Influence evaluation of producer services agglomeration on economic resilience: Evidence from China’s cities

As a new engine of economic development after urbanization’s structural deceleration stage in China, producer services agglomeration on urban economic resilience (ER) requires analysis. Using data from 264 prefecture-level cities and above in China after the global financial crisis, we examine producer services’ impact in terms of diversification (PSD) and specialization (PSS) on urban ER, and also the mediating effect of industrial structure upgrading (ISU). The results show that Cities with more diversified producer services are more resilient to crises, while the effect direction of PSS is the opposite. ISU is partly how PSD and PSS affect ER. Finally, producer services agglomeration’s impact on ER has significant regional heterogeneity. PSD is very conducive to urban ER in the economically developed eastern region and the less developed western region. The more specialized the development of producer services in eastern and north-eastern regions, the less conducive it is to enhancing ER. Our findings can help stabilize China’s economy and achieve high-quality economic development

Integrating compressed CO2 energy storage in an oxy-coal combustion power plant with CO2 capture

To compensate for the high cost of CO2 capture, this study proposes a novel solution that integrates a compressed CO2 energy storage (CCES) system into an oxy-coal combustion power plant with CO2 capture (Oxy_CCES). The integration of energy storage has the potential to create arbitrage from variations in electricity prices. The proposed Oxy_CCES system can achieve a higher net efficiency of 34.1%, and a higher exergy efficiency of 57.5%, than that of a liquified oxygen storage-integrated oxy-coal combustion power plant (Oxy_O2). Two scenarios, i.e., retrofitting an existing oxy-coal combustion power plant (S–I) and building a new plant (S-II), were established to compare the Oxy_CCES and Oxy_O2. In S–I, the payback time of the Oxy_CCES is one year and in the S-II the levelized cost of electricity (LCOE) of the Oxy_CCES increases by 1.8%, which is lower than that of the Oxy_O2. The sensitivity analysis shows that, when the difference between the peak and the valley electricity prices and the capacities of the energy storage systems increase by 50%, the net present value (NPV) and LCOE of the Oxy_CCES system increase by 113.4% and 1.7% respectively, which are lower than the NPV and LCOE increase of the Oxy_O2

Research and Implementation of Integrated Methods of Unsupported Printing and Five-Axis CNC Machining Technology

In traditional 3D printing, the best method for creating overhanging structures is to add supporting materials; however, this often leads to an increase in costs and a decrease in printing efficiency. Therefore, a five-axis CNC machining technology is introduced in this paper, proposing an unsupported 3D printing method. Models requiring support structures were supported by an existing supporting surface by adding two degrees of freedom (rotation and swinging). Moreover, effectiveness of the proposed method was verified by experiment

Coordinated Control of a Wind-Methanol-Fuel Cell System with Hydrogen Storage

This paper presents a wind-methanol-fuel cell system with hydrogen storage. It can manage various energy flow to provide stable wind power supply, produce constant methanol, and reduce CO2 emissions. Firstly, this study establishes the theoretical basis and formulation algorithms. And then, computational experiments are developed with MATLAB/Simulink (R2016a, MathWorks, Natick, MA, USA). Real data are used to fit the developed models in the study. From the test results, the developed system can generate maximum electricity whilst maintaining a stable production of methanol with the aid of a hybrid energy storage system (HESS). A sophisticated control scheme is also developed to coordinate these actions to achieve satisfactory system performance

The Controllable PVA-Chitosan Fiber Prepared by the Near-field Electro Spinning for Tissue Engineering

Abstract: The cells in natural tissues and organs have diverse shapes and arrangements in structure. The tissue engineering scaffolds which have a specific extracellular matrix structure can be prepared by electro spun fibers having a diverse arrangement in structure and thus guide adherent cells grow, proliferate and divide into the regenerative tissue or organs which have specific cell morphology and orientation structure. This study is based on a Near-Field Electros Pinning (NFES) process and uses Polyvinyl Alcohol (PVA) mixed chitosan, a non-toxic, good hydrophobic and biocompatible mixed materials, to prepare a micro/nano-fiber with controllable arrangement used in tissue engineering. The purpose of this research is the realization of getting the fiber with controllable arrangement. In this study, laboratory equipment will be built which integrates a feeding system, a high voltage electric field control system, a on-line image acquisition system and a motion control system of the collection platform. It focuses on the process parameters of the micro/nano direct writing of this material. Meanwhile, verifying the controllability of the implementation of the near-field electrospinning process for preparing composite fiber using this experiment platform

臼歯陶材焼付鋳造冠におけるメタルフレーム形態の力学的検討(英文)

Objectives: The purpose of this study was to find an ideal shape of the metal frame (coping) in the porcelain fused to metal (PFM) crown. The stress distribution was assessed by the load-to-fracture values and a three-dimensional finite element analysis. Methods: Three kinds of coping designs were tested; Design I: Conventional type as control (traditional frame). Design II: 1.0 mm lower than occlusal surface of coping (butterfly frame). Design III: Straight type (flat frame). The load-to-fracture value consisted of three groups (Design I, II and III) of five samples each. The loading location is selected at the area where mesial and distal of the metal frame will coincide with the projection of the occlussal surface. All samples were loaded to fracture at the rate of 0.1 mm/min using a universal-testing machine. The stress distribution was assessed in a three-dimensional finite element model, which consisted of the abutment tooth, cement, metal coping and porcelain. The loading position is the projection point ofbuccal-lingual transitional part of the frame mesial and distal proximal surface on the occlusal surface towards the median, in which the load is in constant value. Loading direction is vertically downward along tooth axis with a load of 2000 N. Results: The mean load-to-fracture value for each group is as follows: Group A (Design I)=1823.0 N±132.7 (S.D.), Group B (Design II)=1940.4 N±147.4 (S.D.), Group C (Design III)=2333.9 N±180.9 (S.D.). The results of the three-dimensional finite element analysis showed that the maximum tensile stress of 84.5 MPa occurred in Design I. The maximum tensile stress in design II and III were 53.8 MPa and 53.3 MPa, respectively, which were the lower than Design I. Conclusions: The results indicated that the butterfly and flat frame designs will increase metal support on proximal porcelain, thus effectively change the stress distribution within the coping and porcelain, optimizing stress distribution in PFM crown under perpendicular load, and enhance structural strength of porcelain of PFM crown

3D Bioprinting tissue analogs: Current development and translational implications

Three-dimensional (3D) bioprinting is a promising and rapidly evolving technology in the field of additive manufacturing. It enables the fabrication of living cellular constructs with complex architectures that are suitable for various biomedical applications, such as tissue engineering, disease modeling, drug screening, and precision regenerative medicine. The ultimate goal of bioprinting is to produce stable, anatomically-shaped, human-scale functional organs or tissue substitutes that can be implanted. Although various bioprinting techniques have emerged to develop customized tissue-engineering substitutes over the past decade, several challenges remain in fabricating volumetric tissue constructs with complex shapes and sizes and translating the printed products into clinical practice. Thus, it is crucial to develop a successful strategy for translating research outputs into clinical practice to address the current organ and tissue crises and improve patients' quality of life. This review article discusses the challenges of the existing bioprinting processes in preparing clinically relevant tissue substitutes. It further reviews various strategies and technical feasibility to overcome the challenges that limit the fabrication of volumetric biological constructs and their translational implications. Additionally, the article highlights exciting technological advances in the 3D bioprinting of anatomically shaped tissue substitutes and suggests future research and development directions. This review aims to provide readers with insight into the state-of-the-art 3D bioprinting techniques as powerful tools in engineering functional tissues and organs

Preparation and Characterization of Nano-Silver-Loaded Antibacterial Membrane via Coaxial Electrospinning

The coaxial electrospinning process has been widely used in the biomedical field, and its process parameters affect product quality seriously. In this paper, the influence of key process parameters of coaxial electrostatic spinning (solution concentration, electrospinning voltage, acceptance distance and liquid supply velocity) on the preparation of a membrane with Chitosan, Polyethylene oxide and nano-silver as the core layer and Polycaprolactone as the shell layer was studied. The optimal combination of key process parameters was obtained by using an orthogonal test, scanning electron microscope, transmission electron microscope and macro-characterization diagram. The results showed that the coaxial electrospun membrane had good mechanical properties (tensile strength is about 2.945 Mpa), hydrophilicity (the water contact angle is about 72.28°) and non-cytotoxicity, which was conducive to cell adhesion and proliferation. The coaxial electrospun membrane with nano-silver has an obvious inhibitory effect on Escherichia coli and Staphylococcus aureus. In summary, the coaxial electrospun membrane that we produced is expected to be used in clinical medicine, such as vascular stent membranes and bionic blood vessels

Influence evaluation of producer services agglomeration on economic resilience: Evidence from China’s cities

AbstractAs a new engine of economic development after urbanization’s structural deceleration stage in China, producer services agglomeration on urban economic resilience (ER) requires analysis. Using data from 264 prefecture-level cities and above in China after the global financial crisis, we examine producer services’ impact in terms of diversification (PSD) and specialization (PSS) on urban ER, and also the mediating effect of industrial structure upgrading (ISU). The results show that Cities with more diversified producer services are more resilient to crises, while the effect direction of PSS is the opposite. ISU is partly how PSD and PSS affect ER. Finally, producer services agglomeration’s impact on ER has significant regional heterogeneity. PSD is very conducive to urban ER in the economically developed eastern region and the less developed western region. The more specialized the development of producer services in eastern and north-eastern regions, the less conducive it is to enhancing ER. Our findings can help stabilize China’s economy and achieve high-quality economic development

LiDAR Positioning Algorithm Based on ICP and Artificial Landmarks Assistance

As one of the automated guided vehicle (AGV) positioning methods, the LiDAR positioning method, based on artificial landmarks, has been widely used in warehousing logistics industries in recent years. However, the traditional LiDAR positioning method based on artificial landmarks mainly depends on the three-point positioning method, the performance of which is limited due to landmarks’ layout and detection requirements. This paper proposes a LiDAR positioning algorithm based on iterative closest point (ICP) and artificial landmarks assistance. It provides improvements based on the traditional ICP algorithm. The result of positioning provided by the landmarks is used as the initial iteration ICP value. The combination of the ICP algorithm and landmarks enables the positioning algorithm to maintain a certain positioning precision when landmark detection is disturbed. By comparing the proposed algorithm with the positioning scheme developed by SICK in Germany, we prove that the combination of the ICP algorithm and landmarks can effectively improve the robustness under the premise of ensuring precision