Publications by authors named "Zhongwu Zhang"

The combination of cold deformation and solution aging is an important technological route for the bar processing of superalloy fasteners. The microstructure evolution and mechanical properties are intimately related to the process parameters. In this study, we systematically elucidate the mechanical properties and microstructure evolution of Fe-15Cr-25Ni alloys in different treatment processes and conduct in-depth analysis of the synergistic strengthening mechanism of fine-crystal strengthening, second-phase strengthening, and work hardening on Fe-15Cr-25Ni alloys.

View Article and Find Full Text PDF

As a crucial industrial, agricultural, and energy base in China, the urban agglomerations in the Yellow River Basin (YRB) have faced increasingly significant pressure for carbon emission reduction since the implementation of the "Dual Carbon" strategy. This study focuses on 615 counties within the major urban agglomerations in the YRB, analyzing the spatiotemporal evolution of carbon budget in land use from 2000 to 2020. Methods such as the normalized revealed comparative advantage (NRCA) index and SOM-K-means model are employed to explore the carbon compensation zoning of counties in the urban agglomerations in the YRB from the perspective of main functional zones.

View Article and Find Full Text PDF

Exploring the spatial distribution of China's intangible cultural heritage resources and its influencing factors is an important foundation for their protection and development and a key step toward the integration of culture and tourism. To analyse the geographical distribution patterns of China's 3610 intangible cultural heritage resources and their influencing factors, we comprehensively applied methods such as spatial analysis and geodetectors. The main findings are as follows: (1) In terms of spatial distribution, China's intangible cultural heritage resources are unevenly distributed, with an overall agglomeration-type distribution.

View Article and Find Full Text PDF

HR3C steel is an austenitic high-temperature-resistant steel. Because of its good strength and high-temperature performance, it has been widely used in ultra-supercritical power plant boilers. With the increasingly frequent start-up and shutdown of thermal power units, leakages of HR3C steel pipes have occasionally occurred due to the embrittlement of HR3C pipe steel after a long service duration.

View Article and Find Full Text PDF

Rapid urbanization has led to ecological destruction and associated issues. Macro policies wield substantial influence over urbanization and its relationship with the environment. Without considering the differences in scale, macro policies may be ineffective at addressing urbanization's adverse impacts on the environment, and even worsen this relationship.

View Article and Find Full Text PDF

Among all the gas disasters, gas concentration exceeding the threshold limit value (TLV) has been the leading cause of accidents. However, most systems still focus on exploring the methods and framework for avoiding reaching or exceeding TLV of the gas concentration from viewpoints of impacts on geological conditions and coal mining working-face elements. The previous study developed a Trip-Correlation Analysis Theoretical Framework and found strong correlations between gas and gas, gas and temperature, and gas and wind in the gas monitoring system.

View Article and Find Full Text PDF

This research aims to explore the multi-focus group method as an effective tool for systematically eliciting business requirements for business information system (BIS) projects. During the COVID-19 crisis, many businesses plan to transform their businesses into digital businesses. Business managers face a critical challenge: they do not know much about detailed system requirements and what they want for digital transformation requirements.

View Article and Find Full Text PDF

Reducing the local stress in the vicinity of the grain boundaries is a favorable way to improve the super-elastic properties of super-elastic alloys. The crystal plasticity finite element method (CPFEM) was applied in this study to simulate the deformation behavior and local stress of a super-elastic Cu-8Al-11Mn (wt.%) alloy containing single grains with various orientations, columnar grains with different misorientation angles, and tri-crystals with distinct grain boundary morphologies.

View Article and Find Full Text PDF

Background: As the world's largest coal producer, China was accounted for about 46% of global coal production. Among present coal mining risks, methane gas (called gas in this paper) explosion or ignition in an underground mine remains ever-present. Although many techniques have been used, gas accidents associated with the complex elements of underground gassy mines need more robust monitoring or warning systems to identify risks.

View Article and Find Full Text PDF

Multicomponent high-entropy alloys (HEAs) can be tuned to a simple phase with some unique alloy characteristics. HEAs with body-centered-cubic (BCC) or hexagonal-close-packed (HCP) structures are proven to possess high strength and hardness but low ductility. The faced-centered-cubic (FCC) HEAs present considerable ductility, excellent corrosion and radiation resistance.

View Article and Find Full Text PDF

Objective: To explore the clinical effect of the simple nucleus pulposus removal and small incision interlaminar window in the treatment of prolapsed and displaced lumbar disc herniation.

Methods: From February 2016 to February 2018, 35 patients with single-segment prolapse and displaced lumbar disc herniation were treated by the simple nucleus pulposus removal and small incision interlaminar window under general anesthesia. Among them, there were 21 males and 14 females;aged (42±17) years;27 cases of L segment, 6 cases of LS segment, 2 cases of L segment;20 cases on the left side, 13 cases on the right side.

View Article and Find Full Text PDF

High-entropy alloys exhibit exceptional mechanical properties at cryogenic temperatures, due to the activation of twinning in addition to dislocation slip. The coexistence of multiple deformation pathways raises an important question regarding how individual deformation mechanisms compete or synergize during plastic deformation. Using in situ neutron diffraction, we demonstrate the interaction of a rich variety of deformation mechanisms in high-entropy alloys at 15 K, which began with dislocation slip, followed by stacking faults and twinning, before transitioning to inhomogeneous deformation by serrations.

View Article and Find Full Text PDF
Article Synopsis
  • Resonant ultrasound spectroscopy (RUS) was employed to study how the material constants of PZT-8 piezoceramics change with temperature from room temperature up to 100 °C.
  • Using a single sample ensured that variations between samples were minimized, resulting in self-consistent data.
  • The RUS measurement error was under 2.35%, and the consistent material constants obtained can be used for precise predictions of device performance under high-temperature conditions in simulations.
View Article and Find Full Text PDF

One of the keys to allowing Mg alloys to serve as biodegradable materials is how to balance their degradation behaviours and mechanical properties in physiological environment. In this study, a novel Mg-6Ho-0.5Zn alloy (wt%) containing profuse basal plane stacking faults (SFs) is prepared.

View Article and Find Full Text PDF

Precipitate size and number density are two key factors for tailoring the mechanical behavior of nanoscale precipitate-hardened alloys. However, during thermal aging, the precipitate size and number density change, leading to either poor strength or high strength but significantly reduced ductility. Here we demonstrate, by producing nanoscale co-precipitates in composition-optimized multicomponent precipitation-hardened alloys, a unique approach to improve the stability of the alloy against thermal aging and hence the mechanical properties.

View Article and Find Full Text PDF

This paper presents a pulse method for determination of resonance frequency of magnetoelastic sensors. The method eliminates the bias field that is necessary in previous methods and also allows fast and accurate detection. The stability tests of the system show an average standard deviation of 129 Hz and an average drift of -10.

View Article and Find Full Text PDF