摘要：以贮箱整底用2219铝合金板材为研究对象,根据实际充液拉深成形过程,开展了充液拉深成形仿真模拟。为探究仿真中不同单元类型对起皱预测的影响,设计并开展了长杆压缩实验,并利用实体单元以及具有不同参考面选择的壳单元进行有限元仿真,分析了不同单元类型下试样的失稳特性。对比实验和仿真结果发现,与实体单元相比,壳单元参考面的选择影响单元厚度方向求解域的连续性,严重失稳情况下单元厚度方向求解域可能发生重叠或缺失,进而造成计算结果偏差较大,并且壳单元忽略薄板沿厚度方向的应力,对失稳的几何响应比实体单元更加敏感。在充液拉深仿真中,零件最终起皱情况对充液压力施加初期零件表面初始几何起皱较为敏感,当零件表面具有一定的初始起皱时,均匀分布的法向充液压力会在失稳起皱区域处形成平衡,并在后续变形过程中演化成更严重的起皱缺陷。

摘要：为妥善保存病理标本,防止病理标本丢失及腐烂,本文设计了一种高效环保的医用标本冷藏柜。该冷藏柜主要由智能温度控制系统、安全报警系统、制冷系统以及显示系统构成,可以保障病理生物标本保存的密封性,做到防水、防破损、防外泄。该冷藏柜可广泛用于医院、研究所等相关单位贵重标本的冷藏保存,具有一定的临床价值。

摘要：The spin-dependent electronic transport properties of a zigzag zinc oxide(ZnO) nanoribbon are studied by using density functional theory with non-equilibrium Green's functions. We calculate the spin-polarized band structure, projected density of states, Bloch states, and transmission spectrum of the ZnO nanoribbon. It is determined that all Bloch states are located at the edge of the ZnO nanoribbon. The spin-up transmission eigenchannels are contributed from Zn 4s orbital,whereas the spin-down transmission eigenchannels are contributed from Zn 4s and O 2p orbitals. By analyzing the current-voltage curves for the opposite spins of the ZnO nanoribbon device, negative differential resistance(NDR) and spin filter effect are observed. Moreover, by constructing the ZnO nanoribbon modified by the Zn-edge defect, the spin-up current is severely suppressed because of the destruction of the spin-up transmission eigenchannels. However, the spin-down current is preserved, thus resulting in the perfect spin filter effect. Our results indicate that the ZnO nanoribbon modulated by the edge defect is a practical design for a spin filter.

摘要：近年来,金属有机框架(MOFs)构建的荧光探针因其在传感领域展现出的卓越性能而备受瞩目.这类荧光探针不仅有效弥补了传统检测技术的诸多不足,还兼具成本低、操作简便、可视化程度高及灵敏度高等显著优势,已广泛应用于传感技术研究.本文系统回顾了近年来国内外在金属有机框架及其复合材料作为荧光探针应用于离子传感方面的研究进展.详细阐述了MOFs及其复合材料荧光探针的设计策略、结构特征、发光特性以及传感机理,并对MOFs类荧光探针的未来发展趋势进行了深入分析与展望.

摘要：[目的]早期快速精准鉴定马尾松和火炬松杂交子代,选育高抗马尾松×火炬松家系,以期更好地防控松材线虫病。[方法]本研究以马尾松为母本,火炬松为父本进行杂交,比对火炬松和油松基因组序列设计特异性引物,筛选马尾松与火炬松种间特异性引物,对杂交后代进行扩增条带分析,建立马尾松×火炬松快速鉴定体系,通过接种松材线虫评价筛选高抗家系。[结果]从150对引物中筛选出12对引物组合用于鉴定,特异性强,稳定性好,且扩增率高。F1代29个家系共88个样本,其中81株鉴定为杂交植株,杂种率为92.05%;F2代21个家系共688个样本,其中279株为杂交植株,杂种率为40.55%;对马尾松×火炬松F2代13个家系进行抗性评价,获得5个高抗家系。[结论]12对引物组合可作为马尾松和火炬松杂交子代真实性鉴定,筛选获得5个高抗家系,为松材线虫病防控和抗性机理研究奠定基础。

摘要：为了满足三通管液压成形过程的监测和过程控制的需求,构建了一个基于有限元数据驱动的机器学习框架用于多物理场的实时预测,包括:数据生成模型构建,建立能够准确描述塑性成形过程的有限元模型;数据集生成,结合成形工艺特点和成形设备参数范围要求进行实验设计,同时通过有限元模拟创建数据集,用于机器学习模型的训练;模型训练,选择机器学习算法就有限元模拟生成的数据集进行学习,建立边界位移与材料内部位移场的映射;多物理场计算,基于预测位移场推导材料内部应变、应力以及厚度场等的分布。采用该框架构建了基于CPB06屈服准则的纯钛三通管液压成形有限元模型,在此基础上通过加载路径全因子模拟实验生成了机器学习数据集,并采用随机森林和梯度提升算法实现了材料内部位移的实时预测,计算出了等效应变、等效应力和管材壁厚的分布。将上述预测模型用于全新工况的三通管液压成形,结果表明,预测误差不超过5%,说明构建的集成有限元方法的机器学习框架可以解决有限元模型无法在线分析的问题,实现对塑性加工过程中多物理场的实时预测。

摘要：The engineering application of natural hyperaccumulators In removing or inactivating metal pollutants from soil and surface water In field trials mostly presents the insurmountable shortcoming of low efficiency owing to their little biomass and slow growth. Based on further understanding of the molecular mechanism of metal uptake, translocation, and also the separation, identification, and cloning of some related functional genes, this article highlights and summarizes In detail the advances in research on transgenlc techniques, such as Agrobacterlurn tumefaciens-medlated transformation and particle bombardment, in breeding of plants for metal resistance and accumulation, and points out that deepening the development of transgenlc plants Is one of the efficient approaches to improving phytoremedlatlon efficiency of metalcontaminated environments. From the viewpoint of sustainable development, governments should strengthen support to the development of genetic engineering for metal resistance and accumulation In plants.

摘要：A series of novel derivatives of indirubin were synthesized and evaluated for their anti-proliferative activity against human cancer cell lines of SGC7901,A549,HL-60,SK-BR-3 and *** of the compounds displayed more potent activity than *** addition,the derivatives showed improved water solubility,which may be favorable to their pharmacokinetic performances.

摘要：An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration. The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its quality. The frequency response characteristic of the accelerometer was measured2 The accelerometer with a resonant frequency of 3549 Hz was demonstrated to show good linear frequency responding characteristics in the range of 100-3000 Hz. The accelerometer also shows good stability and consistency. Experimental results indicate that the outputs of the on- and cross-axis are 147 and 21.3 mV, respectively.

摘要：The deepening process of globalization has given rise to restless cultural exchanges among people from different regions of the world through newspapers,books,and other written ***,the significant differences in languages and cultures have become an insurmountable gap in intercultural *** lubricate cultural exchanges,new translation theories that focus on the transformation of different cultural concepts shall be introduced and *** paper aims to extract applicable notions from Hofstede’s Cultural Dimensions for pragmatic translation studies by laying emphasis on its pragmatic value through case *** such theoretical transplantation,valuable suggestions are proposed to tackle cultural misunderstandings and conflicts encountered amid cultural exchanges.