A sensitive chemiluminescence（CL） method was developed for determining melamine in urine and plasma samples based on the fact that melamine can remarkably enhance the chemiluminescence of Luminol-K3 Fe（CN）6 system...A sensitive chemiluminescence（CL） method was developed for determining melamine in urine and plasma samples based on the fact that melamine can remarkably enhance the chemiluminescence of Luminol-K3 Fe（CN）6 system in alkaline medium. The determination conditions were optimized. Under optimum conditions, the chemiluminescence intensity had a good linear relationship with melamine in the range of 9.0 × 10^-9 - 7.0 × 10^-6 g/mL with a correlation coefficient of 0. 9992. The detection limits （3o） were 3.54 ng/mL for urine sample and 6.58 ng/mL for plasma sample. The average recoveries of melamine were 102.6% for urine sample and 95.1% for plasma sample. Melamine in samples was extracted with liquid-liquid extraction procedures and the assay results coincided very well with that determined with flow injection chemiluminescence method. The method provides a reproducible and stable approach for sensitive detection and quantification of melamine in urine and plasma samples.展开更多
A comparative optimal design of fluid-saturated prismatic cellular metal honeycombs （PCMHs） having different cell shapes is presented for thermal management applications. Based on the periodic topology of each PCMH,...A comparative optimal design of fluid-saturated prismatic cellular metal honeycombs （PCMHs） having different cell shapes is presented for thermal management applications. Based on the periodic topology of each PCMH, a unit cell （UC） for thermal transport analysis was selected to calculate its effective thermal conductivity. Without introducing any empirical coefficient, we modified and extended the analytical model of parallel-series thermal-electric network to a wider porosity range （0.7 ~ 0.98） by considering the effects of two-dimensional local heat conduction in solid ligaments inside each UC. Good agreement was achieved between analytical predictions and numerical simulations based on the method of finite volume. The concept of ligament heat conduction efficiency （LTCE） was proposed to physically explain the mechanisms underlying the effects of ligament configuration on effective thermal conductivity （ETC）. Based upon the proposed theory, a construct strategy was developed for designing the ETC by altering the equivalent interaction angle with the direction of heat flow： relatively small average interaction angle for thermal conduction and relatively large one for thermal insulation.展开更多
In this Paper, the saturate spacing of transverse cracks of the 90° ply is originallycalculated by the 3-D finite element method. Thus, a new approach is put forward for predicting the saturate spacing of transve...In this Paper, the saturate spacing of transverse cracks of the 90° ply is originallycalculated by the 3-D finite element method. Thus, a new approach is put forward for predicting the saturate spacing of transverse cracks.展开更多
1.Research and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many ...1.Research and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many other fields,making them an important basis in the field of three-dimensional(3D)printing.Problems and challenges related to material types,powder properties,formability,viscoelasticity,and so forth also share common features.For example,many metal materials are used in the field of aviation,while metals,polymers,and inorganic materials are used in the field of biomedicine.The most widely used materials in biomedicine are biocompatible.Various homogeneous and non-homogeneous composites are also available for 3D printing,and impose an additional challenge in additive manufacturing;the use of heterogeneous composites in 3D printing is particularly challenging.展开更多
The carbon isotopic compositions of soil organic matter (SOM) and total carbonate (TC) in Xifeng loess-paleosol sequence have been studied. The δ 13CSOM values vary from ?23.8‰ to ?20.2‰, which are higher in interg...The carbon isotopic compositions of soil organic matter (SOM) and total carbonate (TC) in Xifeng loess-paleosol sequence have been studied. The δ 13CSOM values vary from ?23.8‰ to ?20.2‰, which are higher in interglacial than in glacial stages. Contrary to δ 13CSOM values, the δ 13CTC values vary from ?8.5‰ to ?3.6‰ and are lower in interglacial than in glacial stages. The differences (?δ 13C) be- tween the δ 13CSOM and δ 13CTC values vary from 14.1‰ to 19.4‰. Our results from the Xifeng loess- paleosol sequence indicate that the ?δ 13C values represent the ratio of primary carbonate (PC) to secondary carbonate (SC). The ?δ 13C values were high in the loess stages, and the maximal PC-to-SC ratio can reach 6:4. But in the paleosol stages, the ?δ 13C values were low, with a small proportion of PC. The ?δ 13C values in loess-paleosol sequence also indicate the contributions of the dust to the loess sediment in the Chinese Loess Plateau because the dust contains the PC.展开更多
Aerosol observation was conducted for four seasons from September 2001 to August 2002 at five sampling sites in Hangzhou, South China, on PM10 mass, 22 elements （Na, Mg, AI, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu...Aerosol observation was conducted for four seasons from September 2001 to August 2002 at five sampling sites in Hangzhou, South China, on PM10 mass, 22 elements （Na, Mg, AI, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As. Se, Br, Cd, Ba, and Pb）, 5 major ions （F^-, Cl^ , NO3^-, SO4^2- , and NH4^＋）, and organic and elemental carbon （OC and EC）, showing that PM10 mass ranged from 46.7 to 270.8 μg/m^3, with an annual average of 119.2 μg/m^3. Na, AI, Si, S, K, Ca, and Fe were the most abundant elements in PM10, most of S being in the form of SO4^2- . SO4^2-, NO3^-, and NH4^＋ were the major ions, which contributed to about 20% of the PM10 mass. The mean seasonal concentrations for SO4^2- , averaged over all sites, were found to be 18.0, 18.5, 24,Z and 21.4 μg/m^3, for spring, summer, autumn, and winter, respectively, while the corresponding loadings for NO3^- were 7.2, 4.7, 7.1, and 11.2 μg/m^3, and for NH4^＋ were 6.0, 5.9, 8.2, and 9.3 μg/m^3, in the form mostly of NH4NO3 in spring, autumn, and winter, and mostly of （NH4）2SO4 in summer. The low NO3^-/SO4^2- ratio found indicates coal combustion as the major source throughout the year. The mean annual concentrations of OC and EC in PM10 were found to be 21.4, and 4.1 μg/m^3, respectively. Material balance calculation indicated that fugitive dust, the secondary aerosol, and carbonaceous matter were the most abundant species in PM10 for the four seasons, as is characteristic for cities in South China.展开更多
Following the publication of the US National Research Council （N RC） report ＂ Toward PrecMon Medicine.＂ Building a Knowledge Network for Biomedical Research and a New Taxonomy of Diseases＂ in 2011 [1], several n...Following the publication of the US National Research Council （N RC） report ＂ Toward PrecMon Medicine.＂ Building a Knowledge Network for Biomedical Research and a New Taxonomy of Diseases＂ in 2011 [1], several nations have announced that their national research programs would definitely head toward this direction. Now,展开更多
Based on the report given by J. E. Midwinter that the refractive indices n<sub>o</sub> and n<sub>e</sub> oflithium niobate doped with magnesium （MgO:LiNbo<sub>3</sub>） are lower t...Based on the report given by J. E. Midwinter that the refractive indices n<sub>o</sub> and n<sub>e</sub> oflithium niobate doped with magnesium （MgO:LiNbo<sub>3</sub>） are lower than those of LiNbO<sub>3</sub>,S.Sudo et al. achieved for the first time the core-cladding wave guide structure of LiNbO<sub>3</sub>展开更多
A new family of isostructural 3 d-4 f polymetallic complexes,formulated as [Cu_(6)Ln_(5)(μ_(3)OH)_(9)(C_(4)H_(8)O_(2)N)_(6)(C_(5)H_(4)ON)_(6)(H_(2)O)_(9)]·(ClO_(4))_(6)·(H_(2)O)_(22)(Ln=Pr,1;Nd,2;Sm,3;Eu,4;...A new family of isostructural 3 d-4 f polymetallic complexes,formulated as [Cu_(6)Ln_(5)(μ_(3)OH)_(9)(C_(4)H_(8)O_(2)N)_(6)(C_(5)H_(4)ON)_(6)(H_(2)O)_(9)]·(ClO_(4))_(6)·(H_(2)O)_(22)(Ln=Pr,1;Nd,2;Sm,3;Eu,4;Gd,5),was successfully isolated through the simple hydrolysis reaction of 2-aminoisobutyric acid,2-hydroxypyridine,Cu(CH_(3)COO)_(2)·H_(2)O,and Ln(ClO_(4))_(3)·6 H_(2)O.Notably,the [Cu_(6)Ln_(5)] clusters with high molecular symmetry of D_(3h) are rare examples of2-aminoisobutyric acid-based 3 d-4 f clusters.The successful theoretical modeling of 5 yielded that the Gd-Gd exchange is of order 0.2 K,whereas the Gd-Cu exchange is an order of magnitude larger.Magnetization data collected for comp lex 5 yield a magnetic entropy change(-ΔSm) of 19.6 J kg^(-1) K^(-1)<1 at 3 K and 7 T,which may be attributed to the weak magnetic interactions between the component metal ions.展开更多
文摘A sensitive chemiluminescence（CL） method was developed for determining melamine in urine and plasma samples based on the fact that melamine can remarkably enhance the chemiluminescence of Luminol-K3 Fe（CN）6 system in alkaline medium. The determination conditions were optimized. Under optimum conditions, the chemiluminescence intensity had a good linear relationship with melamine in the range of 9.0 × 10^-9 - 7.0 × 10^-6 g/mL with a correlation coefficient of 0. 9992. The detection limits （3o） were 3.54 ng/mL for urine sample and 6.58 ng/mL for plasma sample. The average recoveries of melamine were 102.6% for urine sample and 95.1% for plasma sample. Melamine in samples was extracted with liquid-liquid extraction procedures and the assay results coincided very well with that determined with flow injection chemiluminescence method. The method provides a reproducible and stable approach for sensitive detection and quantification of melamine in urine and plasma samples.
基金supported by the National Natural Science Foundation of China(51506160,11472208,11472209)China Post-Doctoral Science Foundation Project(2015M580845)+1 种基金the Fundamental Research Funds for Xi’an Jiaotong University(xjj2015102)the Beijing Key Lab of Heating,Gas Supply,Ventilating and Air Conditioning Engineering(NR2016K01)
文摘A comparative optimal design of fluid-saturated prismatic cellular metal honeycombs （PCMHs） having different cell shapes is presented for thermal management applications. Based on the periodic topology of each PCMH, a unit cell （UC） for thermal transport analysis was selected to calculate its effective thermal conductivity. Without introducing any empirical coefficient, we modified and extended the analytical model of parallel-series thermal-electric network to a wider porosity range （0.7 ~ 0.98） by considering the effects of two-dimensional local heat conduction in solid ligaments inside each UC. Good agreement was achieved between analytical predictions and numerical simulations based on the method of finite volume. The concept of ligament heat conduction efficiency （LTCE） was proposed to physically explain the mechanisms underlying the effects of ligament configuration on effective thermal conductivity （ETC）. Based upon the proposed theory, a construct strategy was developed for designing the ETC by altering the equivalent interaction angle with the direction of heat flow： relatively small average interaction angle for thermal conduction and relatively large one for thermal insulation.
文摘In this Paper, the saturate spacing of transverse cracks of the 90° ply is originallycalculated by the 3-D finite element method. Thus, a new approach is put forward for predicting the saturate spacing of transverse cracks.
文摘1.Research and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many other fields,making them an important basis in the field of three-dimensional(3D)printing.Problems and challenges related to material types,powder properties,formability,viscoelasticity,and so forth also share common features.For example,many metal materials are used in the field of aviation,while metals,polymers,and inorganic materials are used in the field of biomedicine.The most widely used materials in biomedicine are biocompatible.Various homogeneous and non-homogeneous composites are also available for 3D printing,and impose an additional challenge in additive manufacturing;the use of heterogeneous composites in 3D printing is particularly challenging.
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 40599422, 40523002 ＆ 40121303） the National Key Funds of China （Grant No. 2004CB720200）.
文摘The carbon isotopic compositions of soil organic matter (SOM) and total carbonate (TC) in Xifeng loess-paleosol sequence have been studied. The δ 13CSOM values vary from ?23.8‰ to ?20.2‰, which are higher in interglacial than in glacial stages. Contrary to δ 13CSOM values, the δ 13CTC values vary from ?8.5‰ to ?3.6‰ and are lower in interglacial than in glacial stages. The differences (?δ 13C) be- tween the δ 13CSOM and δ 13CTC values vary from 14.1‰ to 19.4‰. Our results from the Xifeng loess- paleosol sequence indicate that the ?δ 13C values represent the ratio of primary carbonate (PC) to secondary carbonate (SC). The ?δ 13C values were high in the loess stages, and the maximal PC-to-SC ratio can reach 6:4. But in the paleosol stages, the ?δ 13C values were low, with a small proportion of PC. The ?δ 13C values in loess-paleosol sequence also indicate the contributions of the dust to the loess sediment in the Chinese Loess Plateau because the dust contains the PC.
基金supported by the National Natural Science Foun-dation of China (Grants 40675081 and 40599422)
文摘Aerosol observation was conducted for four seasons from September 2001 to August 2002 at five sampling sites in Hangzhou, South China, on PM10 mass, 22 elements （Na, Mg, AI, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As. Se, Br, Cd, Ba, and Pb）, 5 major ions （F^-, Cl^ , NO3^-, SO4^2- , and NH4^＋）, and organic and elemental carbon （OC and EC）, showing that PM10 mass ranged from 46.7 to 270.8 μg/m^3, with an annual average of 119.2 μg/m^3. Na, AI, Si, S, K, Ca, and Fe were the most abundant elements in PM10, most of S being in the form of SO4^2- . SO4^2-, NO3^-, and NH4^＋ were the major ions, which contributed to about 20% of the PM10 mass. The mean seasonal concentrations for SO4^2- , averaged over all sites, were found to be 18.0, 18.5, 24,Z and 21.4 μg/m^3, for spring, summer, autumn, and winter, respectively, while the corresponding loadings for NO3^- were 7.2, 4.7, 7.1, and 11.2 μg/m^3, and for NH4^＋ were 6.0, 5.9, 8.2, and 9.3 μg/m^3, in the form mostly of NH4NO3 in spring, autumn, and winter, and mostly of （NH4）2SO4 in summer. The low NO3^-/SO4^2- ratio found indicates coal combustion as the major source throughout the year. The mean annual concentrations of OC and EC in PM10 were found to be 21.4, and 4.1 μg/m^3, respectively. Material balance calculation indicated that fugitive dust, the secondary aerosol, and carbonaceous matter were the most abundant species in PM10 for the four seasons, as is characteristic for cities in South China.
文摘Following the publication of the US National Research Council （N RC） report ＂ Toward PrecMon Medicine.＂ Building a Knowledge Network for Biomedical Research and a New Taxonomy of Diseases＂ in 2011 [1], several nations have announced that their national research programs would definitely head toward this direction. Now,
基金Project supported by the Foundation of Electronic Materials Research Laboratory,Xi'an Jiaotong University.
文摘Based on the report given by J. E. Midwinter that the refractive indices n<sub>o</sub> and n<sub>e</sub> oflithium niobate doped with magnesium （MgO:LiNbo<sub>3</sub>） are lower than those of LiNbO<sub>3</sub>,S.Sudo et al. achieved for the first time the core-cladding wave guide structure of LiNbO<sub>3</sub>
基金supported by Shenzhen Science and Technology Program (No.JCYJ20180306170859634)National Natural Science Foundation of China (Nos.21773130,21801202,21871219, 21971203 and 21620102002)+4 种基金Shaanxi National Science Foundation (No.2019JQ-016)China Postdoctoral Science Foundation (Nos. 2019T120891 and 2018M643615)Key Laboratory Construction Program of Xi’an Municipal Bureau of Science and Technology (No. 201805056ZD7CG40)Cyrus Chung Ying Tang Foundation and Fundamental Research Funds for Central Universitiessupported by the Deutsche Forschungsgemeinschaft DFG (Nos.314331397,SCHN 615/23-1)。
文摘A new family of isostructural 3 d-4 f polymetallic complexes,formulated as [Cu_(6)Ln_(5)(μ_(3)OH)_(9)(C_(4)H_(8)O_(2)N)_(6)(C_(5)H_(4)ON)_(6)(H_(2)O)_(9)]·(ClO_(4))_(6)·(H_(2)O)_(22)(Ln=Pr,1;Nd,2;Sm,3;Eu,4;Gd,5),was successfully isolated through the simple hydrolysis reaction of 2-aminoisobutyric acid,2-hydroxypyridine,Cu(CH_(3)COO)_(2)·H_(2)O,and Ln(ClO_(4))_(3)·6 H_(2)O.Notably,the [Cu_(6)Ln_(5)] clusters with high molecular symmetry of D_(3h) are rare examples of2-aminoisobutyric acid-based 3 d-4 f clusters.The successful theoretical modeling of 5 yielded that the Gd-Gd exchange is of order 0.2 K,whereas the Gd-Cu exchange is an order of magnitude larger.Magnetization data collected for comp lex 5 yield a magnetic entropy change(-ΔSm) of 19.6 J kg^(-1) K^(-1)<1 at 3 K and 7 T,which may be attributed to the weak magnetic interactions between the component metal ions.
