The virtual synchronous generator(VSG)technology has been proposed to address the problem of system frequency and active power oscillation caused by grid-connected new energy power sources.However,the traditional volt...The virtual synchronous generator(VSG)technology has been proposed to address the problem of system frequency and active power oscillation caused by grid-connected new energy power sources.However,the traditional voltage-current double-closed-loop control used in VSG has the disadvantages of poor disturbance immunity and insufficient dynamic response.In light of the issues above,a virtual synchronous generator voltage outer-loop control strategy based on improved linear autonomous disturbance rejection control(ILADRC)is put forth for consideration.Firstly,an improved first-order linear self-immunity control structure is established for the characteristics of the voltage outer loop;then,the effects of two key control parameters-observer bandwidthω_(0)and controller bandwidthω_(c)on the control system are analyzed,and the key parameters of ILADRC are optimally tuned online using improved gray wolf optimizer-radial basis function(IGWO-RBF)neural network.A simulationmodel is developed using MATLAB to simulate,analyze,and compare the method introduced in this paper.Simulations are performed with the traditional control strategy for comparison,and the results demonstrate that the proposed control method offers superior anti-interference performance.It effectively addresses power and frequency oscillation issues and enhances the stability of the VSG during grid-connected operation.展开更多
AIM: To study the correlation between the patterns of subcellular expression of p16 and CDK4 in colorectal epithelia in the normal-adenoma-carcinoma sequence.METHODS: Paraffin sections of 43 cases of normal colorect...AIM: To study the correlation between the patterns of subcellular expression of p16 and CDK4 in colorectal epithelia in the normal-adenoma-carcinoma sequence.METHODS: Paraffin sections of 43 cases of normal colorectal epithelia and corresponding adenomas as well as carcinomas were analysed immunocytochemically for subcellular expression of p16 and CDK4 proteins.RESULTS: Most carcinomas showed more cytoplasmic overexpression for p16 and CDK4 than the adenomas from which they arised or the adjacent normal mucosa. Most normal or non-neoplastic epithelia showed more p16 and CDK4 expression in the nucleus than their adjacent adenomas and carcinomas. There was a significant difference between the subcellular expression pattern of p16 and CDK4 in normal-adenoma-carcinoma sequence epithelia (P 〈 0.001). Neither p16 nor CDK4 subcellular patterns correlated with histological grade or Dukes' stage.CONCLUSION: Interaction of expression of p16 and CDK4 plays an important role in the Rb/p16 pathway.Overexpression of p16 and CDK4 in the cytoplasm, as well as loss expression of p16 in the nucleusmighlc be important in the evolution of colorectal carcinoma from adenoma and, of adenoma from normal epitheiia.展开更多
This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis (TNM) staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma (RCC) patients. A total of...This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis (TNM) staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma (RCC) patients. A total of 1216 patients who had undergone radical nephrectomy or partial nephrectomy for RCC from 2003 to 2011 were enrolled. All of the patients had pathologically confirmed clear cell RCC (ccRCC). All cases were staged by both the 2002 and 2010 TNM staging systems after pathological review, and survival data were collected. Univariate and multivariate Cox regression models were used to evaluate cancer-specific survival (CSS) and progression-free survival (PFS) after surgery. Continuous variables, such as age and tumour diameter, were calculated as mean values and standard deviations (s.d.) or as median values. Survival was calculated by the Kaplan-Meier method, and the log-rank test assessed differences between groups. Statistically significant differences in CSS and PFS were noted among patients in T3 subgroups using the new 2010 staging system. Therefore, the revised 2010 TNM staging system can lead to a more accurate prediction of the prognosis of ccRCC patients. However, when using the revised 2010 staging system, we found that more than 92% of patients (288/313) with T3 tumours were staged in the T3a subgroup, and their survival data were not significantly different from those of patients with T2b tumours. In addition, T2 subclassification failed to independently predict survival in RCC patients.展开更多
Heterovalent-metal doping is an efficient tool to tune the optoelectronic properties of the famous halide perovskites.Previous studies have focused on the heterovalent-doping in three-dimensional(3D) halide perovskite...Heterovalent-metal doping is an efficient tool to tune the optoelectronic properties of the famous halide perovskites.Previous studies have focused on the heterovalent-doping in three-dimensional(3D) halide perovskites.However, there is a lack of such doping in two-dimensional perovskites which possess unique optoelectronic properties and improved chemical stability as compared to 3D analogues.Here, we present successful doping of Bismuth into the lattice of lead-free, two-dimensional perovskite PEA2SnBr4 single crystals.Structural characterizations demonstrate that the doped crystals possess identical crystal structure and layered morphology with the pristine one.Intriguingly, we find the PL peak and spectral shape can be tailored by tuning the concentration of Bi dopants.Femtosecond transient absorption spectroscopy is performed to understand the underlying mechanism related to tunable PL behaviors, and a clear picture of the Bismuth-doping impact is provided.展开更多
Muon radiography is a promising technique for imaging the internal density structures of targets such as tunnels,pyramids,and volcanoes up to a scale of a few hundred meters by measuring the flux attenuation of cosmic...Muon radiography is a promising technique for imaging the internal density structures of targets such as tunnels,pyramids,and volcanoes up to a scale of a few hundred meters by measuring the flux attenuation of cosmic ray muons after they have traveled through these targets.In this study,we conducted experimental muon radiography of one of the volcanoes in the Wudalianchi area in Northeast China to image its internal density structure.The muon detector used in this study was composed of plastic scintillators and silicon photomultipliers.After approximately one and a half months of observing the crater and conduit of the Laoheishan volcano cone in Wudalianchi from September 23^(rd) to November 10^(th) 2019,more than 3 million muon tracks fulfilling the data selection criteria were collected.Based on the muon samples and high-resolution topography obtained through aerial photogrammetry using an unmanned aerial vehicle,a density image of the Laoheishan volcano cone was constructed.The results obtained in this experiment demonstrate the feasibility of using a radiography technique based on plastic scintillator detectors.To obtain the density distribution,we performed a detailed background analysis and found that low-energy charged particles dominated the background noise.Relatively higher densities were found near the surface of the volcanic cone,whereas relatively lower densities were found near the center of the volcanic cone.The experiment in this study is the first volcano muon tomography study performed in China.Our work provides an important reference for future research.展开更多
Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their po...Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their potential in promoting CO_(2)reduction reaction(CO_(2)RR),however,their low phase stability has limited their application perspective.Herein,we present a reduced graphene oxide(rGO)wrapped CsPbI_3 perovskite nanocrystal(NC)CO_(2)RR catalyst(CsPbI_3/rGO),demonstrating enhanced stability in the aqueous electrolyte.The CsPbI_3/rGO catalyst exhibited>92%Faradaic efficiency toward formate production at a CO_(2)RR current density of~12.7 mA cm^(-2).Comprehensive characterizations revealed the superior performance of the CsPbI_3/rGO catalyst originated from the synergistic effects between the CsPbI_3 NCs and rGO,i.e.,rGO stabilized theα-CsPbI_3 phase and tuned the charge distribution,thus lowered the energy barrier for the protonation process and the formation of~*HCOO intermediate,which resulted in high CO_(2)RR selectivity toward formate.This work shows a promising strategy to rationally design robust metal halide perovskites for achieving efficient CO_(2)RR toward valuable fuels.展开更多
The mechanisms for OH-initiated acenaphthylene degradation reactions are investigated theoretically by using the density function theory method at M06-2X/aug-cc-pVTZ level in the present paper. There are two possible ...The mechanisms for OH-initiated acenaphthylene degradation reactions are investigated theoretically by using the density function theory method at M06-2X/aug-cc-pVTZ level in the present paper. There are two possible reaction pathways for the degradation processes have been predicted: the hydrogen abstraction pathway and the hydroxyl addition elimination pathway. Additionally, the formation mechanism for a series of the products such as epoxide, naphthalene-1,8-dicarbaldehyde, dialdehydes, 1-acenaphthenone and nitroacenaphthylene are discussed in detail as well. From the analyses of the decomposition of OH-acenaphthylene adducts, it is found that the favorable reaction with O2/NO is to form the acenaphthenone rather than epoxide, and the most stable isomer is acenaphthenone react from the C1-site reaction. The advantage reaction pathway with NO2 is to form nitroacenaphthylene and nitroacenaphthylenol from C1-site, too.展开更多
Objective This study aimed to assess the efficacy and safety of traditional Chinese medicine,alone or in combination with oseltamivir,in patients with H1N1 Influenza.Methods In the present study,we searched the Cochra...Objective This study aimed to assess the efficacy and safety of traditional Chinese medicine,alone or in combination with oseltamivir,in patients with H1N1 Influenza.Methods In the present study,we searched the Cochrane Central Register of Controlled Trials,PUBMED,EMBASE,Chinese Biomedical Literature Database,China Science and Technology Journal Database,China National Knowledge Infrastructure Database,and WanFang Data for studies published in or before February 8,2022.Data were extracted and checked by two investigators.Review Manager 5.4 and STATA statistical software 16.0 were used for the data analysis.Results We identified 22 individual studies reporting data from 2292 individuals with H1N1 influenza.Compared with oseltamivir,the fever clearance duration[MD=-3.99,95%CI(-6.89,-1.09)]and sore throat relief time[MD=-5.39,95%CI(-10.19,-0.59)]in the intervention group of traditional Chinese medicine monotherapy or combined with oseltamivir were shorter.Maxingshigan was the primary component of Lianhuaqingwen.The subgroup analyses indicated that Maxingshigan shortened fever clearance time[MD=-3.23,95%CI(-5.60,-0.85)],and also had certain advantages in relieving sore throat[RR=-4.55,95%CI(-10.04,0.95)].However,as for the effective rate,fever duration,cough disappearance time,hospital length of stay,clinical symptoms time as well as viral shedding duration,there were no significant differences between the two groups.Besides,no serious adverse effects were reported in the included studies.Conclusion Although we couldn’t get a definitive conclusion due to the small sample sizes and high risk of bias in the included studies,most traditional Chinese medicine showed similar effects to oseltamivir in treating H1N1 influenza.Some were showed to have a statistically significant shorter time of fever clearance and sore throat remission when they were used alone or in combination with oseltamivir and were well-tolerated treatment,such as Maxingshigan.展开更多
Background:Chinese medicines have shown some advantages in preventing and controlling tumors.Tumor-associated macrophages and the immune factors of the tumor microenvironment all exist in the tumor microenvironment an...Background:Chinese medicines have shown some advantages in preventing and controlling tumors.Tumor-associated macrophages and the immune factors of the tumor microenvironment all exist in the tumor microenvironment and play important role in the development and prognosis of tumors.Thus,targeting tumor-associated macrophages and immune factors to prevent and treat tumors has become a hotspot in the field of antitumor research of the traditional Chinese medicine.Methods:The inhibition of Chinese patent drug Aikang tablets to the growth of lung cancer was evaluated by calculating the relative tumor volume and relative tumor growth rate using the mouse model of human lung cancer xenograft.The effect of Aikang tablets on the tumor microenvironment was studied through the detection of the immune factors in the tumor microenvironment and serum with high-throughput liquid protein chip detection.Tumor-associated macrophages,M1,M2,and M2/M1 were examined histologically and analyzed immunohistochemically.Results:In this study,2.8 and 1.4 g/kg/day Aikang tablets could significantly inhibit the growth of human lung adenocarcinoma(P<0.05).Moreover,2.8,1.4,and 0.7 g/kg/day Aikang tablets significantly downregulated the MCP-3,MIP-2,and IL-2 serum content(P<0.05);1.4 and 0.7 g/kg/day Aikang tablets significantly downregulated the MCP-1 serum content(P<0.05),1.4 g/kg/day Aikang tablets significantly downregulated the MIP-1αserum content(P<0.05).Simultaneously,2.8 g/kg/day Aikang tablets significantly downregulated the MIP-1βcontent in the tumor microenvironment(P<0.01);1.4 g/kg/day Aikang tablets significantly downregulated regulated upon activation,normal T Cell expressed and presumably secreted content in the tumor microenvironment(P<0.01);and 0.7 g/kg/day Aikang tablets significantly downregulated the MCP-1 and MCP-3 contents in tumor microenvironment(P<0.01).The results also showed that 2.8 and 1.4 g/kg/day Aikang tablets significantly increased the number of the M1 subtypes(P<0.05)and decreased the ratio of M2/M1(P<0.01).Conclusions:The results showed that Aikang tablets could inhibit the growth of human lung adenocarcinoma xenograft in mice but not squamous cell carcinoma and small cell carcinoma.Moreover,the mechanism should be related to increasing the number of tumor-associated macrophage subtype M1,decreasing the proportion of tumor-associated macrophage subtypes(M2/M1),and decreasing the level of immune factors in serum and tumor microenvironment.展开更多
Objective To observe the effect of Xiaoer Feire Kechuan oral solution on the extrapulmonary injury induced by Mycoplasma pneumoniae in infant Wistar rats. Methods Infant Wistar rats were infected intranasally with M. ...Objective To observe the effect of Xiaoer Feire Kechuan oral solution on the extrapulmonary injury induced by Mycoplasma pneumoniae in infant Wistar rats. Methods Infant Wistar rats were infected intranasally with M. pneumoniae once a day for four days. In the treatment groups, Xiaoer Feire Kechuan oral solution was administered daily for four days beginning from the day of infection. On day 5, blood of the rats was collected, and blood routine and biochemistry indexes were measured. All rats were sacrificed, and the weight of brain, heart, liver, and kidney was measured to calculate the organ indexes. The GM1 and GALC-Ab content in brain tissue was determined by ELISA. Pathological changes in the brain, heart, liver, kidney, and cerebellum were observed by HE staining. Results Blood routine indexes fluctuated within the normal range in the infection control group and in three of the Xiaoer Feire Kechuan oral solution groups. The serum LDH, CK, and CRE in all three Xiaoer Feire Kechuan oral solution groups were distinctly lower than those in the infection control group (P < 0.01, P < 0.05). Rat brain index and GALC-Ab content in the brain tissue showed an increase in infection control group. In the Xiaoer Feire Kechuan oral solution groups, the GALC-Ab content in brain tissue was decreased significantly. The heart, liver, and kidney tissues showed mild pathological changes in the infection group, which were reversed by Xiaoer Feire Kechuan oral solution treatment. Conclusions The extrapulmonary injury induced by M. pneumoniae in infant Wistar rats was significantly inhibited by Xiaoer Feire Kechuan oral solution.展开更多
Lead-free halide double perovskites have gathered wide scientific interest since they are environmentally friendly and stable.However,compared to the lead perovskites,their optoelectronic properties are compromised.He...Lead-free halide double perovskites have gathered wide scientific interest since they are environmentally friendly and stable.However,compared to the lead perovskites,their optoelectronic properties are compromised.Herein we report a series of bulk lead-free mixed Bi-In halide double perovskites:Cs2AgBi1-xInxCl6(0<x<1).The Cs2AgBi0.125In0.875Cl6breaks the parity-forbidden transition and retains direct band gap structure,having warm-white light emission,with photoluminescence quantum efficiency(PLQE)of 70.3%,much higher than the PLQE of reported lead perovskite materials.Its exciton self-trapping dynamics is investigated.Meanwhile,the Cs2AgBi0.125In0.875Cl6nanocrystals and Cs2AgBi0.125In0.875Cl6microcrystals can be synthesized by modified hot injection and rapid cooling crystallization,respectively.The size effect of Cs2AgBi0.125In0.875Cl6is studied on the photoluminescence(PL)property.Additionally,the bulk material exhibits excellent stability on exposure to light,humidity and air for more than 3 months.It is a promising candidate as highly efficient warm white-light emitting material for road lighting.展开更多
The thermodynamically favorable electrocatalytic oxidation coupled with hydrogen evolution reaction(HER)is considered as a sustainable and promising technique.Nonetheless,it remains a great challenge due to the lack o...The thermodynamically favorable electrocatalytic oxidation coupled with hydrogen evolution reaction(HER)is considered as a sustainable and promising technique.Nonetheless,it remains a great challenge due to the lack of simple,cheap,highefficient electrocatalysts.Here,we successfully develop a simple and scalable electro-deposition and subsequent phosphorization route to fabricate Ni-doped Co_(2)P(Ni-Co_(2)P)nanosheets catalyst using the in-situ released Ni species from defective Ni foam as metal source.Impressively,the as-synthesized Ni-Co_(2)P catalyst exhibits excellent electrochemical 5-hydroxymethylfurfural oxidation reaction(HOR)performance with>99%2,5-furandicarboxylic acid yield and>97%Faradaic efficiency at an ultralow potential of 1.29 V vs.reversible hydrogen electrode(RHE).Experimental characterization and theoretical calculation reveal that the atomically doped Ni species can enhance the adsorption of reactant and thus lower the reaction energy barriers.By coupling the electrocatalytic HOR with HER,the employed two-electrode system using Ni-Co_(2)P and commercial Ni foam as anode and cathode,respectively,exhibits a low cell voltage of 1.53 V to drive a current density of 10 mA·cm^(−2),which is 90 mV lower than that of pure water splitting.This work provides a facile and efficient approach for the preparation of high-performance earth-abundant electrocatalysts toward the concurrent production of H_(2)and value-added chemicals.展开更多
Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocataly...Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocatalytic capability of these flower-like nanocomposites under visible light irradiation was found to be enhanced by up to 4.7-fold compared to commercial P25 TiO2 nanoparticles. The enhanced photocatalytic activity was ascribed to improved light absorption and hot electron inj ection from the photo-excited Au@Ag core to the TiO2 shell.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK...The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.展开更多
Phosphorescent carbon nanodots(CNDs)have generated enormous interest recently,and the CND phosphorescence is usually located in the visible region,while ultraviolet(UV)phosphorescent CNDs have not been reported thus f...Phosphorescent carbon nanodots(CNDs)have generated enormous interest recently,and the CND phosphorescence is usually located in the visible region,while ultraviolet(UV)phosphorescent CNDs have not been reported thus far.Herein,the UV phosphorescence of CNDs was achieved by decreasing conjugation size and in-situ spatial confinement in a NaCNO crystal.The electron transition from the P_(x) to the sp^(2) orbit of the N atoms within the CNDs can generate one-unit orbital angular momentum,providing a driving force for the triplet excitons population of the CNDs.The confinement caused by the NaCNO crystal reduces the energy dissipation paths of the generated triplet excitons.By further tailoring the size of the CNDs,the phosphorescence wavelength can be tuned to 348 nm,and the room temperature lifetime of the CNDs can reach 15.8 ms.As a demonstration,the UV phosphorescent CNDs were used for inactivating gram-negative and gram-positive bacteria through the emission of their high-energy photons over a long duration,and the resulting antibacterial efficiency reached over 99.9%.This work provides a rational design strategy for UV phosphorescent CNDs and demonstrates their novel antibacterial applications.展开更多
基金supported by the Lanzhou Jiaotong University-Southwest Jiaotong University Joint Innovation Fund(LH2024027).
文摘The virtual synchronous generator(VSG)technology has been proposed to address the problem of system frequency and active power oscillation caused by grid-connected new energy power sources.However,the traditional voltage-current double-closed-loop control used in VSG has the disadvantages of poor disturbance immunity and insufficient dynamic response.In light of the issues above,a virtual synchronous generator voltage outer-loop control strategy based on improved linear autonomous disturbance rejection control(ILADRC)is put forth for consideration.Firstly,an improved first-order linear self-immunity control structure is established for the characteristics of the voltage outer loop;then,the effects of two key control parameters-observer bandwidthω_(0)and controller bandwidthω_(c)on the control system are analyzed,and the key parameters of ILADRC are optimally tuned online using improved gray wolf optimizer-radial basis function(IGWO-RBF)neural network.A simulationmodel is developed using MATLAB to simulate,analyze,and compare the method introduced in this paper.Simulations are performed with the traditional control strategy for comparison,and the results demonstrate that the proposed control method offers superior anti-interference performance.It effectively addresses power and frequency oscillation issues and enhances the stability of the VSG during grid-connected operation.
文摘AIM: To study the correlation between the patterns of subcellular expression of p16 and CDK4 in colorectal epithelia in the normal-adenoma-carcinoma sequence.METHODS: Paraffin sections of 43 cases of normal colorectal epithelia and corresponding adenomas as well as carcinomas were analysed immunocytochemically for subcellular expression of p16 and CDK4 proteins.RESULTS: Most carcinomas showed more cytoplasmic overexpression for p16 and CDK4 than the adenomas from which they arised or the adjacent normal mucosa. Most normal or non-neoplastic epithelia showed more p16 and CDK4 expression in the nucleus than their adjacent adenomas and carcinomas. There was a significant difference between the subcellular expression pattern of p16 and CDK4 in normal-adenoma-carcinoma sequence epithelia (P 〈 0.001). Neither p16 nor CDK4 subcellular patterns correlated with histological grade or Dukes' stage.CONCLUSION: Interaction of expression of p16 and CDK4 plays an important role in the Rb/p16 pathway.Overexpression of p16 and CDK4 in the cytoplasm, as well as loss expression of p16 in the nucleusmighlc be important in the evolution of colorectal carcinoma from adenoma and, of adenoma from normal epitheiia.
文摘This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis (TNM) staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma (RCC) patients. A total of 1216 patients who had undergone radical nephrectomy or partial nephrectomy for RCC from 2003 to 2011 were enrolled. All of the patients had pathologically confirmed clear cell RCC (ccRCC). All cases were staged by both the 2002 and 2010 TNM staging systems after pathological review, and survival data were collected. Univariate and multivariate Cox regression models were used to evaluate cancer-specific survival (CSS) and progression-free survival (PFS) after surgery. Continuous variables, such as age and tumour diameter, were calculated as mean values and standard deviations (s.d.) or as median values. Survival was calculated by the Kaplan-Meier method, and the log-rank test assessed differences between groups. Statistically significant differences in CSS and PFS were noted among patients in T3 subgroups using the new 2010 staging system. Therefore, the revised 2010 TNM staging system can lead to a more accurate prediction of the prognosis of ccRCC patients. However, when using the revised 2010 staging system, we found that more than 92% of patients (288/313) with T3 tumours were staged in the T3a subgroup, and their survival data were not significantly different from those of patients with T2b tumours. In addition, T2 subclassification failed to independently predict survival in RCC patients.
基金supported by the National Key Research and Development Program of China (Grant No: 2016YFE0120900 and 2017YFA0204800)the National Natural Science Foundation of China (No.21,703,244, 21,403,226, and 21,533,010)+4 种基金DICP DMTO201601DICP ZZBS201703the Science Challenging Program (JCKY2016212A501)DICP Outstanding Postdoctoral Foundation (2016YB09)the China Postdoctoral Science Foundation (2017M611276)
文摘Heterovalent-metal doping is an efficient tool to tune the optoelectronic properties of the famous halide perovskites.Previous studies have focused on the heterovalent-doping in three-dimensional(3D) halide perovskites.However, there is a lack of such doping in two-dimensional perovskites which possess unique optoelectronic properties and improved chemical stability as compared to 3D analogues.Here, we present successful doping of Bismuth into the lattice of lead-free, two-dimensional perovskite PEA2SnBr4 single crystals.Structural characterizations demonstrate that the doped crystals possess identical crystal structure and layered morphology with the pristine one.Intriguingly, we find the PL peak and spectral shape can be tailored by tuning the concentration of Bi dopants.Femtosecond transient absorption spectroscopy is performed to understand the underlying mechanism related to tunable PL behaviors, and a clear picture of the Bismuth-doping impact is provided.
基金supported by the National Natural Science Foundation of China(Nos.41974064,42174076 and U1865206)Young Elite Scientists Sponsorship Program by CAST(No.2019QNRC001).
文摘Muon radiography is a promising technique for imaging the internal density structures of targets such as tunnels,pyramids,and volcanoes up to a scale of a few hundred meters by measuring the flux attenuation of cosmic ray muons after they have traveled through these targets.In this study,we conducted experimental muon radiography of one of the volcanoes in the Wudalianchi area in Northeast China to image its internal density structure.The muon detector used in this study was composed of plastic scintillators and silicon photomultipliers.After approximately one and a half months of observing the crater and conduit of the Laoheishan volcano cone in Wudalianchi from September 23^(rd) to November 10^(th) 2019,more than 3 million muon tracks fulfilling the data selection criteria were collected.Based on the muon samples and high-resolution topography obtained through aerial photogrammetry using an unmanned aerial vehicle,a density image of the Laoheishan volcano cone was constructed.The results obtained in this experiment demonstrate the feasibility of using a radiography technique based on plastic scintillator detectors.To obtain the density distribution,we performed a detailed background analysis and found that low-energy charged particles dominated the background noise.Relatively higher densities were found near the surface of the volcanic cone,whereas relatively lower densities were found near the center of the volcanic cone.The experiment in this study is the first volcano muon tomography study performed in China.Our work provides an important reference for future research.
基金financial support by Australian Research Council(ARC)supported by the generous funding from Science and Engineering faculty,QUT。
文摘Transformation of greenhouse gas(CO_(2))into valuable chemicals and fuels is a promising route to address the global issues of climate change and the energy crisis.Metal halide perovskite catalysts have shown their potential in promoting CO_(2)reduction reaction(CO_(2)RR),however,their low phase stability has limited their application perspective.Herein,we present a reduced graphene oxide(rGO)wrapped CsPbI_3 perovskite nanocrystal(NC)CO_(2)RR catalyst(CsPbI_3/rGO),demonstrating enhanced stability in the aqueous electrolyte.The CsPbI_3/rGO catalyst exhibited>92%Faradaic efficiency toward formate production at a CO_(2)RR current density of~12.7 mA cm^(-2).Comprehensive characterizations revealed the superior performance of the CsPbI_3/rGO catalyst originated from the synergistic effects between the CsPbI_3 NCs and rGO,i.e.,rGO stabilized theα-CsPbI_3 phase and tuned the charge distribution,thus lowered the energy barrier for the protonation process and the formation of~*HCOO intermediate,which resulted in high CO_(2)RR selectivity toward formate.This work shows a promising strategy to rationally design robust metal halide perovskites for achieving efficient CO_(2)RR toward valuable fuels.
文摘The mechanisms for OH-initiated acenaphthylene degradation reactions are investigated theoretically by using the density function theory method at M06-2X/aug-cc-pVTZ level in the present paper. There are two possible reaction pathways for the degradation processes have been predicted: the hydrogen abstraction pathway and the hydroxyl addition elimination pathway. Additionally, the formation mechanism for a series of the products such as epoxide, naphthalene-1,8-dicarbaldehyde, dialdehydes, 1-acenaphthenone and nitroacenaphthylene are discussed in detail as well. From the analyses of the decomposition of OH-acenaphthylene adducts, it is found that the favorable reaction with O2/NO is to form the acenaphthenone rather than epoxide, and the most stable isomer is acenaphthenone react from the C1-site reaction. The advantage reaction pathway with NO2 is to form nitroacenaphthylene and nitroacenaphthylenol from C1-site, too.
基金This work was supported by the National Administration of Traditional Chinese Medicine Project(2019XZZX-LG04)Chinese Academy of Traditional Chinese Medicine Project(ZZ13-035-02)to S.L.
文摘Objective This study aimed to assess the efficacy and safety of traditional Chinese medicine,alone or in combination with oseltamivir,in patients with H1N1 Influenza.Methods In the present study,we searched the Cochrane Central Register of Controlled Trials,PUBMED,EMBASE,Chinese Biomedical Literature Database,China Science and Technology Journal Database,China National Knowledge Infrastructure Database,and WanFang Data for studies published in or before February 8,2022.Data were extracted and checked by two investigators.Review Manager 5.4 and STATA statistical software 16.0 were used for the data analysis.Results We identified 22 individual studies reporting data from 2292 individuals with H1N1 influenza.Compared with oseltamivir,the fever clearance duration[MD=-3.99,95%CI(-6.89,-1.09)]and sore throat relief time[MD=-5.39,95%CI(-10.19,-0.59)]in the intervention group of traditional Chinese medicine monotherapy or combined with oseltamivir were shorter.Maxingshigan was the primary component of Lianhuaqingwen.The subgroup analyses indicated that Maxingshigan shortened fever clearance time[MD=-3.23,95%CI(-5.60,-0.85)],and also had certain advantages in relieving sore throat[RR=-4.55,95%CI(-10.04,0.95)].However,as for the effective rate,fever duration,cough disappearance time,hospital length of stay,clinical symptoms time as well as viral shedding duration,there were no significant differences between the two groups.Besides,no serious adverse effects were reported in the included studies.Conclusion Although we couldn’t get a definitive conclusion due to the small sample sizes and high risk of bias in the included studies,most traditional Chinese medicine showed similar effects to oseltamivir in treating H1N1 influenza.Some were showed to have a statistically significant shorter time of fever clearance and sore throat remission when they were used alone or in combination with oseltamivir and were well-tolerated treatment,such as Maxingshigan.
文摘Background:Chinese medicines have shown some advantages in preventing and controlling tumors.Tumor-associated macrophages and the immune factors of the tumor microenvironment all exist in the tumor microenvironment and play important role in the development and prognosis of tumors.Thus,targeting tumor-associated macrophages and immune factors to prevent and treat tumors has become a hotspot in the field of antitumor research of the traditional Chinese medicine.Methods:The inhibition of Chinese patent drug Aikang tablets to the growth of lung cancer was evaluated by calculating the relative tumor volume and relative tumor growth rate using the mouse model of human lung cancer xenograft.The effect of Aikang tablets on the tumor microenvironment was studied through the detection of the immune factors in the tumor microenvironment and serum with high-throughput liquid protein chip detection.Tumor-associated macrophages,M1,M2,and M2/M1 were examined histologically and analyzed immunohistochemically.Results:In this study,2.8 and 1.4 g/kg/day Aikang tablets could significantly inhibit the growth of human lung adenocarcinoma(P<0.05).Moreover,2.8,1.4,and 0.7 g/kg/day Aikang tablets significantly downregulated the MCP-3,MIP-2,and IL-2 serum content(P<0.05);1.4 and 0.7 g/kg/day Aikang tablets significantly downregulated the MCP-1 serum content(P<0.05),1.4 g/kg/day Aikang tablets significantly downregulated the MIP-1αserum content(P<0.05).Simultaneously,2.8 g/kg/day Aikang tablets significantly downregulated the MIP-1βcontent in the tumor microenvironment(P<0.01);1.4 g/kg/day Aikang tablets significantly downregulated regulated upon activation,normal T Cell expressed and presumably secreted content in the tumor microenvironment(P<0.01);and 0.7 g/kg/day Aikang tablets significantly downregulated the MCP-1 and MCP-3 contents in tumor microenvironment(P<0.01).The results also showed that 2.8 and 1.4 g/kg/day Aikang tablets significantly increased the number of the M1 subtypes(P<0.05)and decreased the ratio of M2/M1(P<0.01).Conclusions:The results showed that Aikang tablets could inhibit the growth of human lung adenocarcinoma xenograft in mice but not squamous cell carcinoma and small cell carcinoma.Moreover,the mechanism should be related to increasing the number of tumor-associated macrophage subtype M1,decreasing the proportion of tumor-associated macrophage subtypes(M2/M1),and decreasing the level of immune factors in serum and tumor microenvironment.
文摘Objective To observe the effect of Xiaoer Feire Kechuan oral solution on the extrapulmonary injury induced by Mycoplasma pneumoniae in infant Wistar rats. Methods Infant Wistar rats were infected intranasally with M. pneumoniae once a day for four days. In the treatment groups, Xiaoer Feire Kechuan oral solution was administered daily for four days beginning from the day of infection. On day 5, blood of the rats was collected, and blood routine and biochemistry indexes were measured. All rats were sacrificed, and the weight of brain, heart, liver, and kidney was measured to calculate the organ indexes. The GM1 and GALC-Ab content in brain tissue was determined by ELISA. Pathological changes in the brain, heart, liver, kidney, and cerebellum were observed by HE staining. Results Blood routine indexes fluctuated within the normal range in the infection control group and in three of the Xiaoer Feire Kechuan oral solution groups. The serum LDH, CK, and CRE in all three Xiaoer Feire Kechuan oral solution groups were distinctly lower than those in the infection control group (P < 0.01, P < 0.05). Rat brain index and GALC-Ab content in the brain tissue showed an increase in infection control group. In the Xiaoer Feire Kechuan oral solution groups, the GALC-Ab content in brain tissue was decreased significantly. The heart, liver, and kidney tissues showed mild pathological changes in the infection group, which were reversed by Xiaoer Feire Kechuan oral solution treatment. Conclusions The extrapulmonary injury induced by M. pneumoniae in infant Wistar rats was significantly inhibited by Xiaoer Feire Kechuan oral solution.
基金supported by the National Natural Science Foundation of China (21533010, 21525315)the National Key Research and Development Program of China (2017YFA0204800)+2 种基金DICP DMTO201601DICP ZZBS201703the Science Challenging Program (JCKY2016212A501)
文摘Lead-free halide double perovskites have gathered wide scientific interest since they are environmentally friendly and stable.However,compared to the lead perovskites,their optoelectronic properties are compromised.Herein we report a series of bulk lead-free mixed Bi-In halide double perovskites:Cs2AgBi1-xInxCl6(0<x<1).The Cs2AgBi0.125In0.875Cl6breaks the parity-forbidden transition and retains direct band gap structure,having warm-white light emission,with photoluminescence quantum efficiency(PLQE)of 70.3%,much higher than the PLQE of reported lead perovskite materials.Its exciton self-trapping dynamics is investigated.Meanwhile,the Cs2AgBi0.125In0.875Cl6nanocrystals and Cs2AgBi0.125In0.875Cl6microcrystals can be synthesized by modified hot injection and rapid cooling crystallization,respectively.The size effect of Cs2AgBi0.125In0.875Cl6is studied on the photoluminescence(PL)property.Additionally,the bulk material exhibits excellent stability on exposure to light,humidity and air for more than 3 months.It is a promising candidate as highly efficient warm white-light emitting material for road lighting.
基金the National Key Research and Development(R&D)Program of China(No.2020YFA0406103)the National Natural Science Foundation of China(NSFC)(Nos.21725102,51902311,22122506,91961106,22075267,and 21803002)+5 种基金Strategic Priority Research Program of the CAS(No.XDPB14)Anhui Provincial Natural Science Foundation(No.2008085J05)Youth Innovation Promotion Association of CAS(No.2019444)Open Funding Project of National Key Laboratory of Human Factors Engineering(No.SYFD062010K)Users with Excellence Program of Hefei Science Center CAS(No.2020HSCUE003)Fundamental Research Funds for the Central Universities(No.WK2060000039).
文摘The thermodynamically favorable electrocatalytic oxidation coupled with hydrogen evolution reaction(HER)is considered as a sustainable and promising technique.Nonetheless,it remains a great challenge due to the lack of simple,cheap,highefficient electrocatalysts.Here,we successfully develop a simple and scalable electro-deposition and subsequent phosphorization route to fabricate Ni-doped Co_(2)P(Ni-Co_(2)P)nanosheets catalyst using the in-situ released Ni species from defective Ni foam as metal source.Impressively,the as-synthesized Ni-Co_(2)P catalyst exhibits excellent electrochemical 5-hydroxymethylfurfural oxidation reaction(HOR)performance with>99%2,5-furandicarboxylic acid yield and>97%Faradaic efficiency at an ultralow potential of 1.29 V vs.reversible hydrogen electrode(RHE).Experimental characterization and theoretical calculation reveal that the atomically doped Ni species can enhance the adsorption of reactant and thus lower the reaction energy barriers.By coupling the electrocatalytic HOR with HER,the employed two-electrode system using Ni-Co_(2)P and commercial Ni foam as anode and cathode,respectively,exhibits a low cell voltage of 1.53 V to drive a current density of 10 mA·cm^(−2),which is 90 mV lower than that of pure water splitting.This work provides a facile and efficient approach for the preparation of high-performance earth-abundant electrocatalysts toward the concurrent production of H_(2)and value-added chemicals.
基金supportedby the Ministry of Education of Singapore(R-143-000-607-112)the National Natural Science Foundation of China(21673155)
文摘Uniform flower-like TiO2 coated Au nanostars and core-shell Au@Ag nanostars with different amounts of Ag coating were prepared through a facile method by hydrolysis of TiF4 under an acidic environment. The photocatalytic capability of these flower-like nanocomposites under visible light irradiation was found to be enhanced by up to 4.7-fold compared to commercial P25 TiO2 nanoparticles. The enhanced photocatalytic activity was ascribed to improved light absorption and hot electron inj ection from the photo-excited Au@Ag core to the TiO2 shell.
基金supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+22 种基金the CAS Center for Excellence in Particle PhysicsWuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules (IN2P3) in Francethe Istituto Nazionale di Fisica Nucleare (INFN) in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique (F.R.S-FNRS)FWO under the "Excellence of Science-EOS" in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo in Chilethe Charles University Research Centrethe Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft (DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+ in Germanythe Joint Institute of Nuclear Research (JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation (RSF)National Natural Science Foundation of China (NSFC) research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn UniversitySuranaree University of Technology in Thailandthe University of California at Irvine in USA
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.U21A2070,62075198,and 11904326)the Henan Center for Outstanding Overseas Scientists(GZS201903).
文摘Phosphorescent carbon nanodots(CNDs)have generated enormous interest recently,and the CND phosphorescence is usually located in the visible region,while ultraviolet(UV)phosphorescent CNDs have not been reported thus far.Herein,the UV phosphorescence of CNDs was achieved by decreasing conjugation size and in-situ spatial confinement in a NaCNO crystal.The electron transition from the P_(x) to the sp^(2) orbit of the N atoms within the CNDs can generate one-unit orbital angular momentum,providing a driving force for the triplet excitons population of the CNDs.The confinement caused by the NaCNO crystal reduces the energy dissipation paths of the generated triplet excitons.By further tailoring the size of the CNDs,the phosphorescence wavelength can be tuned to 348 nm,and the room temperature lifetime of the CNDs can reach 15.8 ms.As a demonstration,the UV phosphorescent CNDs were used for inactivating gram-negative and gram-positive bacteria through the emission of their high-energy photons over a long duration,and the resulting antibacterial efficiency reached over 99.9%.This work provides a rational design strategy for UV phosphorescent CNDs and demonstrates their novel antibacterial applications.