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Titanium alloy Ti6Al4V is widely used in aerospace, shipbuilding, petrochemical, and other industrial fields. Low-speed wire-cut electrical discharge machining (LS-WEDM) has the advantage of high machining accuracy. However, there are few research studies on the comprehensive effects of the electrical parameters of TC4 (Ti6Al4V) made by LS-WEDM on the machining surface. This paper focuses on LS-WEDM machining of titanium alloy TC4 and investigates the effects of electrical parameters on the surface roughness, kerf width, and cutting speed of TC4 specimens based on orthogonal tests. Five electrical parameters are optimized using the grey correlation method and the response surface method. The surface roughness of 1.744 μm, the kerf width of 215.432 μm, and the cutting speed of 24.759 mm2·min−1 are found to be the best process indicators, with errors of 3.3, 3.2, and 12.5% compared with the predicted values. The optimized results show that the surface roughness value is reduced by 50.9%, the kerf width is reduced by 29.4%, and the cutting speed is increased by 23%, which proves the accuracy of the optimized method.

Objective To investigate the application effects of online teaching practice of Basic Nursing based on Tencent classroom, MOOC, Rain Classroom and QQ group. Methods A total of 733 nursing students of academic year 2018 were investigated by online questionnaire, and the effective recovery rate of the questionnaire was 100. 00%. Results The survey found that 12. 01% of the students had noisy classroom environment, the number of students with weak network signal was 20. 05%, 22. 73% of the students thought that the network was the most important factor affecting online learning, 58. 39% of the students had general classroom interaction, 70. 12% of the students thought their autonomous learning ability is average, 63. 98% of the students had general ability to search and integrate information online. 91. 95% of the students were very satisfied with the online teaching mode of "Four Combinations", and their test scores were ideal. Conclusion Students were generally satisfied with the online teaching mode of "Four Combinations", but it was still necessary to improve the online teaching environment, strengthen the effect of classroom interaction and cultivate students' autonomous learning ability. The new online teaching mode of Basic Nursing Courses in macroteaching could provide reference for the effective implementation of online teaching. (目的 探讨腾讯课堂、MOOC、雨课堂和QQ群“四结合”在线教学模式在大班制《护理学基础》理论课中的应用效果。方法 对桂林医学院2018级护理专业学生733人进行“四结合”在线教学, 采用网络问卷调查学生学情。结果 12. 01%的学生认为上课环境是嘈杂的, 20. 05%学生反映网络信号弱, 22. 73%的学生认为网络是影响在线学习最主要的因素; 58. 39%的学生认为课堂互动一般; 70. 26%的学生反映自主学习能力一般; 63. 98%的学生反映网上搜索整合信息能力一般。91. 95%的学生对“四结合“在线教学模式感到非常满意, 本科生考试成绩平均分94. 37分, 高职生考试成绩平均90. 93分, 考核成绩理想。结论 学生对“四结合”的在线教学模式总体满意, 但仍需要改善网络教学环境、加强课堂互动效果和培养学生自主学习能力。通过充分的课前准备、创新教学设计、完善教学评价, 构建的大班制《护理学基础课程》在线教学新模式, 能为有效实施在线教学提供借鉴。)

Summary: Aquatic products are delicious and rich in high‐quality proteins, and thus have high‐food value and are popular among consumers; however, deterioration of their quality can easily occur when being stored and processed. Proteins, the main components of the muscle tissue of aquatic products, are closely related to the quality of aquatic products, and protein oxidation has become a research hotspot for studying the regulatory mechanisms of aquatic product quality changes. Protein oxidation is one of the main causes of quality deterioration of aquatic products, mainly because of protein cross‐linking and protein degradation caused by oxidation. Related studies have also shown that the changes in the electrostatic charge of proteins owing to oxidation are associated with the muscle water‐holding capacity (WHC). This article introduces the induction mechanism of protein oxidation in aquatic products, focusing on its effects on the quality, such as colour, texture, WHC and summarises the current research progress of aquatic products quality control on this basis to provide theoretical reference for future research. [ABSTRACT FROM AUTHOR]

Hyperspectral image (HSIs) denoising is a preprocessing step that plays a crucial role in many applications used in Earth observation missions. Low-rank tensor representation can be utilized to restore mixed-noise HSIs, such as those affected by mixed Gaussian, impulse, stripe, and deadline noises. Although there is a considerable body of research on spatial and spectral prior knowledge concerning subspace, the correlation between the spectral continuity and the nonlocal sparsity of the spectral and spatial factors is not yet fully understood. To address this deficiency, in the present study, we determined the correlation between these factors using a cascaded technique, and we describe in this paper the double-factor tensor cascaded-rank (DFTCR) minimization method that was used. The information existing in the nonlocal sparsity property of the spatial factor was employed to promote a geometrical feature representation, and a tensor cascaded-rank minimization approach was introduced as a nonlocal self-similarity to promote restoration quality. The continuity between the difference and nonlocal gradient sparsity constraints of the spectral factor was also introduced to learn the basis. Furthermore, to estimate the solutions of the proposed model, we developed an algorithm based on the alternating direction method of multipliers (ADMM). The performance of the DFTCR method was tested by a comparison with eleven established denoising methods for HSIs. The results showed that the proposed DFTCR method exhibited superior performance in the removal of mixed noise from HSIs. [ABSTRACT FROM AUTHOR]

In this article, we report original data on the designation of the primers for full-length cDNA amplification and the internal cDNA amplification of red color-related pigment-binding protein derived from shrimp shell. Data on the color shifts of different soluble proteins under 100 °C 10 min heat treatment and the effects of heating temperatures (from 30 to 100 °C) on the color changes of crude water-soluble proteins are also included in this report. For further details and experimental findings please refer to the article “Isolation and cDNA cloning of a novel red color-related pigment-binding protein derived from the shell of shrimp, Litopenaeus vannamei” (Chuang et al., 2017) [1].

Summary: In the present study, the influences of different origins and harvest periods on the characterisation, structure and antioxidant activity of Porphyra haitanensis polysaccharides (PHPs) were investigated. PHPR03 obtained from the third harvest period (late December) in Raoping possessed the highest content of sulphate group (14.70%), the lowest viscosity (434.34 mL·g−1) and exhibited better antioxidant activity. FTIR spectrum confirmed that PHPs obtained in different origins and harvest periods had similar functional groups (O—H, C—H and C—O group). Thermal gravimetric analysis suggested that PHPR03 has good thermal stability until 182 °C. PHPR03 microstructure was detected using scanning electron microscopy, and it was mainly irregular flocs. Atomic force microscope data showed that its diameter and height ranged from 1.32 to 1.99 μm and 14.16 to 34.92 nm, respectively. X‐ray diffraction and Congo red experiments indicated that PHPR03 belongs to amorphous material with weak rigidity and exists in the form of random coils in an aqueous solution. PHPR03 resulted in a decrease of thiobarbituric acid‐reactive substances value of ground pork. This study provides the theoretical basis for rational utilisation and further applications in the food industry of PHPs. [ABSTRACT FROM AUTHOR]