Modern accumulation rates and a budget of sediment off the Gaoping (Kaoping) River, SW Taiwan: A tidal and flood dominated depositional environment around a submarine canyon

Ninety-two box cores collected during 2004–2006 from an area of ~ 3000 km² off the Gaoping (formerly spelled Kaoping) River, SW Taiwan, were analyzed for fallout radionuclides (²¹⁰Pb, ¹³⁷Cs and ⁷Be) to elucidate sedimentation rates and processes, and for the calculation of a sediment budget. The study area is located at an active collision margin with a narrow shelf and a submarine canyon extending essentially into the river's mouth. The results indicate fairly constant hemipelagic sedimentation in much of the open margin and for most of the time except in the inner shelf and along the axis of the canyon where sediment transport is more dynamic and is controlled by tidal current and wave activities constantly, and by fluvial floods or gravity-driven flows episodically. Sedimentation rates in the study area derived from ²¹⁰Pb and constrained by ¹³⁷Cs vary from 0.04 to 1.5 cm/yr, with the highest rates (> 1 cm/yr) flanking the Gaoping canyon over the upper slope (200–600 m) and the lowest rates (< 0.1 cm/yr) in the distal basin beyond the continental slope. The depocenter delineated from ²¹⁰Pb-based sedimentation rates overlaps with the area covered by a flood layer resulting from super-typhoon Haitang in July 2005. Such correspondence supports the notion that the processes operating on event timescale have bearing on the formation of the sediment strata over centennial or longer timescales.From the distribution of sedimentation rates, sediment deposited in the study area annually is estimated to be 6.6 Mton/yr, accounting for less than 20% of Gaoping River's sediment load. The calculated budget, coupled with the presence of the short-lived ⁷Be and non-steady-state distribution of low levels of ²¹⁰Pb in sediments along the canyon floor, suggests rapid transport of sediment from Gaoping River's mountainous watershed (the source) via the Gaoping (Kaoping) Submarine Canyon and adjacent channels (as the conduit and temporary sink) to the abyssal plain and the Manila Trench in the South China Sea (the ultimate sink).     

LY12铝合金搅拌摩擦焊工艺研究

对LY12铝合金进行了搅拌摩擦焊接工艺试验,并对焊接接头进行了金相观察和力学性能检测.试验结果表明,合理的焊接参数匹配是取得性能优良焊接接头的前提.当旋转速度为905 r/min、焊接速度为33.6 mm/min、肩部压力为48 MPa时施焊,可获得成型良好无缺陷焊接接头,且焊缝区晶粒细小.搅拌摩擦焊焊接轧态LY12铝合金时,焊接时的热输入可部分消除接头处金属的冷作硬化.随着焊接速度的提高,焊接热输入量降低,消除冷作硬化的能力减弱,焊接接头抗拉强度提高.     

深水M型跨接管涡激振动疲劳损伤评估

针对涡激振动引发深水M型跨接管发生疲劳损伤的问题,考虑到M型跨接管非平直管道,弯管的引入对跨接管疲劳评估带来较大的困难,以南海某跨接管为例,通过ABAQUS软件进行跨接管模态分析,形成SHEAR7软件的模态输入文件,对跨接管分区使用SHEAR7软件分析跨接管的顺流涡激振动和横流涡激振动疲劳损伤.     

基于二极管箝位级联拓扑变流器的直驱风电用变流技术

直接驱动型风力发电系统需要全功率变流器作为与电网的接口，多电平变流器的应用得到了广泛关注。二极管箝位五电平级联H桥拓扑，结合了二极管箝位型多电平和级联H桥多电平的优势，只需较少的箝位二极管和独立直流电源，即可进一步提高输出电压等级；使用移相变压器和12脉波整流器作为输入电路.可以方便地应用在使用多相永磁同步发电机的直驱风电系统中。基于拓扑提出了消谐波SPWM和载波相移SPWM相结合的调制方法，能够方便地对二极管箝位级联拓扑进行控制，可以进一步提高等效载波频率，减小器件损耗和滤波器体积。仿真和实验结果证实了所采用的拓扑及其控制方法的有效性。     

MG_7-Ag与AgNOR联用鉴别胃癌与癌前病变

用MG7－Ag和AgNOR法对30例胃癌、20例胃粘膜上皮中重度异型增生、31例肠上皮化生及20例正常胃粘膜进行了研究。结果显示胃癌组MG7－Ag强阳性率高于异型增生和肠上皮化生（P＜0.05）。胃癌细胞核内AgNOR形态和计数与良性病变明显不同。以MG7－Ag强阳性表达和细胞核内AgNOR计数明显增多（＞9．12）或大小不等是团块状分布为阳性指标，MG7－Ag和AgNOR联用，胃癌检出率达90％，显著高于单项使用的检出率（P＜0．025）。结果表明，MG7－Ag与AgNOR联用，对区分胃癌与癌前病变具有重要价值。     

SS7E型电力机车平稳性问题的原因分析及改善

主要对SS7E型电力机车的油压减振器与轴箱拉杆对机车的影响进行分析与研究，并对其进行跟踪性试验，提出了对机车平稳性能改进的方案，并在机车上运用，获得了较好的效果。     

MPEG家族新成员——MPEG-7

分析简要介绍了多媒体数据压缩标准MPEG的发展历程,重点介绍了MPEG-7这一新的多媒体信息编码标准的内容,并通过列举MPEG-7的应用,指出MPEG-7将对工业界以及人们的生活产生深远的影响:     

S7-300PLC构成PROFIBUS-DP网络的原理及应用

讨论用PLC构成PRORBUS-DP网络系统的方法.首先介绍DP网的概念和实现,然后结合一个实际的例子来着重阐明用PLC来实现DP网络的解决方法.     

Road traffic conditions in Kenya: Exploring the policies and traffic cultures from unstructured user-generated data using NLP

Road traffic accidents (RTA) are a prevalent cause of fatality with African countries having the highest fatality index (25–34 per quota). The World Health Organization estimates Kenya's fatality rate due to RTA at 28 per quota. From literature, the country's fatality and injuries have increased by 26% and 46.5%, respectively, since the year 2015. The country is faced with incomplete RTA data capturing, hindering effective planning and policy adjustments to curb the menace. In this paper, we scrapped user-generated data (Twitter) and national transport and safety authority's (NTSA) reports to shed light on traffic safety, practices, and cultures in the country. To this end, we gathered 1,000,000 tweets and 8000 speeding entries between 2015 and 2021 and performed natural language processing (NLP) and quantitative study of the data. We applied NLP and n-gram search of keywords to categorize data into 8 topics: traffic, public service vehicle (PSVs), policing, accident, infrastructure, recklessness, robbery, and corruption. From the data, policing, which touches on all police and law-enforcement-related activity was found to be highly correlated with PSVs, recklessness, accidents, traffic congestion, robbery, infrastructure, and corruption with indices of r(76) = 0.92, 0. 91, 0.87, 0.82, 0.81, 0.76, and 0.70, respectively with p < 0.001. The topic modeling confirmed the identified topics to be the latent discussion issues affecting the public. From the study, PSVs, policing and traffic flow were isolated as key issues that ought to be addressed immediately. The research recommended the integration of driver monitoring systems to strengthen policing. The research, which utilized unstructured data, points to the utility of data mining which would greatly benefit traffic research, particularly African-based studies, that suffer from data inadequacy.     

Kinetic spectrophotometric method for determination of amlodipine besylate in its pharmaceutical tablets

A simple and sensitive kinetic spectrophotometric method has been developed and validated for determination of amlodipine besylate (AML). The method was based on the condensation reaction of AML with 7...