Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fe...Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.展开更多
Background: Prolonged exposure to environmental toxicants like endocrine-disrupting chemicals has been linked to several ovarian pathologies. Exposure to endocrine-disrupting chemicals may start at any time of life fr...Background: Prolonged exposure to environmental toxicants like endocrine-disrupting chemicals has been linked to several ovarian pathologies. Exposure to endocrine-disrupting chemicals may start at any time of life from the fetal stage to adulthood resulting in various health complications The purpose of our study is to compare the concentration levels and association of benzopyrene, bisphenol A and genistein in patients with ovarian tumors and normal control group. We also sort to evaluate the predictive performance of benzopyrene, bisphenol A and genistein in patients with ovarian tumors. Methods: A case-control study was conducted for randomly selected participants involving 30 patients and 30 controls. 30 patients with radiologically diagnosed and histopathological confirmed ovarian tumors were included in the study between January 2022 and December 2022. Urine samples from each group were analyzed using liquid chromatography-mass spectrometry. Descriptive analysis for normally distributed continuous variables was done accordingly. Concentration levels of endocrine-disrupting chemicals were assessed using the Mann-Whitney test. The association of endocrine-disrupting chemicals with pathological ovarian tumors was analyzed using binary logistic regression. Evaluation of the diagnostic performance of endocrine-disrupting chemicals was analyzed using the ROC curve. Results: Overall, patients were significantly (P = 0.000) older than the healthy controls. Mean years (SD) were 36.7 (7.90) and 28.8 years (4.89) for patients and normal women respectively. Endometriomas had the highest incidence of 50%. The level of benzopyrene and bisphenol A in patients was significantly higher than those in the control group, while the level of genistein was significantly higher in normal controls. Benzopyrene and bisphenol A were significantly associated with ovarian cysts, and the incidence of pathological ovarian cysts was positively correlated to these EDCs, with OR value 64.79 (P = 0.005) for benzopyrene and 9.609 (P = 0.001) for bisphenol A. Genistein was significantly negatively correlated with the incidence of pathological ovarian tumors, with OR value of 0.153 (P = 0.007). Diagnostic performance on the AUC for benzopyrene, bisphenol A and genistein&l.展开更多
Reinforcement Learning(RL)based control algorithms can learn the control strategies for nonlinear and uncertain environment during interacting with it.Guided by the rewards generated by environment,a RL agent can lear...Reinforcement Learning(RL)based control algorithms can learn the control strategies for nonlinear and uncertain environment during interacting with it.Guided by the rewards generated by environment,a RL agent can learn the control strategy directly in a model-free way instead of investigating the dynamic model of the environment.In the paper,we propose the sampled-data RL control strategy to reduce the computational demand.In the sampled-data control strategy,the whole control system is of a hybrid structure,in which the plant is of continuous structure while the controller(RL agent)adopts a discrete structure.Given that the continuous states of the plant will be the input of the agent,the state–action value function is approximated by the fully connected feed-forward neural networks(FCFFNN).Instead of learning the controller at every step during the interaction with the environment,the learning and acting stages are decoupled to learn the control strategy more effectively through experience replay.In the acting stage,the most effective experience obtained during the interaction with the environment will be stored and during the learning stage,the stored experience will be replayed to customized times,which helps enhance the experience replay process.The effectiveness of proposed approach will be verified by simulation examples.展开更多
Melon(Cucumis melo L.)has a long history of cultivation worldwide.During cultivation,domestication,and selection breeding,the sugar content of mature melon fruits has been significantly increased.Compared with unsweet...Melon(Cucumis melo L.)has a long history of cultivation worldwide.During cultivation,domestication,and selection breeding,the sugar content of mature melon fruits has been significantly increased.Compared with unsweet melon and wild melon,rapid sucrose accumulation can occur in the middle and late stages of sweet melon fruit development.The phloem unloading pathway during the evolution and development of melon fruit has not been identified and analyzed.In this study,the phloem unloading pathway and the function of related sugar transporters in cultivated and wild melon fruits were analyzed by CFDA[5(6)-carbofluorescein diacetate]and esculin tracing,cytological pathway observation,qRT–PCR,and gene function analysis,etc.Results show that the phloem unloading pathway of wild melon fruit is largely symplastic,whereas the phloem unloading pathway of cultivated melon fruit shifts from symplastic to apoplasmic during development.According to a fruit grafting experiment,the fruit sink accumulates sugars independently.Correlation analysis showed that the expression amounts of several sucrose transporter genes were positively correlated with the sucrose content of melon fruit.Furthermore,CmSWEET10 was proved to be a sucrose transporter located on the plasma membrane of the phloem and highly expressed in the premature stage of sweet melon fruits,which means it may be involved in phloem apoplast unloading and sucrose accumulation in sweet melon fruits.Finally,we summarize a functional model of related enzymes and sugar transporters involved in the apoplast unloading of sweet melon fruits during enlargement and sucrose accumulation.展开更多
In this paper,based on the process data of evaluating the benchmark land prices of collective construction land and agricultural land,the score of influencing factors is calculated,and a regression model between value...In this paper,based on the process data of evaluating the benchmark land prices of collective construction land and agricultural land,the score of influencing factors is calculated,and a regression model between value-added benefits and influencing factors is established.According to the contribution of the government and collectives to value-added benefits,the distribution proportions of different purposes and levels are calculated.The research results show that there are significant differences in the distribution proportion of value-added income among different levels.The government distribution proportion decreases with the decrease of level,while the collective distribution proportion increases with the decrease of level.For each level of decrease in commercial service industry land and industrial and mining warehousing industry land,the government distribution proportion decreases by an average of 2.66%and 2.34%,while the collective distribution proportion increases by an average of 2.66%and 2.34%,respectively.The average distribution proportion of the government in the value-added income of commercial service industry land is 31.58%,which is much higher than the average income of 23.68%in the value-added income of industrial and mining warehousing industry land.展开更多
In addition to the quality and quantity of farmland, the health of farmland has also become an important research direction in the field of farmland protection. In order to comprehensively evaluate the relationship an...In addition to the quality and quantity of farmland, the health of farmland has also become an important research direction in the field of farmland protection. In order to comprehensively evaluate the relationship and distribution of health and farmland production capacity, the depression area behind the Yellow River in Henan Province is taken as the research object. Using production capacity evaluation data and system health evaluation results, the health status and production capacity of farmland in the region are coupled. The results show that high productivity farmland is most distributed in areas with moderate health risks, while low productivity farmland is more distributed in areas with low health risks. Based on their coupling characteristics, the depression area behind the Yellow River can be divided into five types, and management and protection strategies can be formulated separately.展开更多
Multiple-seam gas coproduction is a technology with potential to achieve economic targets.Physical experiments could replicate gas flow dynamics in two seams.In this study,numerical simulation was conducted based on p...Multiple-seam gas coproduction is a technology with potential to achieve economic targets.Physical experiments could replicate gas flow dynamics in two seams.In this study,numerical simulation was conducted based on physical experiments.Through calibration,the simulated results agreed with the experimental results.Three findings were obtained.First,the pressure distribution intrinsically depends on the depressurization effectiveness in each coal seam.The gas pressure difference and interval distance influence the pressure distribution by inhibiting depressurization in the top seams and bottom seams,respectively.Second,the production contribution shows a logarithmic relationship with the permeability ratio.The range of the production contribution difference grows from 11.24%to 99.99%when the permeability ratio increases 50 times.By comparison,reservoir pressure has a limited influence,with a maximum of 13.64%.Third,the interlayer interference of the top seams and bottom seams can be intensified by the reservoir pressure difference and the interval distance,respectively.The proposed model has been calibrated and verified and can be directly applied to engineering,serving as a reference for reservoir combination optimization.In summary,coal seams with a permeability ratio within 10,reservoir pressure difference within 1.50 MPa,and interval distances within 50 m are recommended to coproduce together.展开更多
Realization of negative stiffness(NS)in damping low frequency acoustic and mechanical vibration is relevant in engineering applications.In this work,assemblage of two repelling magnets was used to produce negative mag...Realization of negative stiffness(NS)in damping low frequency acoustic and mechanical vibration is relevant in engineering applications.In this work,assemblage of two repelling magnets was used to produce negative magnetic spring(NMS).A mass–spring system with NMS is experimented where the free and forced vibrations of the system are examined.The anti-phase movement is observed due to the presence of proposed NMS,confirming the analytical solution.We further showed the dynamics of the system containing NS spring could also be derived from Hamilton’s principle.展开更多
Mitogen-activated protein kinase(MAPK)cascades play important roles in plant immunity.Previously,we reported that the potato StMKK1 protein negatively regulates Nicotiana benthamiana resistance to Phytophthora infesta...Mitogen-activated protein kinase(MAPK)cascades play important roles in plant immunity.Previously,we reported that the potato StMKK1 protein negatively regulates Nicotiana benthamiana resistance to Phytophthora infestans.However,the functions of StMKK1 in potato immunity are unknown.To investigate the roles of StMKK1 in potato resistance to different pathogens,such as the potato late-blight pathogen P.infestans,the bacterial wilt pathogen Ralstonia solanacearum,and the gray-mold fungal pathogen Botrytis cinerea,we generated StMKK1 transgenic lines and investigated the response of potato transformants to destructive oomycete,bacterial,and fungal pathogens.The results showed that overexpression and silencing of StMKK1 do not alter plant growth and development.Interestingly,we found that StMKK1 negatively regulated potato resistance to the hemibiotrophic/biotrophic pathogens P.infestans and R.solanacearum,while it positively regulated potato resistance to the necrotrophic pathogen B.cinerea.Further investigation showed that overexpression of StMKK1 suppressed potato pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and salicylic acid(SA)-related responses,while silencing of StMKK1 enhanced PTI and SA-related immune responses.Taken together,our results showed that StMKK1 plays dual roles in potato defense against different plant pathogens via negative regulation of PTI and SA-related signaling pathways.展开更多
We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microc...We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microchip laser generating ~630ps pulses at 8.6 kHz repetition-rate and two amplification stages employing double cladding fiber and rod-type PCF respectively. The MOPA system obtains narrow spectral bandwidth, single-polarized pulses of 9W maximum output average power, corresponding to peak power of 1.7MW.展开更多
Catalytic oxidation of Hgo to Hg~O is an efficient way to remove Hg^(0) from coal-fired flue gas.The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg^(0) oxidation efficie...Catalytic oxidation of Hgo to Hg~O is an efficient way to remove Hg^(0) from coal-fired flue gas.The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg^(0) oxidation efficiency.Therefore,in the present work,wood vessels were used as sacrificial template to obtain Co_(3)O_(4) with ordered pore structure.SEM and BET results show that,when the mass concentrations of Co(NO_(3))_(2)·6H_(2)O was 20%,the obtained catalyst(Co_(3)O_(4) [20%Co(NO_(3))_(2)])possesses better pore structure and higher surface area.It will expose more available surface active sites and lower the mass transfer resistance.Furthermore,XPS results prove that Co_(3)O_(4) [20%Co(NO_(3))_(2)]has the highest ratio of chemisorbed oxygen which plays an important role in Hg^(0) oxidation process.These results lead to a better Hg^(0) oxidation efficiency of Co_(3)O_(4) [20%Co(NO_(3))_(2)],which is about 90%in the temperature range of 200 to 350℃,Furthermore,Co_(3)O_(4) [20%Co(NO_(3))_(2)]has a stable catalytic activity,and its Hg^(0) oxidation efficiency maintains above 90%at 250℃even after 90 h test,A probable reaction mechanism is deduced by the XPS results of the fresh,used and regenerated catalyst of Co_(3)O_(4) [20%Co(NO3)2].Chemisorbed oxygen can react with Hg^(0) forming HgO with the reduction of Co^(3+)to Co^(2)+.And lattice oxygen and gaseous oxygen can supplement the consumption of chemisorbed oxygen to oxidize Co^(2+)to Co^(3+).展开更多
Cancer-associated retinopathy (CAR) typically has a sudden or progressive onset of severe visual loss and an ominous association with an occult malignancy which contains breast cancer. Pathologically, CAR is the degen...Cancer-associated retinopathy (CAR) typically has a sudden or progressive onset of severe visual loss and an ominous association with an occult malignancy which contains breast cancer. Pathologically, CAR is the degeneration of photoreceptors. But the precise mechanism has not been fully established, CAR may result from autoimmune mediated apoptosis. And in recent years, there also have been some results demonstrating that tumor derived angiogenic factors such as VEGF may also confer the development of CAR, which may offer novel avenues for the therapeutic intervention in CAR. Early initiation of immunosuppressive therapy is critical for vision preservation. Future developments in rapid identification and longitudinal quantification of antibody levels would enable individualized management in these patients. The goal of this review was to analyze the epidemiology, the clinical features, the diagnosis and management of retinopathy in the context of recent advances in the elucidation of breast cancer-associated retinopathy (BCAR) pathogenesis.展开更多
[Objectives]This study was conducted to deeply understand the effects of production process on the quality of new types of tobacco sheets with different flavors.[Methods]Based on the pilot production process of thick ...[Objectives]This study was conducted to deeply understand the effects of production process on the quality of new types of tobacco sheets with different flavors.[Methods]Based on the pilot production process of thick pulp method,four different flavors of tobacco sheets were sampled at several links in the production process,for the detection of the contents of the main components in the samples,including propylene glycol,glycerol,menthol and glyceryl triacetate,so as to explore the change trends of various components in the thick pulp process.[Results]The change laws of propylene glycol and glycerol contents had a very high similarity,showing a trend of first decreasing and increasing then.The changes of menthol content and glyceryl triacetate content were greatly affected by the specific flavor formula.As one of the indexes of the new tobacco evaluation system,the alcohol-to-ester ratio data need to be further improved in the actual production and application process.[Conclusions]This study provides basic data support for improving the quality of tobacco sheets.展开更多
This paper first introduces the overview of real estate appraisal theory,the basic situation of real estate appraisal,the basic principles and characteristics of real estate appraisal,and three main appraisal methods....This paper first introduces the overview of real estate appraisal theory,the basic situation of real estate appraisal,the basic principles and characteristics of real estate appraisal,and three main appraisal methods.On this basis,the specific use scope of each method,the meaning of each parameter,and the influencing factors are analyzed.Then,based on the in-depth study of various existing appraisal theories and methods,a new appraisal method is proposed:the appraisal analysis method based on fuzzy analytic hierarchy process.展开更多
Taking Changyuan City of Henan Province,a pilot city of collective commercial construction land reform,as the research object,this paper analyzes the scientific connotation of"same land,same right,same price"...Taking Changyuan City of Henan Province,a pilot city of collective commercial construction land reform,as the research object,this paper analyzes the scientific connotation of"same land,same right,same price"of collective commercial construction land and state-owned land in the unified urban-rural construction land market system,and how to realize"same land,same right,same price".The results show that in order to realize the fair entry of collective construction land into the market,it must base on scientific use control,unify the urban and rural construction land market and adhere to the guidance of market mechanism,and finally realize the sustainable development of the land market.展开更多
According to the reason of quality change,cultivated land is divided into four change types: decrease,increase,land construction project and gradual change. Farmland grading factor method is used to evaluate the quali...According to the reason of quality change,cultivated land is divided into four change types: decrease,increase,land construction project and gradual change. Farmland grading factor method is used to evaluate the quality of cultivated land in Zhengzhou City. The results show that(1) the quality of cultivated land in Zhengzhou City has slightly increased during the study period. Due to the decrease in the amount of cultivated land,the production capacity has declined.(2) The impact of different types of cultivated land change on the quality of regional cultivated land is in the order of gradual change> decrease > increase > land construction project.(3) Zhengzhou City is able to maintain the quality of regional cultivated land through new cultivated land and project construction,but fails to maintain the production capacity. By analyzing the mechanism of regional cultivated land quality change in different types,the relationship between quality changes in various types of areas and overall quality changes could be analyzed,and it could provide policy recommendations for managers to formulate farmland quality and capacity protection,with significant application value.展开更多
The quality change of cultivated land resources requires the scientific deployment of monitoring areas.In this study,Yuzhou City is taken as an example to divide the quality monitoring control areas through the study ...The quality change of cultivated land resources requires the scientific deployment of monitoring areas.In this study,Yuzhou City is taken as an example to divide the quality monitoring control areas through the study of natural quality,utilization level,income level,and utilization characteristics,etc.Compared with the traditional administrative unit division or cultivated land quality division method,the regional homogeneity of this study is stronger,and there are quality differences between regions.It provides precondition and precision guarantee for the monitoring of cultivated land quality.展开更多
At present,the quality protection and early warning of cultivated land in China are actually based on the increase and decrease of the quantity of cultivated land and the change of its quality.The early warning of cul...At present,the quality protection and early warning of cultivated land in China are actually based on the increase and decrease of the quantity of cultivated land and the change of its quality.The early warning of cultivated land quality based on this is easy to cause the problem of missing and wrong alarm.Based on the quality and productivity change of regional cultivated land,early warning on the regional cultivated land quality is conducted in this study respectively,and the results of the two early warning are compared.Moreover,a multi-indicator cultivated land quality early warning based on the quality change,productivity change and auxiliary indicators is proposed.The results show that:early warning of cultivated land quality based on quality and productivity change of cultivated land has certain limitations.Based on multi-indicator early warning,the number of counties with heavy,medium and light warnings in Henan Province is 52,8 and 11 respectively.The multi-indicator early warning result of cultivated land quality is more accurate,which can provide a basis for cultivated land protection and management assessment,and has great application value.展开更多
基金supported by the Program for the National Natural Science Foundation of China(52070077,51879101,51779090)the National Program for Support of Top-Notch Young Professionals of China(2014)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT-13R17)Natural Science Foundation of Hunan Province(2022JJ20013,2021JJ40098).
文摘Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.
文摘Background: Prolonged exposure to environmental toxicants like endocrine-disrupting chemicals has been linked to several ovarian pathologies. Exposure to endocrine-disrupting chemicals may start at any time of life from the fetal stage to adulthood resulting in various health complications The purpose of our study is to compare the concentration levels and association of benzopyrene, bisphenol A and genistein in patients with ovarian tumors and normal control group. We also sort to evaluate the predictive performance of benzopyrene, bisphenol A and genistein in patients with ovarian tumors. Methods: A case-control study was conducted for randomly selected participants involving 30 patients and 30 controls. 30 patients with radiologically diagnosed and histopathological confirmed ovarian tumors were included in the study between January 2022 and December 2022. Urine samples from each group were analyzed using liquid chromatography-mass spectrometry. Descriptive analysis for normally distributed continuous variables was done accordingly. Concentration levels of endocrine-disrupting chemicals were assessed using the Mann-Whitney test. The association of endocrine-disrupting chemicals with pathological ovarian tumors was analyzed using binary logistic regression. Evaluation of the diagnostic performance of endocrine-disrupting chemicals was analyzed using the ROC curve. Results: Overall, patients were significantly (P = 0.000) older than the healthy controls. Mean years (SD) were 36.7 (7.90) and 28.8 years (4.89) for patients and normal women respectively. Endometriomas had the highest incidence of 50%. The level of benzopyrene and bisphenol A in patients was significantly higher than those in the control group, while the level of genistein was significantly higher in normal controls. Benzopyrene and bisphenol A were significantly associated with ovarian cysts, and the incidence of pathological ovarian cysts was positively correlated to these EDCs, with OR value 64.79 (P = 0.005) for benzopyrene and 9.609 (P = 0.001) for bisphenol A. Genistein was significantly negatively correlated with the incidence of pathological ovarian tumors, with OR value of 0.153 (P = 0.007). Diagnostic performance on the AUC for benzopyrene, bisphenol A and genistein&l.
基金supported by Imperial College London,UK,King’s College London,UK and Engineering and Physical Sciences Research Council(EPSRC),UK.
文摘Reinforcement Learning(RL)based control algorithms can learn the control strategies for nonlinear and uncertain environment during interacting with it.Guided by the rewards generated by environment,a RL agent can learn the control strategy directly in a model-free way instead of investigating the dynamic model of the environment.In the paper,we propose the sampled-data RL control strategy to reduce the computational demand.In the sampled-data control strategy,the whole control system is of a hybrid structure,in which the plant is of continuous structure while the controller(RL agent)adopts a discrete structure.Given that the continuous states of the plant will be the input of the agent,the state–action value function is approximated by the fully connected feed-forward neural networks(FCFFNN).Instead of learning the controller at every step during the interaction with the environment,the learning and acting stages are decoupled to learn the control strategy more effectively through experience replay.In the acting stage,the most effective experience obtained during the interaction with the environment will be stored and during the learning stage,the stored experience will be replayed to customized times,which helps enhance the experience replay process.The effectiveness of proposed approach will be verified by simulation examples.
基金This work was supported by the National Natural Science Foundation of China(31972435)the National Key Research and Development Program of China(2019YFD1000300)+1 种基金the Fundamental Research Funds for the Central Universities(2662018QD062)the China Agriculture Research System of MOF and MORA(CARS-25).
文摘Melon(Cucumis melo L.)has a long history of cultivation worldwide.During cultivation,domestication,and selection breeding,the sugar content of mature melon fruits has been significantly increased.Compared with unsweet melon and wild melon,rapid sucrose accumulation can occur in the middle and late stages of sweet melon fruit development.The phloem unloading pathway during the evolution and development of melon fruit has not been identified and analyzed.In this study,the phloem unloading pathway and the function of related sugar transporters in cultivated and wild melon fruits were analyzed by CFDA[5(6)-carbofluorescein diacetate]and esculin tracing,cytological pathway observation,qRT–PCR,and gene function analysis,etc.Results show that the phloem unloading pathway of wild melon fruit is largely symplastic,whereas the phloem unloading pathway of cultivated melon fruit shifts from symplastic to apoplasmic during development.According to a fruit grafting experiment,the fruit sink accumulates sugars independently.Correlation analysis showed that the expression amounts of several sucrose transporter genes were positively correlated with the sucrose content of melon fruit.Furthermore,CmSWEET10 was proved to be a sucrose transporter located on the plasma membrane of the phloem and highly expressed in the premature stage of sweet melon fruits,which means it may be involved in phloem apoplast unloading and sucrose accumulation in sweet melon fruits.Finally,we summarize a functional model of related enzymes and sugar transporters involved in the apoplast unloading of sweet melon fruits during enlargement and sucrose accumulation.
文摘In this paper,based on the process data of evaluating the benchmark land prices of collective construction land and agricultural land,the score of influencing factors is calculated,and a regression model between value-added benefits and influencing factors is established.According to the contribution of the government and collectives to value-added benefits,the distribution proportions of different purposes and levels are calculated.The research results show that there are significant differences in the distribution proportion of value-added income among different levels.The government distribution proportion decreases with the decrease of level,while the collective distribution proportion increases with the decrease of level.For each level of decrease in commercial service industry land and industrial and mining warehousing industry land,the government distribution proportion decreases by an average of 2.66%and 2.34%,while the collective distribution proportion increases by an average of 2.66%and 2.34%,respectively.The average distribution proportion of the government in the value-added income of commercial service industry land is 31.58%,which is much higher than the average income of 23.68%in the value-added income of industrial and mining warehousing industry land.
基金Supported by Henan Provincial Natural Science Foundation Project(212300410168)Basic Research Business Fee Project of Henan Academy of Sciences(220601065).
文摘In addition to the quality and quantity of farmland, the health of farmland has also become an important research direction in the field of farmland protection. In order to comprehensively evaluate the relationship and distribution of health and farmland production capacity, the depression area behind the Yellow River in Henan Province is taken as the research object. Using production capacity evaluation data and system health evaluation results, the health status and production capacity of farmland in the region are coupled. The results show that high productivity farmland is most distributed in areas with moderate health risks, while low productivity farmland is more distributed in areas with low health risks. Based on their coupling characteristics, the depression area behind the Yellow River can be divided into five types, and management and protection strategies can be formulated separately.
基金This research was supported by National Science and Technology Major Project(No.2016ZX05044002-005)and National Natural Science Foundation of China(No.41772155)The first author gratefully acknowledges financial support from China Scholarship Council(No.CSC201906420044)and expresses thanks to Richard Smith and Eric Lysczek for grammar check.
文摘Multiple-seam gas coproduction is a technology with potential to achieve economic targets.Physical experiments could replicate gas flow dynamics in two seams.In this study,numerical simulation was conducted based on physical experiments.Through calibration,the simulated results agreed with the experimental results.Three findings were obtained.First,the pressure distribution intrinsically depends on the depressurization effectiveness in each coal seam.The gas pressure difference and interval distance influence the pressure distribution by inhibiting depressurization in the top seams and bottom seams,respectively.Second,the production contribution shows a logarithmic relationship with the permeability ratio.The range of the production contribution difference grows from 11.24%to 99.99%when the permeability ratio increases 50 times.By comparison,reservoir pressure has a limited influence,with a maximum of 13.64%.Third,the interlayer interference of the top seams and bottom seams can be intensified by the reservoir pressure difference and the interval distance,respectively.The proposed model has been calibrated and verified and can be directly applied to engineering,serving as a reference for reservoir combination optimization.In summary,coal seams with a permeability ratio within 10,reservoir pressure difference within 1.50 MPa,and interval distances within 50 m are recommended to coproduce together.
基金supported by the National Natural Science Foundation of China(11472044,11221202,11632003,11521062)the 111 Project(B160030)
文摘Realization of negative stiffness(NS)in damping low frequency acoustic and mechanical vibration is relevant in engineering applications.In this work,assemblage of two repelling magnets was used to produce negative magnetic spring(NMS).A mass–spring system with NMS is experimented where the free and forced vibrations of the system are examined.The anti-phase movement is observed due to the presence of proposed NMS,confirming the analytical solution.We further showed the dynamics of the system containing NS spring could also be derived from Hamilton’s principle.
基金This work was financed by the National Natural Science Foundation of China(31701770,32072401)the China Postdoctoral Science Foundation(2019T120956 and 2016M600818)+1 种基金the Postdoctoral Science Foundation of Shaanxi Province(2017BSHYDZZ63)the Northwest A&F University Scientific Research Fund for Advanced Talents(2452018028 and 2452017069).
文摘Mitogen-activated protein kinase(MAPK)cascades play important roles in plant immunity.Previously,we reported that the potato StMKK1 protein negatively regulates Nicotiana benthamiana resistance to Phytophthora infestans.However,the functions of StMKK1 in potato immunity are unknown.To investigate the roles of StMKK1 in potato resistance to different pathogens,such as the potato late-blight pathogen P.infestans,the bacterial wilt pathogen Ralstonia solanacearum,and the gray-mold fungal pathogen Botrytis cinerea,we generated StMKK1 transgenic lines and investigated the response of potato transformants to destructive oomycete,bacterial,and fungal pathogens.The results showed that overexpression and silencing of StMKK1 do not alter plant growth and development.Interestingly,we found that StMKK1 negatively regulated potato resistance to the hemibiotrophic/biotrophic pathogens P.infestans and R.solanacearum,while it positively regulated potato resistance to the necrotrophic pathogen B.cinerea.Further investigation showed that overexpression of StMKK1 suppressed potato pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and salicylic acid(SA)-related responses,while silencing of StMKK1 enhanced PTI and SA-related immune responses.Taken together,our results showed that StMKK1 plays dual roles in potato defense against different plant pathogens via negative regulation of PTI and SA-related signaling pathways.
文摘We report a high-peak-power, single-polarized master oscillator power amplification system employing polarization- maintaining Yb-doped rod-type photonic crystal fiber. The MOPA system comprises of a Q-switched microchip laser generating ~630ps pulses at 8.6 kHz repetition-rate and two amplification stages employing double cladding fiber and rod-type PCF respectively. The MOPA system obtains narrow spectral bandwidth, single-polarized pulses of 9W maximum output average power, corresponding to peak power of 1.7MW.
基金the financial supports from the National Natural Science Foundation of China(51978124)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(22021005)the Cheung Kong Scholars Programme of China(T2012049)。
文摘Catalytic oxidation of Hgo to Hg~O is an efficient way to remove Hg^(0) from coal-fired flue gas.The catalyst with ordered pore structure can lower mass transfer resistance resulting in higher Hg^(0) oxidation efficiency.Therefore,in the present work,wood vessels were used as sacrificial template to obtain Co_(3)O_(4) with ordered pore structure.SEM and BET results show that,when the mass concentrations of Co(NO_(3))_(2)·6H_(2)O was 20%,the obtained catalyst(Co_(3)O_(4) [20%Co(NO_(3))_(2)])possesses better pore structure and higher surface area.It will expose more available surface active sites and lower the mass transfer resistance.Furthermore,XPS results prove that Co_(3)O_(4) [20%Co(NO_(3))_(2)]has the highest ratio of chemisorbed oxygen which plays an important role in Hg^(0) oxidation process.These results lead to a better Hg^(0) oxidation efficiency of Co_(3)O_(4) [20%Co(NO_(3))_(2)],which is about 90%in the temperature range of 200 to 350℃,Furthermore,Co_(3)O_(4) [20%Co(NO_(3))_(2)]has a stable catalytic activity,and its Hg^(0) oxidation efficiency maintains above 90%at 250℃even after 90 h test,A probable reaction mechanism is deduced by the XPS results of the fresh,used and regenerated catalyst of Co_(3)O_(4) [20%Co(NO3)2].Chemisorbed oxygen can react with Hg^(0) forming HgO with the reduction of Co^(3+)to Co^(2)+.And lattice oxygen and gaseous oxygen can supplement the consumption of chemisorbed oxygen to oxidize Co^(2+)to Co^(3+).
文摘Cancer-associated retinopathy (CAR) typically has a sudden or progressive onset of severe visual loss and an ominous association with an occult malignancy which contains breast cancer. Pathologically, CAR is the degeneration of photoreceptors. But the precise mechanism has not been fully established, CAR may result from autoimmune mediated apoptosis. And in recent years, there also have been some results demonstrating that tumor derived angiogenic factors such as VEGF may also confer the development of CAR, which may offer novel avenues for the therapeutic intervention in CAR. Early initiation of immunosuppressive therapy is critical for vision preservation. Future developments in rapid identification and longitudinal quantification of antibody levels would enable individualized management in these patients. The goal of this review was to analyze the epidemiology, the clinical features, the diagnosis and management of retinopathy in the context of recent advances in the elucidation of breast cancer-associated retinopathy (BCAR) pathogenesis.
基金Supported by Science and Technology Project of Hubei Xinye reconstituted Tobacco Development Co.,Ltd.(2021JSZZ3BP2B046).
文摘[Objectives]This study was conducted to deeply understand the effects of production process on the quality of new types of tobacco sheets with different flavors.[Methods]Based on the pilot production process of thick pulp method,four different flavors of tobacco sheets were sampled at several links in the production process,for the detection of the contents of the main components in the samples,including propylene glycol,glycerol,menthol and glyceryl triacetate,so as to explore the change trends of various components in the thick pulp process.[Results]The change laws of propylene glycol and glycerol contents had a very high similarity,showing a trend of first decreasing and increasing then.The changes of menthol content and glyceryl triacetate content were greatly affected by the specific flavor formula.As one of the indexes of the new tobacco evaluation system,the alcohol-to-ester ratio data need to be further improved in the actual production and application process.[Conclusions]This study provides basic data support for improving the quality of tobacco sheets.
文摘This paper first introduces the overview of real estate appraisal theory,the basic situation of real estate appraisal,the basic principles and characteristics of real estate appraisal,and three main appraisal methods.On this basis,the specific use scope of each method,the meaning of each parameter,and the influencing factors are analyzed.Then,based on the in-depth study of various existing appraisal theories and methods,a new appraisal method is proposed:the appraisal analysis method based on fuzzy analytic hierarchy process.
文摘Taking Changyuan City of Henan Province,a pilot city of collective commercial construction land reform,as the research object,this paper analyzes the scientific connotation of"same land,same right,same price"of collective commercial construction land and state-owned land in the unified urban-rural construction land market system,and how to realize"same land,same right,same price".The results show that in order to realize the fair entry of collective construction land into the market,it must base on scientific use control,unify the urban and rural construction land market and adhere to the guidance of market mechanism,and finally realize the sustainable development of the land market.
基金Supported by Basic Scientific Research Project of Henan Academy of Sciences(200601078)Henan Youth Science(212300410168)Henan Science and Technology Plan Project (212400410263)。
文摘According to the reason of quality change,cultivated land is divided into four change types: decrease,increase,land construction project and gradual change. Farmland grading factor method is used to evaluate the quality of cultivated land in Zhengzhou City. The results show that(1) the quality of cultivated land in Zhengzhou City has slightly increased during the study period. Due to the decrease in the amount of cultivated land,the production capacity has declined.(2) The impact of different types of cultivated land change on the quality of regional cultivated land is in the order of gradual change> decrease > increase > land construction project.(3) Zhengzhou City is able to maintain the quality of regional cultivated land through new cultivated land and project construction,but fails to maintain the production capacity. By analyzing the mechanism of regional cultivated land quality change in different types,the relationship between quality changes in various types of areas and overall quality changes could be analyzed,and it could provide policy recommendations for managers to formulate farmland quality and capacity protection,with significant application value.
基金Supported by Basic Scientific Research Project of Henan Academy of Sciences(220601065)Henan Youth Science Fund Project(212300410168)。
文摘The quality change of cultivated land resources requires the scientific deployment of monitoring areas.In this study,Yuzhou City is taken as an example to divide the quality monitoring control areas through the study of natural quality,utilization level,income level,and utilization characteristics,etc.Compared with the traditional administrative unit division or cultivated land quality division method,the regional homogeneity of this study is stronger,and there are quality differences between regions.It provides precondition and precision guarantee for the monitoring of cultivated land quality.
基金Supported by Henan Youth Science Foundation(212300410168)Basic Scientific Research Project of Henan Academy of Sciences(220601065)。
文摘At present,the quality protection and early warning of cultivated land in China are actually based on the increase and decrease of the quantity of cultivated land and the change of its quality.The early warning of cultivated land quality based on this is easy to cause the problem of missing and wrong alarm.Based on the quality and productivity change of regional cultivated land,early warning on the regional cultivated land quality is conducted in this study respectively,and the results of the two early warning are compared.Moreover,a multi-indicator cultivated land quality early warning based on the quality change,productivity change and auxiliary indicators is proposed.The results show that:early warning of cultivated land quality based on quality and productivity change of cultivated land has certain limitations.Based on multi-indicator early warning,the number of counties with heavy,medium and light warnings in Henan Province is 52,8 and 11 respectively.The multi-indicator early warning result of cultivated land quality is more accurate,which can provide a basis for cultivated land protection and management assessment,and has great application value.
