Variable stiffness composite laminates(VSCLs)are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences.Aiming to control the thermal postbu...Variable stiffness composite laminates(VSCLs)are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences.Aiming to control the thermal postbuckling and nonlinear panel flutter motions of VSCLs,a full-order numerical model is developed based on the linear quadratic regulator(LQR)algorithm in control theory,the classical laminate plate theory(CLPT)considering von Kármán geometrical nonlinearity,and the first-order Piston theory.The critical buckling temperature and the critical aerodynamic pressure of VSCLs are parametrically investigated.The location and shape of piezoelectric actuators for optimal control of the dynamic responses of VSCLs are determined through comparing the norms of feedback control gain(NFCG).Numerical simulations show that the temperature field has a great effect on aeroelastic tailoring of VSCLs;the curvilinear fiber path of VSCLs can significantly affect the optimal location and shape of piezoelectric actuator for flutter suppression;the unstable panel flutter and the thermal postbuckling deflection can be suppressed effectively through optimal design of piezoelectric patches.展开更多
Wurzite ZnS:Mn nanorods are synthesized via a solvothermal method by using ethylenediamine and water as mixed solvent.The diameters of the nanorods increase and the lengths decrease with the Mn concentration.High reso...Wurzite ZnS:Mn nanorods are synthesized via a solvothermal method by using ethylenediamine and water as mixed solvent.The diameters of the nanorods increase and the lengths decrease with the Mn concentration.High resolution transmission electron microscopic images illustrate that a few cubic ZnS:Mn nanoparticles arise along with hexagonal nanorods on high Mn concentration.The samples set off yellow-orange emission at 590 nm,characteristic of 4 T→ 6 A 1 transition of Mn 2+ at T d symmetry in ZnS.Electron spin resonance spectrum of the nanorods shows that high Mn concentrations produce a broad envelope,whereas six-line hyperfine appears for lower Mn concentrations.These results together with the magnetization curves indicate that all the ZnS:Mn samples are paramagnetic even down to 4 K,which suggests that the ZnS:Mn is not suitable for dilute magnetic semiconductor.展开更多
OBJECTIVE; To observe the influence of Qingrehuatan decoction （QRHT） on serum metabolic profile in young essential hypertension （YEH） patients with abundant phlegm-heat syndrome and provide a basis for treatment w...OBJECTIVE; To observe the influence of Qingrehuatan decoction （QRHT） on serum metabolic profile in young essential hypertension （YEH） patients with abundant phlegm-heat syndrome and provide a basis for treatment with the decoction. METHODS： Twelve male YEH patients were randomly selected and serum samples were collected for examination before and after 4 weeks of thetreatment with QRHT. Twelve healthy males were randomly selected and their serum samples were collected as a control. All serum samples were detected using metabolomic technology with 1H nuclear magnetic resonance. Differences in metabo- lites were studied by principal component analysis and partial least squares-discriminate analysis, which produced scores and Ioadings plots.RESULTS： After 4 weeks of treatment, serum substances could be distinguished between the YEH patients with abundant phlegm-heat syndrome and the control patients. The specific serum endogenous metabolites tended to improve after the treatment. QRHT can appropriately increase the levels of glucose, lactic acid, citric acid, high-density lipoprotein, phosphatidylcholine, glycerophosphate choline, hydroxybutyrate, alanine, and glutamate. QRHT could also decrease the levels of low-density lipoprotein/very low-density lipoprotein, lipids, N-acetyl glycoprotein, and O-acetyl glycoprotein.CONCLUSION： QRHT can effectively ameliorate metabolic disorders in YEH Patients with abundant phlegmheat syndrome. 1H NMR-based metabolo- mic technology can provide an objective basis for the treatment of YEH patients with abundant phlegm-heat syndrome using QRHT.展开更多
Uniform core-shell SiO2@Fe_3O_4@C microspheres were prepared by a one-step hydrothermal method with SiO_2 microspheres as the template, and the hollow Fe_3O_4@C(HFC) microspheres were achieved via etching SiO_2 templa...Uniform core-shell SiO2@Fe_3O_4@C microspheres were prepared by a one-step hydrothermal method with SiO_2 microspheres as the template, and the hollow Fe_3O_4@C(HFC) microspheres were achieved via etching SiO_2 template. By changing the sizes of SiO_2 microspheres, a series of HFC microspheres with variable cavity sizes were obtained to study the relationship between cavity size and microwave absorbing(MA) performance for the first time. The morphology and structure of samples were characterized in detail. The results showed that the MA performance of HFC sample depended on its cavity size. In particular, the hollow structure was good for improving MA performance and could make MA move to the high-frequency region. More importantly, as the cavity size increases, the resonance frequency of HFC-i(i=1,2, 3, 4) samples moved to a low frequency, and the optimal matching thickness of HFC-i samples was increasing. Among all HFC-i samples, HFC-3 showed the most excellent MA performance,which could be mainly explained by the quarter-wavelength matching model, intrinsical magnetic and dielectric loss. Furthermore,the MA performance of HFC mixture blended by the equal mass fraction of HFC-2, HFC-3 and HFC-4 was the comprehensive results of three HFC-i samples. All the above suggested that the cavity size in HFC sample had a great influence on the MA performance.展开更多
We study the heat generation in quantum dot system with Fano resonance by nonequilibrium Green＇s functions method. The Fano resonance influences the heat generation significantly. As increases, the heat generation d...We study the heat generation in quantum dot system with Fano resonance by nonequilibrium Green＇s functions method. The Fano resonance influences the heat generation significantly. As increases, the heat generation decreases gradually. From the study of Q-eV curves, we llnd that the linewidth function F has huge influence on the heat generation. The Q-eV curves display obvious steps when the linewidth function is small. However, these steps disappear with F increasing. As the source-drain bias eV increases, the Q-eVg curves also display interesting behaviors.展开更多
基金Project(JCYJ20190808175801656)supported by the Science and Technology Innovation Commission of Shenzhen,ChinaProject(2021M691427)supported by Postdoctoral Science Foundation of ChinaProject(9680086)supported by the City University of Hong Kong,China。
文摘Variable stiffness composite laminates(VSCLs)are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences.Aiming to control the thermal postbuckling and nonlinear panel flutter motions of VSCLs,a full-order numerical model is developed based on the linear quadratic regulator(LQR)algorithm in control theory,the classical laminate plate theory(CLPT)considering von Kármán geometrical nonlinearity,and the first-order Piston theory.The critical buckling temperature and the critical aerodynamic pressure of VSCLs are parametrically investigated.The location and shape of piezoelectric actuators for optimal control of the dynamic responses of VSCLs are determined through comparing the norms of feedback control gain(NFCG).Numerical simulations show that the temperature field has a great effect on aeroelastic tailoring of VSCLs;the curvilinear fiber path of VSCLs can significantly affect the optimal location and shape of piezoelectric actuator for flutter suppression;the unstable panel flutter and the thermal postbuckling deflection can be suppressed effectively through optimal design of piezoelectric patches.
基金supported by the National Natural Science Foundation of China (Grant No.50721091)
文摘Wurzite ZnS:Mn nanorods are synthesized via a solvothermal method by using ethylenediamine and water as mixed solvent.The diameters of the nanorods increase and the lengths decrease with the Mn concentration.High resolution transmission electron microscopic images illustrate that a few cubic ZnS:Mn nanoparticles arise along with hexagonal nanorods on high Mn concentration.The samples set off yellow-orange emission at 590 nm,characteristic of 4 T→ 6 A 1 transition of Mn 2+ at T d symmetry in ZnS.Electron spin resonance spectrum of the nanorods shows that high Mn concentrations produce a broad envelope,whereas six-line hyperfine appears for lower Mn concentrations.These results together with the magnetization curves indicate that all the ZnS:Mn samples are paramagnetic even down to 4 K,which suggests that the ZnS:Mn is not suitable for dilute magnetic semiconductor.
文摘OBJECTIVE; To observe the influence of Qingrehuatan decoction （QRHT） on serum metabolic profile in young essential hypertension （YEH） patients with abundant phlegm-heat syndrome and provide a basis for treatment with the decoction. METHODS： Twelve male YEH patients were randomly selected and serum samples were collected for examination before and after 4 weeks of thetreatment with QRHT. Twelve healthy males were randomly selected and their serum samples were collected as a control. All serum samples were detected using metabolomic technology with 1H nuclear magnetic resonance. Differences in metabo- lites were studied by principal component analysis and partial least squares-discriminate analysis, which produced scores and Ioadings plots.RESULTS： After 4 weeks of treatment, serum substances could be distinguished between the YEH patients with abundant phlegm-heat syndrome and the control patients. The specific serum endogenous metabolites tended to improve after the treatment. QRHT can appropriately increase the levels of glucose, lactic acid, citric acid, high-density lipoprotein, phosphatidylcholine, glycerophosphate choline, hydroxybutyrate, alanine, and glutamate. QRHT could also decrease the levels of low-density lipoprotein/very low-density lipoprotein, lipids, N-acetyl glycoprotein, and O-acetyl glycoprotein.CONCLUSION： QRHT can effectively ameliorate metabolic disorders in YEH Patients with abundant phlegmheat syndrome. 1H NMR-based metabolo- mic technology can provide an objective basis for the treatment of YEH patients with abundant phlegm-heat syndrome using QRHT.
基金supported by the National Natural Science Foundation of China (20104017)the College Students’ Science and Technology Innovation Activities Plan of Zhejiang (2014R404056)
文摘Uniform core-shell SiO2@Fe_3O_4@C microspheres were prepared by a one-step hydrothermal method with SiO_2 microspheres as the template, and the hollow Fe_3O_4@C(HFC) microspheres were achieved via etching SiO_2 template. By changing the sizes of SiO_2 microspheres, a series of HFC microspheres with variable cavity sizes were obtained to study the relationship between cavity size and microwave absorbing(MA) performance for the first time. The morphology and structure of samples were characterized in detail. The results showed that the MA performance of HFC sample depended on its cavity size. In particular, the hollow structure was good for improving MA performance and could make MA move to the high-frequency region. More importantly, as the cavity size increases, the resonance frequency of HFC-i(i=1,2, 3, 4) samples moved to a low frequency, and the optimal matching thickness of HFC-i samples was increasing. Among all HFC-i samples, HFC-3 showed the most excellent MA performance,which could be mainly explained by the quarter-wavelength matching model, intrinsical magnetic and dielectric loss. Furthermore,the MA performance of HFC mixture blended by the equal mass fraction of HFC-2, HFC-3 and HFC-4 was the comprehensive results of three HFC-i samples. All the above suggested that the cavity size in HFC sample had a great influence on the MA performance.
基金Supported by the National Natural Science Foundation of China under Grant No.11147189Hunan Provincial Natural Science Foundation of China under Grant Nos.11JJ4005,11JJ9018the the Scientific Research Fund of Hunan Provincial Education Department,China under Grant No.10B022
文摘We study the heat generation in quantum dot system with Fano resonance by nonequilibrium Green＇s functions method. The Fano resonance influences the heat generation significantly. As increases, the heat generation decreases gradually. From the study of Q-eV curves, we llnd that the linewidth function F has huge influence on the heat generation. The Q-eV curves display obvious steps when the linewidth function is small. However, these steps disappear with F increasing. As the source-drain bias eV increases, the Q-eVg curves also display interesting behaviors.
