Local adjustment with path-dependence

A primary task of Chinese planning historians is to show how Chinese urbanization expresses the complex and changing relationship between a strong central government and market forces. Here is one kind of cities called Third-front city, making a pure sample to understand Chinese modern institutional design and related spatial phenomena. Such cities were first built for war-preparing in remote Midwestern China in 1960s, under compulsory power and planned arrangement from central government, which seems not a sustainable mode by general acknowledgement. Yet those cities have still went through transformation and gained follow-up development. With the perspective of historical institutionalism, we assume there exists the interaction of institutional path dependence and endogenous incremental change. This paper takes one typical of them, Shiyan in Hubei Province for empirical study. From the Socialist planned economy stage (1960s to 1970s) to China’s Reform stage (since 1980s), we mainly explore how government structural change effected the city’s development outcomes as a core institutional factor, especially where planning got involved. We find that the initial institutional system dominated by central government had ensured rapid rise of Third-front city in early stage, while producing path dependence and long-term urban spatial influences. In face of transformation, general environment of modest reformation in China had provided enough buffer space for new institutions; On the other hand, despite path dependence in terms of industry pattern, finance structure, administrative power and so on, new local actors’ seeking for incremental changes within original institutional framework also generated transformative effects

A POD-Based Reduced-Order Stabilized Crank–Nicolson MFE Formulation for the Non-Stationary Parabolized Navier–Stokes Equations

We firstly employ a proper orthogonal decomposition (POD) method, Crank–Nicolson (CN) technique, and two local Gaussian integrals to establish a PODbased reduced-order stabilized CN mixed finite element (SCNMFE) formulation with very few degrees of freedom for non-stationary parabolized Navier–Stokes equations. Then, the error estimates of the reduced-order SCNMFE solutions, which are acted as a suggestion for choosing number of POD basis and a criterion for updating POD basis, and the algorithm implementation for the POD-based reduced-order SCNMFE formulation are provided, respectively. Finally, some numerical experiments are presented to illustrate that the numerical results are consistent with theoretical conclusions. Moreover, it is shown that the reduced-order SCNMFE formulation is feasible and efficient for finding numerical solutions of the non-stationary parabolized Navier–Stokes equations

A Reduced-Order Extrapolation Spectral-Finite Difference Scheme Based on the POD Method for 2D Second-Order Hyperbolic Equations

In this study, a reduced-order extrapolation spectral-finite difference (ROESFD) scheme based on the proper orthogonal decomposition (POD) method is set up for the two-dimensional (2D) second-order hyperbolic equations. First, the classical spectral-finite difference (CSFD) method for the 2D second-order hyperbolic equations and its stability, convergence, and flaw are introduced. Then, a new ROESFD scheme that has very few degrees of freedom but holds sufficiently high accuracy is set up by the POD method and its implementation is offered. Finally, three numerical examples are offered to explain the validity of the theoretical conclusion. This implies that the ROESFD scheme is viable and efficient for searching the numerical solutions of the 2D second-order hyperbolic equations

Analysis of Influencing Factors of Green Building Energy Consumption Based on Genetic Algorithm

With the advancement of modernization, high energy consumption buildings can no longer meet the needs of social development. Under the background of low carbon and energy saving, the development of green buildings has become the only way, but its energy-saving design effect needs to be further studied. Aiming at lighting and energy consumption, this study carried out multi-factor optimization analysis based on genetic algorithm on factors such as windowing ratio, wall heat transfer coefficient, window heat transfer coefficient, window transmittance and roof insulation coefficient. Firstly, the theory and technical scheme of applying data mining technology to solve the energy-saving design problems of different buildings are proposed and implemented, including the design of new and existing buildings, as well as the determination of decisive parameters and non-decisive parameters. Secondly, computer simulation and theoretical analysis are used to optimize the analysis of the building scheme, so as to find the optimal design range of each influencing factor and the optimal design method of green low-energy building. Multi-factor optimization theory and genetic algorithm principle are summarized, and the heat transfer coefficient of external wall and window of the building is selected as the optimization variable, so as to achieve low energy consumption and enclosure cost of the building. Aiming at better thermal comfort, an optimization model was established. Finally, through empirical research, an energysaving plan was designed, and genetic algorithm was used to obtain the optimal solution for maximizing the incremental benefits obtained by unit input incremental cost. The results indicate that the ideal incremental benefits come from a reasonable and effective combination of technologies, mainly from air conditioning systems and lighting systems; the setting of the benchmark return rate will directly affect the optimization effect of energy-saving plans, providing decision-makers with the optimal combination of energy-saving technologies

Interionic Energy Transfer in Y\u3csub\u3e3\u3c/sub\u3eAl\u3csub\u3e5\u3c/sub\u3eO\u3csub\u3e12\u3c/sub\u3e: Ce\u3csup\u3e3+\u3c/sup\u3e, Pr\u3csup\u3e3+\u3c/sup\u3e Phosphor

We present an investigation of dynamical processes of nonradiative energy transfer (ET)between Ce3+ and Pr3+ , and between Pr3+ ions in Y3Al5O12:Ce3+ , Pr3+ phosphor.Photoluminescence spectroscopy and fluorescence decay patterns are studied as a function ofPr3+ and Ce3+ concentrations. The analysis based on Inokuti–Hirayama model indicates that the ET from the lowest 5d state of Ce3+ to the D12 state of Pr3+ , and the quenching of theD12 state through a cross relaxation involving Pr3+ ions in the ground state are both governed by electric dipole–dipole interaction. An increase in the Ce3+–Pr3+ ET rate followed by the enhanced red emission line of Pr3+ relative to the yellow emission band of Ce3+ on only increasing Ce3+ concentration is observed. This behavior is attributed to the increase in thespectral overlap integrals between Ce3+ emission and Pr3+ excitation due to the fact that the yellow band shifts to the red spectral side with increasing Ce3+ concentration while the red line dose not move. For Ce3+ concentration of 0.01 in YAG:Ce3+ , Pr3+ , the rate constant and critical distance are evaluated to be 4.5×10−36 cm6 s−1 , 0.81 nm for Ce3+–Pr3+ ET and2.4×10−38 cm6 s−1 , 1.30 nm for Pr3+–Pr3+ ET. Spectroscopic study also demonstrates a pronounced ET from the lowest 4f5d of Pr3+ to the 5d of Ce3+ . A proportional dependence of the initial transfer rate on acceptor concentration is observed in each of these ET pathways. The proportional coefficient as the averaged ET parameters for initial decay are determined, meaning the ET efficiency for the same concentration of acceptors follows the order ofPr3+–Pr3+\u3ePr3+–Ce3+\u3eCe3+–Pr3+

Color Control and White Light Generation of Upconversion Luminescence by Operating Dopant Concentrations and Pump Densities in Yb\u3csup\u3e3+\u3c/sup\u3e, Er\u3csup\u3e3+\u3c/sup\u3e, and Tm\u3csup\u3e3+\u3c/sup\u3e Tri-Doped Lu\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e Nanocrystals

We synthesized a series of Yb3+, Er3+ and Tm3+ tri-doped Lu2O3 nanocrystals with various dopant concentrations by the hydrothermal approach. Due to a unique electronic state at the top of the valence band, Lu2O3 based materials exhibit intense upconversion luminescence involving 1G4 → 3H6 of Tm3+ in blue, (2H11/2, 4S3/2) → 4I15/2 in green and 4F9/2 → 4I15/2 in red of Er3+ upon near infrared excitation at 980 nm. The variation of upconversion spectra and color points with dopant concentrations and pump densities are studied in detail on the basis of energy transfer processes. An ideal white upconversion light with color coordinates of (0.327, 0.339) is obtained by controlling the intensity of red, green, and blue emission in Lu1.906Yb0.08Er0.008Tm0.006O3nanocrystals under a pump density of 8 W cm−2. Based on the present experimental data, we may predict the dopant concentrations and pump densities for any color point within or around the white light region in the tri-doped Lu2O3 nanocrystals

Association between blood heavy metal exposure levels and risk of metabolic dysfunction associated fatty liver disease in adults: 2015–2020 NHANES large cross-sectional study

BackgroundThe relationships between heavy metals and fatty liver, especially the threshold values, have not been fully elucidated. The objective of this research was to further investigate the correlation between blood heavy metal exposures and the risk of Metabolic dysfunction Associated Fatty Liver Disease (MAFLD) in adults.MethodsLaboratory data on blood metal exposure levels were obtained from National Health and Nutrition Examination Survey (NHANES) data for the period 2015 to 2020 for a cross-sectional study in adults. Associations between blood levels of common heavy metals and the risk of MAFLD in adults were analyzed using multifactorial logistic regression and ranked for heavy metal importance using a random forest model. Finally, thresholds for important heavy metals were calculated using piecewise linear regression model.ResultsIn a multifactorial logistic regression model, we found that elevated levels of selenium (Se) and manganese (Mn) blood exposure were strongly associated with the risk of MAFLD in adults. The random forest model importance ranking also found that Se and Mn blood exposure levels were in the top two positions of importance for the risk of disease in adults. The restricted cubic spline suggested a non-linear relationship between Se and Mn blood exposure and adult risk of disease. The OR (95% CI) for MAFLD prevalence was 3.936 (2.631–5.887) for every 1 unit increase in Log Mn until serum Mn levels rose to the turning point (Log Mn = 1.10, Mn = 12.61 μg/L). This correlation was not significant (p > 0.05) after serum Mn levels rose to the turning point. A similar phenomenon was observed for serum Se levels, with a turning point of (Log Se = 2.30, Se = 199.55 μg/L).ConclusionBlood heavy metals, especially Se and Mn, are significantly associated with MAFLD in adults. They have a non-linear relationship with a clear threshold