Under the goal of “Carbon Emission Peak and Carbon Neutralization”, the integrated development between various industries and renewable energy(photovoltaic, wind power) is of great significance in China. This paper ...Under the goal of “Carbon Emission Peak and Carbon Neutralization”, the integrated development between various industries and renewable energy(photovoltaic, wind power) is of great significance in China. This paper summarizes the relevant policies, integration schemes and typical cases of the integrated development between renewable energy and other industries. First, the development status of wind and solar generation in China is introduced. Second, we summarize the relevant policies issued by the National Development and Reform Commission, National Energy Administration and other departments to promote the integrated development in photovoltaic and wind power generation in China. Third, eight kinds of photovoltaic three-dimensional development models are described, including “photovoltaic + agriculture, industry, environmental protection, transportation, architecture, communication, hydrogen and ecology”. Fourth, eight kinds of wind power threedimensional development models are summarized, including “Offshore wind power + marine ranch, marine energy, marine tourism, marine oil and gas, hydrogen, communication, Energy Island” and “Onshore wind power+ courtyard”. In the future, the promotion and application of the above integrated development projects will be accelerated. This overview aims to provide reference for the design in photovoltaic and wind energy systems and help potential investors to make decisions.展开更多
Glial cell line-derived neurotrophic factor recombinant adenovirus vector-transfected bone marrow mesenchymal stem cells were induced to differentiate into neuron-like cells using inductive medium containing retinoic ...Glial cell line-derived neurotrophic factor recombinant adenovirus vector-transfected bone marrow mesenchymal stem cells were induced to differentiate into neuron-like cells using inductive medium containing retinoic acid and epidermal growth factor. Cell viability, micro- tubule-associated protein 2-positive cell ratio, and the expression levels of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43 protein in the su- pernatant were significantly higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mes- enchymal stem cells. Furthermore, microtubule-associated protein 2, glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein743 mRNA levels in cell pellets were statistically higher in glial cell line-derived neurotrophic factor/bone marrow mesen- chymal stem cells compared with empty virus plasmid-transfected bone marrow mesenchymal stem cells. These results suggest that glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells have a higher rate of induction into neuron-like cells, and this enhanced differentiation into neuron-like cells may be associated with up-regulated expression of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43.展开更多
BACKGROUND: Cerebral injury in adult mammals can induce neural precursor cells (NPCs) to proliferate and migrate towards the focal zone, but it is unclear whether endogenous NPCs can migrate towards regions distal ...BACKGROUND: Cerebral injury in adult mammals can induce neural precursor cells (NPCs) to proliferate and migrate towards the focal zone, but it is unclear whether endogenous NPCs can migrate towards regions distal to the hemorrhagic focus or whether NPCs differentiate in the peripheral hemorrhagic region. OBJECTIVE: To investigate the distribution of endogenous NPCs in different brain regions of rats with experimental cerebral hemorrhage, as well as NPC proliferation and differentiation with time. DESIGN, TIME AND SE'B'ING: A randomized, controlled animal experiment was performed at the Department of Neurobiology, Luzhou Medical College, between January 2007 and October 2008. MATERIALS: Bromodeoxyuridine (BrdU) was purchased from Roche, Germany. Mouse anti-rat BrdU monoclonal antibody, rabbit anti-nestin polyclonal antibody, rabbit anti-neuron specific enolase (NSE) polyclonal antibody were purchased from Wuhan Boster, China. Rabbit anti-glial fibrillary acidic protein (GFAP) polyclonal antibody was purchased from Sigma, USA. METHODS: Thirty-five adult Sprague Dawley rats were randomly divided into three groups: (1) cerebral hemorrhage group (n = 25), rats were stereotaxically administered 50 p L autologous arterial blood via the dorsal caudate putamen to induce cerebral hemorrhage; (2) sham-surgery group (n = 5), rats underwent surgery but did not receive blood injection; (3) blank control group (n = 5), rats received no surgery and blood administration. At 2 hours after surgery, all rats were intraperitoneally administered BrdU. MAIN OUTCOME MEASURES: Distribution and proliferation of BrdU-positive cells were observed by immunohistochemical staining. BrdU-positive cell differentiation into neurons and glial cells in the peripheral hemorrhagic region was detected by double-label immunofluorescence. RESULTS: Immunohistochemistry results revealed that BrdU-positive cells existed not only in the peripheral hemorrhagic region, such as the subependymal layer and hippocampal dentate gyrus, but also in the lateral septal nucleus, diagonal band, habenular nucleus, and cerebral cortex. Following cerebral hemorrhage, BrdU-positive cells in the peripheral hemorrhagic region gradually increased (P 〈 0.05), and peaked at 7 14 days. Double-label immunofluorescence showed that with time after cerebral hemorrhage, BrdU/nestin-positive cells decreased, but BrdU/GFAP- and BrdU/NSE-positive cells increased in the peripheral cerebral hemorrhagic region (P 〈 0.05). CONCLUSION: Cerebral hemorrhage can induce the proliferation of endogenous NPCs, which peaks at 1-2 weeks after hemorrhage. NPCs can also migrate towards the regions distal to the hemorrhagic focus, such as a diagonal band or lateral septal nucleus. NPCs can gradually differentiate with increasing time after hemorrhage.展开更多
In this paper, we obtained a kind of lump solutions of the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation with the assistance of Mathematica. Some contour plots with different determinant values are seq...In this paper, we obtained a kind of lump solutions of the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation with the assistance of Mathematica. Some contour plots with different determinant values are sequentially made to show that the corresponding lump solutions tend to zero when x2+y2→∞. Particularly, lump solutions with specific values of the include parameters are plotted, as illustrative examples. Finally, a combination of stripe soliton and lump soliton is discussed to the KP-BBM equation, in which such a solution presents two different interesting phenomena: lump-kink and lump-soliton. Simultaneously, breather rational soliton solutions are displayed.展开更多
This study used a flame atomic absorption spectrometer (FAAS) and atomic fluorescence spec-trophotometer (AFS) to detect the concentrations of chromium (Cr), cadmium (Cd), lead (Pb), hy-drargyrum (Hg) and arsenic (As)...This study used a flame atomic absorption spectrometer (FAAS) and atomic fluorescence spec-trophotometer (AFS) to detect the concentrations of chromium (Cr), cadmium (Cd), lead (Pb), hy-drargyrum (Hg) and arsenic (As) in soils and three genotypes of vegetables in greenhouse, as well as analyzed the physical and chemical properties of soils, including soil pH, soil organic matter (OM), basic nutrients, electrical conductivity (EC) and cation exchange capacity (CEC) in Guan- zhong areas, Shaanxi province, China. The results showed that comparing to subsoil, the sampled topsoil is enriched in Cr, Cd, Pb, As and Hg. Cd (0.83 - 3.17 mg·kg-1) and Hg (0.40 - 1.44 mg·kg-1) are exceeding the limited value stated in “the 2006 Greenhouse Vegetable Producing Environmental Quality Evaluation Standards” of 0.40 mg·kg-1 and 0.35 mg·kg-1 respectively. However, Nanzhuang greenhouse soil is within the limits. The heavy metal pollution index (HPI) of soil in Sanyuan (8.10) is the highest and in Dongzhang (4.23) is the lowest. The contents of Pb (0.201 - 0.376 mg·kg-1) were exceeding the limited value (0.20 mg·kg-1) in vegetables species, and Cd (0.0363 - 0.0572 mg·kg-1) in some place were also exceeding the limited value (0.05 mg·kg-1). Greenhouse soils were becoming acidified year after year;the ratios of N, P and K in soil were seriously imbalanced. According to the impacting factors, OM, pH, available P, EC and CEC have obviously effected the accumulation of Cr and Hg. However, there was not enough evidence for the effects of available nitrogen and available potassium.展开更多
Based on observational data of arid,semi-arid and semi-humid areas in Northwest China,the characteristics of surface-wa ter heat transfer and land-surface parameters were compared and analyzed.The results show that th...Based on observational data of arid,semi-arid and semi-humid areas in Northwest China,the characteristics of surface-wa ter heat transfer and land-surface parameters were compared and analyzed.The results show that the annual mean net radi ation was largest in the semi-humid area,followed by the semi-arid area,and then the arid area:77.72 W/m^2,67.73 W/m^2,and 55.47 W/m^2,respectively.The annual mean sensible heat flux was largest in the arid area,followed by the semi-arid and semi-humid areas,while latent heat flux showed the reverse.The annual mean sensible heat flux in arid,semi-arid,and semi-humid areas was 85.7 W/m^2,37.59 W/m^2,and 27.55 W/m^2,respectively.The annual mean latent heat flux was 0 W/m^2,26.08 W/m^2,and 51.19 W/m2,respectively.The annual mean soil-heat flux at the 5-cm soil layer in arid,semi-arid,and semi-humid areas was 1.00 W/m^2,0.82 W/m^2,and 1.25 W/m^2,respectively.The annual mean surface albedo was larg est in the arid area,followed by the semi-humid area;and the smallest was in the semi-arid area:0.24,0.21,and 0.18,re spectively.The annual mean Bowen ratio in the semi-arid area was about 2.06,and that in semi-humid area was about 0.03.The annual mean soil thermal conductivity in the arid,semi-arid,and semi-humid areas was 0.26 W/(m k),1.15 W/(m k),and 1.20 W/(m k),respectively.展开更多
PM2.5 and PM10 were the main air pollutants during winter in Lanzhou New District,China.In this paper,WRF model output combined with hourly monitoring data of pollutant concentration was used to analyze characteristic...PM2.5 and PM10 were the main air pollutants during winter in Lanzhou New District,China.In this paper,WRF model output combined with hourly monitoring data of pollutant concentration was used to analyze characteristics of the concentration change and to study the relationship between meteorological elements and PM10/PM2.5 in Lanzhou New District in January,2018.Meanwhile,the concentration changes of PM2.5 and PM10 were predicted by wavelet analysis combined with BP neural network.The results show that:(1)Due to the cold front process in winter,PM2.5 was negatively correlated with the water vapor mixing rate.PM10 was positively correlated with air temperature and negatively correlated with air pressure.(2)There was an inversion layer in the atmosphere near the high value day of PM2.5 and PM10,the surface was controlled by low pressure,low wind speed,and the situation of low value day of PM2.5 was the opposite.On the day of high value of PM10,the air temperature below 600 hPa was higher,and the wind speed near the surface was also higher.(3)Wavelet analysis combined with BP(Back Propagation)neural network had a good prediction effect on PM2.5,which could basically reflect the hourly change of PM2.5 concentration.However,the simulation effect of PM10 was poor,and the input parameters of surrounding pollutants should be added to improve the prediction effect.展开更多
Solar energy is clean and renewable energy that plays an important role in mitigating impacts of environmental problems and climate change.Solar radiation received on the earth's surface determines the efficiency ...Solar energy is clean and renewable energy that plays an important role in mitigating impacts of environmental problems and climate change.Solar radiation received on the earth's surface determines the efficiency of power generation and the location and layout of photovoltaic arrays.In this paper,the average daily solar radiation of 77 stations in China from 1957 to 2016 was analyzed in terms of spatial and temporal characteristics.The results indicate that Xinjiang,the Qinghai-Tibet Plateau,North,Central and East China show a decreasing trend with an average of 2.54×10^(−3)MJ/(m^(2)⋅10a),while Northwest and Northeast China are basically stabilized,and Southwest China shows a clear increasing trend with an average increase of 1.79×10^(−3)MJ/(m^(2)⋅10a).The average daily solar radiation in summer and winter in China from 1957 to 2016 was 18.74 MJ/m^(2)and 9.09 MJ/m^(2),respectively.Except for spring in Northwest,East and South China,and summer in northeast China,the average daily solar radiation in all other regions show a downward trend.A critical point for the change is 1983 in the average daily solar radiation.Meanwhile,large-scale(25−30 years)oscillation changes are more obvious,while small-scale(5−10 years)changes are stable and have a global scope.The average daily solar radiation shows an increasing-decreasing gradient from west to east,which can be divided into three areas west of 80°E,80°E−100°E and east of 100°E.The average daily solar radiation was 2.07 MJ/m^(2)in the 1980s,and that in 1990s lower than that in the 1960s and the 1970s.The average daily solar radiation has rebounded in the 21st century,but overall it is still lower than the average daily solar radiation from 1957 to 2016(13.87 MJ/m^(2)).展开更多
We successfully constructed wide classes of exact solutions for the Burgers equation by using the generalized simplest equation method. This method yielded a Bäcklund transformation between the Burgers equatio...We successfully constructed wide classes of exact solutions for the Burgers equation by using the generalized simplest equation method. This method yielded a Bäcklund transformation between the Burgers equation and a related constraint equation. By dealing with the constraint equation, we obtained the traveling wave solutions and non-traveling wave solutions of the Burgers equation.展开更多
There are many types of atmospheric heat engines in land-air systems.The accurate definition,calculation and interpretation of the efficiency of atmospheric heat engines are key to understanding energy transfer and tr...There are many types of atmospheric heat engines in land-air systems.The accurate definition,calculation and interpretation of the efficiency of atmospheric heat engines are key to understanding energy transfer and transformation of landair systems.The atmosphere over the Qinghai-Tibet Plateau(QTP)in summer can be regarded as a positive heat engine.The study of the heat engine efficiency is helpful to better understand land-air interaction and thermal-dynamic processes on the QTP.It also provides a new perspective to explain the impact of the QTP on the climate of China,East Asia and even the world.In this paper,we used MOD08 and ERA5 reanalysis data to calculate the atmospheric heat engine efficiency,surface heat source and atmospheric heat source on the QTP in summer(May to September)from 2000 to 2020.The average atmospheric heat engine efficiency on the QTP in summer from 2000 to 2020 varies between 1.2%and 1.5%,which is less than 1.6%;the heat engine efficiency in summer is higher than that in June,July and August;the Qaidam Basin is the region with the highest atmospheric heat engine efficiency,followed by the western QTP.The mean surface heat source on the QTP in summer from 2000 to 2020 is 96.0 W m^(−2),the atmospheric heat source is 90.7 W m^(−2),and the release of precipitation condensation latent heat is the most important component of the atmospheric heat source on the QTP in summer.There is a strong and significant positive correlation between the atmospheric heat engine efficiency and the surface heat source on the QTP in summer.The precipitation condensation latent heat is the most important component of the atmospheric heat source in summer and can reflect the precipitation process.There is a strong and significant negative correlation between the atmospheric heat engine efficiency and the atmospheric heat source on the QTP in summer.展开更多
Angular optical trapping based on Janus microspheres has been proven to be a novel method to achieve controllable rotation.In contrast to natural birefringent crystals,Janus microspheres are chemically synthesized of ...Angular optical trapping based on Janus microspheres has been proven to be a novel method to achieve controllable rotation.In contrast to natural birefringent crystals,Janus microspheres are chemically synthesized of two compositions with different refractive indices.Thus,their structures can be artificially regulated,which brings excellent potential for fine and multi-degree-of-freedom manipulation in the optical field.However,it is a considerable challenge to model the interaction of heterogeneous particles with the optical field,and there has also been no experimental study on the optical manipulation of microspheres with such designable refractive index distributions.How the specific structure affects the kinematic properties of Janus microspheres remains unknown.Here,we report systematic research on the optical trapping and rotating of various ratio-designable Janus microspheres.We employ an efficient T-matrix method to rapidly calculate the optical force and torque on Janus microspheres to obtain their trapped postures and rotational characteristics in the optical field.We have developed a robust microfluidic-based scheme to prepare Janus microspheres.Our experimental results demonstrate that within a specific ratio range,the rotation radii of microspheres vary linearly and the orientations of microsphere are always aligned with the light polarization direction.This is of great importance in guiding the design of Janus microspheres.And their orientations flip at a particular ratio,all consistent with the simulations.Our work provides a reliable theoretical analysis and experimental strategy for studying the interaction of heterogeneous particles with the optical field and further expands the diverse manipulation capabilities of optical tweezers.展开更多
The research on circularly polarized luminescence(CPL)has garnered significant attention in recent years due to its many potential applications.One aspect of this research involves the pursuit of chiral materials that...The research on circularly polarized luminescence(CPL)has garnered significant attention in recent years due to its many potential applications.One aspect of this research involves the pursuit of chiral materials that posess both high luminescence efficiency and dissymmetry factors.The investigation of CPL behavior is of paramount importance because the structural information of chiral luminescent systems in the excited state can be uncovered.The objective of this review is to offer a comprehensive overview of the latest advancements in the CPL research field,with a particular focus on the development of chiral emissive materials,including organic,inorganic,and hybrid substances.Furthermore,this review outlines the recent applications of these materials in areas such as displays,photoelectric devices,anticounterfeiting measures,and sensors.Finally,we highlight the primary challenges and potential prospects of CPL materials.Our aspiration is that this endeavor will contribute new perspectives and insights that further advancements in related research fields.展开更多
Chiral nano-assemblies with amplified optical activity have attracted particular interest for their potential application in photonics, sensing and catalysis. Yet it still remains a great challenge to realize their re...Chiral nano-assemblies with amplified optical activity have attracted particular interest for their potential application in photonics, sensing and catalysis. Yet it still remains a great challenge to realize their real applications because of the instability of these assembled nanostructures. Herein, we demonstrate a facile and efficient method to fabricate ultra-stable chiral nanostructures with strong chiroptical properties. In these novel chiral nanostructures, side-by-side assembly of chiral cysteine-modified gold nanorods serves as the core while mesoporous silica acts as the shell. The chiral core-shell nanostructures exhibit an evident plasmonic circular dichroism (CD) response originating from the chiral core. Impressively, such plasmonic CD signals can be easily manipulated by changing the number as well as the aspect ratio of Au nanorods in the assemblies located at the core. In addition, because of the stabilization effect of silica shells, the chiroptical performance of these core-shell nanostructures is significantly improved in different chemical environments.展开更多
The misfolding and aggregation ofα-synuclein(α-syn)is closely associated with Parkinson’s disease(PD).Here,chiral dimanganese trioxide(Mn_(2)O_(3))nanoparticles(NPs)were prepared for PD treatment enhanced by a noni...The misfolding and aggregation ofα-synuclein(α-syn)is closely associated with Parkinson’s disease(PD).Here,chiral dimanganese trioxide(Mn_(2)O_(3))nanoparticles(NPs)were prepared for PD treatment enhanced by a noninvasive electromagnetic field(MF).The affinity constants of D-NPs towardα-syn monomer(mono)orα-syn fibril were 3.5 times or 5.2 times higher,respectively,than those of L-NPs,and the mechanical force generated by NPs under a MF further promoted the interaction between NPs andα-syn to amplify the difference between L-NPs and D-NPs.As the synergy effect of the preferentially affinity ability and MF-induced mechanical forces,D-NPs exhibited a better inhibitory efficiency onα-syn fibrillization than L-NPs.Furthermore,after differentially cellular uptake of L-/D-NPs via the caveolin-mediated pathway,as reactive oxygen species(ROS)-scavengers,D-NPs possess higher efficiency in decreasing intracellular ROS level than L-NPs to provide higher cytoprotective efficiency to neuron cells.In vivo data showed that after treatment with D-NPs under a MF for 60 days,α-syn concentration in the cerebrospinal fluid of PD mice decreased 81%,while dopamine level in the brain of PD mice increased 2.3-fold.These findings indicated the potential of utilizing the synergic interplay of chiral NPs and MF for treating disease and opened a new path to explore the nanoscale chirality for regulating the biological effect.展开更多
A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high ...A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS)measurement.^(75)Se(Ⅳ) and ^(75)Se(Ⅵ)were prepared and used as tracers during the experiments.The volatility of selenium during solution evaporation was investigated to establish a reliable water samples pretreatment procedure.The parameters which affect the uptake of Se(Ⅳ)and Se(Ⅵ)on Dowex1×8 resin was optimized and the procedure for Se(Ⅳ)and Se(Ⅵ)separation was proposed.Both Se(Ⅳ)and Se(Ⅵ)are retained on the column in natural or alkaline solution with high distribution coefficient.The successive gradient elution of pre-concentrated species of selenium with HNO_(3)solution allows to differentiate between them.Se(Ⅳ)and Se(Ⅵ)finally were eluted with 0.05 mol/L HNO_(3) and 5.0 mol/L HNO_(3),respectively.The proposed method has been successfully verified using the certified reference materials(CRMs)of real water samples,and spiked recoveries for real samples were 98%-104%with 5%relative standard deviations(RSDs).The developed procedure is proved to be reliable and can be used for the rapid determination of selenium species in environmental water samples.展开更多
基金the National Key R&D Program of China(2018YFB1502800)National Natural Science Foundation of China(No.42330601)the CREEI(ZY-KJHB-20220005).
文摘Under the goal of “Carbon Emission Peak and Carbon Neutralization”, the integrated development between various industries and renewable energy(photovoltaic, wind power) is of great significance in China. This paper summarizes the relevant policies, integration schemes and typical cases of the integrated development between renewable energy and other industries. First, the development status of wind and solar generation in China is introduced. Second, we summarize the relevant policies issued by the National Development and Reform Commission, National Energy Administration and other departments to promote the integrated development in photovoltaic and wind power generation in China. Third, eight kinds of photovoltaic three-dimensional development models are described, including “photovoltaic + agriculture, industry, environmental protection, transportation, architecture, communication, hydrogen and ecology”. Fourth, eight kinds of wind power threedimensional development models are summarized, including “Offshore wind power + marine ranch, marine energy, marine tourism, marine oil and gas, hydrogen, communication, Energy Island” and “Onshore wind power+ courtyard”. In the future, the promotion and application of the above integrated development projects will be accelerated. This overview aims to provide reference for the design in photovoltaic and wind energy systems and help potential investors to make decisions.
文摘Glial cell line-derived neurotrophic factor recombinant adenovirus vector-transfected bone marrow mesenchymal stem cells were induced to differentiate into neuron-like cells using inductive medium containing retinoic acid and epidermal growth factor. Cell viability, micro- tubule-associated protein 2-positive cell ratio, and the expression levels of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43 protein in the su- pernatant were significantly higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mes- enchymal stem cells. Furthermore, microtubule-associated protein 2, glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein743 mRNA levels in cell pellets were statistically higher in glial cell line-derived neurotrophic factor/bone marrow mesen- chymal stem cells compared with empty virus plasmid-transfected bone marrow mesenchymal stem cells. These results suggest that glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells have a higher rate of induction into neuron-like cells, and this enhanced differentiation into neuron-like cells may be associated with up-regulated expression of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43.
文摘BACKGROUND: Cerebral injury in adult mammals can induce neural precursor cells (NPCs) to proliferate and migrate towards the focal zone, but it is unclear whether endogenous NPCs can migrate towards regions distal to the hemorrhagic focus or whether NPCs differentiate in the peripheral hemorrhagic region. OBJECTIVE: To investigate the distribution of endogenous NPCs in different brain regions of rats with experimental cerebral hemorrhage, as well as NPC proliferation and differentiation with time. DESIGN, TIME AND SE'B'ING: A randomized, controlled animal experiment was performed at the Department of Neurobiology, Luzhou Medical College, between January 2007 and October 2008. MATERIALS: Bromodeoxyuridine (BrdU) was purchased from Roche, Germany. Mouse anti-rat BrdU monoclonal antibody, rabbit anti-nestin polyclonal antibody, rabbit anti-neuron specific enolase (NSE) polyclonal antibody were purchased from Wuhan Boster, China. Rabbit anti-glial fibrillary acidic protein (GFAP) polyclonal antibody was purchased from Sigma, USA. METHODS: Thirty-five adult Sprague Dawley rats were randomly divided into three groups: (1) cerebral hemorrhage group (n = 25), rats were stereotaxically administered 50 p L autologous arterial blood via the dorsal caudate putamen to induce cerebral hemorrhage; (2) sham-surgery group (n = 5), rats underwent surgery but did not receive blood injection; (3) blank control group (n = 5), rats received no surgery and blood administration. At 2 hours after surgery, all rats were intraperitoneally administered BrdU. MAIN OUTCOME MEASURES: Distribution and proliferation of BrdU-positive cells were observed by immunohistochemical staining. BrdU-positive cell differentiation into neurons and glial cells in the peripheral hemorrhagic region was detected by double-label immunofluorescence. RESULTS: Immunohistochemistry results revealed that BrdU-positive cells existed not only in the peripheral hemorrhagic region, such as the subependymal layer and hippocampal dentate gyrus, but also in the lateral septal nucleus, diagonal band, habenular nucleus, and cerebral cortex. Following cerebral hemorrhage, BrdU-positive cells in the peripheral hemorrhagic region gradually increased (P 〈 0.05), and peaked at 7 14 days. Double-label immunofluorescence showed that with time after cerebral hemorrhage, BrdU/nestin-positive cells decreased, but BrdU/GFAP- and BrdU/NSE-positive cells increased in the peripheral cerebral hemorrhagic region (P 〈 0.05). CONCLUSION: Cerebral hemorrhage can induce the proliferation of endogenous NPCs, which peaks at 1-2 weeks after hemorrhage. NPCs can also migrate towards the regions distal to the hemorrhagic focus, such as a diagonal band or lateral septal nucleus. NPCs can gradually differentiate with increasing time after hemorrhage.
文摘In this paper, we obtained a kind of lump solutions of the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation with the assistance of Mathematica. Some contour plots with different determinant values are sequentially made to show that the corresponding lump solutions tend to zero when x2+y2→∞. Particularly, lump solutions with specific values of the include parameters are plotted, as illustrative examples. Finally, a combination of stripe soliton and lump soliton is discussed to the KP-BBM equation, in which such a solution presents two different interesting phenomena: lump-kink and lump-soliton. Simultaneously, breather rational soliton solutions are displayed.
文摘This study used a flame atomic absorption spectrometer (FAAS) and atomic fluorescence spec-trophotometer (AFS) to detect the concentrations of chromium (Cr), cadmium (Cd), lead (Pb), hy-drargyrum (Hg) and arsenic (As) in soils and three genotypes of vegetables in greenhouse, as well as analyzed the physical and chemical properties of soils, including soil pH, soil organic matter (OM), basic nutrients, electrical conductivity (EC) and cation exchange capacity (CEC) in Guan- zhong areas, Shaanxi province, China. The results showed that comparing to subsoil, the sampled topsoil is enriched in Cr, Cd, Pb, As and Hg. Cd (0.83 - 3.17 mg·kg-1) and Hg (0.40 - 1.44 mg·kg-1) are exceeding the limited value stated in “the 2006 Greenhouse Vegetable Producing Environmental Quality Evaluation Standards” of 0.40 mg·kg-1 and 0.35 mg·kg-1 respectively. However, Nanzhuang greenhouse soil is within the limits. The heavy metal pollution index (HPI) of soil in Sanyuan (8.10) is the highest and in Dongzhang (4.23) is the lowest. The contents of Pb (0.201 - 0.376 mg·kg-1) were exceeding the limited value (0.20 mg·kg-1) in vegetables species, and Cd (0.0363 - 0.0572 mg·kg-1) in some place were also exceeding the limited value (0.05 mg·kg-1). Greenhouse soils were becoming acidified year after year;the ratios of N, P and K in soil were seriously imbalanced. According to the impacting factors, OM, pH, available P, EC and CEC have obviously effected the accumulation of Cr and Hg. However, there was not enough evidence for the effects of available nitrogen and available potassium.
文摘Based on observational data of arid,semi-arid and semi-humid areas in Northwest China,the characteristics of surface-wa ter heat transfer and land-surface parameters were compared and analyzed.The results show that the annual mean net radi ation was largest in the semi-humid area,followed by the semi-arid area,and then the arid area:77.72 W/m^2,67.73 W/m^2,and 55.47 W/m^2,respectively.The annual mean sensible heat flux was largest in the arid area,followed by the semi-arid and semi-humid areas,while latent heat flux showed the reverse.The annual mean sensible heat flux in arid,semi-arid,and semi-humid areas was 85.7 W/m^2,37.59 W/m^2,and 27.55 W/m^2,respectively.The annual mean latent heat flux was 0 W/m^2,26.08 W/m^2,and 51.19 W/m2,respectively.The annual mean soil-heat flux at the 5-cm soil layer in arid,semi-arid,and semi-humid areas was 1.00 W/m^2,0.82 W/m^2,and 1.25 W/m^2,respectively.The annual mean surface albedo was larg est in the arid area,followed by the semi-humid area;and the smallest was in the semi-arid area:0.24,0.21,and 0.18,re spectively.The annual mean Bowen ratio in the semi-arid area was about 2.06,and that in semi-humid area was about 0.03.The annual mean soil thermal conductivity in the arid,semi-arid,and semi-humid areas was 0.26 W/(m k),1.15 W/(m k),and 1.20 W/(m k),respectively.
基金research and development plan of Gansu Province in 2018"Experimental study on atmospheric environment characteristics of near-ground boundary layer in Lanzhou New District serving fine functional zoning"(18YF1FA100)the Opening Fund of Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,CAS(Grant No.LPCC2018006)the Lanzhou City University Doctoral Research Initiation Fund(Grant No.LZCU-BS2019-13).
文摘PM2.5 and PM10 were the main air pollutants during winter in Lanzhou New District,China.In this paper,WRF model output combined with hourly monitoring data of pollutant concentration was used to analyze characteristics of the concentration change and to study the relationship between meteorological elements and PM10/PM2.5 in Lanzhou New District in January,2018.Meanwhile,the concentration changes of PM2.5 and PM10 were predicted by wavelet analysis combined with BP neural network.The results show that:(1)Due to the cold front process in winter,PM2.5 was negatively correlated with the water vapor mixing rate.PM10 was positively correlated with air temperature and negatively correlated with air pressure.(2)There was an inversion layer in the atmosphere near the high value day of PM2.5 and PM10,the surface was controlled by low pressure,low wind speed,and the situation of low value day of PM2.5 was the opposite.On the day of high value of PM10,the air temperature below 600 hPa was higher,and the wind speed near the surface was also higher.(3)Wavelet analysis combined with BP(Back Propagation)neural network had a good prediction effect on PM2.5,which could basically reflect the hourly change of PM2.5 concentration.However,the simulation effect of PM10 was poor,and the input parameters of surrounding pollutants should be added to improve the prediction effect.
基金support provided by the National Key R&D Program of China(2018YFB1502800).
文摘Solar energy is clean and renewable energy that plays an important role in mitigating impacts of environmental problems and climate change.Solar radiation received on the earth's surface determines the efficiency of power generation and the location and layout of photovoltaic arrays.In this paper,the average daily solar radiation of 77 stations in China from 1957 to 2016 was analyzed in terms of spatial and temporal characteristics.The results indicate that Xinjiang,the Qinghai-Tibet Plateau,North,Central and East China show a decreasing trend with an average of 2.54×10^(−3)MJ/(m^(2)⋅10a),while Northwest and Northeast China are basically stabilized,and Southwest China shows a clear increasing trend with an average increase of 1.79×10^(−3)MJ/(m^(2)⋅10a).The average daily solar radiation in summer and winter in China from 1957 to 2016 was 18.74 MJ/m^(2)and 9.09 MJ/m^(2),respectively.Except for spring in Northwest,East and South China,and summer in northeast China,the average daily solar radiation in all other regions show a downward trend.A critical point for the change is 1983 in the average daily solar radiation.Meanwhile,large-scale(25−30 years)oscillation changes are more obvious,while small-scale(5−10 years)changes are stable and have a global scope.The average daily solar radiation shows an increasing-decreasing gradient from west to east,which can be divided into three areas west of 80°E,80°E−100°E and east of 100°E.The average daily solar radiation was 2.07 MJ/m^(2)in the 1980s,and that in 1990s lower than that in the 1960s and the 1970s.The average daily solar radiation has rebounded in the 21st century,but overall it is still lower than the average daily solar radiation from 1957 to 2016(13.87 MJ/m^(2)).
文摘We successfully constructed wide classes of exact solutions for the Burgers equation by using the generalized simplest equation method. This method yielded a Bäcklund transformation between the Burgers equation and a related constraint equation. By dealing with the constraint equation, we obtained the traveling wave solutions and non-traveling wave solutions of the Burgers equation.
基金This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK010303)the Numerical Simulation of the Effect of Soil Temperature on Precipitation Prediction(Grant No.QHMS2019015).
文摘There are many types of atmospheric heat engines in land-air systems.The accurate definition,calculation and interpretation of the efficiency of atmospheric heat engines are key to understanding energy transfer and transformation of landair systems.The atmosphere over the Qinghai-Tibet Plateau(QTP)in summer can be regarded as a positive heat engine.The study of the heat engine efficiency is helpful to better understand land-air interaction and thermal-dynamic processes on the QTP.It also provides a new perspective to explain the impact of the QTP on the climate of China,East Asia and even the world.In this paper,we used MOD08 and ERA5 reanalysis data to calculate the atmospheric heat engine efficiency,surface heat source and atmospheric heat source on the QTP in summer(May to September)from 2000 to 2020.The average atmospheric heat engine efficiency on the QTP in summer from 2000 to 2020 varies between 1.2%and 1.5%,which is less than 1.6%;the heat engine efficiency in summer is higher than that in June,July and August;the Qaidam Basin is the region with the highest atmospheric heat engine efficiency,followed by the western QTP.The mean surface heat source on the QTP in summer from 2000 to 2020 is 96.0 W m^(−2),the atmospheric heat source is 90.7 W m^(−2),and the release of precipitation condensation latent heat is the most important component of the atmospheric heat source on the QTP in summer.There is a strong and significant positive correlation between the atmospheric heat engine efficiency and the surface heat source on the QTP in summer.The precipitation condensation latent heat is the most important component of the atmospheric heat source in summer and can reflect the precipitation process.There is a strong and significant negative correlation between the atmospheric heat engine efficiency and the atmospheric heat source on the QTP in summer.
基金National Natural Science Foundation of China(52075383,61927808)National Key Research and Development Program of China(2022YFF0605501).
文摘Angular optical trapping based on Janus microspheres has been proven to be a novel method to achieve controllable rotation.In contrast to natural birefringent crystals,Janus microspheres are chemically synthesized of two compositions with different refractive indices.Thus,their structures can be artificially regulated,which brings excellent potential for fine and multi-degree-of-freedom manipulation in the optical field.However,it is a considerable challenge to model the interaction of heterogeneous particles with the optical field,and there has also been no experimental study on the optical manipulation of microspheres with such designable refractive index distributions.How the specific structure affects the kinematic properties of Janus microspheres remains unknown.Here,we report systematic research on the optical trapping and rotating of various ratio-designable Janus microspheres.We employ an efficient T-matrix method to rapidly calculate the optical force and torque on Janus microspheres to obtain their trapped postures and rotational characteristics in the optical field.We have developed a robust microfluidic-based scheme to prepare Janus microspheres.Our experimental results demonstrate that within a specific ratio range,the rotation radii of microspheres vary linearly and the orientations of microsphere are always aligned with the light polarization direction.This is of great importance in guiding the design of Janus microspheres.And their orientations flip at a particular ratio,all consistent with the simulations.Our work provides a reliable theoretical analysis and experimental strategy for studying the interaction of heterogeneous particles with the optical field and further expands the diverse manipulation capabilities of optical tweezers.
基金supported by the Chirality Major Research Plan of the National Natural Science Foundation of China(grant nos.92256304 and 92056204).
文摘The research on circularly polarized luminescence(CPL)has garnered significant attention in recent years due to its many potential applications.One aspect of this research involves the pursuit of chiral materials that posess both high luminescence efficiency and dissymmetry factors.The investigation of CPL behavior is of paramount importance because the structural information of chiral luminescent systems in the excited state can be uncovered.The objective of this review is to offer a comprehensive overview of the latest advancements in the CPL research field,with a particular focus on the development of chiral emissive materials,including organic,inorganic,and hybrid substances.Furthermore,this review outlines the recent applications of these materials in areas such as displays,photoelectric devices,anticounterfeiting measures,and sensors.Finally,we highlight the primary challenges and potential prospects of CPL materials.Our aspiration is that this endeavor will contribute new perspectives and insights that further advancements in related research fields.
基金This work was supported by the National Basic Research Program of China (No. 2014CB931801, Z. Y. T.), the National Natural Science Foundation of China (No. 21475029, Z. Y. T.), the Instrument Developing Project of the Chinese Academy of Sciences (No. YZ201311) and the CAS-CSIRO Cooperative Research Program (No. GJHZ1503).
文摘Chiral nano-assemblies with amplified optical activity have attracted particular interest for their potential application in photonics, sensing and catalysis. Yet it still remains a great challenge to realize their real applications because of the instability of these assembled nanostructures. Herein, we demonstrate a facile and efficient method to fabricate ultra-stable chiral nanostructures with strong chiroptical properties. In these novel chiral nanostructures, side-by-side assembly of chiral cysteine-modified gold nanorods serves as the core while mesoporous silica acts as the shell. The chiral core-shell nanostructures exhibit an evident plasmonic circular dichroism (CD) response originating from the chiral core. Impressively, such plasmonic CD signals can be easily manipulated by changing the number as well as the aspect ratio of Au nanorods in the assemblies located at the core. In addition, because of the stabilization effect of silica shells, the chiroptical performance of these core-shell nanostructures is significantly improved in different chemical environments.
基金supported by the National Natural Science Foundation of China (32071400,51902136)
文摘The misfolding and aggregation ofα-synuclein(α-syn)is closely associated with Parkinson’s disease(PD).Here,chiral dimanganese trioxide(Mn_(2)O_(3))nanoparticles(NPs)were prepared for PD treatment enhanced by a noninvasive electromagnetic field(MF).The affinity constants of D-NPs towardα-syn monomer(mono)orα-syn fibril were 3.5 times or 5.2 times higher,respectively,than those of L-NPs,and the mechanical force generated by NPs under a MF further promoted the interaction between NPs andα-syn to amplify the difference between L-NPs and D-NPs.As the synergy effect of the preferentially affinity ability and MF-induced mechanical forces,D-NPs exhibited a better inhibitory efficiency onα-syn fibrillization than L-NPs.Furthermore,after differentially cellular uptake of L-/D-NPs via the caveolin-mediated pathway,as reactive oxygen species(ROS)-scavengers,D-NPs possess higher efficiency in decreasing intracellular ROS level than L-NPs to provide higher cytoprotective efficiency to neuron cells.In vivo data showed that after treatment with D-NPs under a MF for 60 days,α-syn concentration in the cerebrospinal fluid of PD mice decreased 81%,while dopamine level in the brain of PD mice increased 2.3-fold.These findings indicated the potential of utilizing the synergic interplay of chiral NPs and MF for treating disease and opened a new path to explore the nanoscale chirality for regulating the biological effect.
基金The financial support from National Natural Science Foundation of China(Nos.22061132004,U21A20442,22106059,22106057,21771093)Fundamental Research Funds for the Central Universities of China(No.lzujbky-2021-kb11,lzujbky-2021-sp41)Gansu guiding program of Science and Technology Innovation(No.20JR10RA610)are gratefully appreciated。
文摘A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS)measurement.^(75)Se(Ⅳ) and ^(75)Se(Ⅵ)were prepared and used as tracers during the experiments.The volatility of selenium during solution evaporation was investigated to establish a reliable water samples pretreatment procedure.The parameters which affect the uptake of Se(Ⅳ)and Se(Ⅵ)on Dowex1×8 resin was optimized and the procedure for Se(Ⅳ)and Se(Ⅵ)separation was proposed.Both Se(Ⅳ)and Se(Ⅵ)are retained on the column in natural or alkaline solution with high distribution coefficient.The successive gradient elution of pre-concentrated species of selenium with HNO_(3)solution allows to differentiate between them.Se(Ⅳ)and Se(Ⅵ)finally were eluted with 0.05 mol/L HNO_(3) and 5.0 mol/L HNO_(3),respectively.The proposed method has been successfully verified using the certified reference materials(CRMs)of real water samples,and spiked recoveries for real samples were 98%-104%with 5%relative standard deviations(RSDs).The developed procedure is proved to be reliable and can be used for the rapid determination of selenium species in environmental water samples.