Analysis on Development of Farmer Tourism Market in China

With the rapid increase of farmers’ income and the rapid development of tourism, the tourism demand of farmers is increasingly growing, but the development of tourism market for farmers has not been given much attention. This paper summarized the overall situation of development of the farmer tourism, analyzed the consumption characteristics and supply characteristics of the farmer tourism in depth, and discussed the development potential of the farmer tourism. On the basis of discussion and analysis, it came up with recommendations including attaching greater importance to the farmer tourism market, developing marketable products, changing the traditional concept of consumption and enhancing tourism promotion activities, in the hope that both the government and enterprises pay more attention to the farmer tourism market

Study on the Development of Rural Tourism in Liaoning Province

As an important old industrial base in Northeast China, Liaoning Province is facing good opportunities for development in the context of rural tourism booming. This paper summarizes the concept and function of rural tourism, analyzes the present situation and characteristics of rural tourism development in Liaoning Province, and points out the main problems. Finally, to make Liaoning's rural tourism develop better and faster and provide a reference for other regions, the following recommendations are made: focusing on the development of experience-based rural tourism products; improving the level of rural tourism service and reception; strengthening the construction and renovation of rural tourism infrastructure

Fluidity and Strength of Loess-Based Quick Consolidated Backfill Material with One High-Water Content

To study the flow and strength characteristics of loess-based backfill materials, orthogonal tests were used to design a cemented backfill material combining loess, high-water content materials, cement, and fly ash. By using the range, analysis of variance, and multi-variate regression analysis, influences of four key factors on the initial setting time, diffusivity, compressive strength, and shear strength of the backfill material were investigated. These four factors included the mass concentration of loess water (A), the content of high-water content materials (B), cement content (C), and content of fly ash (D). The results showed that the initial setting time, diffusivity, compressive strength, and shear strength of the backfill material were 13~33 min, 400~580 mm, 0.917–3.605 MPa, and 0.360–0.722 MPa, respectively, all distributed in wide ranges. For the initial setting time, the four factors were listed in descending order as A > D > B > C according to their influences; for diffusivity, the four factors were listed as A > B > C > D; for the compressive strength, the four factors were ranked as A > C > D > B; for the shear strength, the four factors were ranked such that A > C > D > B. With regard to the comprehensive index, the four factors were such that A > B > D > C. That is, the factors were listed in descending order as the mass concentration of loess water, cement content, the content of fly ash, and content of high-water content materials according to their significance in influencing characteristics of the loess-based backfill material. Comprehensive analysis indicated that the fluidity of the material was mainly influenced by the mass concentration of loess water, and the two were negatively correlated. The hydro-consolidation effect of materials with high-water contents accelerated material solidification. The strength of the backfill material was mainly influenced by the cement content while only slightly affected by contents of other materials. In this way, a prediction model for characteristic parameters, namely, fluidity and strength, of the loess-based backfill material under the action of various factors was established

Model Updating Method Based on Kriging Model for Structural Dynamics

Model updating in structural dynamics has attracted much attention in recent decades. And high computational cost is frequently encountered during model updating. Surrogate model has attracted considerable attention for saving computational cost in finite element model updating (FEMU). In this study, a model updating method using frequency response function (FRF) based on Kriging model is proposed. The optimal excitation point is selected by using modal participation criterion. Initial sample points are chosen via design of experiment (DOE), and Kriging model is built using the corresponding acceleration frequency response functions. Then, Kriging model is improved via new sample points using mean square error (MSE) criterion and is used to replace the finite element model to participate in optimization. Cuckoo algorithm is used to obtain the updating parameters, where the objective function with the minimum frequency response deviation is constructed. And the proposed method is applied to a plane truss model FEMU, and the results are compared with those by the second-order response surface model (RSM) and the radial basis function model (RBF). The analysis results showed that the proposed method has good accuracy and high computational efficiency; errors of updating parameters are less than 0.2%; damage identification is with high precision. After updating, the curves of real and imaginary parts of acceleration FRF are in good agreement with the real ones

Guiding sustainable urban development via a multi-level ecological framework integrating natural and social indicators

Establishing a sustainable landscape pattern to cope with worsening ecological problems is an internationally recognized practice. However, previous studies have not considered the joint supply equilibrium of ecosystem services (ESs) and coupling with social systems. In this study, we propose an ecological security pattern framework composed of multi-level ecological elements, based on ESs, human impacts, and improved connectivity. The ordered weighted averaging decision model was used to analyze the four types of ESs specified by the Millennium Ecosystem Assessment and extract core patches. Based on potential corridors extracted by the minimum cumulative resistance model, ecological corridors were further classified by improved connectivity analysis coupled with the human modification index. The approach was tested using data from Dalian, Liaoning Province, China. The results show that the most service capabilities declined to varying degrees over the past 10 years. Forests, arable land, and grasslands had relatively high levels of comprehensive ecological services. Regulating services showed a significant decline in three or more land types. The principle of landscape ecology promotes the establishment of a buffer zone. In Dalian, the areas of the ecological core patch and buffer zone were 2,167.88 and 5,377.38 km2, respectively. The three levels of potential ecological corridors totaled 1079.78 km. The ecological elements and ESs assessment results obtained using the proposed method provide spatial guidance for ecological management, thereby ensuring the sustainable development of large cities

Optimization Method Based on Hybrid Surrogate Model for Pulse-Jet Cleaning Performance of Bag Filter

The pulse-jet cleaning process is a critical part of the bag filter workflow. The dust-cleaning effect has a significant impact on the operating stability of bag filters. Aiming at the multi-parameter optimization problem involved in the pulse-jet cleaning process of bag filters, the construction method of hybrid surrogate models based on second-order polynomial response surface models (PRSMs), radial basis functions (RBFs), and Kriging sub-surrogate models is investigated. With four sub-surrogate model hybrid modes, the corresponding hybrid surrogate models, namely PR-HSM, PK-HSM, RK-HSM, and PRK-HSM, are constructed for the multi-parameter optimization involved in the pulse-jet cleaning process of bag filters, and their objective function is the average pressure on the inner side wall of the filter bag at 1 m from the bag bottom. The genetic algorithm is applied to search for the optimal parameter combination of the pulse-jet cleaning process. The results of simulation experiments and optimization calculations show that compared with the sub-surrogate model PRSM, the evaluation indices RMSE, R2, and RAAE of the hybrid surrogate model RK-HSM are 9.91%, 4.41%, and 15.60% better, respectively, which greatly enhances the reliability and practicability of the hybrid surrogate model. After using the RK-HSM, the optimized average pressure F on the inner side wall of the filter bag at 1 m from the bag bottom is −1205.1605 Pa, which is 1321.4543 Pa higher than the average pressure value under the initial parameter condition set by experience, and 58.4012 Pa to 515.2836 Pa higher than using the three sub-surrogate models, verifying its usefulness

Heparanase enhances nerve-growth-factor-induced PC12 cell neuritogenesis via the p38 MAPK pathway

Heparanase is involved in the cleavage of the HS (heparan sulfate) chain of HSPGs (HS proteoglycans) and hence participates in remodelling of the ECM (extracellularmatrix) and BM(basement membrane). In the present study we have shown that NGF (nerve growth factor) promoted nuclear enrichment of EGR1 (early growth response 1), a transcription factor for heparanase, and markedly induced heparanase expression in rat adrenal pheochromocytoma (PC12) cells. K252a, an antagonist of the NGF receptor TrkA (tyrosine kinase receptor A), decreased heparanase protein expression induced by NGF in PC12 cells. Suramin, a heparanase inhibitor, decreased heparanase in PC12 cells and blocked NGF-induced PC12 neuritogenesis. Stable overexpression of heparanase activated p38 MAPK (mitogenactivated protein kinase) by phosphorylation and enhanced the neurite outgrowth induced by NGF, whereas knock down of heparanase impaired this process. However, overexpression of latent pro-heparanase with a Y156A mutation still led to enhanced NGF-induced neurite outgrowth and increased p38 MAPK phosphorylation. Inhibition of p38 MAPK by SB203580 suppressed the promotion of NGF-induced neuritogenesis by the wild-type and mutant heparanase. The impaired differentiation by knock down of heparanase could be restored by transfection of wild-type or mutant heparanase in PC12 cells. The results of the present study suggest that heparanase, at least in the nonenzymatic form, may promote NGF-induced neuritogenesis via the p38 MAPK pathway