%）. The effects of heat treatment on microstructure evolution and phase stability during long-term thermal exposure of the deposits were investigated. Results show that the microquasi-crystalline phase, Al12（Fe,V）3Si and AlmF e metastable phases coexisted with α-Al in the as-produced alloy. Annealing at 400 ℃ resulted in decomposition of microquasi-crystalline phase and supersaturated α-Al into Al12（Fe, V）3Si phase in the fusion zone, accompanied by the decrease in alloy hardness. The activation energy of this decomposition process was 115 k J/mol. A more homogenous microstructure was obtained after annealing at 400 °C for 60 min,which was resistant to coarsening exposed at 425 °C up to 500 h. The Al12（Fe,V）3Si and AlmF e phases were coarsened at 475 and 525℃ with increasing the exposure time. Coarsening of Al12（Fe,V）3Si phase was attributed to a combination of volume diffusion and grain boundary diffusion mechanism of Fe. Heat treatment at 600℃ resulted in accelerated microstructure coarsening and formation of large-sized equilibrium phases, which signi？cantly degraded the room temperature microhardness.
基金supported by the National Natural Science Foundation of China (No.52374124)National Youth Science Foundation of China (No.52204135)+3 种基金Xing Liao Talent Plan (No.XLYC2202004)Young Elite Scientists Sponsorship Program by CAST (No.2023QNRC001)Liaoning Province International Science and Technology Cooperation Plan (No.2022JH2/1070004)Liaoning Natural Science Foundation Program (No.2022-BS-327)。
文摘The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development distance,with the coefficient gradually decreasing as the coordinated development distance increases.These findings provide a theoretical guideline for designing similar slope shape parameters and conducting stability analysis.
文摘This study's primary purpose was to explore the role of tourism development in enhancing well-being in a highly populated developing economy by focusing on the case study of Pakistan Several econometric techniques and approaches were used on annual time series data covering the 1990-2016 period to investigate the causal relationship of well-being with tourism development,political stability,economics,and population growth.The findings suggested that tourism development enhances economic growth and well-being,hence providing support for the tourism-led growth hypothesis However,population growth and political instability exhibited a negative relationship with well-being;in addition,the level of political stability determined tourism activities.Hence,this study is unique due to its specific focus on the role of political stability and tourism development in the enhancement of wellbeing in a highly populated developing economy Moreover,the practical implications of the study have been provided in light of the main findings.
基金the result of current research"Political Economic Studies of the Reshaping of the International Division of Labour System and China’s Industrial Restructuring Strategy"(project number:14BJL048)an ordinary project supported by China’s National Social Sciences Fund+1 种基金"Studies of the Paris Agreement and Cooperation between China,Japan and South Korea on Carbon Emission Reduction"(project number:AS1620)a project of the Asia Research Centre of Nankai University
文摘Green development is an important concept based on China's needs and the international situation.Green development will greatly help China choose its path for economic growth.In the newly ratified Paris Agreement,the carbon emission reduction target willingly and determinedly proposed by China is very challenging.It will increase China's cost per unit of carbon dioxide emissions,slow China's economy growth,and set the upper limit for China's carbon emissions in the future.Facing these challenges,China needs to properly conduct carbon allocations under restrictions and promote green and low carbon development of the Chinese economy primarily by reinforcing structural adjustments and optimizing energy structures,upgrading industrial structures,being actively involved in international cooperation on carbon emission reduction and using other positive strategies.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFA0301601)the National Natural Science Foundation of China(Grant No.11674301)+1 种基金Anhui Initiative in Quantum Information Technologies,China(Grant No.AHY120000)Shanghai Municipal Science and Technology Major Project,China(Grant No.2019SHZDZX01).
文摘For an atomic gravimeter,the measured value of the Earth’s gravity acceleration g is the projection of the local gravity on the direction of Raman laser beams.To accurately measure the g,the Raman laser beams should be parallel to the g direction.We analyze the tilt effect of the Raman beams on g measurement and present a general method for the tilt adjustment.The systematic error caused by the tilt angle is evaluated as 0(+0,0.8)µGal(1µGal=10 nm/s^2)and the drift is also compensated in real time.Our method is especially suitable for the portable atomic gravimeter which focuses on the mobility and field applications.
文摘The purpose of this paper is to use cross country regression analysis on a large set of countries from around the world for the year 2007 to test the hypothesis that greater instability, political or economic leads to reduced levels of human rights. The results of the paper＇s econometric analysis tend to support the hypothesis that increased levels of either political instability or economic instability are detrimental to human rights within countries.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19040101)the Key Research Program of the Chinese Academy of Sciences (Grant No. ZDRW-ZS-2016-6 and KGFZD-135-17-009-1)
文摘This case study of the Hexi Corridor, Northwestern China, utilizes statistical methods to estimate quantitatively the interaction at a regional level between climate change, ancient social developments, and political coping strategies over the past 2000 years. The data is sourced from high-resolution reconstructions of climate series(temperature and precipitation), and historical records of cultivated land, war, population, and changes in regional administrative systems. The results show that moisture conditions played a more significant role than temperature in driving land reclamation in the Hexi Corridor. Analysis also showed a negative correlation between war frequency and the area of cultivated land in the Corridor over 20-year time intervals. Population growth was found to have a significant positive correlation with the cultivated land area during the study period. The results indicate that a climate-induced decline in agricultural production and the subsequent fluctuations in population could act as a trigger for social unrest, which is especially true at the mutual decadal time-scales. However, the interaction with administrative reform also suggests that, in the face of social and economic turmoil, a reasonable administrative hierarchy could strengthen the social governance of regional government, and promote social stability and economic development at a regional level. The study substantiates this notion with empirical quantitative evidence.
基金supported by the National Natural Science Foundation of China(31270580)the Key Research and Development Program of Zhejiang Province,China(2018C02036)+1 种基金the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD19B06)the Special Fund for Agro-scientific Research in the Public Interest of China(201103026)
文摘Mealybugs, such as Phenacoccus solenopsis, are highly sexually dimorphic. Winged adult males present such remarkable morphological differences from females that, to the untrained eye, conspecific adults of both sexes of P. solenopsis may be considered as two different insect species. A method to investigate sex-dimorphic mechanisms is by evaluating gene expression using RT-qPCR. However, the accuracy and consistency of this technique depend on the reference gene(s) selected. In this study, we analyzed the expression of 10 candidate reference genes in male and female P. solenopsis at different development stages, using common algorithms including the ?Ct method, NormFinder, geNorm, BestKeeper, and a web-based analysis tool, RefFinder. The results showed that EF1-β, RP-L32 and RP-18 S were selected as the most stable genes by both the ?Ct method and NormFinder; TUB-α was the most stable gene identified by BestKeeper; and RP-L40 and RP-L32 were the most stable genes ranked by geNorm. RefFinder, a comprehensive analysis software, ranked the ten genes and determined EF1-β and RP-L32 as the most suitable reference genes for the various developmental stages in male and female P. solenopsis. Furthermore, the two most suitable reference genes were validated by examining expression of the juvenile hormone acid O-methytransferase(JHAMT) gene. Results of the validation portion of the study showed that JHAMT expression was sex-biased towards males and exhibited a dynamic and classic expression pattern among the P. solenopsis developmental stages. The results can help further our knowledge on the molecular mechanisms underlying sexual dimorphic development in P. solenopsis.
基金Periodical achievement of the provincial-level project Population, Resources. Environment and Economic Development of Jiangxi su
文摘Based on impact of human activities on regional information system, this paper focuses on sedating, adjusting and testing methodology adopted for the regional sustainable development. The case study of Jiangxi Province aims to show how to simulate, adjust and test regional sustainable development in all provinces.
基金supported by the National Natural Science Foundation of China(Nos.42272319,42101132 and 42172314).
文摘A numerical simulation platform that analyzes the variation of the slope factor of safety with time instantaneously is proposed based on heat conduction theory to study the law of stability development of permafrost slopes during thawing.This platform considers ice-water phase change,elastoplastic constitutive behavior and strength reduction in thawing permafrost and can evaluate the factor of safety of permafrost slopes with different slope angles and water contents.Results indicate that under different slope angles and water contents,the evolution of the factor of safety with time displays two stages:nonlinearly decreasing at first and then essentially remaining constant.During the decreasing stage,the plastic slip line overlaps with the thawing front.In this stage,the selfweight of the post-thawed permafrost layer increases continuously while the shear strength of the frozen-thaw interface keeps unchanged.This is the main reason leading to the decrease in the factor of safety.In the second stage,the thawing depth increases continuously while the position of the plastic slip line remains unchanged,resulting in a constant safety factor stage.
