OBJECTIVE:To eliminate ineffective or interfering compounds from the eight absorbed compounds(8ACs),identify the primary ACs that represent the multifunctional therapeutic effects of Zhiqiao(Fructus Aurantii Submaturu...OBJECTIVE:To eliminate ineffective or interfering compounds from the eight absorbed compounds(8ACs),identify the primary ACs that represent the multifunctional therapeutic effects of Zhiqiao(Fructus Aurantii Submaturus)and Houpo(Cortex Magnoliae Officinalis)(FM),along with elucidating their underlying mechanisms.METHODS:Key multifunctional ACs were screened through ex vivo-to-in vitro extrapolation(ex vivo dose=serum concentration)and validated in vivo,with efficacy assessed via contribution(dose=FM content).Functional magnetic resonance imaging analyzed brain regions's blood oxygen level-dependent(BOLD)changes,and the molecular mechanisms were analyzed by transcriptome of the dentate gyrus(DG).RESULTS:The results showed that representative 2ACs(Nobiletin+Magnolol)and 3ACs(Nobiletin+Magnolol+Meranzin hydrate)screened on ex vivo experiment by the criteria of contribution ranking contributed 80.72%-126.74%of the antidepressant and prokinetic effects of the FM(improvement of depressive-like behaviours,gastrointestinal disorder,monoamine neurotransmitters,ghrelin,endocrine hormones,pro-inflammatory factors,oxidative stress indicators).In addition,3ACs demonstrated superiority over 2ACs in improving depression and levels of multiple stress mediators.Zhiqiao(Fructus Aurantii Submaturus)(FRA)reduced acute stress-induced hyperactivation of the cingulate cortex,thalamus,hypothalamus,and entorhinal cortex and elevated BOLD signaling in the insular cortex,temporal association cortex.Furthermore,FRA upregulated pathways of neurotransmitter receptor activity and serotonergic synaptic function and downregulated inflammation-related pathways at the genetic level.CONCLUSION:2ACs and 3ACs closely reflected FM's multifunctional effect in antidepressant and prokinetic.FRA restores stress-impaired neural connectivity in functional brain regions and improves synaptic plasticity and neurogenesis at the genetic level.展开更多
Perovskite-type complex oxides ABO3 （A=Sr, La; B=Mn, Fe, Co） were prepared by citric acid method. The degradation of water-solubilized dyes was carried out using the mixed oxides as photocatalyst. The surface absorb...Perovskite-type complex oxides ABO3 （A=Sr, La; B=Mn, Fe, Co） were prepared by citric acid method. The degradation of water-solubilized dyes was carried out using the mixed oxides as photocatalyst. The surface absorbed oxygen was analyzed using X-ray photoelectron spectroscopy （XPS）. The results indicated that there was a relationship between the photocatalytic activity and the content of the surface absorbed oxygen. The higher the content of the surface absorbed oxygen was, the better the performance of the photocatalyst.展开更多
Qing-Fei-Pai-Du decoction(QFPDD)is a Chinese medicine compound formula recommended for combating corona virus disease 2019(COVID-19)by National Health Commission of the People's Republic of China.The latest clinic...Qing-Fei-Pai-Du decoction(QFPDD)is a Chinese medicine compound formula recommended for combating corona virus disease 2019(COVID-19)by National Health Commission of the People's Republic of China.The latest clinical study showed that early treatment with QFPDD was associated with favorable outcomes for patient recovery,viral shedding,hospital stay,and course of the disease.However,the effective constituents of QFPDD remain unclear.In this study,an UHPLC-Q-Orbitrap HRMS based method was developed to identify the chemical constituents in QFPDD and the absorbed prototypes as well as the metabolites in mice serum and tissues following oral administration of QFPDD.A total of 405 chemicals,including 40 kinds of alkaloids,162 kinds of flavonoids,44 kinds of organic acids,71 kinds of triterpene saponins and 88 kinds of other compounds in the water extract of QFPDD were tentatively identified via comparison with the retention times and MS/MS spectra of the standards or refereed by literature.With the help of the standards and in vitro metabolites,195 chemical components(including 104 prototypes and 91 metabolites)were identified in mice serum after oral administration of QFPDD.In addition,165,177,112,120,44,53 constituents were identified in the lung,liver,heart,kidney,brain,and spleen of QFPDD-treated mice,respectively.These findings provided key information and guidance for further investigation on the pharmacologically active substances and clinical applications of QFPDD.展开更多
The relationship between Charpy absorbed energy and the fracture toughness by means of the (crack tip opening displacement (CTOD)) method was analyzed based on the Weibull stress criterion. The Charpy absorbed energy ...The relationship between Charpy absorbed energy and the fracture toughness by means of the (crack tip opening displacement (CTOD)) method was analyzed based on the Weibull stress criterion. The Charpy absorbed energy and the fracture toughness were measured for the SN490B steel under the ductile-brittle transition temperature region. For the instrumented Charpy impact test, the curves between the loading point displacement and the load against time were recorded. The critical Weibull stress was taken as a fracture controlled parameter, and it could not be affected by the specimen configuration and the loading pattern based on the local approach. The parameters controlled brittle fracture are obtained from the Charpy absorbed energy results, then the fracture toughness for the compact tension (CT) specimen is predicted. It is found that the results predicted are in good agreement with the experimental. The fracture toughness could be evaluated by the Charpy absorbed energy, because the local approach gives a good description for the brittle fracture even though the Charpy impact specimen or the CT specimen is used for the given material.展开更多
To address the problem of conventional approaches for mechanical property determination requiring destructive sampling, which may be unsuitable for in-service structures, the authors proposed a method for determining ...To address the problem of conventional approaches for mechanical property determination requiring destructive sampling, which may be unsuitable for in-service structures, the authors proposed a method for determining the quasi-static fracture toughness and impact absorbed energy of ductile metals from spherical indentation tests (SITs). The stress status and damage mechanism of SIT, mode I fracture, Charpy impact tests, and related tests were frst investigated through fnite element (FE) calculations and scanning electron microscopy (SEM) observations, respectively. It was found that the damage mechanism of SITs is diferent from that of mode I fractures, while mode I fractures and Charpy impact tests share the same damage mechanism. Considering the diference between SIT and mode I fractures, uniaxial tension and pure shear were introduced to correlate SIT with mode I fractures. Based on this, the widely used critical indentation energy (CIE) model for fracture toughness determination using SITs was modifed. The quasi-static fracture toughness determined from the modifed CIE model was used to evaluate the impact absorbed energy using the dynamic fracture toughness and energy for crack initiation. The efectiveness of the newly proposed method was verifed through experiments on four types of steels: Q345R, SA508-3, 18MnMoNbR, and S30408.展开更多
The effect of the size of radiotherapy photon beams on the absorbed dose to an Al2O3 dosimeter was investigated using the Monte Carlo method. The EGSnrc/DOSRZnrc program code was used to simulate the absorbed dose to ...The effect of the size of radiotherapy photon beams on the absorbed dose to an Al2O3 dosimeter was investigated using the Monte Carlo method. The EGSnrc/DOSRZnrc program code was used to simulate the absorbed dose to the Al2O3 dosimeter, as well as the absorbed dose to water at the corresponding position in the absence of the dosimeter. The incident beams were 60Co γ and 6 MV with a different beam radius ranging from 0.1 cm to 2 cm. Results revealed that the absorbed dose ratio factor depends on the size of the incident photon beam. When the radius of the incident beam is smaller than that of the dosimeter, the absorbed dose ratio factor decreases as the incident beam size increases. The absorbed dose ratio factor reaches its minimum when the radius of the incident beam is almost the same as that of the dosimeter. When the radius of the incident beam is larger than that of the dosimeter, the absorbed dose ratio factor increases as the incident beam size increases. The maximum difference among these absorbed dose ratio factors can be up to 14% in 60Co γ beams and 23% in 6 MV beams. However, when the size of the incident beam is much larger than that of the dosimeter, the effect of the incident beam size on the absorbed dose ratio factor becomes quite small. The maximum discrepancy between the absorbed dose ratio factors and the average value is not more than 1%.展开更多
The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported. The distributions of beta dose were measured by an extra...The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported. The distributions of beta dose were measured by an extrapolation ionization chamber at definite depthes corresponding to some superficial organs and tissues such as the radiosensitive layer of the skin, cornea, sclera, anterior chamber and lens of eyeball.The ratios among superficial absorbed dose D (0.07) and average absorbed doses at the depthes 1,2,3,4,5 and 6 mm are also obtained with Cross's methods. They can be used for confining the deterministic effects of some superficial tissues and organs such as the skin and the components of eyeball for weakly penetrating radiations.展开更多
Ensuring reliability and traceability of the unit of absorbed dose of intense photon and electron radiation, used in radiation technologies in industry, is based on the creation of a system of sample measures and meth...Ensuring reliability and traceability of the unit of absorbed dose of intense photon and electron radiation, used in radiation technologies in industry, is based on the creation of a system of sample measures and methods of transmission with minimal loss of dimensional accuracy of the unit of absorbed dose from the sample tools to working dosimeters and is a necessary basis of yield growth, of increase of labour productivity and the introduction of innovative products. The measuring capabilities of the State primary special standard of power unit of absorbed dose of intensity photon, electron and beta radiation for radiation technologies and of the standards of the absorbed dose of photon and electron radiation, used for radiation monitoring of radiation pro- cesses.展开更多
The present study investigates the effect of the addition of nanoparticles into epoxy resins as the matrix on the impact absorbed energy of CFRP （carbon fiber reinforced polymer）. Impact absorbed energy is one of th...The present study investigates the effect of the addition of nanoparticles into epoxy resins as the matrix on the impact absorbed energy of CFRP （carbon fiber reinforced polymer）. Impact absorbed energy is one of the main properties to evaluate the CFRP＇s performance for transportation and aerospace structures. Two types of nanoparticle, namely nanofibers and nano-silica beads, were added into the epoxy resin to improve the impact absorption capacity of the CFRP. Two modified additives and conventional epoxy resins were quantitatively compared. The impact test results showed that impact absorbed energy for nanofibers was higher than nano-silica beads, and nanofibers as the additive promoted about 11% of impact absorbed energy compared with neat epoxy resin.展开更多
The tumbling dynamics of individual absorbed polymer chains in shear flow is studied by employing multi-particle collision dynamics simulation techniques combined with molecular dynamics simulations.We find that the d...The tumbling dynamics of individual absorbed polymer chains in shear flow is studied by employing multi-particle collision dynamics simulation techniques combined with molecular dynamics simulations.We find that the dependence of tumbling frequencies on shear rate is independent of both adsorption strength and surface corrugate.展开更多
It is worth studying whether enterprises receiving government subsidies can transform them into innovative achievements under the constraints of enterprise resources.The data from the three industries of electronics,p...It is worth studying whether enterprises receiving government subsidies can transform them into innovative achievements under the constraints of enterprise resources.The data from the three industries of electronics,pharmaceuticals,and information technology during 2013-2016 were empirical tested to verify the moderating effect of the absorbed slack on the relationship between government subsidies and enterprise innovation.The results show that government subsidies can promote enterprise innovation;absorbed slack promotes enterprise innovation;the absorbed slack of enterprises plays a positive moderation role in the relationship between government subsidy and enterprise innovation.In other words,the enterprises with high absorbed slack can promote the innovation of enterprises by government subsidies.The conclusions provide theoretical guidance for government departments to select the most suitable enterprises which accept innovative subsidies.展开更多
Radiotherapy is the most widely applied oncologic treatment modality utilizing ionizing radiation. A high degree of accuracy, reliability and reproducibility is required for a successful treatment outcome. Measurement...Radiotherapy is the most widely applied oncologic treatment modality utilizing ionizing radiation. A high degree of accuracy, reliability and reproducibility is required for a successful treatment outcome. Measurement using ionization chamber is a prerequisite for absorbed dose determination for external beam radiotherapy. Calibration coefficient is expressed in terms of air kerma and absorbed dose to water traceable to Secondary Standards Dosimetry Laboratory. The objective of this work was to evaluate the level of accuracy of ionization chamber used for clinical radiotherapy beam determination. Measurement and accuracy determination were carried out according to IAEA TRS 398 protocol. Clinical farmers type ionization chamber measurement and National Reference standard from Secondary Standards Dosimetry Laboratory were both exposed to cobalt-60 beam and measurement results compared under the same environmental conditions. The accuracy level between National Reference Standard and clinical radiotherapy standard was found to be −1.92% and −2.02% for air kerma and absorbed dose to water respectively. To minimize the effect of error and maximize therapeutic dose during treatment in order to achieve required clinical outcome, calibration factor was determined for air kerma (Nk) as 49.7 mGy/nC and absorbed dose to water ND, as 52.9 mGy/nC. The study established that radiotherapy beam measurement chain is prone to errors. Hence there is a need to independently verify the accuracy of radiation dose to ensure precision of dose delivery. The errors must be accounted for during clinical planning by factoring in calibration factor to minimize the systematic errors during treatment, and thereby providing enough room to achieve ±5% dose delivery to tumor target as recommended by ICRU.展开更多
Since the early times, radioprotection has been focused on the human being. Currently this approach has changed, being now also necessary to take care of the protection of the environment from unwanted effects of ioni...Since the early times, radioprotection has been focused on the human being. Currently this approach has changed, being now also necessary to take care of the protection of the environment from unwanted effects of ionizing radiation. To this end, several institutions (UNSCEAR, ICRP, IAEA, DOE, ACRP) and consortia of institutions (FASSET, ERICA) have established procedures in order to protect the biota of such effects. Developed procedures are based on the calculation of the absorbed dose in biota (ICRP, DOE, IAEA), or on environmental risk assessment―ERA (DOE, ACRP, FASSET, ERICA);but even in this latter approach the parameters used are related to the absorbed doses in biota. The calculation of dose is the standard procedure in human radioprotection, and this points such an approach as the most interesting for providing a convergence between human and nonhuman (= biota) radioprotections. On the other hand, the ERA approach is easier to apply, because this methodology is used in several countries for non-radioactive contamination assessments. Since the world radioprotection system follows a number of institutions (UNSCEAR, ICRP, IAEA and regulatory institutions of member countries) that use dose calculation, this appears to be the way for biota radioprotection. We here review and comment the evolution of the concepts and approaches of the recommendations for radioprotection of non-human biota.展开更多
To understand the biogeochemical transfer of iodine, the absorbability and bioaccumulation of iodine in tested vegetables(radish, spinach and Chinese cabbage) are examined by applying iodic fertilizer composed of kelp...To understand the biogeochemical transfer of iodine, the absorbability and bioaccumulation of iodine in tested vegetables(radish, spinach and Chinese cabbage) are examined by applying iodic fertilizer composed of kelp and diatomaceous earth. The experimental results show that when iodine in soil is not excessive, the concentrations of iodine in tested vegetables increase as the content of iodine in soil increases. The absorbability and enrichment degree of iodine in various vegetables and in various parts of the same vegetable are different, which explains that the concentration of iodine in plant is determined by the plant type and the physiological action of plant. The patience order of tested vegetables to excessive iodine is Chinese cabbage>spinach>radish. These results have theoretical and practical significance in opening up a new way for ameliorating poor iodine environment with artificial means.展开更多
This paper presents an extended model predictive controller for maximizing the absorbed power of a point absorber wave energy converter. Owing to the great influence of controller parameters upon the absorbed power, t...This paper presents an extended model predictive controller for maximizing the absorbed power of a point absorber wave energy converter. Owing to the great influence of controller parameters upon the absorbed power, the optimization of these parameters is carried out for the first time by a firefly algorithm(FA). Error, the difference between output velocity of buoy and input wave speed which leads to power maximization in the optimized MPC is compared with the classical MPC. Simulation results indicate that given the high accuracy and acceptable speed of the algorithm, it can adjust the parameters of the controller to the point where system error decreased effectively and the absorbed energy increased about 4 MW.展开更多
Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight ...Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight guanine analogs[N-2-（2＇-nitrobenzoyl）-guanine, N-2-（3＇-nitrohenzoyl）-guanine, N-2-（4＇-nitrobenzoyl）-guanine, N-2-（2＇-hydroxybenzoyl）-guanine, N-2-（4＇-methoxylbenzoyl）-guanine, N-2-（4＇-chloricbenzoyl）-guanine, N-2-（4＇- me- thylicbenzoyl）-guanine and N-2-（3＇,5＇-dinitrobenzoyl）-guanine] with different substituted benzoyls, except N-2-（4＇-chloricbenzoyl）-guanine, were newly synthesized. In contrast with guanine, they exhibit wider ultraviolet absorbent range, higher molar extinction coefficient and lower fluorescence intensity.展开更多
Laminated continental shale oil reservoirs have the potential for commercial development.In this paper,a new simulation method for interlayer and intra-layer coupled flow in laminated shale reservoirs is established.T...Laminated continental shale oil reservoirs have the potential for commercial development.In this paper,a new simulation method for interlayer and intra-layer coupled flow in laminated shale reservoirs is established.This method simulates the structural characteristics of shale-sandstone longitudinal interlayer distribution by dual-porositysystem,and combines with chemical reaction model to characterize the desorption process of ad-/absorbed oil from kerogen in shale layers.Then,the intra-layer and interlayer interfacial flow mechanism in the depletion process is investigated,and the contribution of interfacial flow and desorption is analyzed.The results indicate that the sandstone layer is the main oil-producing layer,accounting for over 90%of the total oil production.However,the interlayer flow and kerogen desorption in the shale layers make significant contributions,resulting in an enhancement of 13.41%and 42.64%in the total oil production,respectively.Additionally,the desorption of ad-/absorbed oil from kerogen enhances the energy of both the shale and sandstone layers,significantly increasing their production.Moreover,higher pressure drawdown,total organic carbon(TOC)content,desorption rate,and horizontal permeability of sandstone layers are advantageous for the exploitation of shale oil.展开更多
Objective:To build the database of the absorbed fractions(AFs)and specific absorbed fractions(SAFs),in order to accurately assess the internal radiation dose in non-human biota.Methods:A voxel-based Portunus haanii ph...Objective:To build the database of the absorbed fractions(AFs)and specific absorbed fractions(SAFs),in order to accurately assess the internal radiation dose in non-human biota.Methods:A voxel-based Portunus haanii phantom was established based on the computed tomography(CT)images.A set of AFs and SAFs were calculated with Monte Carlo toolkit Geant4 for the emission of monoenergetic photons and electrons with energies ranging from 10 keV to 5 MeV.Results:The mass of the voxel-based Portunus haanii phantom(392.2 g)was in agreement with the actual mass(389.2 g),indicating the reliability of the phantom.The calculated AFs and SAFs,based on the voxel-based Portunus haanii phantom,provided precise and reliable data for conducting internal radiation dose calculations specifically tailored to the Chinese Red Swimming Crab(Portunus haanii).The results indicated that the self-AFs and self-SAFs were affected by both the radiation energy and the mass of the source/target organ.Moreover,the AFs and SAFs for cross irradiation,were not only dependent on the energy and the mass of the target organ,but also on the relative position of the source and target organs.Conclusion:These results serve as a valuable resource for accurately evaluating the internal radiation exposure of this species.展开更多
Objective： To detect absorbed bioactive compounds of the water extract whose pharmacodynamic effect was craniocerebral protection for quality control assessment. Methods： Anthraquinones in water extract of rhubarb ...Objective： To detect absorbed bioactive compounds of the water extract whose pharmacodynamic effect was craniocerebral protection for quality control assessment. Methods： Anthraquinones in water extract of rhubarb （WER）, in cerebrospinal fluid （CSF） of patients with traumatic brain injury （TBI） and in ipsilateral cortex of TBI rats following oral WER were respectively explored by ultra performance liquid chromatography with photodiode array detector （UPLC-PDA） method developed in the present study. The effects of anthraquinones absorbed into injured cortex on superoxidase dismutase （SOD） activity in TBI rats were detected. The antioxidative anthraquinones absorbed into target organ were evaluated for quality control of WER. Results： Anthraquinones in WER were aloe-emodin, rhein, emodin, chrysophanol, and physcion. Only the last anthraquinone was found in CSF and in ipsilateral cortex under this chromatographic condition. Physcion increased SOD activity in TBI rats significantly. Conclusions： Physcion was the main active compound of rhubarb against craniocerebral injury via antioxidant pathway. According to our strategy, the exploration of physcion suggested the possibility of a novel quality control of WER in treating TBI injury.展开更多
Aims accurate remote estimation of the fraction of absorbed photosynthetically active radiation(fAPAR)is essential for the light use efficiency(LUE)models.Currently,one challenge for the LUE models is lack of knowledg...Aims accurate remote estimation of the fraction of absorbed photosynthetically active radiation(fAPAR)is essential for the light use efficiency(LUE)models.Currently,one challenge for the LUE models is lack of knowledge about the relationship between fAPAR and the normalized difference vegetation index(NDVI).Few studies have tested this relationship against field measurements and evaluated the accuracy of the remote estimation method.this study aimed to reveal the empirical relationship between NDVI and fAPAR and to improve algorithms for remote estimation of fAPAR.Methods to investigate the method of remote estimation of fAPAR seasonal dynamics,the CASA(Carnegie-ames-stanford approach)model and spectral vegetation indices(VIs)were used for in situ measure-ments of spectral reflectance and fAPAR during the growing season of a maize canopy in Northeast China.Important Findingsthe results showed that the fAPAR increased rapidly with the day of year during the vegetative stage,it remained relatively stable at the stage of reproduction,and finally decreased slowly during the senescence stage.In addition,fAPAR green[fAPAR_(green)=fAPAR_(green) -fAPAR_(green) LAI_(max))]showed clearer seasonal trends than fAPAR.the NDVI,red-edge NDVI,wide dynamic range vegetation index,red-edge position(REP)and REP with sentinel-2 bands derived from hyperspectral remote sensing data were all significantly positively related to fAPAR green during the entire growing season.In a comparison of the predictive performance of VIs for the whole growing season,REP was the most appropriate spectral index,and can be recommended for monitoring seasonal dynamics of fAPAR in a maize canopy.展开更多
基金Supported by the Jiangsu Province’s Colleges and Universities(Integration of Chinese and Western Medicine)the National Natural Science Foundation of China[Methanism on Molecular and Hippocampus-Thalamus Neurocircuitry of Rapid Prokinetic and Antidepressant by Shugan Following Acute Stress(81973589)]The Relationship Between Stress,Ghrelin Signaling,Liver-Soothing and Antidepressant Prokinetic Mechanisms(81573797)。
文摘OBJECTIVE:To eliminate ineffective or interfering compounds from the eight absorbed compounds(8ACs),identify the primary ACs that represent the multifunctional therapeutic effects of Zhiqiao(Fructus Aurantii Submaturus)and Houpo(Cortex Magnoliae Officinalis)(FM),along with elucidating their underlying mechanisms.METHODS:Key multifunctional ACs were screened through ex vivo-to-in vitro extrapolation(ex vivo dose=serum concentration)and validated in vivo,with efficacy assessed via contribution(dose=FM content).Functional magnetic resonance imaging analyzed brain regions's blood oxygen level-dependent(BOLD)changes,and the molecular mechanisms were analyzed by transcriptome of the dentate gyrus(DG).RESULTS:The results showed that representative 2ACs(Nobiletin+Magnolol)and 3ACs(Nobiletin+Magnolol+Meranzin hydrate)screened on ex vivo experiment by the criteria of contribution ranking contributed 80.72%-126.74%of the antidepressant and prokinetic effects of the FM(improvement of depressive-like behaviours,gastrointestinal disorder,monoamine neurotransmitters,ghrelin,endocrine hormones,pro-inflammatory factors,oxidative stress indicators).In addition,3ACs demonstrated superiority over 2ACs in improving depression and levels of multiple stress mediators.Zhiqiao(Fructus Aurantii Submaturus)(FRA)reduced acute stress-induced hyperactivation of the cingulate cortex,thalamus,hypothalamus,and entorhinal cortex and elevated BOLD signaling in the insular cortex,temporal association cortex.Furthermore,FRA upregulated pathways of neurotransmitter receptor activity and serotonergic synaptic function and downregulated inflammation-related pathways at the genetic level.CONCLUSION:2ACs and 3ACs closely reflected FM's multifunctional effect in antidepressant and prokinetic.FRA restores stress-impaired neural connectivity in functional brain regions and improves synaptic plasticity and neurogenesis at the genetic level.
基金the National Natural Science Foundation of China (20671069)
文摘Perovskite-type complex oxides ABO3 （A=Sr, La; B=Mn, Fe, Co） were prepared by citric acid method. The degradation of water-solubilized dyes was carried out using the mixed oxides as photocatalyst. The surface absorbed oxygen was analyzed using X-ray photoelectron spectroscopy （XPS）. The results indicated that there was a relationship between the photocatalytic activity and the content of the surface absorbed oxygen. The higher the content of the surface absorbed oxygen was, the better the performance of the photocatalyst.
基金the National Key Research and Development Program of China(2020YFC0845400)the NSF of China(81922070)+3 种基金Shanghai Science and Technology Innovation Action Plans(20S2190150020S21900900)supported by Shanghai Science and Technology Committeethe Three-year Action Plan of Shanghai TCM Development(ZY-(2018-2020)-CCCX-5001)Program of Shanghai Academic/Technology Research Leader(18XD1403600)。
文摘Qing-Fei-Pai-Du decoction(QFPDD)is a Chinese medicine compound formula recommended for combating corona virus disease 2019(COVID-19)by National Health Commission of the People's Republic of China.The latest clinical study showed that early treatment with QFPDD was associated with favorable outcomes for patient recovery,viral shedding,hospital stay,and course of the disease.However,the effective constituents of QFPDD remain unclear.In this study,an UHPLC-Q-Orbitrap HRMS based method was developed to identify the chemical constituents in QFPDD and the absorbed prototypes as well as the metabolites in mice serum and tissues following oral administration of QFPDD.A total of 405 chemicals,including 40 kinds of alkaloids,162 kinds of flavonoids,44 kinds of organic acids,71 kinds of triterpene saponins and 88 kinds of other compounds in the water extract of QFPDD were tentatively identified via comparison with the retention times and MS/MS spectra of the standards or refereed by literature.With the help of the standards and in vitro metabolites,195 chemical components(including 104 prototypes and 91 metabolites)were identified in mice serum after oral administration of QFPDD.In addition,165,177,112,120,44,53 constituents were identified in the lung,liver,heart,kidney,brain,and spleen of QFPDD-treated mice,respectively.These findings provided key information and guidance for further investigation on the pharmacologically active substances and clinical applications of QFPDD.
基金The work is supported by the National Natural Science Foundation of China under grant No.50275107by Fok Ying Tung Education Foundation under grant No.81405.
文摘The relationship between Charpy absorbed energy and the fracture toughness by means of the (crack tip opening displacement (CTOD)) method was analyzed based on the Weibull stress criterion. The Charpy absorbed energy and the fracture toughness were measured for the SN490B steel under the ductile-brittle transition temperature region. For the instrumented Charpy impact test, the curves between the loading point displacement and the load against time were recorded. The critical Weibull stress was taken as a fracture controlled parameter, and it could not be affected by the specimen configuration and the loading pattern based on the local approach. The parameters controlled brittle fracture are obtained from the Charpy absorbed energy results, then the fracture toughness for the compact tension (CT) specimen is predicted. It is found that the results predicted are in good agreement with the experimental. The fracture toughness could be evaluated by the Charpy absorbed energy, because the local approach gives a good description for the brittle fracture even though the Charpy impact specimen or the CT specimen is used for the given material.
基金Supported by National Natural Science Foundation of China(Grant No.52275154)National Key Research and Development Project of China(Grant No.2016YFF0203005).
文摘To address the problem of conventional approaches for mechanical property determination requiring destructive sampling, which may be unsuitable for in-service structures, the authors proposed a method for determining the quasi-static fracture toughness and impact absorbed energy of ductile metals from spherical indentation tests (SITs). The stress status and damage mechanism of SIT, mode I fracture, Charpy impact tests, and related tests were frst investigated through fnite element (FE) calculations and scanning electron microscopy (SEM) observations, respectively. It was found that the damage mechanism of SITs is diferent from that of mode I fractures, while mode I fractures and Charpy impact tests share the same damage mechanism. Considering the diference between SIT and mode I fractures, uniaxial tension and pure shear were introduced to correlate SIT with mode I fractures. Based on this, the widely used critical indentation energy (CIE) model for fracture toughness determination using SITs was modifed. The quasi-static fracture toughness determined from the modifed CIE model was used to evaluate the impact absorbed energy using the dynamic fracture toughness and energy for crack initiation. The efectiveness of the newly proposed method was verifed through experiments on four types of steels: Q345R, SA508-3, 18MnMoNbR, and S30408.
基金supported by the Science and Technology Project for University and Research Institute of Dongguan of China (No. 200910814045)
文摘The effect of the size of radiotherapy photon beams on the absorbed dose to an Al2O3 dosimeter was investigated using the Monte Carlo method. The EGSnrc/DOSRZnrc program code was used to simulate the absorbed dose to the Al2O3 dosimeter, as well as the absorbed dose to water at the corresponding position in the absence of the dosimeter. The incident beams were 60Co γ and 6 MV with a different beam radius ranging from 0.1 cm to 2 cm. Results revealed that the absorbed dose ratio factor depends on the size of the incident photon beam. When the radius of the incident beam is smaller than that of the dosimeter, the absorbed dose ratio factor decreases as the incident beam size increases. The absorbed dose ratio factor reaches its minimum when the radius of the incident beam is almost the same as that of the dosimeter. When the radius of the incident beam is larger than that of the dosimeter, the absorbed dose ratio factor increases as the incident beam size increases. The maximum difference among these absorbed dose ratio factors can be up to 14% in 60Co γ beams and 23% in 6 MV beams. However, when the size of the incident beam is much larger than that of the dosimeter, the effect of the incident beam size on the absorbed dose ratio factor becomes quite small. The maximum discrepancy between the absorbed dose ratio factors and the average value is not more than 1%.
文摘The methods of determining the superficial absorbed dose distributions in a water phantom by means of the experiments and available theories have been reported. The distributions of beta dose were measured by an extrapolation ionization chamber at definite depthes corresponding to some superficial organs and tissues such as the radiosensitive layer of the skin, cornea, sclera, anterior chamber and lens of eyeball.The ratios among superficial absorbed dose D (0.07) and average absorbed doses at the depthes 1,2,3,4,5 and 6 mm are also obtained with Cross's methods. They can be used for confining the deterministic effects of some superficial tissues and organs such as the skin and the components of eyeball for weakly penetrating radiations.
文摘Ensuring reliability and traceability of the unit of absorbed dose of intense photon and electron radiation, used in radiation technologies in industry, is based on the creation of a system of sample measures and methods of transmission with minimal loss of dimensional accuracy of the unit of absorbed dose from the sample tools to working dosimeters and is a necessary basis of yield growth, of increase of labour productivity and the introduction of innovative products. The measuring capabilities of the State primary special standard of power unit of absorbed dose of intensity photon, electron and beta radiation for radiation technologies and of the standards of the absorbed dose of photon and electron radiation, used for radiation monitoring of radiation pro- cesses.
文摘The present study investigates the effect of the addition of nanoparticles into epoxy resins as the matrix on the impact absorbed energy of CFRP （carbon fiber reinforced polymer）. Impact absorbed energy is one of the main properties to evaluate the CFRP＇s performance for transportation and aerospace structures. Two types of nanoparticle, namely nanofibers and nano-silica beads, were added into the epoxy resin to improve the impact absorption capacity of the CFRP. Two modified additives and conventional epoxy resins were quantitatively compared. The impact test results showed that impact absorbed energy for nanofibers was higher than nano-silica beads, and nanofibers as the additive promoted about 11% of impact absorbed energy compared with neat epoxy resin.
基金supported by the National Natural Science Foundation of China (No. 21274153)
文摘The tumbling dynamics of individual absorbed polymer chains in shear flow is studied by employing multi-particle collision dynamics simulation techniques combined with molecular dynamics simulations.We find that the dependence of tumbling frequencies on shear rate is independent of both adsorption strength and surface corrugate.
文摘It is worth studying whether enterprises receiving government subsidies can transform them into innovative achievements under the constraints of enterprise resources.The data from the three industries of electronics,pharmaceuticals,and information technology during 2013-2016 were empirical tested to verify the moderating effect of the absorbed slack on the relationship between government subsidies and enterprise innovation.The results show that government subsidies can promote enterprise innovation;absorbed slack promotes enterprise innovation;the absorbed slack of enterprises plays a positive moderation role in the relationship between government subsidy and enterprise innovation.In other words,the enterprises with high absorbed slack can promote the innovation of enterprises by government subsidies.The conclusions provide theoretical guidance for government departments to select the most suitable enterprises which accept innovative subsidies.
文摘Radiotherapy is the most widely applied oncologic treatment modality utilizing ionizing radiation. A high degree of accuracy, reliability and reproducibility is required for a successful treatment outcome. Measurement using ionization chamber is a prerequisite for absorbed dose determination for external beam radiotherapy. Calibration coefficient is expressed in terms of air kerma and absorbed dose to water traceable to Secondary Standards Dosimetry Laboratory. The objective of this work was to evaluate the level of accuracy of ionization chamber used for clinical radiotherapy beam determination. Measurement and accuracy determination were carried out according to IAEA TRS 398 protocol. Clinical farmers type ionization chamber measurement and National Reference standard from Secondary Standards Dosimetry Laboratory were both exposed to cobalt-60 beam and measurement results compared under the same environmental conditions. The accuracy level between National Reference Standard and clinical radiotherapy standard was found to be −1.92% and −2.02% for air kerma and absorbed dose to water respectively. To minimize the effect of error and maximize therapeutic dose during treatment in order to achieve required clinical outcome, calibration factor was determined for air kerma (Nk) as 49.7 mGy/nC and absorbed dose to water ND, as 52.9 mGy/nC. The study established that radiotherapy beam measurement chain is prone to errors. Hence there is a need to independently verify the accuracy of radiation dose to ensure precision of dose delivery. The errors must be accounted for during clinical planning by factoring in calibration factor to minimize the systematic errors during treatment, and thereby providing enough room to achieve ±5% dose delivery to tumor target as recommended by ICRU.
文摘Since the early times, radioprotection has been focused on the human being. Currently this approach has changed, being now also necessary to take care of the protection of the environment from unwanted effects of ionizing radiation. To this end, several institutions (UNSCEAR, ICRP, IAEA, DOE, ACRP) and consortia of institutions (FASSET, ERICA) have established procedures in order to protect the biota of such effects. Developed procedures are based on the calculation of the absorbed dose in biota (ICRP, DOE, IAEA), or on environmental risk assessment―ERA (DOE, ACRP, FASSET, ERICA);but even in this latter approach the parameters used are related to the absorbed doses in biota. The calculation of dose is the standard procedure in human radioprotection, and this points such an approach as the most interesting for providing a convergence between human and nonhuman (= biota) radioprotections. On the other hand, the ERA approach is easier to apply, because this methodology is used in several countries for non-radioactive contamination assessments. Since the world radioprotection system follows a number of institutions (UNSCEAR, ICRP, IAEA and regulatory institutions of member countries) that use dose calculation, this appears to be the way for biota radioprotection. We here review and comment the evolution of the concepts and approaches of the recommendations for radioprotection of non-human biota.
文摘To understand the biogeochemical transfer of iodine, the absorbability and bioaccumulation of iodine in tested vegetables(radish, spinach and Chinese cabbage) are examined by applying iodic fertilizer composed of kelp and diatomaceous earth. The experimental results show that when iodine in soil is not excessive, the concentrations of iodine in tested vegetables increase as the content of iodine in soil increases. The absorbability and enrichment degree of iodine in various vegetables and in various parts of the same vegetable are different, which explains that the concentration of iodine in plant is determined by the plant type and the physiological action of plant. The patience order of tested vegetables to excessive iodine is Chinese cabbage>spinach>radish. These results have theoretical and practical significance in opening up a new way for ameliorating poor iodine environment with artificial means.
文摘This paper presents an extended model predictive controller for maximizing the absorbed power of a point absorber wave energy converter. Owing to the great influence of controller parameters upon the absorbed power, the optimization of these parameters is carried out for the first time by a firefly algorithm(FA). Error, the difference between output velocity of buoy and input wave speed which leads to power maximization in the optimized MPC is compared with the classical MPC. Simulation results indicate that given the high accuracy and acceptable speed of the algorithm, it can adjust the parameters of the controller to the point where system error decreased effectively and the absorbed energy increased about 4 MW.
基金Supported by the Foundation for University Key Teachers from the Ministry of Education of China(No.0024951)
文摘Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight guanine analogs[N-2-（2＇-nitrobenzoyl）-guanine, N-2-（3＇-nitrohenzoyl）-guanine, N-2-（4＇-nitrobenzoyl）-guanine, N-2-（2＇-hydroxybenzoyl）-guanine, N-2-（4＇-methoxylbenzoyl）-guanine, N-2-（4＇-chloricbenzoyl）-guanine, N-2-（4＇- me- thylicbenzoyl）-guanine and N-2-（3＇,5＇-dinitrobenzoyl）-guanine] with different substituted benzoyls, except N-2-（4＇-chloricbenzoyl）-guanine, were newly synthesized. In contrast with guanine, they exhibit wider ultraviolet absorbent range, higher molar extinction coefficient and lower fluorescence intensity.
基金financially supported by the National Natural Science Foundation of China(Project No.42090024).
文摘Laminated continental shale oil reservoirs have the potential for commercial development.In this paper,a new simulation method for interlayer and intra-layer coupled flow in laminated shale reservoirs is established.This method simulates the structural characteristics of shale-sandstone longitudinal interlayer distribution by dual-porositysystem,and combines with chemical reaction model to characterize the desorption process of ad-/absorbed oil from kerogen in shale layers.Then,the intra-layer and interlayer interfacial flow mechanism in the depletion process is investigated,and the contribution of interfacial flow and desorption is analyzed.The results indicate that the sandstone layer is the main oil-producing layer,accounting for over 90%of the total oil production.However,the interlayer flow and kerogen desorption in the shale layers make significant contributions,resulting in an enhancement of 13.41%and 42.64%in the total oil production,respectively.Additionally,the desorption of ad-/absorbed oil from kerogen enhances the energy of both the shale and sandstone layers,significantly increasing their production.Moreover,higher pressure drawdown,total organic carbon(TOC)content,desorption rate,and horizontal permeability of sandstone layers are advantageous for the exploitation of shale oil.
基金funded by National Natural Science Foundation of China(11905106)the Fundamental Research Funds for the Central Universities(30921013110)+1 种基金Provincial Ecological Environment Research Project of Jiangsu(2022017)the Graduate student scientific research innovation projects in Jiangsu province(SJCX22_0118),China.
文摘Objective:To build the database of the absorbed fractions(AFs)and specific absorbed fractions(SAFs),in order to accurately assess the internal radiation dose in non-human biota.Methods:A voxel-based Portunus haanii phantom was established based on the computed tomography(CT)images.A set of AFs and SAFs were calculated with Monte Carlo toolkit Geant4 for the emission of monoenergetic photons and electrons with energies ranging from 10 keV to 5 MeV.Results:The mass of the voxel-based Portunus haanii phantom(392.2 g)was in agreement with the actual mass(389.2 g),indicating the reliability of the phantom.The calculated AFs and SAFs,based on the voxel-based Portunus haanii phantom,provided precise and reliable data for conducting internal radiation dose calculations specifically tailored to the Chinese Red Swimming Crab(Portunus haanii).The results indicated that the self-AFs and self-SAFs were affected by both the radiation energy and the mass of the source/target organ.Moreover,the AFs and SAFs for cross irradiation,were not only dependent on the energy and the mass of the target organ,but also on the relative position of the source and target organs.Conclusion:These results serve as a valuable resource for accurately evaluating the internal radiation exposure of this species.
基金Supported by the Fund for Key Labo ratory of Traditional Chinese Medicine Gan of State Administration of Traditional Chinese Medicinethe Major Research Plan of the National Natural Science Foundation of China(No.90409010)was partly supported by the Huge Project to Boost Chinese Drug Development(No.2009ZX09304-003)
文摘Objective： To detect absorbed bioactive compounds of the water extract whose pharmacodynamic effect was craniocerebral protection for quality control assessment. Methods： Anthraquinones in water extract of rhubarb （WER）, in cerebrospinal fluid （CSF） of patients with traumatic brain injury （TBI） and in ipsilateral cortex of TBI rats following oral WER were respectively explored by ultra performance liquid chromatography with photodiode array detector （UPLC-PDA） method developed in the present study. The effects of anthraquinones absorbed into injured cortex on superoxidase dismutase （SOD） activity in TBI rats were detected. The antioxidative anthraquinones absorbed into target organ were evaluated for quality control of WER. Results： Anthraquinones in WER were aloe-emodin, rhein, emodin, chrysophanol, and physcion. Only the last anthraquinone was found in CSF and in ipsilateral cortex under this chromatographic condition. Physcion increased SOD activity in TBI rats significantly. Conclusions： Physcion was the main active compound of rhubarb against craniocerebral injury via antioxidant pathway. According to our strategy, the exploration of physcion suggested the possibility of a novel quality control of WER in treating TBI injury.
基金National Natural Science Foundation of China(41330531)the R&D Special Fund for Public Welfare Industry(Meteorology)Project(GYHY201106027)the State Key Development Program of Basic Research(2010CB951303).
文摘Aims accurate remote estimation of the fraction of absorbed photosynthetically active radiation(fAPAR)is essential for the light use efficiency(LUE)models.Currently,one challenge for the LUE models is lack of knowledge about the relationship between fAPAR and the normalized difference vegetation index(NDVI).Few studies have tested this relationship against field measurements and evaluated the accuracy of the remote estimation method.this study aimed to reveal the empirical relationship between NDVI and fAPAR and to improve algorithms for remote estimation of fAPAR.Methods to investigate the method of remote estimation of fAPAR seasonal dynamics,the CASA(Carnegie-ames-stanford approach)model and spectral vegetation indices(VIs)were used for in situ measure-ments of spectral reflectance and fAPAR during the growing season of a maize canopy in Northeast China.Important Findingsthe results showed that the fAPAR increased rapidly with the day of year during the vegetative stage,it remained relatively stable at the stage of reproduction,and finally decreased slowly during the senescence stage.In addition,fAPAR green[fAPAR_(green)=fAPAR_(green) -fAPAR_(green) LAI_(max))]showed clearer seasonal trends than fAPAR.the NDVI,red-edge NDVI,wide dynamic range vegetation index,red-edge position(REP)and REP with sentinel-2 bands derived from hyperspectral remote sensing data were all significantly positively related to fAPAR green during the entire growing season.In a comparison of the predictive performance of VIs for the whole growing season,REP was the most appropriate spectral index,and can be recommended for monitoring seasonal dynamics of fAPAR in a maize canopy.
