A new switched capacitor resonator and its research

In bandpass sigma delta modulator, resonator is the key block. This paper proposed a new resonator which can simplify the circuit implementation when designing bandpass modulator with lowpass prototype. The effect of finite gain, finite bandwidth, and path mismatch on the resonator is analyzed. The function of the proposed resonator and the devired equations about path mismatch have been verified by switched capacitor software SWITCAP.     

我国宜一步到位发展高速磁悬浮列车——先行建设宁沪杭甬高速磁悬浮列车线

高速磁悬浮列车是 2 1世纪新型的、理想的交通工具 ,具有较多的优越性 ,其技术已趋成熟。我国应跨越轮轨铁路 ,一步到位发展磁悬浮列车。长江三角洲地区经济、社会飞速发展 ,区域需要建立快速、安全、舒适、清洁、节能的高速主通道。先在沪宁线或沪杭甬线上建试验段 ,然后建设宁—沪—杭—甬高速磁悬浮列车线 ,成为区域内实现 2小时经济圈的主通道     

探索城市景观桥梁的建筑造型

本文通过对单体景观桥梁和群组景观桥梁的典型工程的分析,阐述了建筑师对于城市景观桥梁的造型的理解和探索,通过案例总结出不同种类景观桥梁造型的塑造方法并以建筑师的表达方式来满足社会对景观桥梁的需求。     

基于带偏好DEA模型的长株潭城市群公路交通效率评价

从城市群公路交通系统的输入和输出角度出发, 给出城市群公路交通效率的输入输出指标体系, 建立数据包络分析 (data envelopment analysis, DEA) 模型及带偏好DEA (A-prefer-DEA, PDEA) 模型, 进而对长株潭、长三角和珠三角城市群公路交通效率进行有效计算和综合评价.传统DEA模型的评价结果表明:长株潭城市群公路交通效率为DEA弱有效, 长三角和珠三角公路交通效率为DEA有效;PDEA模型评价结果更直观, 长三角、珠三角和长株潭公路交通效率值分别为1.678 2、1.577 9和0.866 2, 长株潭公路交通效率与长三角和珠三角的差距比较明显.     

长江三角洲地区传统饮食文化资源的赋存及关联研究

传统饮食文化资源是区域文化资源的重要构成部分,是地区历史文化和人文风情的具体体现。将传统饮食文化资源解构为饮食类非物质文化遗产和中华老字号两个部分,分析长三角地区传统文化资源的赋存及空间关联情况。研究表明,长三角地区传统饮食文化资源的赋存具有明显的空间分异特点,文化资源在类型上存在诸多共性之处,体现了吴越文化的特点。文化资源的相互关联呈现出地区和类型两方面的差异,需要构建不同的传统饮食文化资源保护传承和协同开发的路径和模式。     

广义Delta算子系统的H_∞性能分析及控制

针对广义Delta算子系统的H∞性能分析及H∞控制问题,本文采用Delta算子方法,利用线性矩阵不等式,对广义Delta算子系统进行H∞性能分析。通过分析得到使广义Delta算子系统容许且具有H∞性能的充分必要条件。在此基础上,进一步考虑了广义Delta算子系统的H∞控制问题,对于不是容许且具有指定H∞性能的广义Delta算子系统,基于线性矩阵不等式,给出了广义Delta算子系统状态反馈H∞控制器的存在条件和设计方法,并利用MATLAB-LMI工具箱,对给出的数值算例进行计算和分析。结果表明,所得闭环广义离散系统容许且满足H∞性能,证明了本文所给出的判别方法的有效性。Delta算子方法在广义离散系统的性能研究中可以良好应用。     

低可容空间河流三角洲沉积层序与聚煤模式

为了揭示低可容空间河流三角洲沉积背景下层序发育及聚煤特征,以鲁西南二叠系山西组为例进行了层序地层和聚煤作用研究.识别出强制海退(BFSR)造成的陆表侵蚀不整合面(SU)及其对应的整合面(CC*)、河流侵蚀面(RES)、古土壤层(PSS)、最大海退面(MRS)、海泛面(FS)、最大海泛面(MFS)7种层序界面,将煤系划分为12个准层序(2种准层序类型)、2个四级层序、1个三级层序,提出了低可容空间沉积背景下河流三角洲沉积体系聚煤模式.结果表明:低可容空间河流三角洲沉积背景下基准面与沉积界面基本一致,准层序以侵蚀面和海泛面为界并主要沉积于基准面上升半旋回;绝对海平面下降速率超过基底沉降速率是层序边界形成的主要驱动力;平面上聚煤中心位于下三角洲平原和间湾湖泊环境,指出剩余可容空间大小及新增可容空间产生速率是泥炭沉积的关键因素.     

Climate history of the middle reach of the Yangtze river over the past 9000 years: A speleothem isotopic record from Za cave, Hubei, China

A stalagmite in Qingjiang, Hubei, has yielded the records of hydrogen and oxygen as well as carbon isotopic changes and provided a climate history of 9000 years. The hydrogen iso-topic ratio in fluid inclusions and the oxygen isotopic ratio in stalagmite calcite are controlled by meteoric water, which is in response to ambient temperature or precipitation amount. The carbon isotopic ratio, sensitive to the nature of vegetation, also can be used to reconstruct the climate history. The carbon-14 and U-series dated stalagmite records reveal that climate oscillated in the middle reach of Yangtze river over the past 9000 years:(1) 9.0-6.5 kaBP, a cooler and more humid condition; (2) 6.5-4.0 kaBP,with warmer and drier weather; (3) 4.0-2.0 kaBP, cold weather with heavy precipitation, and (4)2.0 kaBP to present, tendency to be warmer and drier.     

纳雍地区龙潭组中段沉积序列模式及沉积体系的初步研究

本文在对贵州省纳雍地区龙潭组中段一剖面详细研究的基础上,划分出八种主要岩相类型,在此基础上,运用马尔可夫链分析法建立了该段的两种主要序列模式,通过沉积序列分析认为:该区龙潭组中段为一受潮汐影响的三角洲体系。     

Acute β-Hydroxy-β-Methyl Butyrate Suppresses Regulators of Mitochondrial Biogenesis and Lipid Oxidation While Increasing Lipid Content in Myotubes

Leucine modulates synthetic and degradative pathways in muscle, possibly providing metabolic benefits for both athletes and diseased populations. Leucine has become popular among athletes for improving performance and body composition, however little is known about the metabolic effects of the commonly consumed leucine‐derived metabolite β‐hydroxy‐β‐methyl butyrate (HMB). Our work measured the effects of HMB on metabolic protein expression, mitochondrial content and metabolism, as well as lipid content in skeletal muscle cells. Specifically, cultured C2C12 myotubes were treated with either a control or HMB ranging from 6.25 to 25 μM for 24 h and mRNA and/or protein expression, oxygen consumption, glucose uptake, and lipid content were measured. Contrary to leucine's stimulatory effect on metabolism, HMB‐treated cells exhibited significantly reduced regulators of lipid oxidation including peroxisome proliferator‐activated receptor alpha (PPARα) and PPARβ/δ, as well as downstream target carnitine palmitoyl transferase, without alterations in glucose or palmitate oxidation. Furthermore, HMB significantly inhibited activation of the master regulator of energetics, AMP‐activated protein kinase. As a result, HMB‐treated cells also displayed reduced total mitochondrial content compared with true control or cells equivocally treated with leucine. Additionally, HMB treatment amplified markers of lipid biosynthesis (PPARγ and fatty acid synthase) as well as consistently promoted elevated total lipid content versus control cells. Collectively, our results demonstrate that HMB did not improve mitochondrial metabolism or content, and may promote elevated cellular lipid content possibly through heightened PPARγ expression. These observations suggest that HMB may be most beneficial for populations interested in stimulating anabolic cellular processes.