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This paper investigates the corrosion behavior of Fe-SG series metals with different graphite nodule counts to molten Al by using the ultrasonic vibration hot-dip aluminum experimental method. Fe-SG series metals to aluminum melt exhibited a much better corrosion resistance compared to H13 tool steel. As the graphite nodule count increases, the hot melting loss rate of Fe-SG series metals gradually decreases, indicating an improvement in corrosion resistance to aluminum melt. Scanning and EDS analysis of the samples after hot-dip aluminum testing revealed that the thickness of the product layer increased progressively with the extension of hot-dip aluminum time. Through the analysis of the structure and composition of the product layer, it was found that the corrosion products in H13 steel were composed of Fe2Al5 and FeAl3. In addition to the two phases, the product layer of the Fe-SG series metals also contained granularly distributed Fe–Al–Si intermetallic compounds within the Fe2Al5 phase. This resulted in a better corrosion resistance to aluminum melt.

Soil acidification is a global environmental problem with significant impacts on agricultural production, environmental protection, and ecosystem health. Soil acidification is widespread in China, affecting crop yields, agricultural product quality, and biodiversity. Since the 1980s, much work has been done on acidic soils in China, but it is controversial whether excessive nitrogen fertilizer application can lead to soil acidification mechanisms. To address the above issues, we conducted a meta-analysis of 115 published papers to integrate and analyze the effects of N fertilizer application on soil acidification and biological properties from 1980 to 2024. We also quantified the effect of nitrogen fertilization on soil acidification and biological changes under different climatic conditions. The results showed that under long-term application of nitrogen fertilizers in China from 1980 to 2024, soil pH decreased by an average of 15.27%, and the activities of soil urease, nitrate reductase, nitrite reductase, catalase, glutamate dehydrogenase, and glutamate synthetase decreased by an average of 9.82–22.37%. The soil microbial community richness (Chao1 index) increased by 6.53%, but the community diversity (Shannon index) decreased by 15.42%. Among the dominant soil microorganisms, the relative abundance of bacteria decreased by an average of 9.67–29.38% and the abundance of gene expression of nifH, amoA-AOA, amoA-AOB, and qnorB decreased by 9.92–19.83%. In addition, we found that the mean annual temperature and rainfall impacted soil acidification via their effect on soil microbial diversity and community composition. This study provides a scientific basis for an in-depth understanding of the spatial and temporal variation of soil acidification and biological properties in China.

Ferrite-martensite (F/M) dual-phase ductile iron with different relative amounts of martensite was fabricated via intercritical quenching in the present study. The mechanical properties and tribological behavior were investigated. The strength of ductile iron increased linearly with the increase of martensite level, while the ductility decreased rapidly. Fracture surface morphology analysis indicated that ductile fracture was predominant when the proportion of martensite in ductile iron was less than 20%. However, the samples with more than 40% martensite exhibited brittle fractures. Wear tests indicated that F/M dual-phase ductile iron exhibited a significantly lower friction coefficient compared with directly quenched ductile iron. Additionally, the martensite amounts affected the tribological behavior of ductile iron significantly. Abrasive wear was predominant in ductile iron with small amounts of martensite, while delamination wear was the main wear mechanism in case of ductile iron with high amounts of martensite.

The mechanical properties and tribological behavior of ductile iron tempered at different temperatures were investigated. The tempered sample was composed of spheroidal graphite, α phase, and carbides. The strength and hardness decreased near-linearly but the plasticity increased with the increase of tempering temperature, which was mainly because carbon atoms precipitated from martensite and thus reduced the distortion of martensite. Wear tests indicated that the friction coefficient of the sample tempered at 420 °C decreased first and then increased with the increasing loads and exhibited the lowest friction coefficient of 0.37. No obvious change was detected for the friction coefficient of the sample tempered at 500 °C at different loads. The friction coefficient of the sample tempered at 580 °C increased to a stable value with the increase of loads. The wear rate of tempered ductile iron was increased with the increase of tempering temperature, which indicated that hardness was the critical factor for wear properties of ductile iron. The main wear mechanisms of tempered ductile iron were adhesive and abrasive wear. Adhesive wear was predominant for the sample tempered at low temperature but was gradually replaced by abrasive wear with the increase of tempering temperature and normal loads.

Magnetron sputtering was used to deposit (Ti, Al)N films with different Al/Ti atomic ratios by changing the current of the Al target and to study their tribological properties. The phase composition, microstructure and elemental distribution of films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS). The influence of the ratio between Al and Ti atoms on the tribological properties and the mechanical properties of the films was analyzed. The conclusions showed that there was a tendency for films to shift from the crystalline to the amorphous state as the Al/Ti atomic ratio increases. Herein, changes in film microhardness were related to the substitution relationship between Ti atoms and Al atoms. Especially, when the Al/Ti atomic ratio was 0.54, coefficient of friction (COF) and specific wear rate were the lowest. Compared with TiN film, (Ti, Al)N films have higher microhardness due to the solid solution hardening caused by the substitution between Al and Ti atoms to produce lattice distortion. These factors make films have excellent tribology performance.

Background Helicobacter pylori (H.pylori) infection is strongly associated with peptic ulcer, gastric cancer, gastric lymphoma, and other diseases. A new dual therapy has proven effective in the eradication of H.pylori, but it has not been verified in some areas with a high prevalence of H.pylori infection in central China. Objective To explore the clinical efficacy of rabeprazole combined with amoxicillin or furazolidone dual therapy in the eradication of H.pylori infection. Methods 161 patients with a first diagnosis of H.pylori infection were recruited from Department of Gastroenterology, Henan Provincial People's Hospital during April 2020 to October 2021, and randomized into three groups with different 14-day therapies: group A (n=55) received a twice-daily quadruple therapy consisting of rabeprazole (20 mg) + bismuth potassium citrate (220 mg) + amoxicillin (1 000 mg) + furazolidone (100 mg) , group B (n=54) received a three-time daily dual therapy consisting of rabeprazole (20 mg) + high-dose amoxicillin (1 000 mg) , and group C (n=52) received a three-time daily dual therapy consisting of rabeprazole (20 mg) + high-dose furazolidone (100 mg) . The eradication rate, side effects and cost-effectiveness ratio were compared among the groups. Results Intention-to-treat analysis (ITT) revealed that, the eradication rates of H.pylori in groups A, B and C were 83.6% (46/55) , 81.5% (44/54) and 48.1% (25/52) , respectively. Per-protocol (PP) analysis found that, the eradication rates of H.pylori in groups A, B and C were 88.5% (46/52) , 83.0% (44/53) and 51.0% (25/49) , respectively. Both analyses demonstrated that groups A, B had higher eradication rates of H.pylori than group C (P

Background Helicobacter pylori (H. pylori) infection induced precancerous lesions of gastric mucosa mostly in adulthood. However, it is debatable whether these pathological changes could also occur in children. Objective To investigate the relationship between H. pylori infection and precancerous lesions of gastric mucosa in children hospitalized due to upper gastrointestinal symptoms in central plain area of China. Methods A total of 1 015 children under the age of 18 years old were enrolled. These children attended the People's Hospital of Zhengzhou University for upper gastrointestinal symptoms such as abdominal pain, bloating, nausea, vomiting, hiccups, and acid reflux from August 2018 to July 2021. All children underwent gastroscopy, from which gastric mucosal biopsy tissues were taken for rapid urease test and histopathological examination. The clinical and pathological data of the patients were collected retrospectively. The children were divided into infected and uninfected groups according to H. pylori infection status. The age, sex, endoscopic diagnosis, and H. pylori infection rate were compared between children in infected and uninfected groups. The incidence of precancerous lesions of gastric mucosa, inflammatory activity and the degree of inflammatory cell infiltration were compared between infected and uninfected groups, meanwhile these tests were also compared in children of different age groups. Results Among the 1 015 children, 854 (84.14%) were infected with H. pylori and 161 (15.86%) were not infected. H. pylori-infected children were significantly older than those of non-infected subjects (P