Search

The automated ball indentation method（ ABI） which is a new way to evaluate the mechanical properties of the materials has been studied in recent years. In order to explore the applicability of the ABI method to evaluate the fracture toughness of metallic materials,some ABI tests were performed by using the Q235B steel. The fracture toughness got from the ABI tests were compared with that from the conventional fracture tests. The results of comparison show that the error between the two methods was less than 10%. As a result,the ABI method can be used to evaluate the fracture toughness of the Q235B steel.

Flowslide in loessic regions, characterized by their elongated shape and tendency to slide and accumulate along channels or gentle hillslopes, frequently lead to devastating and unpredictable disasters. The Yongguang 1# flowslide in Minxian County, Gansu Province, caused by the Minxian-Zhangxian Ms6.6 earthquake at 7:45AM on July 22, 2013, claimed twelve lives and had a volume of approximately 23x104 m³. The landslide had a vertical difference of 175m between its front and rear edges, a total length of 1 030 m, and a ratio of 0.17, classifying it as a long-runout landslide. This paper explored the characteristics of the sliding process and the sliding velocities of different portions of the flowslide through field survey and a comprehensive analysis of the observation data of the sliding process, while also analyzing the sliding mechanism. Triggered by earthquake, the runout process of the flowslide has been affected by local terrain. The flowslide experienced two complex sliding stages of acceleration and deceleration. Initially, the landslide slid as a whole in the front platform area for 50 to 130 m, and then the front sliding body with an volume of about 6x104 m³ continued to slide along the front channel for 740 m, resulting in a maximum runout distance of 870 m. The entire sliding process lasted about 7 hours, with a maximum sliding speed of approximately 10.6 m/s, and an average sliding speed of 0.034 m/s. The formation of the Yongguang 1# landslide was influenced by the coupled effects of seismic activity and early-precipitation. The earthquake, preceded by heavy rainfall, led to infiltration and softening of the soil. During the sliding process, the high water content in the sliding zone generated high pore water pressure, and in some cases, liquefaction occurred. The channel-shaped topography and low permeability of the sliding zone soil caused a very slow dissipation of pore water pressure, resulting in a significant reduction in frictional resistance in the sliding zone soil throughout the entire sliding process, with a noticeable velocity-sustaining effect. These factors are the primary reasons for the long-runout of the Yongguang 1# landslide. [ABSTRACT FROM AUTHOR]

On October 3, 2021, a large landslide occurred at the loess-mudstone interface in Nandianzi, Lingtai, its successful early warning measures preventing casualties. In order to investigate the occurrence mechanism behind the Nandianzi landslide, a basic investigation was conducted, covering the topography, lithology, hydrogeological conditions, and human engineering activities related to the landslide. Based on the characteristics and differences of the crack development of the landslide, the landslide mass was divided into five blocks. The characteristics of each block were thoroughly analyzed through qualitative and quantitative analysis. The specific sliding situation of different parts of the landslide was analyzed, and further evidence was provided for the objective rationality of landslide classification and zoning, as well as the analysis of landslide mechanisms. Ultimately, it is concluded that the main causes of landslide disasters are as follows: (1) Large-scale excavation and earthwork activities at the lower and middle parts of the slope and the toe, leading to slope steepening and reduced resistance to sliding; (2) Formation of slope depressions, causing inadequate drainage and softening of the rock layer contact surface, thereby diminishing slope stability; and (3) Prolonged heavy rainfall that leads to instability and causes significant loss. While the Nandianzi landslide in Lintai county represents a successfully averted disaster, it serves as a noteworthy case study and a cautionary example for scientifically and standardizedly approaching urban construction and rural revitalization in China. This study holds significance value for monitoring, early warning, risk assessmen, and engineering treatment in comparable regions. [ABSTRACT FROM AUTHOR]

The copolymer of the mixed polyether modified polysiloxane was prepared by hydrogen-containing silicone oil and three types of allyl polyoxyethylene polyoxyel ether. The solution with xylene mass fraction of 20% was prepared and used for demulsification and dehydration of heavy oil in Bohai oilfield. Compared with the demulsifier in use on the platform, the color of the effluent was slightly worse when the self-made homemade demulsifier was used, but the dehydration speed was faster. When the demulsifier was used in 100 mL oil with water content of 10% and 60%, the dehydration volume in 40 minutes is not less than 8 mL and 53 mL, and the dehydration interface is smooth. The new demulsifier is expected to be used as a new demulsifier in Bohai heavy oil field, and worth further study. [ABSTRACT FROM AUTHOR]

In response to the high wax content in the JZ crude oil, a variety of carboxylic acid ester copolymer type pour point depressants (PPDs) were synthesized and the depressant of LF -- 04 was chosen as the best one. Subsequently, factors affecting its effect on the depression were analyzed. It was found that the optimum heat processing temperature for the JZ crude oil with the additive of LF--04 is above 50°C, and the optimal PPD concentration is 400mg/l. In addition, the pour point of the crude oil was reduced from original 21 °C to 9 °C with the presence of 400 mg/L inhibitor, and correspondingly, the abnormal point was reduced from 45°C to 40°C. Apart from the above, at the temperature of 25°C and shear rate of 16 s-1, the apparent viscosity of the crude oil with the addition of LF--04 at the concentration of 400 mg/L was decreased by 70. 5%. Consequently, based on the the good static stability, depressant of LF -- 04 has good prospects of popularization and application in oil fields. [ABSTRACT FROM AUTHOR]

Objective: To explore the effect of regional synergistic treatment system on the treatment time and short-term prognosis of patients with ST-segment elevation myocardial infarction (STEMI)., Methods: A retrospective analysis of the clinical data of STEMI patients who admitted to emergency center of Suzhou Kowloon Hospital Affiliated to Shanghai Jiaotong University School of Medicine and underwent primary percutaneous coronary intervention (PPCI) from January 2013 to January 2017 were conducted. All patients were divided into two groups, group A was the patients who underwent the PPCI before the establishment of the acute chest pain area co-treatment system (from January 2013 to December 2014), and group B was the patients who received the treatment after the establishment of the area co-treatment system (from January 2015 to January 2017). The length of time from onset of symptoms to the balloon dilatation (S2B), the length of time from the first medical contact to the balloon dilatation (FMC2B), the length of time from entering the gate of hospital to the balloon dilatation (D2B), and the incidence of 90-day end point events (including heart failure, all-cause death, and other related adverse events) were collected. The relations of the establishment of the acute chest pain area co-treatment system and the incidence of 90-day end point events were analyzed by multivariable Logistic regression analysis., Results: Among the 221 enrolled patients with STEMI, 83 patients were in group A and 138 patients were in group B respectively. Compared with group A, S2B time [minutes: 180 (140, 210) vs. 201 (154, 225)], FMC2B time [minutes: 89 (78, 100) vs. 94 (83, 107)] and D2B time [minutes: 66 (62, 70) vs. 85 (72, 99)] were significantly shortened in group B (all P < 0.05), the incidence of 90-day end point events were significantly decreased (heart failure: 20.3% vs. 32.5%, all-cause death: 1.4% vs. 7.2%, other related adverse events: 23.2% vs. 36.1%, all P < 0.05). It was shown by multivariable Logistic regression analysis that the establishment of the acute chest pain area co-treatment system could lower the incidence of 90-day end point events [heart failure: odds ratio (OR) = 1.904, 95% confidence interval (95%CI) = 0.968-1.004, P = 0.048; all-cause death: OR = 11.724, 95%CI = 0.955-1.048, P = 0.013; other related adverse events: OR = 1.925, 95%CI = 1.049-3.530, P = 0.034]., Conclusions: The construction of regional synergistic treatment system can shorten the emergency treatment time of STEMI patients and reduce the incidence of 90-day end point events including heart failure and death.

Objective: To survey E-cadherin (E-cad) expression in tumor tissue and serum of esophageal squamous cell carcinoma patients, and to observe the clinical significance of their expression., Methods: Forty-eight samples of esophageal squamous cell carcinoma tissue, 23 samples of erosive esophagitis tissue, 24 samples of normal esophagus tissue and the corresponding sera were obtained. We used immunohistochemistry (IHC) to detect expression of E-cad in the tissues and enzyme-linked immunosorbent assay (ELISA) to examine expression of E-cad in the serum. Furthermore, we collected complete clinicopathological data from the participating patients., Results: The expression level of E-cad in the esophageal squamous cell carcinoma tissue was lower than that in normal esophagus tissues and erosive esophagitis tissues (P<0.05). Moreover, the expression level of E-cad was related to the depth of invasion, the status of lymph node metastasis and the level of differentiation of esophageal squamous cell carcinoma (P<0.05). The expression level of serum E-cad of esophageal squamous cell carcinoma patients was obviously higher than that in the serum of normal esophagus controls and erosive esophagitis patients (P<0.05). But the expression level of E-Cad in the serum of esophageal squamous cell carcinoma patients was unrelated to clinicopathological features. The expression level of E-cad in the tissue was not correlated with that in the serum(P=0.134)., Conclusion: The expression of E-cad in tissues may assistin the diagnosis and prognosis of esophageal squamous cell carcinoma. The expression of E-cad in the serum may assistin the diagnostic screening of esophageal squamous cell carcinoma.