渡槽整体结构环境激励模态试验

为获得渡槽整体结构动力特性,开展单向SIMO法、双向MIMO法环境激励模态试验,选用增强频域分解法识别纵向、横向、竖向、横竖双向模态参数.结果表明:2种方法识别出的模态大多数谱峰明显、识别效果较好;纵向模态以排架结构振动为主,槽身整体平动或转动或不动;前4阶横向模态以排架结构振动为主,槽身整体平动或转动或横摇,第5阶模...     

对现代园林植物景观设计的理性思考

植物景观设计是现代园林景观设计的重要内容．针对现代园林植物景观设计中出现的问题和误区,提出了现代园林植物景观设计应遵循自然为先的原则．     

视频点播系统交互式功能的设计与实现

针对视频点播系统的交互特性,在使用MPEG标准的基础上,利用空间换效率的思想,建立Ⅰ帧文件及其索引,进而提出了单道交互式功能的调度模型,实现了类视频录像系统的交互式功能,如快进、快退、暂停、随机读取和恢复播放等．根据IP组播技术的特点,为用户建立专用的类视频录像操作的数据通道提供非单道模式下的数据传输,并利用流的分离与合并技术,给出了流共享机制下实现交互式功能的解决方案．单道交互式功能的测试显示出播放、快进和快退等状态能够进行平滑切换,达到录像机相应操作状态的效果．     

基于类别不平衡的企业信用风险违约测度探索 ——以制造业上市公司为例

针对所获取的类别不平衡的深沪A股制造业上市公司财务数据,为了预测制造业上市公司信用违约情况,提出基于欠采样改进的Lasso-Logistic模型;首先通过计算WOE和IV值,剔除风险识别能力和稳定性较差的变量,接着从"数据"层面对现有的Lasso-Logistic模型进行批量欠采样处理,最后结合"算法"层面对Lasso...     

创新:现代编辑传播的核心——读《编辑创新与现代传播》

创新是知识经济时代对现代编辑传播的核心要求.《编辑创新与现代传播》对这一命题做了四个方面的重要诠释:创新思维乃基础、创新能力为根本、理论创新应先行、实践创新是目的,从而以创新为理论圆点,构建了现代编辑主体的自我超越与发展之途,为编辑主体行为实践提供了具有活性的生命因子.     

Act in contravention: a non-planar coupled electrode design utilizing "tip effect" for ultra-high areal capacity,long cycle life zinc-based batteries

Aqueous zinc-based batteries (ZBBs) have great potential as commercial energy storage devices.However,the poor cycling stability of zinc anode under high areal ...     

铝箔碎屑收集负压管仿真优化设计

针对铝箔剪切机的碎屑收集问题,该文研究基于计算流体力学(CFD)使用负压管收集方法。在分析流场压力-速度耦合分布特征的基础上,探讨了不同管路结构对双支管吸力的影响规律,并给出管路优化设计建议。仿真结果表明：设置2个挡板时,第2个支管可形成有效负压及吸力,但在第1个支管附近会形成较大的低速回流区,气流流出支管;当2个支管共用1个出口时,2个支管均可产生负压及吸力,但支管与出口距离不一致时会导致支管速度差异达72.17%;优化后的等距型管路结构的支管速度差异降低至约2%,可在支管口形成均匀吸力,满足工业需求;随着挡板高度增加,支管口速度值、支管口速度差异分别呈现增大、减小趋势;支管与主管倒角设置对气流有良好的导向作用,支管速度可提高约9.64%。     

Cystic fibrosis transmembrane conductance regulator—emerging regulator of cancer

Mutations of cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis, the most common life-limiting recessive genetic disease among Caucasians. CFTR mutations have also been linked to increased risk of various cancers but remained controversial for a long time. Recent studies have begun to reveal that CFTR is not merely an ion channel but also an important regulator of cancer development and progression with multiple signaling pathways identified. In this review, we will first present clinical findings showing the correlation of genetic mutations or aberrant expression of CFTR with cancer incidence in multiple cancers. We will then focus on the roles of CFTR in fundamental cellular processes including transformation, survival, proliferation, migration, invasion and epithelial–mesenchymal transition in cancer cells, highlighting the signaling pathways involved. Finally, the association of CFTR expression levels with patient prognosis, and the potential of CFTR as a cancer prognosis indicator in human malignancies will be discussed.     

Differentiated cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer

Since the creation of Dolly via somatic cell nuclear transfer (SCNT), more than a dozen species of mammals have been cloned using this technology. One hypothesis for the limited success of cloning via SCNT (1%-5%) is that the clones are likely to be derived from adult stem cells. Support for this hypothesis comes from the findings that the reproductive cloning efficiency for embryonic stem cells is five to ten times higher than that for somatic cells as donors and that cloned pups cannot be produced directly from cloned embryos derived from differentiated B and T cells or neuronal cells. The question remains as to whether SCNT-derived animal clones can be derived from truly differentiated somatic cells. We tested this hypothesis with mouse hematopoietic cells at different differentiation stages: hematopoietic stem cells, progenitor cells and granulocytes. We found that cloning efficiency increases over the differentiation hierarchy, and terminally differentiated postmitotic granulocytes yield cloned pups with the greatest cloning efficiency.