Research Progress on Laser-Assisted Precision Machining Technology.

As a revolutionary advanced manufacturing technology, the core of laser-assisted machining technology lies in the innovation of traditional machining technology. It uses a laser to precisely modify the surface of the workpiece material through clever integration. This process can lead to significant changes in the microstructure, thermodynamic properties, and physical properties of the workpiece's cutting layer, greatly facilitating the removal of material by the cutting tool.

Perceived peer relationships and achievement motivation: Subject-specific dynamics in a Chinese high school learning context.

Aim: This study employed a three-wave random intercept cross-lagged panel model (RI-CLPM) to investigate whether a reciprocal relationship exists between perceived peer relationships (intimacy and conflict) and achievement motivation in math and English in the Chinese context.

Samples: A total of 4040 high school students were tracked with their perceived intimacy and conflict with peers and achievement motivation levels in math and English over three academic years since Grade 10.

Results: A reciprocal association was found between perceived peer intimacy and achievement motivation in English, and the predictive effect of intimacy on achievement motivation in English was the same as the reverse association.

Screening of COPD patients using the COPD diagnostic questionnaire and a portable spirometer in primary healthcare institutions: a cross-sectional, diagnostic study.

Background: Portable spirometers and chronic obstructive pulmonary disease (COPD) diagnostic questionnaires are commonly used for screening patients with COPD in primary healthcare institutions, but their accuracy is often inadequate. This study aimed to explore the accuracy of combining these two tools in screening for COPD.

Methods: Participants aged ≥ 40 years were recruited from primary healthcare institutions between July 2022 and July 2023.

Fused extracellular vesicles from M macrophages and human umbilical cord mesenchymal stem cells for the targeted regulation of macrophage pyroptosis in periprosthetic osteolysis.

The development of strategies for the prevention and treatment of aseptic loosening of prostheses stands as a critical area of global research interest. The pyroptosis of local macrophages triggered by wear particles plays a pivotal role in the onset of periprosthetic osteolysis and subsequent loosening. Extracellular vesicles, carrying the surface components and regulatory molecules of their parent cells, embody the cellular characteristics and biological functions of these progenitors.

Research Progress on Precision Tool Alignment Technology in Machining.

In the field of numerical control machining, tool alignment technology is a key link to ensure machining accuracy and quality. Tool alignment refers to determining the correct position of the tool relative to the workpiece, and its accuracy directly affects the precision of part machining. With the development of precision machining technology, the research and application of cutting technology are increasingly valued.

NO recovery from wastewater and flue gas via microbial denitrification: Processes and mechanisms.

Nitrous oxide (NO) is increasingly regarded as a significant greenhouse gas implicated in global warming and the depletion of the ozone layer, yet it is also recognized as a valuable resource. This paper comprehensively reviews innovative microbial denitrification techniques for recovering NO from nitrogenous wastewater and flue gas. Critical analysis is carried out on cutting-edge processes such as the coupled aerobic-anoxic nitrous decomposition operation (CANDO) process, semi-artificial photosynthesis, and the selective utilization of microbial strains, as well as flue gas absorption coupled with heterotrophic/autotrophic denitrification.

A reciprocal association between interpersonal relationship quality and student's positive affect: A three-wave random intercept cross-lagged study in a Chinese primary mathematics learning context.

Aim: This study adopted a three-wave random intercept cross-lagged panel model to explore the longitudinal reciprocal relationships between (a) the teacher-student relationship (TSR) quality and (b) the parent-child relationship (PCR) quality and positive affect among Chinese primary school students.

Samples: Two primary school student samples, including 3505 and 2505 students, were tracked with their perceived relationship quality with math teachers and parents and their positive affect levels in mathematics learning over three academic years.

Results: The results demonstrated that more closeness with parents could significantly predict students' subsequent higher level of positive affect in mathematics learning.

Groundwater chemical characteristic analysis and water source identification model study in Gubei coal mine, Northern Anhui Province, China.

This study aims to accurately identify mine water sources and reduce the hazards caused by water inrush accidents in coal mines. Taking the Gubei coal mine as an example, the water quality results of the water samples from the Cenozoic unconsolidated aquifer, Permian sandstone fracture aquifer, and Carboniferous Taiyuan Formation limestone karst fracture aquifer in the mine area were tested, and K+Na, Ca, Mg, Cl, SO, HCO, TDS (Total Dissolved Solids), and pH were selected as the main indicators to study the water chemistry characteristics of the aquifer through water chemistry component analysis, major ion content analysis, Piper trilinear analysis, and correlation analysis. Thirty-five groups of water samples were randomly selected and imported into SPSS software for factor analysis (FA) and downsized to three main factors as the input variables of the artificial neural network model.

Risk assessment of nitrate groundwater contamination using GIS-based machine learning methods: A case study in the northern Anhui plain, China.

Long-term agricultural activities have affected the sustainable development of groundwater in the Northern Anhui Plain, East China. It is, therefore, important to identify areas at high groundwater pollution risk in the Northern Anhui Plain to ensure effective protection of regional water resources. In this study, 60 groundwater samples were collected from the shallow aquifer of the plain and analyzed for nitrate (NO) concentrations.

Supramolecular chitin-based hydrogels with self-adapting and fast-degradation properties for enhancing wound healing.

Due to the features of high porosity, high water content, and tunable viscoelasticity, hydrogels have attracted numerous attentions in the promotion of wound closure. However, the lack of abilities to adapt the wounds of complex shapes and prevent postoperative adhesion limits their therapeutic outcomes in wound healing. To address the above challenges, the supramolecular chitin-based (SMCT) hydrogels are created via the host-guest pre-assembly strategy of β-cyclodextrin (βCD) and adamantane (Ad).

Groundwater pollution source identification and health risk assessment in the North Anhui Plain, eastern China: Insights from positive matrix factorization and Monte Carlo simulation.

Groundwater contaminants from natural and anthropogenic sources pose a serious threat to the ecological environment and public health. In this study, 30 groundwater samples were collected from shallow wells at a large central water source in the North Anhui Plain, eastern China. Hydrogeochemical methods, positive matrix factorization (PMF) model, and Monte Carlo simulation were used to determine the characteristics, sources, and human health risks of inorganic and organic analytes in groundwater.

Oxoammonium salt-promoted diverse functionalization of saturated cyclic amines with dinucleophiles.

Oxoammonium salt-promoted diverse functionalization of saturated cyclic amines with different dinucleophiles under mild conditions is presented. Specifically, when thiocyanate is used as a 1,3-dinucleophile, hexahydrothiazolo[4,5-]pyridin-2(3)-one derivatives are formed the formation of the β-TEMPO-tethered cyclic iminium ion as a key intermediate. By contrast, when benzene-1,2-diamine is used as a 1,4-dinucleophile, 2-alkylquinoxaline derivatives are afforded generation of the β-oxo cyclic iminium ion as a key intermediate.

Data-driven multi-joint waveguide bending sensor based on time series neural network.

Due to the bulky interrogation devices, traditional fiber optic sensing system is mainly connected by wire or equipped only for large facilities. However, the advancement in neural network algorithms and flexible materials has broadened its application scenarios to bionics. In this paper, a multi-joint waveguide bending sensor based on color dyed filters is designed to detect bending angles, directions and positions.

Source apportionment and ecological health risks assessment from major ions, metalloids and trace elements in multi-aquifer groundwater near the Sunan mine area, Eastern China.

Evaluating the ecological health risks created by major ions, metalloids and trace elements concentrations in groundwater and pollution sources were essential to effectively protect groundwater resources. For this study, A total of 93 samples were collected from multiple aquifers in the Sunan mining area, eastern China. The Positive matrix factorization (PMF) model results revealed the following sources, in percentages.

B(CF)-Catalyzed α,β-Difunctionalization and C-N Bond Cleavage of Saturated Amines with Benzo[]isoxazoles: Access to Quinoline Derivatives.

Herein, we disclose a strategy to realize α,β-difunctionalization and C-N bond cleavage of saturated amines with benzo[]isoxazoles via a B(CF)-catalyzed consecutive hydrogen-borrowing and [4 + 2] cycloaddition followed by a C-N bond cleavage process. In general, the reactions proceed efficiently in the absence of any oxidant and metal catalyst to afford a broad range of quinoline derivatives starting from easily accessible substrates in an atom-economical manner.

Oxoammonium Salt-Promoted Multifunctionalization of Saturated Cyclic Amines Based On β-Oxo Cyclic Iminium Ion Intermediates.

Herein we describe a convenient method for multiple C(sp)-H bond functionalization of saturated cyclic amines through oxoammonium salt-promoted oxidation to afford a β-oxo cyclic iminium ion as a key intermediate, followed by cascade addition with thiocyanate and diverse N-, O-, and S-containing nucleophiles in the green solvent and EtOH. Notably, chiral spiro azapolyheterocycles were prepared enantioselectively (>20:1 dr, up to 99% ee) when cysteine or serine esters were used as substrates. Moreover, the concise late-stage modification of several natural product derivatives was accomplished using this method.

Hydrogeochemical Processes and Connection of Multi-Layer Groundwater System in Sunan Mining Area, Eastern China.

Groundwater is an important freshwater resource in the world and serves as the main source of water for mining areas in Northern China. Coal mining may cause changes in water quality. As such, to identify ways to prevent water contamination, this study investigates the hydrogeochemical processes and transport paths of a complex aquifer system in the Sunan mining area in Northern China.

Statistical analyses of hydrochemistry in multi-aquifers of the Pansan coalmine, Huainan coalfield, China: implications for water-rock interaction and hydraulic connection.

Understanding the groundwater hydrogeochemical processes and aquifer hydraulic connections are essential for effective prevention of water inrush in concealed coal mines. In this study, 40 groundwater samples were collected from the loose layer aquifer (LA), coal measure aquifer (CA), and limestone aquifer (LA) in the Pansan coal mine, Huanan coalfield, China, and the major ion concentrations were analyzed by bivariate diagrams (Na + K - Cl versus Ca + Mg - SO - HCO and CAI-I versus CAI-II), multivariate statistical methods, and receptor model in order to identify the water-rock interactions and aquifer hydraulic connections. Piper diagram showed that groundwater in LA and TA was dominated by the Na-Cl type, while groundwater in CA was mainly of the Na-HCO type.

Two-Dimensional Design Strategy to Construct Smart Fluorescent Probes for the Precise Tracking of Senescence.

The tracking of cellular senescence usually depends on the detection of senescence-associated β-galactosidase (SA-β-gal). Previous probes for SA-β-gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous β-gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes.