Spatial Heterogeneity of Soil Mite Community and its Spatial Relationship with Environmental Factors in Maoer Mountains

Limei Zhang,Lingjun Meng,Chuanwei Guo,Meixiang Gao,Dong Liu,Xueping Zhang 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.12

Maoer Mountain National Forest Ecological Station is located in Heilongjiang Province. By using the statistical spatial analysis method, which showed that the soil mites community and species richness of mites spatial heterogeneity. Also, which is illustrated that the spatial effect relationship with the environmental factors. The results of crossvariogram and simple Mantel test showed that positive relationships between soil mite communities, specific mite species and environmental factors were detected. Among the environmental factors, soil pH showed significant affects on spatial heterogeneity of soil mite species in both years. When considering the relationships between soil mite species, positive correlations and specific mite species were also observed. Spatial heterogeneities of soil mite communities and most of the soil mite species were regulated by structured factors, in which environmental variables might be important drivers. Thus, it is implied that abundances of soil mite community and most of the soil mite species showed aggregated spatially heterogeneity, and significant relationship between such heterogeneity and environmental factors were detected.

Optimal Operation Schedule Strategy of High-power Pulsed Loads in Shipboard Power System

Zhang Yan,Ji Feng,Gao Xueping,Ma Fan,Hu Qi 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

With the vigorous development of the scientifi c and technological revolution, new military and engineering loads with high power and pulse characteristics are becoming reality for the shipboard power system (SPS) application. These loads are usually called high-power pulsed loads (HPPLs) because of their high peak power, low average power and short cycle time. The HPPLs can cause voltage drop and even system instability to the SPS, thus bringing severe challenges to their power supplying system. To address these issues, an optimal operation schedule of HPPLs in SPS is studied in this paper. Firstly, the models of HPPLs for SPS power optimization are proposed based on the real back-end load connection way of them. Then the mixed integer programming problem aiming at maximizing the operation effi ciency of the HPPLs within the SPS support capability is constructed. Finally, some typical cases are studied to verify the fl exibility and eff ectiveness of the proposed strategy. The results indicate that the proposed strategy can eff ectively maximize the operational effi ciency of HPPLs in the SPS, and the superiority becomes more obvious as the number of HPPLs increases.

SOC balance‑based decentralized control strategy for hybrid energy storage in integrated power systems

Xueping Gao,Lijun Fu,Yan Zhang,Feng Ji 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

The hybrid energy storage systems (HESSs) in vessel integrated power systems can support pulse load and improve system stability. However, the unbalanced SOC of different energy storage devices can cause over-charge and over-discharge which damages the energy storage devices and affects the stable operation of the entire system, especially when there are multiple groups of HESSs. Therefore, a decentralized control strategy for the HESSs in integrated power systems (IPSs) based on extended droop control combined with SOC balance control is proposed in this paper. In the proposed strategy, SOC recovery control is introduced to the virtual capacitance droop coefficient of the supercapacitor, and SOC equalization control is introduced to the virtual resistance droop coefficient of the lithium battery to adjust the output characteristics of the HESS according to the SOC. Then the frequency response characteristics are analyzed and the stability of the system is calculated. Finally, the hardware in loop simulation is conducted to verify the effectiveness of the proposed strategy. Comparisons show that the proposed strategy can compensate for the pulse load according to the responding characteristics of the HESS and achieve SOC balance between different energy storage devices under various working conditions.

A Demand Side Management Strategy to Reduce the Impact of High Power Pulse Load Integration

Gao Xueping,Zhang Yan,Ji Feng,Fu Lijun 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

High pulsed power loads (HPPLs) are highly non-linear and can cause signifi cant stability and power quality issues in a microgrid. Developing alternative methods for controlling and analyzing the microgrid with multiple HPPLs will provide insight into tradeoff s that can be made during the design phase. In this paper, a demand side management strategy of HPPLs in a microgrid is formulated. Firstly, the HPPLs are divided into energy storage connected high power pulse loads (EHPPLs) and direct connected high power pulse loads (DHPPLs) according to the power use of the back-end loads, and the energy management models of both the EHPPLs and the DHPPLs are built. Then the demand side management strategy to minimize the impacts of running HPPLs is proposed. Finally, three typical cases are studied to verify the fl exibility and eff ectiveness of the proposed method. The simulation and experiment results indicate that the proposed strategy can eff ectively reduce the peak power demand of the HPPLs, thus reducing the impact on the microgrid

Rheological and Thermal Properties of Acrylonitrile-Acrylamide Copolymers: Influence of Polymerization Temperature

Wu Xueping,Lu Chunxiang,Wu Gangping,Zhang Rui,Ling Licheng The Korean Fiber Society 2005 Fibers and polymers Vol.6 No.2

An attempt was made to correlate the polymerization temperature and rheological and thermal properties of acrylonitrile (AN)-acrylamide (AM) copolymers. The copolymers were synthesized at different polymerization temperature. The copolymer structure was characterized by gel permeation chromatography (GPC) and Infrared spectrum (IR). The rheological and thermal properties were investigated by a viscometer and differential scanning calorimeter-thermogrametric (DSC-TG) analysis, respectively. When the polymerization temperature increased from $41^{\circ}C\;to\;65^{\circ}C$, the molecular weight $(\bar{M}_w)$ of copolymers decreased from 1,090,000 to 250,000, while its conversion increased from $18\%\;to\;63\%$, and the polymer composition changed slightly. To meet the requirements of carbon fibers, the rheological and thermal properties of products were also investigated. It was found that the relationship between viscosity and $\bar{M}_w$ was nonlinear and the viscosity index (n) decreased from 3.13 to 2.69, when the solution temperature increased from $30^{\circ}C\;to\;65^{\circ}C$. This suggests the dependence of viscosity upon $\bar{M}_w$ is higher at lower solution temperature. According to the result of activation energy, the sensivity of viscosity to solution temperature is higher for AN-AM copolymers synthesized at higher polymerization temperature. The result of thermal analysis shows that the copolymers obtained at higher polymerization temperature are easier to cyclization evidenced from lower initiation temperature. The weight loss behavior changed irregularly with polymerization temperature due to irregular change of liberation heat.

Transcriptome analysis reveals synergistic modulation of E-cadherin/N-cadherin in hMSC aggregates chondrogenesis

Wang Xueping,Zhang Yan,Yang Jun 한국유전학회 2023 Genes & Genomics Vol.45 No.5

Background N-cadherin-mediated cell adhesion is a vital inductor for mesenchymal condensation in chondrogenesis. Recent studies have revealed the involvement of E-cadherin in enhancing the multipotency of mesenchymal stem cells (MSCs) and limb development; however, the signaling crosstalk of E/N-cadherin remains unclear. Objective This study aimed to explore the synergistic modulation of E/N-cadherin in the chondrogenic differentiation of MSC aggregates. Methods Human E/N-cadherin-functionalized (hE/N-cad-Fc) poly (lactic-co-glycolic acid) (PLGA) microparticles (hE/N-cad-PLGA) were incorporated into the human MSC (hMSC) aggregates to upregulate the expression of the corresponding endogenous cadherin. The chondrogenic differentiation of the hMSC aggregates was initiated by hE/N-cad-PLGA, controlling the release of transforming growth factor-β (TGF-β). A transcriptome analysis was used to assess differentially expressed genes (DEGs) modulated by hE/N-cad-Fc in hMSC aggregate chondrogenesis. Gene functions and signaling pathways were assessed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The associated biological pathways were assessed by a protein–protein interaction (PPI) network analysis, and the results were further confirmed by real-time quantitative PCR (qPCR) and western blotting. Results A total of 1083 DEGs, comprising 111 upregulated and 972 downregulated genes, were discovered to be related to the enhanced chondrogenic differentiation modulated by hE/N-cad-Fc. The GO and KEGG functional enrichment analyses revealed that hE/N-cad-Fc synergistically regulated the p53-related survival signaling pathway. PPI analysis revealed that mitogen-activated protein kinases (MAPK) caspase regulation is a core aspect of the chondrogenic differentiation process, confirmed by western blotting. Conclusion To the best of our knowledge, our study is the first to reveal that the synergistic modulation of E/N-cadherin enhances the chondrogenic differentiation of hMSCs via the ERK1/2-p53 signaling axis.

Removal of aqueous vanadium(V) by green synthesized iron nanoparticles supported on corn straw biochar

Kun Rong,Xueping Li,Qian Yang,Ruimin Li,Zaiwang Zhang,Meiling Zou,Huanqiang Zheng,Juanjuan Liu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Iron nanoparticles supported on corn straw biochar (PE-FeNPs@BC) were used to remove V(V). This materialwas prepared by using Yali pear peel extract-supported iron nanoparticles (PE-FeNPs) as the functionalbody and corn straw biochar (BC) as the support. The synthesis conditions such as Fe/C massratio and synthesis temperature were optimized. The material was characterized by SEM-EDS, FTIR,XRD, and XPS. The results showed that particle agglomeration was reduced, and the dispersion wasimproved after PE-FeNPs were supported on BC. The removal effect was better in the pH range of 2–6,and the removal efficiency was the highest at pH 3.7. At 25 ℃ and pH 3.7, the maximum adsorptioncapacity qm of V(V) was 362.7 mg/g, and 95.1 % of 90 mg/L V(V) was removed. The coexisting NaCl orNaNO3 had a weaker effect on the removal of V(V). The adsorption reactions followed the pseudosecond-order model and Langmuir model, and chemical adsorption was the dominant process. The mainreaction mechanism of PE-FeNPs@BC with V(V) was as follows: adsorbed V5+ was reduced to V4+ by Fe0and Fe2+ and then removed by co-precipitation in the forms of xFe2O3yV2O5zH2O and VO2H2O. Thisstudy promotes the reuse of waste pear peel and can provide an environmentally friendly method forremoving V(V) pollution.

Partially A-optimal blocked multi-factor designs

Xiaodi Wang,Xueping Chen,Yingshan Zhang 한국통계학회 2018 Journal of the Korean Statistical Society Vol.47 No.1

In this paper, we propose a partially A-optimal criterion for block designs where multiple factors are arranged. The number of levels of each factor is assumed to be arbitrary and unequal block sizes are allowed. A sufficient condition is derived for a design to be partially A-optimal among all feasible designs. Then the properties of the selected design and its relation with orthogonal arrays are studied. Methods of constructing designs satisfying the sufficient condition are also given.

The Effects of Minimum Quantity Lubrication (MQL) on Machining Force, Temperature, and Residual Stress

Xia Jinan,Beizhi Li,Xueping Zhang,Steven Y. Liang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

Minimum quantity lubrication (MQL) machining has achieved noticeable attention in both academic and industry research areas dueto its minimum costs and maximum environmental protection. This paper focuses on the analysis of the effects of MQL parameterssuch as the flow rate of lubricant and the air-oil mixture ratio on cutting performances in terms of cutting force, cutting temperature,and residual stress. Additionally, the cutting performances in MQL machining are also compared with the dry and flood coolingmachining. The results show that the cutting fluid can considerably reduce the cutting force and cutting temperature in machining. For MQL machining, there is a maximum effective flow rate of lubricant and it is influenced by the cutting speed. When the flow rateof lubricant is beyond the maximum effective value, the air-oil mixture ratio will no longer affect the cutting performances inmachining. This research can support the process planning in achieving the desired residual stress profile by strategically adjustingthe MQL parameters.

Structure evolution in carbon molecular sieve membranes derived from binaphthol-6FDA polyimide and their gas separation performance

Guoxiong Deng,Yilei Wang,Xueping Zong,Jiangzhou Luo,Xuezhen Wang,Chunxue Zhang,Song Xue 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.94 No.-

Here we reported a causal relationship between the molecular structure of binaphthol-based polyimideprecursor and the pore-size distribution of the derived carbon membrane. The binaphthol-basedpolyamide acid is synthesized from 2,20-diol-1,10-binaphthyl-6,60-diamine and 4,40-(hexafluoroisopro-pylidene)diphthalic anhydride (6FDA). Then, an azeotropic imidiaztion method was used to synthesizethe polyimide with naphthol groups (XS1). When the imidization is carried out by using acetic anhydride,the polyimide with acetyl groups (XS4) is achieved. The CMS membranes prepared by pyrolyzing XS1 andXS4 at 500, 550, and 600 ℃ are named using the temperature as the suffix, such as XS1-500. Their poreevolution has been investigated using TGA, FTIR, XRD, and Raman measurements. The trimodal pore-sizedistribution is in the carbon molecular sieve (CMS) membranes derived from XS4 and the CMS onesderived from XS1 exhibit a bimodal pore structure. Among them, XS4-500 exhibits the highest gaspermeabilities of 3332 barrer for CO2, 773 barrer for O2, and 119 barrer for N2. XS1-500 only affords theCO2, O2, and N2 permeabilities of 1086, 230, and 30.2 barrer. The esterification of naphthol not justdisturbs the hydrogen bonds between polyimide chains but also affects the pore generation of thederived CMS membranes. Our work provides an effective way to enhance the gas permeability of a CMSmembrane derived from the binaphthol-based polyimide.