The deformation and failure of coal and rock is energy-driving results according to thermodynamics.It is important to study the strain energy characteristics of coal-rock composite samples to better understand the def...The deformation and failure of coal and rock is energy-driving results according to thermodynamics.It is important to study the strain energy characteristics of coal-rock composite samples to better understand the deformation and failure mechanism of of coal-rock composite structures.In this research,laboratory tests and numerical simulation of uniaxial compressions of coal-rock composite samples were carried out with five different loading rates.The test results show that strength,deformation,acoustic emission(AE)and energy evolution of coal-rock composite sample all have obvious loading rate effects.The uniaxial compressive strength and elastic modulus increase with the increase of loading rate.And with the increase of loading rate,the AE energy at the peak strength of coal-rock composites increases first,then decreases,and then increases.With the increase of loading rate,the AE cumulative count first decreases and then increases.And the total absorption energy and dissipation energy of coal-rock composite samples show non-linear increasing trends,while release elastic strain energy increases first and then decreases.The laboratory experiments conducted on coal-rock composite samples were simulated numerically using the particle flow code(PFC).With careful selection of suitable material constitutive models for coal and rock,and accurate estimation and calibration of mechanical parameters of coal-rock composite sample,it was possible to obtain a good agreement between the laboratory experimental and numerical results.This research can provide references for understanding failure of underground coalrock composite structure by using energy related measuring methods.展开更多
Two national stalagmite standard （GBW04412, GBW04413） and one international coral standard （RKM4） have been determined by using thermal ionization mass spectrometry （TIMS） method. The values of （ 234 U/ 238 U）...Two national stalagmite standard （GBW04412, GBW04413） and one international coral standard （RKM4） have been determined by using thermal ionization mass spectrometry （TIMS） method. The values of （ 234 U/ 238 U） act , （ 230 Th/ 234 U） act and age are all consistent in error range with the standard values obtained by using α spectrometry.展开更多
A gold immunochromatographic sensor （GICS） was developed for the rapid detection of 26 sulfonamides in honey samples. The sensor was based on a group-specific monoclonal antibody （mAb） that can recognize all 26 su...A gold immunochromatographic sensor （GICS） was developed for the rapid detection of 26 sulfonamides in honey samples. The sensor was based on a group-specific monoclonal antibody （mAb） that can recognize all 26 sulfonamides. Three haptens （hapten I with a thiazole ring, hapten 2 with a benzene ring, and hapten 3 with a straight carbon chain） were used for antigen preparation. With hybridoma technology, a group-specific mAb was screened with a 50% maximal inhibitory concentration （IC50） against sulfathizole （STZ） and the other 25 analogues ranging from 0.08 to 90.18 ng/mL. Mono-dispersed gold nanoparticles were conjugated with the mAb to develop the lateral immunochromatographic strip. A labeled antibody concentration of 0.1 pg/mL and a coating antigen concentration of 0.2 μg/mL in the test line were chosen for strip preparation. Under optimized conditions, the visual limits of detection （vLOD） for the concentrations of STZ, sulfamethoxazole, sulfamethizole, sulfadiazine, sulfamerazine, sulfadimethoxine, sulfamonomethoxine, sulfameter, sulfamethoxypyridazine, and sulfachloropyridazine were 5, 0.25, 0.25, 10, 5, 10, 25, 2.5, 5, 0.25, and 10 μg/kg, respectively. Scanner analysis in honey samples revealed good performance for detection of the 26 sulfonamides. Commercial honey samples were tested with the sensor and positive results were confirmed with high-performance liquid chromatography. The proposed strip sensor provides a convenient method for the rapid and reliable determination of sulfonamides pollutants in honey samples.展开更多
The thermodynamic systems and dynamic model suitable for determining the nonlinear chemical fingerprints of samples were analyzed.The results indicated that the damp nonlinear chemical reactions in close systems away ...The thermodynamic systems and dynamic model suitable for determining the nonlinear chemical fingerprints of samples were analyzed.The results indicated that the damp nonlinear chemical reactions in close systems away from the equilibrium and open systems without the complementarity of the dissipation substances have important significance for the throng characterization and whole content analysis of chemical components in samples.Various factors influencing on nonlinear chemical fingerprint,such as reactant species and their concentrations,electrode types,temperature,stir rate,the sort,dosage and granularity of the sample,etc.were amply researched by a nonlinear chemistry reaction,namely,damp B-Z oscillation which used acetone and glucose as the main dissipative substances.In addition,the quantitative information on the whole of chemical components in samples and the traits and applications of the fingerprint were investigated.The method and its important conditions for determining nonlinear chemistry fingerprint used in distinguishing and evaluating complex samples were successfully put forward.展开更多
Data processing of small samples is an important and valuable research problem in the electronic equipment test. Because it is difficult and complex to determine the probability distribution of small samples, it is di...Data processing of small samples is an important and valuable research problem in the electronic equipment test. Because it is difficult and complex to determine the probability distribution of small samples, it is difficult to use the traditional probability theory to process the samples and assess the degree of uncertainty. Using the grey relational theory and the norm theory, the grey distance information approach, which is based on the grey distance information quantity of a sample and the average grey distance information quantity of the samples, is proposed in this article. The definitions of the grey distance information quantity of a sample and the average grey distance information quantity of the samples, with their characteristics and algorithms, are introduced. The correlative problems, including the algorithm of estimated value, the standard deviation, and the acceptance and rejection criteria of the samples and estimated results, are also proposed. Moreover, the information whitening ratio is introduced to select the weight algorithm and to compare the different samples. Several examples are given to demonstrate the application of the proposed approach. The examples show that the proposed approach, which has no demand for the probability distribution of small samples, is feasible and effective.展开更多
During environment testing, the estimation of random vibration signals （RVS） is an important technique for the airborne platform safety and reliability. However, the available meth- ods including extreme value envel...During environment testing, the estimation of random vibration signals （RVS） is an important technique for the airborne platform safety and reliability. However, the available meth- ods including extreme value envelope method （EVEM）, statistical tolerances method （STM） and improved statistical tolerance method （ISTM） require large samples and typical probability distri- bution. Moreover, the frequency-varying characteristic of RVS is usually not taken into account. Gray bootstrap method （GBM） is proposed to solve the problem of estimating frequency-varying RVS with small samples. Firstly, the estimated indexes are obtained including the estimated inter- val, the estimated uncertainty, the estimated value, the estimated error and estimated reliability. In addition, GBM is applied to estimating the single flight testing of certain aircraft. At last, in order to evaluate the estimated performance, GBM is compared with bootstrap method （BM） and gray method （GM） in testing analysis. The result shows that GBM has superiority for estimating dynamic signals with small samples and estimated reliability is proved to be 100% at the given confidence level.展开更多
Background Chronic obstructive pulmonary diseases （COPD） is an emerging population at risk for invasive infection of Aspergillus. Isolation of Aspergillus from lower respiratory tract （LRT） samples is important fo...Background Chronic obstructive pulmonary diseases （COPD） is an emerging population at risk for invasive infection of Aspergillus. Isolation of Aspergillus from lower respiratory tract （LRT） samples is important for the diagnosis of invasive pulmonary aspergillosis （IPA）. The purpose of this study was to investigate the value of Aspergillus isolation from LRT samples for the diagnosis and prognosis of IPA in COPD population. Methods Clinical record with Aspergillus spp. isolation in COPD and immunocompromised patients was reviewed in a retrospective study. Patients were categorized and compared according to their severity of illness （admitted to general ward or ICU） and immunological function （COPD or immunocompromised）. Results Multivariate statistical analysis showed that, combined with Aspergillus spp. isolation, APACHE II scores 〉18, high cumulative doses of corticosteroids （〉350 mg prednisone or equivalent dose） and more than four kinds of broad-spectrum antibiotics received in hospital may be predictors of IPA in COPD （0R=9.076, P=0.001; 0R=4.073, P=-0.026; OR=4.448, P=-0.021, respectively）. The incidence of IPA, overall mortality, mortality of patients with IPA and mortality of patients with Aspergillus spp. colonization were higher in COPD patients in ICU than in general ward, but were similar between COPD and immunocompromised patients. Conclusions Aspergillus spp. isolation from LRT in COPD may be of similar importance as in immunocompromised patients, and may indicate an increased diagnosis possibility of IPA and worse prognosis when these patients received corticosteroids, antibiotics, and need to admit to ICU. Aspergillus spp. isolation from LRT samples combined with certain risk factors mav be useful in differentiating colonization from IPA and evaluating the prognosis of IPA in COPD patients.展开更多
基金Projects(51774196,51804181,51874190)supported by the National Natural Science Foundation of ChinaProject(2019GSF111020)supported by the Key R&D Program of Shandong Province,ChinaProject(201908370205)supported by the China Scholarship Council。
文摘The deformation and failure of coal and rock is energy-driving results according to thermodynamics.It is important to study the strain energy characteristics of coal-rock composite samples to better understand the deformation and failure mechanism of of coal-rock composite structures.In this research,laboratory tests and numerical simulation of uniaxial compressions of coal-rock composite samples were carried out with five different loading rates.The test results show that strength,deformation,acoustic emission(AE)and energy evolution of coal-rock composite sample all have obvious loading rate effects.The uniaxial compressive strength and elastic modulus increase with the increase of loading rate.And with the increase of loading rate,the AE energy at the peak strength of coal-rock composites increases first,then decreases,and then increases.With the increase of loading rate,the AE cumulative count first decreases and then increases.And the total absorption energy and dissipation energy of coal-rock composite samples show non-linear increasing trends,while release elastic strain energy increases first and then decreases.The laboratory experiments conducted on coal-rock composite samples were simulated numerically using the particle flow code(PFC).With careful selection of suitable material constitutive models for coal and rock,and accurate estimation and calibration of mechanical parameters of coal-rock composite sample,it was possible to obtain a good agreement between the laboratory experimental and numerical results.This research can provide references for understanding failure of underground coalrock composite structure by using energy related measuring methods.
文摘Two national stalagmite standard （GBW04412, GBW04413） and one international coral standard （RKM4） have been determined by using thermal ionization mass spectrometry （TIMS） method. The values of （ 234 U/ 238 U） act , （ 230 Th/ 234 U） act and age are all consistent in error range with the standard values obtained by using α spectrometry.
基金This work is financially supported by the Key Programs from MOST （Nos. 2016YFD0401101 and 2016YFF0202300）, the National Natural Science Foundation of China （Nos. 21631005, 21522102 and 21503095）, and grants from Natural Science Foundation of Jiangsu Province, MOF and MOE （Nos. BE2016307, BK20150138, CMB21S1614, CLE02N1515 and JUSRP51715A）.
文摘A gold immunochromatographic sensor （GICS） was developed for the rapid detection of 26 sulfonamides in honey samples. The sensor was based on a group-specific monoclonal antibody （mAb） that can recognize all 26 sulfonamides. Three haptens （hapten I with a thiazole ring, hapten 2 with a benzene ring, and hapten 3 with a straight carbon chain） were used for antigen preparation. With hybridoma technology, a group-specific mAb was screened with a 50% maximal inhibitory concentration （IC50） against sulfathizole （STZ） and the other 25 analogues ranging from 0.08 to 90.18 ng/mL. Mono-dispersed gold nanoparticles were conjugated with the mAb to develop the lateral immunochromatographic strip. A labeled antibody concentration of 0.1 pg/mL and a coating antigen concentration of 0.2 μg/mL in the test line were chosen for strip preparation. Under optimized conditions, the visual limits of detection （vLOD） for the concentrations of STZ, sulfamethoxazole, sulfamethizole, sulfadiazine, sulfamerazine, sulfadimethoxine, sulfamonomethoxine, sulfameter, sulfamethoxypyridazine, and sulfachloropyridazine were 5, 0.25, 0.25, 10, 5, 10, 25, 2.5, 5, 0.25, and 10 μg/kg, respectively. Scanner analysis in honey samples revealed good performance for detection of the 26 sulfonamides. Commercial honey samples were tested with the sensor and positive results were confirmed with high-performance liquid chromatography. The proposed strip sensor provides a convenient method for the rapid and reliable determination of sulfonamides pollutants in honey samples.
基金supported by the National Key Technologies R & DProgram (2009GJD20033)the International Scientific and Technological Cooperation Project (2007DFA40680) from the Ministry of Scienceand Technology of China
文摘The thermodynamic systems and dynamic model suitable for determining the nonlinear chemical fingerprints of samples were analyzed.The results indicated that the damp nonlinear chemical reactions in close systems away from the equilibrium and open systems without the complementarity of the dissipation substances have important significance for the throng characterization and whole content analysis of chemical components in samples.Various factors influencing on nonlinear chemical fingerprint,such as reactant species and their concentrations,electrode types,temperature,stir rate,the sort,dosage and granularity of the sample,etc.were amply researched by a nonlinear chemistry reaction,namely,damp B-Z oscillation which used acetone and glucose as the main dissipative substances.In addition,the quantitative information on the whole of chemical components in samples and the traits and applications of the fingerprint were investigated.The method and its important conditions for determining nonlinear chemistry fingerprint used in distinguishing and evaluating complex samples were successfully put forward.
文摘Data processing of small samples is an important and valuable research problem in the electronic equipment test. Because it is difficult and complex to determine the probability distribution of small samples, it is difficult to use the traditional probability theory to process the samples and assess the degree of uncertainty. Using the grey relational theory and the norm theory, the grey distance information approach, which is based on the grey distance information quantity of a sample and the average grey distance information quantity of the samples, is proposed in this article. The definitions of the grey distance information quantity of a sample and the average grey distance information quantity of the samples, with their characteristics and algorithms, are introduced. The correlative problems, including the algorithm of estimated value, the standard deviation, and the acceptance and rejection criteria of the samples and estimated results, are also proposed. Moreover, the information whitening ratio is introduced to select the weight algorithm and to compare the different samples. Several examples are given to demonstrate the application of the proposed approach. The examples show that the proposed approach, which has no demand for the probability distribution of small samples, is feasible and effective.
基金supported by Aviation Science Foundation of China (No. 20100251006)the Technological Foundation Project (No. J132012C001)
文摘During environment testing, the estimation of random vibration signals （RVS） is an important technique for the airborne platform safety and reliability. However, the available meth- ods including extreme value envelope method （EVEM）, statistical tolerances method （STM） and improved statistical tolerance method （ISTM） require large samples and typical probability distri- bution. Moreover, the frequency-varying characteristic of RVS is usually not taken into account. Gray bootstrap method （GBM） is proposed to solve the problem of estimating frequency-varying RVS with small samples. Firstly, the estimated indexes are obtained including the estimated inter- val, the estimated uncertainty, the estimated value, the estimated error and estimated reliability. In addition, GBM is applied to estimating the single flight testing of certain aircraft. At last, in order to evaluate the estimated performance, GBM is compared with bootstrap method （BM） and gray method （GM） in testing analysis. The result shows that GBM has superiority for estimating dynamic signals with small samples and estimated reliability is proved to be 100% at the given confidence level.
文摘Background Chronic obstructive pulmonary diseases （COPD） is an emerging population at risk for invasive infection of Aspergillus. Isolation of Aspergillus from lower respiratory tract （LRT） samples is important for the diagnosis of invasive pulmonary aspergillosis （IPA）. The purpose of this study was to investigate the value of Aspergillus isolation from LRT samples for the diagnosis and prognosis of IPA in COPD population. Methods Clinical record with Aspergillus spp. isolation in COPD and immunocompromised patients was reviewed in a retrospective study. Patients were categorized and compared according to their severity of illness （admitted to general ward or ICU） and immunological function （COPD or immunocompromised）. Results Multivariate statistical analysis showed that, combined with Aspergillus spp. isolation, APACHE II scores 〉18, high cumulative doses of corticosteroids （〉350 mg prednisone or equivalent dose） and more than four kinds of broad-spectrum antibiotics received in hospital may be predictors of IPA in COPD （0R=9.076, P=0.001; 0R=4.073, P=-0.026; OR=4.448, P=-0.021, respectively）. The incidence of IPA, overall mortality, mortality of patients with IPA and mortality of patients with Aspergillus spp. colonization were higher in COPD patients in ICU than in general ward, but were similar between COPD and immunocompromised patients. Conclusions Aspergillus spp. isolation from LRT in COPD may be of similar importance as in immunocompromised patients, and may indicate an increased diagnosis possibility of IPA and worse prognosis when these patients received corticosteroids, antibiotics, and need to admit to ICU. Aspergillus spp. isolation from LRT samples combined with certain risk factors mav be useful in differentiating colonization from IPA and evaluating the prognosis of IPA in COPD patients.
