Unraveling the Phase Stability and Physical Property of Modulated Martensite in Ni2Mn1.5In0.5 Alloys by First-Principles Calculations

Large magnetic field-induced strains can be achieved in modulated martensite for Ni-Mn-In alloys; however, the metastability of the modulated martensite imposes serious constraints on the ability of these alloys to serve as promising sensor and actuator materials. The phase stability, magnetic properties, and electronic structure of the modulated martensite in the Ni₂Mn_1.5In_0.5 alloy are systematically investigated. Results show that the 6M and 5M martensites are metastable and will eventually transform to the NM martensite with the lowest total energy in the Ni₂Mn_1.5In_0.5 alloy. The physical properties of the incommensurate 7M modulated martensite (7M–IC) and nanotwinned 7M martensite (7M−(52¯)2) are also calculated. The austenite (A) and 7M−(52¯)2 phases are ferromagnetic (FM), whereas the 5M, 6M, and NM martensites are ferrimagnetic (FIM), and the FM coexists with the FIM state in the 7M–IC martensite. The calculated electronic structure demonstrates that the splitting of Jahn–Teller effect and the strong Ni–Mn bonding interaction lead to the enhancement of structural stability.     

Preparation and characterization of pure phase CdMnTe nanopowders by a hydrothermal route

In this paper, CdMnTe nanopowders with uniform shapes were prepared through a facile hydrothermal route using 3-mercaptopropionic acid (MPA) as the stabilizer and modifier. The effects of different experimental conditions including Cd-to-MPA ratio, pH value and reaction temperature on the phase composition and formation mechanism of as-prepared nanopowders were studied. XRD results indicated as-prepared CdMnTe nanopowders were pure phase and had cubic sphalerite structure with high crystallinity. SEM and Rietveld refinement clearly showed that the powders were about 10–100 nm in size. In PL measurement, there was a strong luminescence peak in the infrared region 1.717–1.826 eV. Compared with the CdMnTe single crystal, a blue shift of about 0.109 eV indicated a wider band gap. In UV-vis spectra, the absorption peak of the sample blue shifted with the decrease of crystal size, which indicated an obvious quantum confinement effect (QCE) in nanopowders. The optimal conditions for the preparation of CdMnTe nanopowders are 180 °C for 24 h with the molar ratio 1 : 1 of Cd : MPA at pH 13. In particular, the growth kinetics and possible formation mechanism of the nanopowders were proposed.

CdMnTe high-quality and pure phase nanopowders, with diameters of 20 nm to 100 nm, were synthesized by a hydrothermal route using mercapto propionic acid as the stabilizer. A CdMnTe single crystal was produced by melting method and flash sintering using CdMnTe nanopowder.     

Application of Iron Tailings-Based Composite Supplementary Cementitious Materials (SCMs) in Green Concrete

How to treat the iron tailings of mining solid waste with high value is an urgent problem on a global scale. In recent years, the application of iron tailings in the building materials industry has attracted the attention of many scholars. The conversion of iron tailings into green building materials helps achieve carbon neutrality and high-value utilization of solid waste, and promotes sustainable development. Although iron tailings have been extensively studied as supplementary cementitious materials, the performance of concrete is not ideal due to its low activity. In this study, the hybrid supplementary cementitious materials system was prepared by iron tailings, phosphorus slag, and steel slag, and the effects of supplementary cementitious materials type, iron tailings content, iron tailings grinding time, and supplementary cementitious materials content on concrete performance were studied. The compressive properties, iron tailings properties, pore structure, interfacial transition zone, and element distribution of hydration products of concrete were tested by compressive strength tests, X-ray Diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS), Mercury Intrusion Porosimetry (MIP), Backscattering Electron Tests (BSE), and Energy Dispersive Spectrometer (EDS). The results show that further grinding improves the iron tailings activity. There is a synergistic mechanism between steel slag and phosphorus slag in the composite supplementary cementitious materials, which overcomes the low activity defect of iron tailings and produces concrete with a compressive strength exceeding 40 MPa. The composite supplementary cementitious materials can optimize the interfacial transition zone of the concrete interface and reduce the calcium–silicon ratio of the hydration products. However, it will deteriorate the pore structure of the concrete matrix, cause part of the concrete matrix to be damaged and lead to a loss of compressive strength, and the loss is acceptable. This work broadens the methods of comprehensive utilization of iron tailings and also provides a reference for a more detailed understanding of the properties of iron tailings-based concrete.     

Local Electrochemical Corrosion Properties of a Nano-SiO2/MAO Composite Coating on an AM60B-Mg Alloy

In order to improve the corrosion resistance of the automotive AM60B-Mg alloy, a nano-SiO₂/MAO composite coating was prepared on the surface of the alloy. The electrochemical properties were studied in an 80 °C corrosion environment using potentiodynamic polarization tests. Local Electrochemical Impedance Spectroscopy (LEIS) was used to study the corrosion mechanisms of coating defect zone. The microstructure and phase of the samples were observed by confocal laser microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Macroscopic electrochemical test results showed that the impedance of the nano-SiO₂/MAO coating was much higher than that of the MAO coating, by about 433 times. Local electrochemical test results showed that the minimum impedance of the nano-SiO₂/MAO coating was 1–2 orders of magnitude higher than the maximum impedance of the MAO coating. The defective SiO₂/MAO coating still had high corrosion resistance compared to the defective MAO coating. A physical model of local corrosion mechanisms was proposed.     

Insight into biomass feedstock on formation of biochar-bound environmentally persistent free radicals under different pyrolysis temperatures

Environmentally persistent free radicals (EPFRs) in biochars have the ability of catalytic formation of reactive oxygen species, which may pose potential oxidative stresses to eco-environment and human health. Therefore, comprehending the formation and characteristics of EPFRs in biochars is important for their further applications. In this study, the woody lignocellulosic biomass (wood chips, pine needle and barks), non-woody lignocellulosic biomass (rice husk, corn stover, and duckweed), and non-lignocellulosic biomass (anaerobically digested sludge) were selected as biomass feedstock to prepare biochars under different pyrolysis temperatures (200–700 °C). The impact of biomass feedstock on formation of biochar-bound EPFRs was systematically compared. Elemental compositions and atomic ratios of H/C and O/C varied greatly among different biomass feedstocks and the subsequently resulting biochars. EPFRs in biochars derived from the studied lignocellulosic biomass have similar levels of spin concentrations (10¹⁸–10¹⁹ spins per g) except for lower EPFRs in biochars under 200 and 700 °C; however, sludge-based biochars, a typical non-lignocellulosic-biomass-based biochar, have much lower EPFRs (10¹⁶ spins per g) than lignocellulosic-biomass-based biochars under all the studied pyrolysis temperatures. Values of g factors ranged from 2.0025 to 2.0042 and line width was in the range of 2.15–11.3 for EPFRs in the resulting biochars. Spin concentrations of biochar-bound EPFRs increased with the increasing pyrolysis temperatures from 200 to 500 °C, and then decreased rapidly from 500 to 700 °C and oxygen-centered radicals shifted to carbon-centered radicals with the increasing pyrolysis temperatures from 200 to 700 °C for all the studied biomass feedstock. 300–500 °C was the appropriate pyrolysis temperature range for higher levels of spin concentrations of biochar-bound EPFRs. Moreover, EPFRs'' concentrations had significantly positive correlation with C contents and weak or none correlation with contents of transition metals. Overall, different types of biomass feedstock have significant impact on the formation of EPFRs in the resulting biochars.

Environmentally persistent free radicals (EPFRs) in biochars have the ability of catalytic formation of reactive oxygen species, which may pose potential oxidative stresses to eco-environment and human health.     

非酒精性脂肪性肝炎患者肝脏受控衰减参数的变化

目的 探讨瞬时弹性记录仪(FibroScan)检测肝脏受控衰减参数(CAP)诊断非酒精性脂肪性肝炎(NASH)的效能.方法 2016年1月～2020年1月我院收治的NASH患者142例和同期健康体检者130例,使用FibroScan检测肝脏CAP值.采用受试者工作特征曲线(ROC)并计算曲线下面积(AUC)评价CAP值...     

阵发性运动障碍25例临床分析

目的总结阵发性运动障碍患者的诱发因素、临床特征以及治疗特点。方法收集阵发性运动障碍患者25例,均进行神经科常规检查以及视频脑电和核磁共振扫描,部分患者进行单光子发射计算机断层扫描,并对其诱发因素、发病年龄以及临床表现进行分析,观察对抗癫药物治疗的效果。结果25例患者中,散发14例,有家族史患者8例,继发性3例。其中阵发性运动源性舞蹈样徐动症/运动障碍共19例,对小剂量卡马西平治疗有显著效果。结论不同类型的阵发性运动障碍诱发因素不同,对卡马西平的治疗效果也不同;继发性阵发性运动障碍要重视原发病治疗。     

Empagliflozin in the treatment of heart failure and type 2 diabetes mellitus: Evidence from several large clinical trials

Heart failure coexists with type 2 diabetes mellitus, which seriously affects the clinical treatment and prognosis. At present, the treatment for patients with established heart failure and type 2 diabetes mellitus is usually combined with two treatment strategies for heart failure and type 2 diabetes mellitus. Recently, increasing studies showed that empagliflozin, a sodium-glucose co-transporter-2 inhibitor, has a positive effect on the treatment of patients with established heart failure and type 2 diabetes mellitus. Here, we summarize the latest and current understanding of the management for patients with established heart failure and type 2 diabetes mellitus and further present contemporary treatment options, sodium-glucose co-transporter-2 inhibitor, for these particular populations.     

直腰旋转平推法治疗腰椎间盘突出症效果分析

目的:观察直腰旋转平推法治疗腰椎间盘突出症的临床疗效。方法:569例腰椎间盘突出症患者,随机分为直腰旋转平推法治疗组301例,常规推拿治疗组268例。两组均每日治疗一次,10次为一疗程,1个疗程后进行临床疗效观察。结果:治疗组疗效明显优于对照组(P<0.05)。结论:直腰旋转平推法治疗腰椎间盘突出症疗效确切,优于常规推拿治疗。     

Transcatheter closure of inferior sinus venosus defect using a patent ductus arteriosus occluder following simulation with a 3D-printed model

BackgroundTranscatheter closure of inferior sinus venosus defect (ISVD) is still contraindication. To explore whether transcatheter closure with patent ductus arteriosus (PDA) occluders is possible for ISVD.MethodsFrom June 2014 to March 2021, 12 patients were recruited diagnosed as <25 mm ISVD. The three-dimensional printing (3DP) heart model was produced based on multi-slice computed tomography (MSCT) scans. Preoperative closure simulation was planned on the personalized 3D model for each patient. Follow-up including electrocardiography (ECG), transthoracic echocardiography (TTE), and X-ray was traced.Results3DP models of 12 patients were successfully printed. Twelve patients had been diagnosed with <25 mm ISVD and 4 of them had another secundum atrial septal defect (ASD). All patients were produced interventional therapy successfully. PDA occluder was implanted to closed ISVD, and ASD was closed using ASD occluder simultaneously. The average diameter of ISVD measured by TTE was (12.67±3.80), and the average diameter of sagittal axes and longitudinal axes measured by the 3D-printed model was (17.08±3.20) and (18.42±4.62) mm, respectively. The average size of PDA (diameter of pulmonary artery side) was (28.17±3.35) mm. Compared with the preoperative, the X-ray cardiothoracic ratio (0.51±0.04 vs. 0.47±0.06, P=0.007) and the right ventricle anterior-posterior diameter (31.17±5.65 vs. 24.58±3.75 mm, P<0.001) of postoperative was significantly decreased. During the average (47.75±27.52) months follow-up, it has achieved satisfying results, and there were no severe adverse events such as device transposition, death, and pericardial tamponade occurred.ConclusionsAssisting by 3D heart model, transcatheter closure of ISVD with PDA occluder had an excellent outcome. This method provides a new considerable treatment strategy for ISVD.