Simulating Solute Transport in Porous Media Using Model Reduction Techniques

In this study, we introduce a numerical method to reduce the solute transport equation into a reduced form that can replicate the behavior of the model described by the original equation. The basic idea is to collect an ensemble of data of state variables (say, solute concentration), called snapshots, by running the original model, and then use the proper orthogonal decomposition (POD) techniques (or the Karhunen-Loeve decomposition) to create a set of basis functions that span the snapshot collection. The snapshots can be reconstructed using these basis functions. The solute concentration at any time and location in the domain is expressed as a linear combination of these basis functions, and a Galerkin procedure is applied to the original model to obtain a set of ordinary differential equations for the coefficients in the linear representation. The accuracy and computational efficiency of the reduced model have been demonstrated using several one-dimensional and two-dimensional

Effects of Different Fertilization Treatments on Soil, Leaf Nutrient and Fruit Quality of Citrus grandis var. longanyou

The five-year-old “Longanyou” trees were used as the experimental material to study the effects of different fertilization treatments. The nutrient contents in soil and leaves, fruit yield and quality were determined, and then the correlations were analyzed. The results showed that: 1) The soil nutrient contents of 0 - 20 cm depth were more than the 20 - 40 cm, and the trends of nutrient contents of the 0 - 20 cm soil layers were as follows: treatment 2 (T2) > treatment 3 (T3) > treatment 4 (T4) > treatment 1(T1) > control (CK). However, the 20 - 40 cm depth had not significant difference between different treatments, but T2, T4 and T3 were higher than T1 and CK. It indicated that the soil effective nutrient content increased in T2 and T3. 2) Compared with the control, the content of K and B elements was improved obviously in leaves with the increase of organic manure application. The contents of P (1.60 g·kg-1), B (26.00 mg·kg-1) and Mg (1.18 g·kg-1) were the highest, and other nutrients contents were also higher, indicating that T2 could effectively improve the leaves’ nutrient contents. 3) The fruit yield per plant was the highest in T2 (95.40 kg plant-1), and the single fruit weight, total sugar, sugar and acid ratio, vitamin C were also the highest, but titratable acid was lower. It indicated that T2 effectively improved fruit yield and quality. 4) There were positive correlations between multiple factors of soil nutrients and the quality index, such as fruit peel thickness, total sugar, solid acid ratio, sugar and acid ratio, Vc content and single yield etc. There was significant correlation between K, B, Zn, Fe contents and fruit yield and quality index, and the contents of B, Zn and Fe in leaves were significantly correlated with soil nutrient, indicating that the contents of K, B, Zn, Fe in soil and leaf were closely related to fruit yield and quality. In sum, the T2 was the best fertilization scheme for orchard management practice of “Longanyou”.

Horizontal convection in a rectangular enclosure driven by a linear temperature profile

The horizontal convection in a square enclosure driven by a linear temperature profile along the bottom boundary is investigated numerically by using a finite difference method.The Prandtl number is fixed at 4.38,and the Rayleigh number Ra ranges from107 to 1011.The convective flow is steady at a relatively low Rayleigh number,and no thermal plume is observed,whereas it transits to be unsteady when the Rayleigh number increases beyond the critical value.The scaling law for the Nusselt number Nu changes from Rossby’s scaling Nu~Ra^(1/5)in a steady regime to Nu~Ra^(1/4)in an unsteady regime,which agrees well with the theoretically predicted results.Accordingly,the Reynolds number Re scaling varies from Re~Ra^(3/11)to Re~Ra^(2/5).The investigation on the mean flows shows that the thermal and kinetic boundary layer thickness and the mean temperature in the bulk zone decrease with the increasing Ra.The intensity of fluctuating velocity increases with the increasing Ra.

Effectiveness of Group-Based Interventions for Fall Prevention Among Community-Dwelling Older Adults—7 Regions,6 PLADs,China,2019–2020

Summary What is already known about this topic?Many of the current studies focusing on fall prevention interventions have been conducted in hospital settings within a select few urban areas in China,thus yielding limited evidence on the effectiveness of large-scale,multicenter,community-based interventions.

Association of KIR Genotypes and Haplotypes with Susceptibility to Chronic Hepatitis B Virus Infection in Chinese Han Population

Killer immunoglobulin-like receptor （KIR） genes can regulate the activation of NK and T cells upon interaction with HLA class I molecules. Hepatitis B virus （HBV） infection has been regarded as a multi-factorial disorder disease. Previous studies revealed that KIRs were involved in HCV and HIV infection or clearance. The aim of this study was to explore the possibility of the inheritance of KIR genotypes and haplotypes as a candidate for susceptibility to persistent HBV infection or HBV clearance. The sequence specific primer polymerase chain reaction （SSP-PCR） was employed to identify the KIR genes and pseudogenes in 150 chronic hepatitis B （CHB） patients, 251 spontaneously recovered （SR） controls, and 412 healthy controls. The frequencies of genotype G7 M, FZ1 increased in CHB patients compared with healthy control subjects. The frequency of genotype AH was higher in SR controls than that in both CHB patients and healthy controls. The carriage frequencies of genotype G and AH were higher; while, the frequencies of AF and AJ were lower in SR controls than those in healthy control subjects. The frequency of A haplotype was lower, whereas, the frequency of B haplotype was higher in CHB patients and SR controls than those in healthy controls. In healthy controls, haplotype 4 was found lower compared with that in CHB patients and SR controls and the frequency of haplotype 5 was higher in SR controls than that in other two groups. Based on these findings, it seems that the genotypes M and FZ1 are HBV susceptive genotypes; AH, on the other hand, may be protective genotypes that facilitate the clearance of HBV. It appears that the haplotype 4 is HBV susceptive haplotype, whereas, haplotype 5 may be the protective haplotype that facilitates the clearance of HBV. Cellular ＆ Molecular Immunology. 2008;5（6）：457-463.

Characteristics of Falls Among Older People-China,2018

What is already known about this topic?The incidence of falls among older people is 20.7%in China.Falls are the top cause for death from injuries in people aged 65 years and above,and mortality rates increase with age in China.There are few reports on the epidemiological characteristics of falls in older people nationwide in recent years.What is added by this report?This study found that among older people with falls reported in the National Injury Surveillance System(NISS)in 2018,there were more females than males.The peak time for falls was in the morning.Home was the most common site where falls occurred,and leisure activities and housework were the main activities when falls occurred.After falling,the lower limbs and head were most often injured with bruises and fractures.The degree of injury was mainly mild and moderate.What are the implications for public health practice?Data based on the NISS can be used as an additional data source for research on falls in China.This study identified priorities for the control and prevention of falls.