[Bmim]BF4离子液体中微波辅助制备TiO2催化剂及活性研究

采用微波加热合成离子液体[Bmim]BF4,以该离子液体为反应介质,在微波辐射条件下制备TiO2光催化剂,在高压汞灯下用甲基橙溶液测试其光催化降解性能;并用XRD,IR,TG对其进行测试和表征。结果表明,制备TiO2光催化剂的较佳条件是:离子液体2.0mL,微波辐射功率600W、反应温度70℃、反应时间35min。并且用[Bmim]BF4作为反应介质,能够显著提高TiO2的光催化活性,所制备的TiO2不需要经过高温煅烧,就表现出极高的光催化活性。该催化剂对甲基橙的降解率在1.5h就可达到93.7%。     

惠州市出口贸易对环境影响的实证分析

惠州经济的高速发展和伴生的环境污染问题,是在我国经济加速融入全球经济的背景下发生的。文章基于惠州1987-2009年的时间序列数据,通过实证方法分析出口贸易对环境(SO2)的影响,指出随着时间的推移,出口的增长,将不利于惠州环境的改善;如果在贸易自由化,同时实施更严格的环境管制,可以促进贸易与环境协调发展,进而实现惠州良好的规模效应、结构效应、技术效应以及要素优化配置等的结果。     

浅析B2C服装电子商务企业如何吸引风险投资

初创期B2C服装电子商务企业高风险、高投入、高预期收益的特性使我国B2C服装电子商务企业在发展过程中时刻伴随着风险投资的身影,但如何吸引风险投资是B2C服装电子商务企业面临的一个难题。文章在分析风险投资选择项目的标准的基础上,从创业管理团队、商业模式两个方面论述了初创期B2C服装电子商务企业如何吸引风险投资。     

Responses to oral glucose challenge differ by physical activity volume and intensity: A pilot study

BackgroundOne-hour postprandial hyperglycemia is associated with increased risk of type 2 diabetes and cardiovascular disease. Physical activity (PA) has short-term beneficial effects on post-meal glucose response. This study compared the oral glucose tolerance test results of 3 groups of people with habitually different levels of PA.MethodsThirty-one adults without diabetes (age 25.9 ± 6.6 years; body mass index 23.8 ± 3.8 kg/m²; mean ± SD) were recruited and divided into 3 groups based on self-reported PA volume and intensity: low activity < 30 min/day of moderate-intensity activity (n = 11), moderately active ≥ 30 min/day of moderate-intensity PA (n = 10), and very active ≥ 60 min/day of PA at high intensity (n = 10). Participants completed an oral glucose tolerance test (50 g glucose) with capillary blood samples obtained at baseline, 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min post-ingestion.ResultsThere were no significant differences between groups for age or body fat percentage or glycated hemoglobin (p > 0.05). The groups were significantly different in terms of baseline glucose level (p = 0.003) and, marginally, for gender (p = 0.053) and BMI (p = 0.050). There was a statistically significant effect of PA on the 1-h postprandial glucose results (p = 0.029), with differences between very active and low activity groups (p = 0.008) but not between the moderately active and low activity groups (p = 0.360), even when baseline glucose level and gender differences were accounted for. For incremental area under the curve there was no significant effect of activity group once gender and body fat percentage had been accounted for (p = 0.401). Those in the low activity group took 15 min longer to reach peak glucose level than those in the very active group (p = 0.012).ConclusionThe results suggest that high levels of PA have a beneficial effect on postprandial blood glucose profiles when compared to low and moderate levels of activity.     

NiCo_2O_4纳米结构阵列的水热合成与氧析出特性研究

钴酸镍纳米材料具有良好的电催化氧析出反应(Oxygen Evolution Reaction,OER)活性,是一种很有发展潜力的非贵金属电催化材料。文章以碳纤维纸为基底,采用水热合成的方法对纳米结构钴酸镍的生长进行了系统的研究,分别考察了生长温度、前驱体浓度和配比、生长时间对产物的形貌、尺寸、物相结构、OER电化学性能的影响,通过对比分析后发现在生长温度100℃、生长时间5h、镍钴比为2:1时所获得的多孔片状钴酸镍纳米结构具有最佳的OER特性。     

基于MIP-SLA的叶片陶瓷型芯光固化成型技术

为解决航空发动机空心涡轮叶片陶瓷型芯的3D打印难题,研究基于图像投影的复杂结构陶瓷型芯光固化成型（mask-image projection stereolithography,MIP-SLA）方法。搭建MIP-SLA工艺系统平台,对陶瓷浆料的制备和打印工艺参数的配置进行研究。分析利用球磨机将光敏树脂和陶瓷颗粒进行混合制备陶瓷浆料时,光敏树脂类型、固相含量、陶瓷颗粒粒径、分散剂含量和球磨时间对陶瓷浆料性能的影响。对不同配置参数下的打印效果进行对比分析,对确定的最佳打印工艺参数进行打印效果验证。     

Utility of P-SEP,sTREM-1 and suPAR as Novel Sepsis Biomarkers in SARS-CoV-2 Infection

The coronavirus disease 2019 is a highly contagious viral infection caused by SARS-CoV-2 virus, member of coronaviridae family. It causes life threatening complications due to complexity and rapid onset course of the disease. Early identification of high-risk patients who require close monitoring and aggressive treatment remains challengeable till date. Novel biomarkers which help to identify high risk patients at the early stage is high priority. Objective of this review to find utility of P-SEP, sTREM-1 and suPAR for diagnosis, risk stratification and prognosis of SARS-CoV-2 infected cases. Soluble receptors like, P-SEP, sTREM-1 and suPAR have been involved in immune regulation in SARS-CoV-2 infection and elevate more in severe cases. A comprehensive research of databases like PubMed, EMBASE, CNKI and Web of Science was performed for relevant studies. A total of nine out of fifteen research literature in initial screening were included for this review. Interestingly all studies have reported high levels of P-SEP, sTREM-1 and suPAR in SARS-CoV-2 infected cases and the biomarkers positively correlated with severity of infection. This implies that P-SEP, sTREM-1 and suPAR can be implemented as surrogate marker in blood profile for early diagnosis, risk stratification and prognosis in SARS-CoV-2 for better management in Indian population at the current situation.     

Combined effects of exposure to hypoxia and cool on walking economy and muscle oxygenation profiles at tibialis anterior

We investigated combined effects of ambient temperature (23°C or 13°C) and fraction of inspired oxygen (21%O₂ or 13%O₂) on energy cost of walking (C_w: J·kg^?1·km^?1) and economical speed (ES). Eighteen healthy young adults (11 males, seven females) walked at seven speeds from 0.67 to 1.67 m s^?1 (four min per stage). Environmental conditions were set; thermoneutral (N: 23°C) with normoxia (N: 21%O₂) = NN; 23°C (N) with hypoxia (H: 13%O₂) = NH; cool (C: 13°C) with 21%O₂ (N) = CN, and 13°C (C) with 13%O₂ (H) = CH. Muscle deoxygenation (HHb) and tissue O₂ saturation (StO₂) were measured at tibialis anterior. We found a significantly slower ES in NH (1.289 ± 0.091 m s^?1) and CH (1.275 ± 0.099 m s^?1) than in NN (1.334 ± 0.112 m s^?1) and CN (1.332 ± 0.104 m s^?1). Changes in HHb and StO₂ were related to the ES. These results suggested that the combined effects (exposure to hypoxia and cool) is nearly equal to exposure to hypoxia and cool individually. Specifically, acute moderate hypoxia slowed the ES by approx. 4%, but acute cool environment did not affect the ES. Further, HHb and StO₂ may partly account for an individual ES.     

Between-limb differences in running technique induces asymmetric negative joint work during running

Negative work, which is mainly generated by eccentric muscle contraction, has an important influence on the associated muscle damage. Generally, mechanical parameters are determined for one side of a lower extremity on the assumption of negligible between-limb differences. However, between-limb differences in the negative work of lower extremity joints during running remain unclear. This study examines between-limb differences in negative work and associated mechanical parameters during the contact phase of running. Twenty-five young adult males voluntarily participated in this study. Each participant was asked to run on a straight runway at a speed of 3.0?m?s^?1. Negative work, amplitude, duration of negative power, moment, and angular velocity were computed for both sides of the lower extremities. Significant differences were found in negative work between limbs for the hip (18.9?±?11.7%), knee (13.6?±?10.4%), and ankle (11.8?±?8.5%) joints. For the hip joint, asymmetric negative work was attributable to the between-limb difference in the amplitude of negative power owing to a corresponding difference in the moment. The between-limb differences concerning the duration and amplitude of negative power could explain the asymmetric negative work in the knee joint. The asymmetric negative work of the ankle joint was attributable to the between-limb difference in the amplitude and duration of the negative power and the moment. These results indicate that asymmetric negative work was generated in each lower extremity joint; however, the major mechanical parameters corresponding to the negative work are not the same across the joints.     

一种机载重轨InSAR高精度三维定位方法

在重轨干涉实际测量中,两次飞行航迹难以保持高度重合,飞行高度和姿态不稳定,干涉图像对存在明显不规则的相对形变,难以进行三维定位。通过分析重轨机载InSAR图像对的几何形变和形成原因,提出一种从精准的InSAR成像几何关系出发,通过修正成像参数,实现机载重轨InSAR高精度三维定位的方法。该方法通过引入地面控制点,实现干涉图像对精准的相对定位,生成高精度DEM;并利用高精度DEM,实现机载重轨InSAR高精度三维定位。对比检查点实测结果和定位结果,表明该方法可有效地解决机载重轨InSAR的三维定位困难的问题。