Magnetic porous nano-carbon catalysts supported silver nanoparticles derived from chitin and their application in catalytic reduction reactions

The exploitation of recycled carbonaceous catalysts from renewable biomass resources such as chitin is a crucial issue for the development of the sustainable society. In this article, the chitin-based N and O doped carbon microspheres (ChC) were fabricated by a simple dissolution, sol–gel transformation, and the carbonization methods. Subsequently, the novel magnetic Ag-Fe₃O₄@chitin-based carbon microspheres catalyst (MChC) was successfully constructed through the in situ redox reaction. The as-prepared MChC possessed rich micropores with high-surface area, and a narrow size distribution (50–120 μm). The Ag-Fe₃O₄ nanoparticles were immobilized through the interaction with C, N, and O atoms in the pores of MChC. The reduction of 4-nitrophenol was applied to evaluate the catalytic activity of MChC. 4-Nitrophenol (4-NP) could be fully reduced to 4-aminophenol (4-AP) in 5 min with the catalyst MChC-45. Moreover, MChC could be collected in solution with an external magnet in 8 s and remained relatively high-catalytic activity after 10 cycle times. This work provided novel ideas for the fabrication of doped carbon material from biomass and promoted its utilization in nanocatalytic applications.     

基于电机效率的纯电动汽车传动系统参数匹配研究

为降低能耗、提高续航里程,本文提出了以提高电机效率为目标的纯电动汽车三档变速传动方案.首先,在分析电机工作特性的基础上提出了三档传动系统参数匹配方法;然后以某纯电动汽车为研究对象,对其驱动系统进行了改动:方案一在不改变原车型动力系统参数的情况下将传动系统由一档改为三档,并运用所提出的方法确定各档位的传动比;方案二在满足整车动力性指标要求下对电机重新选型并匹配三档传动系统;最后利用ADVISOR软件进行NEDC工况仿真分析.结果表明:在不改变原车型动力系统参数的情况下,采用三档传动可使整车的动力性和经济性都有一定的提升,续航里程提高了 9.2％,百公里电耗降低了 1.28 kW·h;重新选型电机后,采用三档传动续航里程提高了 14.1％,百公里电耗降低了 1.87kW·h.     

刮板输送机减速箱箱体模拟分析

为了解决刮板输送机减速箱箱体振动损坏的问题,利用数值模拟软件对箱体静力学进行分析,确定了输出箱螺栓孔为受力薄弱点,同时对固有频率振动云图进行分析发现,由于共振现象箱体出现平移振动.当传动系统出现振动时,造成齿轮在啮合时出现冲击受力,此时齿面的受力呈现不均匀性.最后对额定工况下的箱体最大动应力曲线呈现波动的态势,波动的应力值围绕14.1 MPa进行上下幅动,与0.0388 s的应力云图呈现一致,波动应力最大值为18.6 MPa,为刮板输送机减速器箱体优化提供一定的参考.     

职业能力导向下的高职实用性体育课程改革探析——以常州信息职业技术学院为例

现行的高职体育教学多是沿用普通高等学校的课程体系,课程内容并未反映高职教育应有的教育特点,没有很好地发挥体育教学与职业教育相衔接的教学效果.通过职业能力导向下高职实用性体育课程的实施,可以很好地培养学生未来工作岗位所需要的职业体能,提高职业身体素质,从而更好地服务高职教育的发展.     

Scanning tunneling spectroscopic study of monolayer 1T-TaS2 and 1T-TaSe2

Nano Research - The isostructural and isoelectronic transition-metal-dichalcogenides 1T-TaS2 and 1T-TaSe2 are layered materials with intricate electronic structures. Combining the molecular beam...     

碳脱氧在钢包顶渣改质中的应用

 为了进一步降低夹杂物缺陷并提高产品质量,基于碳脱氧进行了钢包顶渣改质的研究。冷轧产品的生产工艺为铁水预处理→转炉→RH精炼→连铸,为减少钢中夹杂物质量分数,需要进行钢包顶渣改质,同时降低钢包顶渣TFe质量分数。采用粒碳部分替代铝渣球的方法进行基于碳脱氧工艺的钢包顶渣改质,试验结果表明,顶渣改质效果良好,在顶渣TFe质量分数、中间包钢水游离氧明显降低的同时铸坯中Al₂O₃夹杂物得到优化;“30 kg粒渣+铝渣球”工艺降低生产成本5.16元/t(钢)。     

Nanomaterials for radiotherapeutics-based multimodal synergistic cancer therapy

Over the past decade, numerous studies have attempted to enhance the effectiveness of radiotherapy (external beam radiotherapy and internal radioisotope therapy) for cancer treatment. However, the low radiation absorption coefficient and radiation resistance of tumors remain major critical challenges for radiotherapy in the clinic. With the development of nanomedicine, nanomaterials in combination with radiotherapy offer the possibility to improve the efficiency of radiotherapy in tumors. Nanomaterials act not only as radiosensitizers to enhance radiation energy, but also as nanocarriers to deliver therapeutic units in combating radiation resistance. In this review, we discuss opportunities for a synergistic cancer therapy by combining radiotherapy based on nanomaterials designed for chemotherapy, photodynamic therapy, photothermal therapy, gas therapy, genetic therapy, and immunotherapy. We highlight how nanomaterials can be utilized to amplify antitumor radiation responses and describe cooperative enhancement interactions among these synergistic therapies. Moreover, the potential challenges and future prospects of radio-based nanomedicine to maximize their synergistic efficiency for cancer treatment are identified.

     

基于滑动式切比雪夫方法的广播星历插值分析

利用滑动式切比雪夫多项式拟合卫星坐标,详细介绍滑动式切比雪夫多项式拟合原理,并通过实例对比分析普通的切比雪夫多项式和滑动式切比雪夫多项式拟合卫星坐标的精度。结果表明,滑动式切比雪夫多项式拟合卫星坐标的精度比普通的切比雪夫多项式拟合精度高,在插值端点处能够很好地克服振荡和跳跃现象。