The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays a...The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.展开更多
Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail steels.In this work,the au...Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail steels.In this work,the austenite dynamic recrystallization(DRX)behaviors of a eutectoid pearlite rail steel were studied using a thermo-mechanical simulator with hot deformation parameters frequently employed in rail production lines.The single-pass hot deformation results reveal that the prior austenite grain sizes(PAGSs)for samples with different deformation reductions decrease initially with an increase in deformation temperature.However,once the deformation temperature is beyond a certain threshold,the PAGSs start to increase.It can be attributed to the rise in DRX volume fraction and the increase of DRX grain with deformation temperature,respectively.Three-pass hot deformation results show that the accumulated strain generated in the first and second deformation passes can increase the extent of DRX.In the case of complete DRX,PAGS is predominantly determined by the deformation temperature of the final pass.It suggests a strategic approach during industrial production where part of the deformation reduction in low temperature range can be shifted to the medium temperature range to release rolling mill loads.展开更多
In order to explore the deformation of the pile body of the circular occluded pile retaining structure under earth pressure, this paper carries out on-site monitoring in combination with the actual project, and obtain...In order to explore the deformation of the pile body of the circular occluded pile retaining structure under earth pressure, this paper carries out on-site monitoring in combination with the actual project, and obtains the deformation characteristics and change rules of the occluded pile by measuring the strain and displacement of the pile body. The research conclusion can provide a certain reference value for the pile body design of bite pile in similar projects.展开更多
Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features.Therefore,quantitatively quality control of polysaccharides based on their chemical charac-teristics i...Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features.Therefore,quantitatively quality control of polysaccharides based on their chemical charac-teristics is important for their application in biomedical and functional food sciences.However,poly-saccharides are mixed macromolecular compounds that are difficult to isolate and lack standards,making them challenging to quantify directly.In this study,we proposed an improved saccharide mapping method based on the release of specific oligosaccharides for the assessment of Hericium eri-naceus polysaccharides from laboratory cultured and different regions of China.Briefly,a polysaccharide from H.erinaceus was digested by b-(1-3)-glucanase,and the released specific oligosaccharides were labeled with 8-aminopyrene-1,3,6-trisulfonic-acid(APTS)and separated by using micellar electrokinetic chromatography(MEKC)coupled with laser induced fluorescence(LIF),and quantitatively estimated.MEKC presented higher resolution compared to polysaccharide analysis using carbohydrate gel elec-trophoresis(PACE),and provided great peak capacity between oligosaccharides with polymerization degree of 2(DP2)and polymerization degree of 6(DP6)in a dextran ladder separation.The results of high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector(HPSEC-MALLS-RI)showed that 12 h was sufficient for complete digestion of polysaccharides from H.erinaceus.Laminaritriose(DP3)was used as an internal standard for quantifi-cation of all the oligosaccharides.The calibration curve for DP3 showed a good linear regression(R2>0.9988).The limit of detection(LOD)and limit of quantification(LOQ)values were 0.05 mg/mL and 0.2 mg/mL,respectively.The recovery for DP3 was 87.32(±0.03)%in the three independent injections.To sum up,this proposed method is helpful for improving the quality control of polysaccharides from H.erinaceus as well as other materials.展开更多
In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the ...In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the occlusal pile after the excavation process of the foundation pit through the model test. The test results show that the bending moment of the pile increases and then decreases with the increase of soil depth under horizontal load, and the bending moment reaches the maximum near the excavation surface of the foundation pit;the test results can provide a reference for the design of occluded pile body in practical engineering.展开更多
Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degr...Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degree centrality, betweenness centra- lity and closeness centrality are taken into consideration in the proposed method. Numerical examples are used to illustrate the effectiveness of the proposed method.展开更多
Vacuum distillation is a technique suitable for low boiling and melting point materials,to remove the heavy and low vapor pressure impurities at low level.As indium has low melting point and high boiling point,it is s...Vacuum distillation is a technique suitable for low boiling and melting point materials,to remove the heavy and low vapor pressure impurities at low level.As indium has low melting point and high boiling point,it is suitable for refining by vacuum distillation.First,saturation vapor pressure for major elements in crude indium was calculated by the Clausius–Clay Prang equation,which could approximately predict the temperature and pressure during vacuum distillation process.Second,the activity coefficients for In–Cd,In–Zn,In–Pb,In–Tl at 1373 K,and In–Sn at 1573 K were acquired by means of molecular interaction on volume model.Vapor–liquid equilibrium composition diagrams of those above systems in crude indium were drawn based on activity coefficients.These diagrams could estimate the compositions of products in each process during the refinement of crude indium.Finally,1.2–1.6 ton crude indium was used per day when vacuum distillation experiments were carried out,and experimental results are in good agreement with the predicted values of the vapor–liquid equilibrium composition diagrams.展开更多
The study on alternative combination rules in Dempster- Shafer theory (DST) when evidences are in conflict has emerged again recently as an interesting topic, especially in data/information fusion applications. The ...The study on alternative combination rules in Dempster- Shafer theory (DST) when evidences are in conflict has emerged again recently as an interesting topic, especially in data/information fusion applications. The earlier researches have mainly focused on investigating the alternative which would be appropriate for the conflicting situation, under the assumption that a conflict is identified. However, the current research shows that not only the combination rule but also the classical conflict coefficient in DST are not correct to determine the conflict degree between two pieces of evidences. Most existing methods of measuring conflict do not consider the open world situation, whose frame of discernment is incomplete. To solve this problem, a new conflict representa- tion model to determine the conflict degree between evidences is proposed in the generalized power space, which contains two parameters: the conflict distance and the conflict coefficient of inconsistent evidences. This paper argues that only when the con- flict measure value in the new representation model is high, it is safe to say the evidences are in conflict. Experiments illustrate the efficiency of the proposed conflict representation model.展开更多
The case when the source of information provides precise belief function/mass, within the generalized power space, has been studied by many people. However, in many decision situations, the precise belief structure is...The case when the source of information provides precise belief function/mass, within the generalized power space, has been studied by many people. However, in many decision situations, the precise belief structure is not always available. In this case, an interval-valued belief degree rather than a precise one may be provided. So, the probabilistic transformation of imprecise belief function/mass in the generalized power space including Dezert-Smarandache (DSm) model from scalar transformation to sub-unitary interval transformation and, more generally, to any set of sub-unitary interval transformation is provided. Different from the existing probabilistic transformation algorithms that redistribute an ignorance mass to the singletons involved in that ignorance pro- portionally with respect to the precise belief function or probability function of singleton, the new algorithm provides an optimization idea to transform any type of imprecise belief assignment which may be represented by the union of several sub-unitary (half-) open intervals, (half-) closed intervals and/or sets of points belonging to [0,1]. Numerical examples are provided to illustrate the detailed implementation process of the new probabilistic transformation approach as well as its validity and wide applicability.展开更多
Due to the extensive use of xylooligosaccharides(XOS)as functional food ingredients,many inferior goods and even adulterants are generally found in the market,which may pose a health hazard to certain populations.Chro...Due to the extensive use of xylooligosaccharides(XOS)as functional food ingredients,many inferior goods and even adulterants are generally found in the market,which may pose a health hazard to certain populations.Chromatography method such as high-performance liquid chromatography(HPLC)and high-performance thin-layer chromatography(HPTLC)is traditionally applied for the quality analysis of XOS.However,it is time consuming due to the prolonged separation and pre-or post-derivatization procedure.In this study,a fast saccharide mapping method based on matrix-assisted laser desorption/time-of-flight mass spectrometry(MALDI-TOF-MS)was developed for the quality consistency analysis of 22 batches of XOS collected from different manufacturers in China.The time needed for saccharides analysis using MALDI-MS was less than 30 min for one plate,at least 6 times faster than that by the traditional HPTLC chromatography method.In addition,MALDI-MS possessed higher resolution for XOS with DP4-DP7 based on the difference of m/z,which is hardly separated using HPTLC.The results showed that XOS were present only in samples XY01-XY11,samples XY12-XY14 only consisted of hex oligosaccharides,and samples XY15-XY22 were free of oligosaccharides.These indicate that the quality consistency of XOS products in the China market was poor,which should be carefully investigated.展开更多
Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides, a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized. The structures were characte...Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides, a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized. The structures were characterized by ^1H NMR, MS and elementary analysis. There ability to inhibit angiogenesis were evaluated by chick embryo chorioallantoic membrane assay at 10^-5 mol/L. Compounds 7a and 7b displayed obvious antiangiogenic activity.展开更多
How to efficiently measure the distance between two basic probability assignments(BPAs) is an open issue. In this paper, a new method to measure the distance between two BPAs is proposed, based on two existing measu...How to efficiently measure the distance between two basic probability assignments(BPAs) is an open issue. In this paper, a new method to measure the distance between two BPAs is proposed, based on two existing measures of evidence distance. The new proposed method is comprehensive and generalized. Numerical examples are used to illustrate the effectiveness of the proposed method.展开更多
Activated ceria (CeO2/γ-Al2O3) prepared by impregnation was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and hydrogen temperature-programmed reduction (TPR). The desulfurizati...Activated ceria (CeO2/γ-Al2O3) prepared by impregnation was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and hydrogen temperature-programmed reduction (TPR). The desulfurization of the activated ceria was investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TG). The results showed that ceria could be highly dispersed or crystallized on the surface of γ-alumina. The reduction temperatures of 0.1CeO2/γ-Al2O3, 0.45CeO2/7-A1203, and CeO2 ranged from 250℃ to 470℃, 330℃ to 550℃, and 350℃ to 550℃, respectively. The reduction peak temperature of 0.45CeO2/γ-Al2O3 was higher than that of 0.1CeO2/γ-Al2O3, which was consistent with the reduction temperature of CeO2. 02 participated in the reaction between ceria and sulfur dioxide. The desulfurization product was cerium(III) sulfate. The intensity of the hydroxyl band decreased with the formation of sulfate species.展开更多
Practical application of a Si anode in a high-energy-density battery cannot be achieved due to the huge volume expansion of these anodes.Researchers have focused on binders of the anode to restrict volume expansion in...Practical application of a Si anode in a high-energy-density battery cannot be achieved due to the huge volume expansion of these anodes.Researchers have focused on binders of the anode to restrict volume expansion in order to address this issue,as the hydrogen bonds and mechanical properties of binders can be used to enhance adhesion and accommodate the volume changes of a Si anode.Herein,we comprehensively consider binders’hydrogen bonds,mechanical properties,stability,and compatibility with the electrolyte solution,and design an ether-/ester-/fluorine-rich composite polymer,named P(TFEMAco-IBVE).The proposed binder formula possesses outstanding stability,adhesion,and mechanical strength;moreover,it can accommodate the dramatic volume changes of a Si electrode and exhibits excellent electrochemical performance,achieving a high areal capacity of about 5.4 mA·h·cm^(-2).This novel polymer design may be applied to other electrode materials in the next generation of lithium-ion batteries.展开更多
Recently, velocity prediction and modeling have been focus of the geophysical exploration in the high temperature and high pressure of the south China sea area, especially for new offshore exploratory areas. The error...Recently, velocity prediction and modeling have been focus of the geophysical exploration in the high temperature and high pressure of the south China sea area, especially for new offshore exploratory areas. The error is large with great difficulty owing to fewer exploratory wells and misunderstanding. Firstly, on the basis of three typical velocity prediction and modeling examples in Ying-Qiong basin, it’s easy to put forward the corresponding not common but urgent problem in each instance, then combined with the velocity problem and misunderstanding to expand method discussion and solution, which include geological model to guide the velocity interpretation and analysis, the establishment of forward velocity of the auxiliary model explaining and constructing high precision velocity model. This research basically solves existing velocity problems in gas exploration of south China sea in recent years, and proposes corresponding solution and application, which is of great significance to the further exploration and productive practice.展开更多
Three-dimensional image reconstruction with Feldkamp,Davis,and Kress(FDK)algorithm is the most time consuming part in Micro-CT.The parallel algorithm based on the computer cluster is capable of accelerating image reco...Three-dimensional image reconstruction with Feldkamp,Davis,and Kress(FDK)algorithm is the most time consuming part in Micro-CT.The parallel algorithm based on the computer cluster is capable of accelerating image reconstruction speed;however,the hardware is very expensive.In this paper,using the most current graphics processing units(GPU),we present a method based on common unified device architecture(CUDA)for speeding up the Micro-CT image reconstruction process.The most time consuming filtering and back-projection parts of the FDK algorithm are parallelized for the CUDA architecture.The CUDA-based reconstruction speed and image qualities are compared with CPU results for the projecting data of the Micro-CT system.The results show that the 3D image reconstruction speed based on CUDA is ten times faster than the speed with CPU.In conclusion the FDK algorithm based on CUDA for Micro-CT can reconstruct the 3D image right after the end of data acquisition.展开更多
The switchable oil layer driven by electrowetting gives visible color and light valve control, which is the basis of Electro-Fluidic Displays. The colored oil’s property is a key factor that influences the Electro-Fl...The switchable oil layer driven by electrowetting gives visible color and light valve control, which is the basis of Electro-Fluidic Displays. The colored oil’s property is a key factor that influences the Electro-Fluidic Displays switching behavior. A purple oil was formulated by the oil-soluble purple dye in decane in this study. The dye molecule itself is nonpolar and it doesn’t dissolve in water. The concentration of colored oil influenced the oil/water interfacial tension and oil viscosity. The relationship of EFD switching behavior with oil/water interfacial tension, oil viscosity, and oil conductivity has been systematically investigated. The oil/water interfacial tension decreased with increasing oil concentration, in the meanwhile, the conductivity increased. Oil conductivity was one of the key factors that influenced the Electro-Fluidic Displays optical property. We found for the first time that at the lower oil concentration (2% - 10%), the interfacial tension plays a main role effect on the rupture voltage and response time, but as the conductivity of higher concentration of colored oil increased (at 20%), the rupture voltage-controlled both by conductivity and interfacial tension.展开更多
Accurate prediction of compressive strength of concrete is one of the key issues in the concrete industry. In this paper, a prediction method of fly ash-slag concrete compressive strength based on multiple adaptive re...Accurate prediction of compressive strength of concrete is one of the key issues in the concrete industry. In this paper, a prediction method of fly ash-slag concrete compressive strength based on multiple adaptive regression splines (MARS) is proposed, and the model analysis process is determined by analyzing the principle of this algorithm. Based on the Concrete Compressive Strength dataset of UCI, the MARS model for compressive strength prediction was constructed with cement content, blast furnace slag powder content, fly ash content, water content, reducing agent content, coarse aggregate content, fine aggregate content and age as independent variables. The prediction results of artificial neural network (BP), random forest (RF), support vector machine (SVM), extreme learning machine (ELM), and multiple nonlinear regression (MnLR) were compared and analyzed, and the prediction accuracy and model stability of MARS and RF models had obvious advantages, and the comprehensive performance of MARS model was slightly better than that of RF model. Finally, the explicit expression of the MARS model for compressive strength is given, which provides an effective method to achieve the prediction of compressive strength of fly ash-slag concrete.展开更多
When the existing information does not contain all categories,the Generalized Evidence Theory(GET)can deal with information fusion.However,the question of how to determine the number of categories through GET is still...When the existing information does not contain all categories,the Generalized Evidence Theory(GET)can deal with information fusion.However,the question of how to determine the number of categories through GET is still intriguing.To address this question,a modified k-means clustering,named centers initialized clustering is proposed,filling the gap of identification and complement of the frame of discernment.Based on this clustering method,the number of cat-egories is determined.The initialized centers selected by center density keep the cluster results con-stant,enhancing the stability of clustering results.Besides,constructing Generalized basic Probability Assignment(GBPA)modules in a conservative way improves the reliability of the results.The mass of empty set in combined GBPAs is the indicator of the number of categories.Experiments on real and artificial data sets are conducted to show the effectiveness.展开更多
A new potassium nitrate (KNO3)]diatomite shape-stabilized composite phase change material (SS- CPCM) was prepared by the mixing and sintering method. KNO3 served as the phase change material (PCM) for thermal en...A new potassium nitrate (KNO3)]diatomite shape-stabilized composite phase change material (SS- CPCM) was prepared by the mixing and sintering method. KNO3 served as the phase change material (PCM) for thermal energy storage, while diatomite acted as the carrier matrix to provide the structural strength and prevent the leakage of PCM. It was found that KNO3 could be retained 65 wt% into pores and on surfaces of diatomite without the leakage of melted KNO3 from the SS-CPCM. The calculated filling rate of molten KNO3 that could enter into the disc-like shape pore of diatomite verified the scanning elec- tronic microscopy images of SS-CPCM. X-ray diffraction and Fourier transform infrared spectroscopy results showed that no reaction occurred between KNO3 and diatomite, performing good compatibility. Accord- ing to the differential scanning calorimetry results, after 50 thermal cycles, the phase change temperatures for melting and freezing of SS-CPCM with 65 wt% KNO3 were changed from 330.23 ℃ and 332.90 ℃ to 330.11 ℃ and 332.84 ℃ and corresponding latent heats varied from 60.52 J/g and 47.30 J/g to 54.64 J/g and 41.25 J/g, respectively. The KNO3/diatomite SS-CPCM may be considered as a potential storage media in solar power plants for thermal energy storage.展开更多
基金This work was supported by the National Key Research and Development Program(Nos.2022YFB3503600 and 2021YFA0718500)Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA15360102)National Natural Science Foundation of China(Nos.12273042 and 12075258).
文摘The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.
基金financially supported by the National Natural Science Foundation of China(Nos.52293395 and 52293393)the Xiongan Science and Technology Innovation Talent Project of MOST,China(No.2022XACX0500)。
文摘Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail steels.In this work,the austenite dynamic recrystallization(DRX)behaviors of a eutectoid pearlite rail steel were studied using a thermo-mechanical simulator with hot deformation parameters frequently employed in rail production lines.The single-pass hot deformation results reveal that the prior austenite grain sizes(PAGSs)for samples with different deformation reductions decrease initially with an increase in deformation temperature.However,once the deformation temperature is beyond a certain threshold,the PAGSs start to increase.It can be attributed to the rise in DRX volume fraction and the increase of DRX grain with deformation temperature,respectively.Three-pass hot deformation results show that the accumulated strain generated in the first and second deformation passes can increase the extent of DRX.In the case of complete DRX,PAGS is predominantly determined by the deformation temperature of the final pass.It suggests a strategic approach during industrial production where part of the deformation reduction in low temperature range can be shifted to the medium temperature range to release rolling mill loads.
文摘In order to explore the deformation of the pile body of the circular occluded pile retaining structure under earth pressure, this paper carries out on-site monitoring in combination with the actual project, and obtains the deformation characteristics and change rules of the occluded pile by measuring the strain and displacement of the pile body. The research conclusion can provide a certain reference value for the pile body design of bite pile in similar projects.
基金the National Natural Science Foundation of China(Grant No.:81673389)the Science and Technology Development Fund,Macao SAR,China(File Nos.:0075/2018/A2,034/2017/A1 and 0017/2019/AKP)+1 种基金the Guangdong Key Project for Modernization of Lingnan Herbs(Project No.:2020B1111110006)the Multi-Year Research Grant from the University of Macao(File Nos.:MYRG2018-00083-ICMS,MYRG2019-00128-ICMS,and CPG2022-00014-ICMS).
文摘Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features.Therefore,quantitatively quality control of polysaccharides based on their chemical charac-teristics is important for their application in biomedical and functional food sciences.However,poly-saccharides are mixed macromolecular compounds that are difficult to isolate and lack standards,making them challenging to quantify directly.In this study,we proposed an improved saccharide mapping method based on the release of specific oligosaccharides for the assessment of Hericium eri-naceus polysaccharides from laboratory cultured and different regions of China.Briefly,a polysaccharide from H.erinaceus was digested by b-(1-3)-glucanase,and the released specific oligosaccharides were labeled with 8-aminopyrene-1,3,6-trisulfonic-acid(APTS)and separated by using micellar electrokinetic chromatography(MEKC)coupled with laser induced fluorescence(LIF),and quantitatively estimated.MEKC presented higher resolution compared to polysaccharide analysis using carbohydrate gel elec-trophoresis(PACE),and provided great peak capacity between oligosaccharides with polymerization degree of 2(DP2)and polymerization degree of 6(DP6)in a dextran ladder separation.The results of high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector(HPSEC-MALLS-RI)showed that 12 h was sufficient for complete digestion of polysaccharides from H.erinaceus.Laminaritriose(DP3)was used as an internal standard for quantifi-cation of all the oligosaccharides.The calibration curve for DP3 showed a good linear regression(R2>0.9988).The limit of detection(LOD)and limit of quantification(LOQ)values were 0.05 mg/mL and 0.2 mg/mL,respectively.The recovery for DP3 was 87.32(±0.03)%in the three independent injections.To sum up,this proposed method is helpful for improving the quality control of polysaccharides from H.erinaceus as well as other materials.
文摘In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the occlusal pile after the excavation process of the foundation pit through the model test. The test results show that the bending moment of the pile increases and then decreases with the increase of soil depth under horizontal load, and the bending moment reaches the maximum near the excavation surface of the foundation pit;the test results can provide a reference for the design of occluded pile body in practical engineering.
基金supported by the National Natural Science Foundation of China(61174022)the National High Technology Research and Development Program of China(863 Program)(2013AA013801)+2 种基金the Open Funding Project of State Key Laboratory of Virtual Reality Technology and Systems,Beihang University(BUAA-VR-14KF-02)the General Research Program of the Science Supported by Sichuan Provincial Department of Education(14ZB0322)the Fundamental Research Funds for the Central Universities(XDJK2014D008)
文摘Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degree centrality, betweenness centra- lity and closeness centrality are taken into consideration in the proposed method. Numerical examples are used to illustrate the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China (No. 51104079 and U1202271)Fundamental Research of Yunnan Province (No. 2013FZ033)
文摘Vacuum distillation is a technique suitable for low boiling and melting point materials,to remove the heavy and low vapor pressure impurities at low level.As indium has low melting point and high boiling point,it is suitable for refining by vacuum distillation.First,saturation vapor pressure for major elements in crude indium was calculated by the Clausius–Clay Prang equation,which could approximately predict the temperature and pressure during vacuum distillation process.Second,the activity coefficients for In–Cd,In–Zn,In–Pb,In–Tl at 1373 K,and In–Sn at 1573 K were acquired by means of molecular interaction on volume model.Vapor–liquid equilibrium composition diagrams of those above systems in crude indium were drawn based on activity coefficients.These diagrams could estimate the compositions of products in each process during the refinement of crude indium.Finally,1.2–1.6 ton crude indium was used per day when vacuum distillation experiments were carried out,and experimental results are in good agreement with the predicted values of the vapor–liquid equilibrium composition diagrams.
基金supported by the National Natural Science Foundation of China (60572161 60874105)+4 种基金the Excellent Ph.D. Paper Author Foundation of China (200443)the Postdoctoral Science Foundation of China (20070421094)the Program for New Century Excellent Talents in University (NCET-08-0345)the Shanghai Rising-Star Program(09QA1402900)the Ministry of Education Key Lab of Intelligent Computing & Signal Processing (2009ICIP03)
文摘The study on alternative combination rules in Dempster- Shafer theory (DST) when evidences are in conflict has emerged again recently as an interesting topic, especially in data/information fusion applications. The earlier researches have mainly focused on investigating the alternative which would be appropriate for the conflicting situation, under the assumption that a conflict is identified. However, the current research shows that not only the combination rule but also the classical conflict coefficient in DST are not correct to determine the conflict degree between two pieces of evidences. Most existing methods of measuring conflict do not consider the open world situation, whose frame of discernment is incomplete. To solve this problem, a new conflict representa- tion model to determine the conflict degree between evidences is proposed in the generalized power space, which contains two parameters: the conflict distance and the conflict coefficient of inconsistent evidences. This paper argues that only when the con- flict measure value in the new representation model is high, it is safe to say the evidences are in conflict. Experiments illustrate the efficiency of the proposed conflict representation model.
基金supported by the National Natural Science Foundation of China (60572161 60874105)+5 种基金the Excellent Ph.D. Paper Author Foundation of China (200443)the Postdoctoral Science Foundation of China (20070421094)the Program for New Century Excellent Talents in University (NCET-08-0345)the Shanghai Rising-Star Program(09QA1402900)the "Chenxing" Scholarship Youth Found of Shanghai Jiaotong University (T241460612)the Ministry of Education Key Laboratory of Intelligent Computing & Signal Processing (2009ICIP03)
文摘The case when the source of information provides precise belief function/mass, within the generalized power space, has been studied by many people. However, in many decision situations, the precise belief structure is not always available. In this case, an interval-valued belief degree rather than a precise one may be provided. So, the probabilistic transformation of imprecise belief function/mass in the generalized power space including Dezert-Smarandache (DSm) model from scalar transformation to sub-unitary interval transformation and, more generally, to any set of sub-unitary interval transformation is provided. Different from the existing probabilistic transformation algorithms that redistribute an ignorance mass to the singletons involved in that ignorance pro- portionally with respect to the precise belief function or probability function of singleton, the new algorithm provides an optimization idea to transform any type of imprecise belief assignment which may be represented by the union of several sub-unitary (half-) open intervals, (half-) closed intervals and/or sets of points belonging to [0,1]. Numerical examples are provided to illustrate the detailed implementation process of the new probabilistic transformation approach as well as its validity and wide applicability.
基金funded by grants from the National Natural Science Foundation of China(No.81673389)the National Key R&D Program of China(2019YFC1711300)+1 种基金the Science and Technology Development Fund,Macao SAR(File no.0075/2018/A2,034/2017/A1 and 0017/2019/AKP)the University of Macao(File no.MYRG2018-00083-ICMS,MYRG2019-00128-ICMS,CPG2020-00021-ICMS)。
文摘Due to the extensive use of xylooligosaccharides(XOS)as functional food ingredients,many inferior goods and even adulterants are generally found in the market,which may pose a health hazard to certain populations.Chromatography method such as high-performance liquid chromatography(HPLC)and high-performance thin-layer chromatography(HPTLC)is traditionally applied for the quality analysis of XOS.However,it is time consuming due to the prolonged separation and pre-or post-derivatization procedure.In this study,a fast saccharide mapping method based on matrix-assisted laser desorption/time-of-flight mass spectrometry(MALDI-TOF-MS)was developed for the quality consistency analysis of 22 batches of XOS collected from different manufacturers in China.The time needed for saccharides analysis using MALDI-MS was less than 30 min for one plate,at least 6 times faster than that by the traditional HPTLC chromatography method.In addition,MALDI-MS possessed higher resolution for XOS with DP4-DP7 based on the difference of m/z,which is hardly separated using HPTLC.The results showed that XOS were present only in samples XY01-XY11,samples XY12-XY14 only consisted of hex oligosaccharides,and samples XY15-XY22 were free of oligosaccharides.These indicate that the quality consistency of XOS products in the China market was poor,which should be carefully investigated.
文摘Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides, a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized. The structures were characterized by ^1H NMR, MS and elementary analysis. There ability to inhibit angiogenesis were evaluated by chick embryo chorioallantoic membrane assay at 10^-5 mol/L. Compounds 7a and 7b displayed obvious antiangiogenic activity.
基金supported by the National High Technology Research and Development Program of China(863 Program)(2013AA013801)the National Natural Science Foundation of China(61174022+4 种基金61573290)the open funding project of State Key Laboratory of Virtual Reality Technology and Systemsthe Beihang University(BUAA-VR-14KF-02)the General Research Program of Natural Science of Sichuan Provincial Department of Education(14ZB0322)the Self-financing Program of State Ethnic Affairs Commission of China(14SCZ014)
文摘How to efficiently measure the distance between two basic probability assignments(BPAs) is an open issue. In this paper, a new method to measure the distance between two BPAs is proposed, based on two existing measures of evidence distance. The new proposed method is comprehensive and generalized. Numerical examples are used to illustrate the effectiveness of the proposed method.
基金the finical support from the National Natural Science Foundation of China (Nos. 51264023, 51364020, and U1202271)the Program for Innovative Research Team in Universities of the Ministry of Education of China (No. IRT1250)the Yunnan Province Science and Technology Talents (No. 2014HA003)
文摘Activated ceria (CeO2/γ-Al2O3) prepared by impregnation was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and hydrogen temperature-programmed reduction (TPR). The desulfurization of the activated ceria was investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TG). The results showed that ceria could be highly dispersed or crystallized on the surface of γ-alumina. The reduction temperatures of 0.1CeO2/γ-Al2O3, 0.45CeO2/7-A1203, and CeO2 ranged from 250℃ to 470℃, 330℃ to 550℃, and 350℃ to 550℃, respectively. The reduction peak temperature of 0.45CeO2/γ-Al2O3 was higher than that of 0.1CeO2/γ-Al2O3, which was consistent with the reduction temperature of CeO2. 02 participated in the reaction between ceria and sulfur dioxide. The desulfurization product was cerium(III) sulfate. The intensity of the hydroxyl band decreased with the formation of sulfate species.
基金This study was supported by funding from the National Key Research and Development Program of China(2018YFB0104300)the Key Project of the Sichuan Science and Technology Department(2018GZ0546).
文摘Practical application of a Si anode in a high-energy-density battery cannot be achieved due to the huge volume expansion of these anodes.Researchers have focused on binders of the anode to restrict volume expansion in order to address this issue,as the hydrogen bonds and mechanical properties of binders can be used to enhance adhesion and accommodate the volume changes of a Si anode.Herein,we comprehensively consider binders’hydrogen bonds,mechanical properties,stability,and compatibility with the electrolyte solution,and design an ether-/ester-/fluorine-rich composite polymer,named P(TFEMAco-IBVE).The proposed binder formula possesses outstanding stability,adhesion,and mechanical strength;moreover,it can accommodate the dramatic volume changes of a Si electrode and exhibits excellent electrochemical performance,achieving a high areal capacity of about 5.4 mA·h·cm^(-2).This novel polymer design may be applied to other electrode materials in the next generation of lithium-ion batteries.
文摘Recently, velocity prediction and modeling have been focus of the geophysical exploration in the high temperature and high pressure of the south China sea area, especially for new offshore exploratory areas. The error is large with great difficulty owing to fewer exploratory wells and misunderstanding. Firstly, on the basis of three typical velocity prediction and modeling examples in Ying-Qiong basin, it’s easy to put forward the corresponding not common but urgent problem in each instance, then combined with the velocity problem and misunderstanding to expand method discussion and solution, which include geological model to guide the velocity interpretation and analysis, the establishment of forward velocity of the auxiliary model explaining and constructing high precision velocity model. This research basically solves existing velocity problems in gas exploration of south China sea in recent years, and proposes corresponding solution and application, which is of great significance to the further exploration and productive practice.
基金the financial support by National Nature Science Foundation of China(Grant No.30070261).
文摘Three-dimensional image reconstruction with Feldkamp,Davis,and Kress(FDK)algorithm is the most time consuming part in Micro-CT.The parallel algorithm based on the computer cluster is capable of accelerating image reconstruction speed;however,the hardware is very expensive.In this paper,using the most current graphics processing units(GPU),we present a method based on common unified device architecture(CUDA)for speeding up the Micro-CT image reconstruction process.The most time consuming filtering and back-projection parts of the FDK algorithm are parallelized for the CUDA architecture.The CUDA-based reconstruction speed and image qualities are compared with CPU results for the projecting data of the Micro-CT system.The results show that the 3D image reconstruction speed based on CUDA is ten times faster than the speed with CPU.In conclusion the FDK algorithm based on CUDA for Micro-CT can reconstruct the 3D image right after the end of data acquisition.
文摘The switchable oil layer driven by electrowetting gives visible color and light valve control, which is the basis of Electro-Fluidic Displays. The colored oil’s property is a key factor that influences the Electro-Fluidic Displays switching behavior. A purple oil was formulated by the oil-soluble purple dye in decane in this study. The dye molecule itself is nonpolar and it doesn’t dissolve in water. The concentration of colored oil influenced the oil/water interfacial tension and oil viscosity. The relationship of EFD switching behavior with oil/water interfacial tension, oil viscosity, and oil conductivity has been systematically investigated. The oil/water interfacial tension decreased with increasing oil concentration, in the meanwhile, the conductivity increased. Oil conductivity was one of the key factors that influenced the Electro-Fluidic Displays optical property. We found for the first time that at the lower oil concentration (2% - 10%), the interfacial tension plays a main role effect on the rupture voltage and response time, but as the conductivity of higher concentration of colored oil increased (at 20%), the rupture voltage-controlled both by conductivity and interfacial tension.
文摘Accurate prediction of compressive strength of concrete is one of the key issues in the concrete industry. In this paper, a prediction method of fly ash-slag concrete compressive strength based on multiple adaptive regression splines (MARS) is proposed, and the model analysis process is determined by analyzing the principle of this algorithm. Based on the Concrete Compressive Strength dataset of UCI, the MARS model for compressive strength prediction was constructed with cement content, blast furnace slag powder content, fly ash content, water content, reducing agent content, coarse aggregate content, fine aggregate content and age as independent variables. The prediction results of artificial neural network (BP), random forest (RF), support vector machine (SVM), extreme learning machine (ELM), and multiple nonlinear regression (MnLR) were compared and analyzed, and the prediction accuracy and model stability of MARS and RF models had obvious advantages, and the comprehensive performance of MARS model was slightly better than that of RF model. Finally, the explicit expression of the MARS model for compressive strength is given, which provides an effective method to achieve the prediction of compressive strength of fly ash-slag concrete.
基金supported by the National Natural Science Foundation of China(No.61973332)the JSPS Invitational Fellowships for Research in Japan(Short-term).
文摘When the existing information does not contain all categories,the Generalized Evidence Theory(GET)can deal with information fusion.However,the question of how to determine the number of categories through GET is still intriguing.To address this question,a modified k-means clustering,named centers initialized clustering is proposed,filling the gap of identification and complement of the frame of discernment.Based on this clustering method,the number of cat-egories is determined.The initialized centers selected by center density keep the cluster results con-stant,enhancing the stability of clustering results.Besides,constructing Generalized basic Probability Assignment(GBPA)modules in a conservative way improves the reliability of the results.The mass of empty set in combined GBPAs is the indicator of the number of categories.Experiments on real and artificial data sets are conducted to show the effectiveness.
基金supported by the Program for New Century Excellent Talents in University (Grant No. NCET-08-828)the Program for the China Geological Survey (No. 1212011120323)the Fundamental Research Funds for the Central Universities (No. 2011YXL003)
文摘A new potassium nitrate (KNO3)]diatomite shape-stabilized composite phase change material (SS- CPCM) was prepared by the mixing and sintering method. KNO3 served as the phase change material (PCM) for thermal energy storage, while diatomite acted as the carrier matrix to provide the structural strength and prevent the leakage of PCM. It was found that KNO3 could be retained 65 wt% into pores and on surfaces of diatomite without the leakage of melted KNO3 from the SS-CPCM. The calculated filling rate of molten KNO3 that could enter into the disc-like shape pore of diatomite verified the scanning elec- tronic microscopy images of SS-CPCM. X-ray diffraction and Fourier transform infrared spectroscopy results showed that no reaction occurred between KNO3 and diatomite, performing good compatibility. Accord- ing to the differential scanning calorimetry results, after 50 thermal cycles, the phase change temperatures for melting and freezing of SS-CPCM with 65 wt% KNO3 were changed from 330.23 ℃ and 332.90 ℃ to 330.11 ℃ and 332.84 ℃ and corresponding latent heats varied from 60.52 J/g and 47.30 J/g to 54.64 J/g and 41.25 J/g, respectively. The KNO3/diatomite SS-CPCM may be considered as a potential storage media in solar power plants for thermal energy storage.