This experiment obtained different laser energy density(LED) by changing SLM molding process parameters.The surface morphology, surface quality, and microstructure of as-fabricated samples were studied. The effects of...This experiment obtained different laser energy density(LED) by changing SLM molding process parameters.The surface morphology, surface quality, and microstructure of as-fabricated samples were studied. The effects of scanning speed, hatching space, and laser power on surface quality were analyzed, and the optimal LED range for surface quality was determined. The results show that pores and spherical particles appear on the sample’s surface when low LED is applied, while there are lamellar structures on the sides of the samples. Cracks appear on the sample’s surface,and the splash phenomenon increases when a high LED is taken. At the same time, a large amount of unmelted powder adhered to the side of the sample. The surface quality is the best when the LED is 150-170 J/mm^(3). The preferred hatch space is currently 0.05-0.09 mm, the laser power is 200-350 W, and the average surface roughness value is(15.1±3) μm.The average surface hardness reaches HV404±HV3, higher than the forging standard range of HV340-HV395.Increasing the LED within the experiment range can increase the surface hardness, yet an excessively high LED will not further increase the surface hardness. The microstructure is composed of needle-like α’-phases with a length of about 20μm, in a crisscross ‘N’ shape, when the LED is low. The β-phase grain boundary is not obvious, and the secondaryphase volume fraction is high;when the LED is high, the α’-phase of the microstructure is in the form of coarse slats, and the secondary-phase is composed of a small amount of secondary α’-phase, the tertiary α’-phase and the fourth α’-phase disappear, and the volume fraction of the secondary-phase becomes low.展开更多
Objective:This paper aims to determine the reliability and validity of the Chinese version of a tool that assesses the quality of life in idiopathic pulmonary fibrosis(cATAQ-IPF)in patients with interstitial lung dise...Objective:This paper aims to determine the reliability and validity of the Chinese version of a tool that assesses the quality of life in idiopathic pulmonary fibrosis(cATAQ-IPF)in patients with interstitial lung disease(ILD).Methods:We used the process of scale introduction to establish cATAQ-IPF.The content validity of the scale was evaluated by six experts.A total of 92 patients with ILD completed the cATAQ-IPF,St.George's respiratory questionnaire(SGRQ),and The Medical Research Council dyspnoea scale at the baseline,and 15 patients completed cATAQ-IPF at the follow-up period 2 weeks later.Thus,yielding data were used to assess various psychometric properties of cATAQ-IPE Intraclass correlation coefficient(ICC),Cronbach'sαcoefficient,content validity index(CVI),item-level CVI(I-CVI),Pearson's coefficients,criterion-relation validity,and known-group validity were used for data analysis.Results:The cATAQ-IPF showed excellent test-retest reliability(ICC=0.95),except for the therapy domain(Cronbach'sα=0.60)and acceptable internal consistency(Cronbach'sα=0.96 for the total).The scale-level CVI was 0.80,and the I-CVI was in the range of 0.78-1.00.The total cATAQ-IPF score was strongly correlated with the SGRQ total score(r=0.71,P<0.01).The cATAQ-IPF score of patients with ILD was 250.74±47.39,and that of patients with IPF was 287.90±22.56.Patients with IPF possessed considerable impairments in health-related quality of life according to the cATAQ-IPF score(t=4.94,P<0.01).Conclusions:The cATAQ-IPF is a reliable and valid instrument for the evaluation of quality of life of Chinese patients with various forms of ILD.展开更多
The technique of phase measuring profilometry using a single phase step method is proposed.This method can automatically obtain phase value at each pixel by using a discret cosine transform algorithm.The method is abl...The technique of phase measuring profilometry using a single phase step method is proposed.This method can automatically obtain phase value at each pixel by using a discret cosine transform algorithm.The method is able to automatically recognize any position between depression and elevation on an object surface.Theoretical analysis and experimental verification are presented.展开更多
A temperature measurement model of radiation thermometry for the surface covered by participating media was developed. The model was based on the radiation heat transfer of participating media and principles of radiat...A temperature measurement model of radiation thermometry for the surface covered by participating media was developed. The model was based on the radiation heat transfer of participating media and principles of radiation pyrometers, and solved by integral formulation of discrete ordinate method on spectral waveband. The influence of water mist on the indicated temperature of Raytek MR1SB one/two color pyrometer was discussed. Mie theory was used to calculate the radiative properties of water mist. In order to verify the model, a laboratory temperature measurement experiment was executed. The result shows that temperature of radiation thermometry is sensitive to the spectral response wavelength of pyrometer, and the simulated temperature of pyrometer agrees well with the experimental measurements on a suitable wavelength. The simulated temperature was lower than the real temperature of surface for one-color pyrometer, and it could be higher or lower than the real one for two-color pyrometer with the influence of participating media.展开更多
Objective: To study the mechanism and effects of different scraping techniques on body surface blood perfusion volume and local skin temperature of healthy subjects and to provide a baseline for microcirculation and e...Objective: To study the mechanism and effects of different scraping techniques on body surface blood perfusion volume and local skin temperature of healthy subjects and to provide a baseline for microcirculation and energy metabolism for the evaluation of the therapeutic effects of scraping. Methods: Changes of the local blood perfusion volume and skin temperature of healthy subjects before and after applying different scraping techniques were observed with a laser Doppler imager combined with an infrared thermographic device and the resulting data was analyzed with imaging and processing software for statistical analysis. Results: Local blood perfusion volume and skin temperature all increased after both reinforcing and reducing scraping techniques. The value of blood flow 60 and 90 min after the reducing technique was significantly higher than that after the reinforcing technique (P<0.01), while the skin temperature increased after both techniques but was not significantly different between the two (P>0.05). Conclusion: Scraping can significantly improve the local blood perfusion volume, increase skin temperature and promote local blood circulation and metabolism of tissues.展开更多
Symmetry is conventionally described in a polarized manner that the system is either completely symmetric or completely asymmetric.Using group theoretical approach to overcome this dichotomous problem,we introduce the...Symmetry is conventionally described in a polarized manner that the system is either completely symmetric or completely asymmetric.Using group theoretical approach to overcome this dichotomous problem,we introduce the degree of symmetry(DoS) as a non-negative continuous number ranging from zero to unity.Do S is defined through an average of the fidelity deviations of Hamiltonian or quantum state over its transformation group G,and thus is computable by making use of the completeness relations of the irreducible representations of G.The monotonicity of Do S can effectively probe the extended group for accidental degeneracy while its multi-valued natures characterize some(spontaneous) symmetry breaking.展开更多
基金Projects(51975006, 51505006) supported by the National Natural Science Foundation of China。
文摘This experiment obtained different laser energy density(LED) by changing SLM molding process parameters.The surface morphology, surface quality, and microstructure of as-fabricated samples were studied. The effects of scanning speed, hatching space, and laser power on surface quality were analyzed, and the optimal LED range for surface quality was determined. The results show that pores and spherical particles appear on the sample’s surface when low LED is applied, while there are lamellar structures on the sides of the samples. Cracks appear on the sample’s surface,and the splash phenomenon increases when a high LED is taken. At the same time, a large amount of unmelted powder adhered to the side of the sample. The surface quality is the best when the LED is 150-170 J/mm^(3). The preferred hatch space is currently 0.05-0.09 mm, the laser power is 200-350 W, and the average surface roughness value is(15.1±3) μm.The average surface hardness reaches HV404±HV3, higher than the forging standard range of HV340-HV395.Increasing the LED within the experiment range can increase the surface hardness, yet an excessively high LED will not further increase the surface hardness. The microstructure is composed of needle-like α’-phases with a length of about 20μm, in a crisscross ‘N’ shape, when the LED is low. The β-phase grain boundary is not obvious, and the secondaryphase volume fraction is high;when the LED is high, the α’-phase of the microstructure is in the form of coarse slats, and the secondary-phase is composed of a small amount of secondary α’-phase, the tertiary α’-phase and the fourth α’-phase disappear, and the volume fraction of the secondary-phase becomes low.
基金The authors are grateful for financial support from the China Medical Board(NO.10-020-201211)
文摘Objective:This paper aims to determine the reliability and validity of the Chinese version of a tool that assesses the quality of life in idiopathic pulmonary fibrosis(cATAQ-IPF)in patients with interstitial lung disease(ILD).Methods:We used the process of scale introduction to establish cATAQ-IPF.The content validity of the scale was evaluated by six experts.A total of 92 patients with ILD completed the cATAQ-IPF,St.George's respiratory questionnaire(SGRQ),and The Medical Research Council dyspnoea scale at the baseline,and 15 patients completed cATAQ-IPF at the follow-up period 2 weeks later.Thus,yielding data were used to assess various psychometric properties of cATAQ-IPE Intraclass correlation coefficient(ICC),Cronbach'sαcoefficient,content validity index(CVI),item-level CVI(I-CVI),Pearson's coefficients,criterion-relation validity,and known-group validity were used for data analysis.Results:The cATAQ-IPF showed excellent test-retest reliability(ICC=0.95),except for the therapy domain(Cronbach'sα=0.60)and acceptable internal consistency(Cronbach'sα=0.96 for the total).The scale-level CVI was 0.80,and the I-CVI was in the range of 0.78-1.00.The total cATAQ-IPF score was strongly correlated with the SGRQ total score(r=0.71,P<0.01).The cATAQ-IPF score of patients with ILD was 250.74±47.39,and that of patients with IPF was 287.90±22.56.Patients with IPF possessed considerable impairments in health-related quality of life according to the cATAQ-IPF score(t=4.94,P<0.01).Conclusions:The cATAQ-IPF is a reliable and valid instrument for the evaluation of quality of life of Chinese patients with various forms of ILD.
文摘The technique of phase measuring profilometry using a single phase step method is proposed.This method can automatically obtain phase value at each pixel by using a discret cosine transform algorithm.The method is able to automatically recognize any position between depression and elevation on an object surface.Theoretical analysis and experimental verification are presented.
基金The support of this work by the National Natural Science Foundation of China under Grant No.50074006 is gratefully acknowledged.
文摘A temperature measurement model of radiation thermometry for the surface covered by participating media was developed. The model was based on the radiation heat transfer of participating media and principles of radiation pyrometers, and solved by integral formulation of discrete ordinate method on spectral waveband. The influence of water mist on the indicated temperature of Raytek MR1SB one/two color pyrometer was discussed. Mie theory was used to calculate the radiative properties of water mist. In order to verify the model, a laboratory temperature measurement experiment was executed. The result shows that temperature of radiation thermometry is sensitive to the spectral response wavelength of pyrometer, and the simulated temperature of pyrometer agrees well with the experimental measurements on a suitable wavelength. The simulated temperature was lower than the real temperature of surface for one-color pyrometer, and it could be higher or lower than the real one for two-color pyrometer with the influence of participating media.
基金supported by a national Natural Science Foundation awarded project (81173346):Research of biological efficacy and mechanism on different techniques of scraping therapy
文摘Objective: To study the mechanism and effects of different scraping techniques on body surface blood perfusion volume and local skin temperature of healthy subjects and to provide a baseline for microcirculation and energy metabolism for the evaluation of the therapeutic effects of scraping. Methods: Changes of the local blood perfusion volume and skin temperature of healthy subjects before and after applying different scraping techniques were observed with a laser Doppler imager combined with an infrared thermographic device and the resulting data was analyzed with imaging and processing software for statistical analysis. Results: Local blood perfusion volume and skin temperature all increased after both reinforcing and reducing scraping techniques. The value of blood flow 60 and 90 min after the reducing technique was significantly higher than that after the reinforcing technique (P<0.01), while the skin temperature increased after both techniques but was not significantly different between the two (P>0.05). Conclusion: Scraping can significantly improve the local blood perfusion volume, increase skin temperature and promote local blood circulation and metabolism of tissues.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11421063,11534002,11475254the National 973Program under Grant Nos.2014CB921403,2012CB922104,and 2014CB921202
文摘Symmetry is conventionally described in a polarized manner that the system is either completely symmetric or completely asymmetric.Using group theoretical approach to overcome this dichotomous problem,we introduce the degree of symmetry(DoS) as a non-negative continuous number ranging from zero to unity.Do S is defined through an average of the fidelity deviations of Hamiltonian or quantum state over its transformation group G,and thus is computable by making use of the completeness relations of the irreducible representations of G.The monotonicity of Do S can effectively probe the extended group for accidental degeneracy while its multi-valued natures characterize some(spontaneous) symmetry breaking.