PREDICTION OF THE RHEOLOGICAL PROPERTIES OF STAR—TYPE BRANCHED POLYMER SOLUTIONS BY MEANS OF THE FIXED SPECTRUM MODEL

The Rouse-Zimm model with slippage was improved and the basic parameters of modelwere modified to explain the rheological properties of star-type branched polymersolutions. The theoretical results show good agreement with experimental data.

The impact of Internet access on household dietary quality:Evidence from rural China

Over the past few decades,the Internet has rapidly diffused across China.The spread of the Internet has had a profound economic and social impact on Chinese rural areas.Existing research shows that Internet access significantly impacts agricultural production and improves smallholder farmers’income.Beyond these,the Internet can affect other dimensions of social welfare.However,research about the impact of Internet access on dietary quality in rural China remains scarce.This study utilizes multi-period panel data from Fixed Observation Point in rural China from 2009 to 2015 to estimate the impact of Internet access on dietary quality and food consumption of rural households and conducts a causal analysis.Regression models with time and household fixed effects allow robust estimation while reducing potential issues of unobserved heterogeneity.The estimates show that Internet access has significantly increased rural household dietary quality(measured by the Chinese Diet Balance Index).Further research finds that Internet access has increased the consumption of animal products,such as aquatic and dairy products.We also examine the underlying mechanisms.Internet access improves dietary quality and food consumption mainly through increasing household income and food expenditure.These results encourage the promotion of Internet access as a valuable tool for nutritional improvements,especially in rural areas.

A Mixed Model Analysis of a Fertilizer Experiment on Oil Palm in Nigeria

Mixed model analysis procedure was used to analyze the effect of fertilizer application on the Fresh Fruit Bunch (FFB) yield of oil palm. This was with a view to achieve the most appropriate and a robust model for analyzing yield response for fertilizer application in oil palm. In this study, a mixed model analysis procedure was used to analyze yield data obtained from a fertilizer trial conducted between 1997 and 2005. In mixed effect model, replicates and years were used as block. In contrast the fixed effect ANOVA model usually lumped up replicates and years as a random error. In the model replicates were used as block with no block interaction, replicates as block with allowance for block-fertilizer interaction, years as block with allowance for block-fertilizer interaction, and years and replicates as block with allowance for year fertilizer and replicate-fertilizer interaction. Mixed model theory was also used to provide the explicit description of the design matrices in the models. Also, hypotheses relevant to each model were formulated and used to test for specific effects in the models such as, fixed part, random part and interacting parts using appropriate error terms as determined by the derived Expected Mean Squares (EMS). The results revealed that at 5% significant level (p

Stability of rat models of fluid percussion-induced traumatic brain injury: comparison of three different impact forces

Fluid percussion-induced traumatic brain injury models have been widely used in experimental research for years. In an experiment, the stability of impaction is inevitably affected by factors such as the appearance of liquid spikes. Management of impact pressure is a crucial factor that determines the stability of these models, and direction of impact control is another basic element. To improve experimental stability, we calculated a pressure curve by generating repeated impacts using a fluid percussion device at different pendulum angles. A stereotactic frame was used to control the direction of impact. We produced stable and reproducible models, including mild, moderate, and severe traumatic brain injury, using the MODEL01-B device at pendulum angles of 6°, 11° and 13°, with corresponding impact force values of 1.0 ± 0.11 atm（101.32 ± 11.16 k Pa）, 2.6 ± 0.16 atm（263.44 ± 16.21 k Pa）, and 3.6 ± 0.16 atm（364.77 ± 16.21 k Pa）, respectively. Behavioral tests, hematoxylin-eosin staining, and magnetic resonance imaging revealed that models for different degrees of injury were consistent with the clinical properties of mild, moderate, and severe craniocerebral injuries. Using this method, we established fluid percussion models for different degrees of injury and stabilized pathological features based on precise power and direction control.

Characterization of P-nitrophenol Adsorption Kinetic Properties in Batch and Fixed Bed Adsorbers

P-nitrophenol（PNP） adsorption in batch and fixed bed adsorbers was studied. The homogeneous surface diffusion model（HSDM） based on external mass transfer and intraparticle surface diffusion was used to describe the adsorption kinetics for PNP in stirred batch adsorber at various initial concentrations and activated carbon dosages. The fixed bed model considering both external and internal mass transfer resistances as well as axial dispersion with non-linear isotherm was utilized to predict the fixed bed breakthrough curves for PNP adsorption under the conditions of different flow rates and inlet concentrations. The equilibrium parameters and surface diffusivity（Ds） were obtained from separate experiments in batch adsorber. The obtained value of Ds is 4.187×1012 m2/s. The external film mass transfer coefficient（kf） and axial dispersion coefficient（DL） were estimated by the correlations of Goeuret and Wike-Chang. The Biot number determined by HSDM indicated that the adsorption rate of PNP onto activated carbon in stirred batch was controlled by intraparticle diffusion and film mass transfer. A sensitivity analysis was carried out and showed that the fixed bed model calculations were sensitive to Ds and kf, but insensitive to DL. The sensitivity analysis and Biot number both confirm that intraparticle diffusion and film mass transfer are the controlling mass transfer mechanism in fixed bed adsorption system.

Empirical Study on the Effect of Abolishing Agricultural Tax on Farmers' Income

The panel dataset which covered the socio-economic data of 31 provinces （municipalities and autonomous region） in China from 2000-2007 was used to do empirical analysis on the effect of abolishing agricultural taxes on farmers＇ income by referring to the fixed effect estimation method. It found that the abolition of agricultural taxes increased farmer＇s net income per capita by 2%. Combining with the results of empirical analysis, related policy suggestions were put forward to increase farmers＇ income.

Relationship between Insecticide Spray and Infestation Level of Rice Planthopper in Large Spatial Scale and in Long Term

[Objective] This study aimed at revealing the effect of insecticide spray on the infestation level of rice planthopper in large spatial scale and in long term. [Method] The data set included twenty counties from 1991 to 2009. Therefore fixed effect model was established to evaluate the effect of insecticide spray on the infes- tation level of rice planthopper. The OLS method was used to estimate the fixed ef- fect model. [Result] The regression results of the fixed effect model suggested that one period lag insecticide spray had a significant effect on the infestation level of rice planthopper. [Conclusion] Even though rice planthopper is a migratory rice pest, insecticide spray has a significant effect on the infestation level of rice planthopper in large spatial scale and in long term.

Relationship between Resistance of Rice Stem Borer and Insecticide Use Intensity in South China

[Objective] This study aimed to survey the effect of insecticide use intensity on the resistance of rice stem borer in South China. [Method] The data includes 19 counties from Guangdong Province and Guangxi Province from 1991 to 2010. A fixed effect model was established to evaluate the effect of insecticide use intensity on the resistance of rice stem borer. [Result] The regression results suggest that one-period lagged total number of insecticide sprays has significant effect on the infestation level of rice stem borer. [Conclusion] Although rice stem borer is a migratory rice pest, insecticide use intensity has significant effect on the resistance level of rice stem borer in South China.

Digital finance and renewable energy consumption:evidence from China

While digital finance and renewable energy consumption(REC)are two timely issues,it remains unclear whether the former affects the latter,especially in developing economies.This paper examines the impact of digital finance on China’s REC between 2011 and 2018 and explores the underlying mechanisms.Results show that digital finance,along with its coverage breadth and usage depth,significantly improved REC in China and that digital finance in the area of credit has had the most significant impact.Additionally,the results show that loan scale and income level are the main mediation variables,through which digital finance affects REC.The findings also suggest that economic growth and technological progress have increased REC in China,while carbon dioxide emissions have had no meaningful effect on this consumption.The results further indicate that policymakers must pay close attention to the role of digital finance when formulating policies on REC.To promote REC and environmental sustainability,developing economies like China should strengthen the breadth and depth of digital finance development,focus on the influence channels of digital finance,and promote economic growth and technological progress.

Acupuncture and vitamin B_(12) injection for Bell's palsy:no high-quality evidence exists

OBJECTIVE： To assess the efficacy of acupuncture combined with vitamin B12 acupoint injection versus acupuncture alone to reduce incomplete recovery in patients with Bell＇s palsy. DATA RETRIEVAL： A computer-based online retrieval of Medline, Web of Science, CNKI, CBM databases until April 2014 was performed for relevant trials, using the key words ＂Bell＇s palsy or idiopathic facial palsy or facial palsy＂ and＂acupuncture or vitamin B12 or methylcobalamin＂. STUDY SELECTION： All randomized controlled trials that compared acupuncture with acupuncture combined with vitamin B12 in patients with Bell＇s palsy were included in the me- ta-analysis. The initial treatment lasted for at least 4 weeks. The outcomes of incomplete facial recovery were monitored. The scoring index varied and the definition of healing was consistent. The combined effect size was calculated by using relative risk （RR） with 95% confidence interval （C/） using the fixed effect model of Review Manager. MAIN OUTCOME MEASURES： Incomplete recovery rates were chosen as the primary outcome. RESULTS： Five studies involving 344 patients were included in the final analysis. Results showed that the incomplete recovery rate of Bell＇s palsy patients was 44.50% in the acupuncture combined with vitamin B12 group but 62.57% in the acupuncture alone group. The major acupoints were Taiyang （EX-HN5）, Jiache （ST6）, Dicang （ST4） and Sibai （ST2）. The combined effect size showed that acupuncture combined with vitamin B12 was better than acupuncture alone for the treatment of Belrs palsy （RR = 0.71, 95%CI： 0.58-0.87; P = 0.001）, this result held true when 8 patients lost to follow up in one study were included into the analyses （RR = 0.70, 95%CI： 0.58-0.86; P = 0.0005）. In the subgroup analyses, the therapeutic effect in patients of the electroacupuncture subgroup was better than in the non-electroacupuncture subgroup （P = 0.024）. There was no significant dif- ference in the incomplete recovery rate by subgroup analysis on drug types and treatment period. Most of the included studies were moderate or low quality, and bias existed. CONCLUSION： In patients with Bell＇s palsy, acupuncture combined with vitamin 812 can reduce the risk of incomplete recovery compared with acupuncture alone in our meta-analysis. Because of study bias and methodological limitations, this conclusion is uncertain and the clinical appli- cation of acupuncture combined with vitamin B12 requires further exploration.

A LIMITED ORDER CAPACITY STOCHASTIC INVENTORY MODEL WITH A FIXED COST FOR ORDER: THE DISCOUNTED CASE

This paper considers a single-item, periodic-review inventory model with linear ordercosts, a convex function representing expected one-period costs, nonegative i.i.d. demandsand a fixed cost for order. Stockouts are backordered. All data are stationary Both finiteand infinite horizon problems are treated.

Tax and Fee Burden of Rural Households and Economic Growth in China

This paper is based on the fixed follow-up observation data of the countryside in Shanxi and Zhejiang provinces of china. It gives positive analysis of the tax and fee burden of rural households in these two provinces as weU as the tendency of its development since the mid-1980s. It is found from the analysis that the model of tax and fee burden is completely different between these two provinces and each model brings quite different effects. In the Shanxi burden model focusing on the collection of fees, farmers pay less taxes and fees, but they have to pay more compared with their income, thus resulting in a lack of the stamina for rural household economy even causing the economy to be thrown into a state of stagnancy. In the Zhejiang burden model focusing on tax, farmers pay more tax, but its percentage is lower compared with their income, with the result that the rural household economy has a strong stamina for growth. With the coming system of ＂transforming fees into taxes＂ to be trial-implemented in the rural areas, the pilot experience in Anhui Province is truly important, but comparatively speaking, the practice in Zhejiang is of more immediate significance.

Empirical Analysis of the Impact of Urbanization Development on Food Production

In order to clarify the impact of urbanization development on food production,based on panel data from 31 provinces(municipalities,autonomous regions)in China from 2005 to 2015,using a fixed effect model,the paper found that the urbanization rate has a negative impact on per capita food production,and finally made the related policy recommendations.The above research is of significance for promoting the development of urbanization and ensuring food security.

An Empirical Study on the Effectiveness of Technology Market Promoting Technological Innovation Capability—Based on panel data in the Yangtze River Delta

Based on panel data such as 2009-2018 R&D expenditures,full-time equivalent of R&D personnel,Number of valid invention patents,and technology market turnover in China's Shanghai,Jiangsu,Zhejiang,and Anhui provinces(cities),using Griliches-Jaffe knowledge to produce Function,construct Time fixed effects model,conduct empirical research on the main factors affecting the technological innovation capability of the Yangtze River Delta,focusing on the relationship between the technological market and technological innovation capability.The results show that human capital and R&D expenditures have a significant and positive impact on the technological innovation capacity of the Yangtze River Delta.Although the technology market has a positive effect on the scientific and technological innovation capacity of the Yangtze River Delta,the effect is not significant.Propose countermeasures and suggestions to strengthen the influence of the technology market on technological innovation.

The Impact of Global Value Chain Embedment on Energy Conservation and Emissions Reduction:Theory and Empirical Evidence

An in-depth investigation into the effect of embedment in global value chain(GVC)on energy conservation and emissions reduction is of great significance for scientifically assessing the environmental impact of GVC participation,and promoting high-quality development in China.This paper incorporates GVC embedment,energy consumption and carbon emissions into the same analysis framework for the first time.Based on the WIOD database,this paper theoretically and empirically examines the impact and mechanism of global value chain embeddedness on carbon emission reduction from two dimensions:energy consumption intensity and energy consumption structure.The study found that GVC embedment significantly reduced the industry’s carbon emission intensity;developing economies’embedment in GVC helped reduce their carbon emission intensity,while the effect was not obvious in developed economies.GVC embedment had a significant inhibitory effect on the carbon emissions in both upstream and downstream industries,but not conducive to carbon reduction of lowtech manufacturing.The mechanism test shows that the GVC embedment not only exhibits the dual effects of energy conservation and emissions reduction,but also has a significant impact on carbon emissions by reducing the energy consumption intensity and improving the energy consumption structure.

Efficient Estimation and Variable Selection in Dynamic Panel Data Partially Linear Varying Coefficient Models with Incidental Parameter

This paper is concerned with the statistical inference of partially linear varying coefficient dynamic panel data model with incidental parameter, including efficient estimation of the parametric and nonparametric components and consistent determination of the lagged order. For the parametric component, we propose an efficient semiparametric generalized method-of-moments（GMM） estimator and establish its asymptotic normality. For the nonparametric component, B-spline series approximation is employed to estimate the unknown coefficient functions, which are shown to achieve the optimal nonparametric convergence rate. A consistent estimator of the variance of error component is also constructed. In addition, by using the smooth-threshold GMM estimating equations, we propose a variable selection method to identify the significant order of lagged terms automatically and remove the irrelevant regressors by setting their coefficient to zeros. As a result, it can consistently determine the true lagged order and specify the significant exogenous variables. Further studies show that the resulting estimator has the same asymptotic properties as if the true lagged order and significant regressors were known prior, i.e., achieving the oracle property. Numerical experiments are conducted to evaluate the finite sample performance of our procedures. An example of application is also illustrated.

Mass transfer mechanisms in fixed-bed adsorption of erythromycin

The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined.The equilibrium data in a batch system was well described by a Langmuir isotherm.The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity,ionic strength and pH.A mathematical model was used to simulate the mass transfer mechanism,taking film mass transfer,pore diffusion and axial dispersion into account.The model predictions were consistent with the experi-mental data and were consequently used to determine the mass transfer coefficients.

Maximal Moment Inequality for Partial Sums of Strong Mixing Sequences and Application

Some maximal moment inequalities for partial sums of the strong mixing random variable sequence are established. These inequalities use moment sums as up-boundary and improve the corre- sponding ones obtained by Shao （1996）. To show the application of the inequalities, we apply them to discuss the asymptotic normality of the weight function estimate for the fixed design regression model.

Can Increasing Teachers’Teaching Autonomy Help Improve Instructional Quality?-Based on the Results of TALIS 2018

Teaching autonomy is an important power of teachers as professionals and also a key factor affecting instructional quality.Based on the relevant data of the Teaching and Learning International Survey(TALIS)2018,this study analyzes teachers’teaching autonomy and its effect on instructional quality.It finds that,firstly,as compared to those in the countries of the Organization for Economic Co-operation and Development(OECD),teachers in Shanghai,China,have greater teaching autonomy,but there is still room for improvement in this regard.They have sufficient autonomy in determining the instructional content and disciplining students,but not in assessing students’learning.Secondly,increasing the teaching autonomy in Shanghai can significantly improve instructional quality.Increasing their autonomy in assessing students’learning has the greatest effect on improving instructional quality,while increasing the autonomy in choosing teaching methods has the least effect,which is culturally different from the situation in OECD countries.Thirdly,the influence of teaching autonomy on instructional quality is positively moderated by teaching efficacy,which means that teachers need to have the“ability”in addition to the“autonomy.”Based on this,suggestions are also made.

Neighborhood impacts on household participation in payments for ecosystem services programs in a Chinese nature reserve:A methodological exploration

Payments for Ecosystem Services(PES)programs have been implemented in both developing and developed countries to conserve ecosystems and the vital services they provide.These programs also often seek to maintain or improve the economic wellbeing of the populations living in the corresponding(usually rural)areas.Previous studies suggest that PES policy design,presence or absence of concurrent PES programs,and a variety of socioeconomic and demographic factors can influence decisions of households to participate or not in the PES program.However,neighborhood impacts on household participation in PES have rarely been addressed.This study explores potential neighborhood effects on villagers'enrollment in the Grain-to-Green Program(GTGP),one of the largest PES programs in the world,using data from China's Fanjingshan National Nature Reserve.We utilize a fixed effects logistic regression model in combination with the eigenvector spatial filtering(ESF)method to explore whether neighborhood size affects household enrollment in GTGP.By comparing the results with and without ESF,we find that the ESF method can help account for spatial autocorrelation properly and reveal neighborhood impacts that are otherwise hidden,including the effects of area of forest enrolled in a concurrent PES program,gender and household size.The method can thus uncover mechanisms previously undetected due to not taking into account neighborhood impacts and thus provides an additional way to account for neighborhood impacts in PES programs and other studies.