CGCS2000国家大地坐标系在石油勘探领域的推广应用研究

本文根据国家测绘局对于推广使用CGCS2000的政策要求,分析了BJ-54坐标系的缺陷及其在石油勘探生产中存在的问题,介绍了2000国家大地坐标系及其框架,就石油勘探生产中使用CGCS2000可能面临的问题进行了详细的论述,并提出了如何逐步实施的解决方案。     

母线保护在化工企业特殊主接线上的应用

文中阐述了RCS-915GS微机母线保护在某企业主接线的实际应用情况,针对6kV主接线中的特有运行方式的保护方案配置做了详细的分析,对于同类设施的安装、保护维护和使用具有参考和借鉴作用。     

水分胁迫下肥料配比对葡萄光合速率与氮代谢的影响--测试文章

以无核白鸡心葡萄为试材，设置3个水平的水分处理和3个肥料配比，研究水分胁迫下肥料配比对无核白鸡心葡萄叶片叶面积、叶绿素含量、光合速率及氮代谢相关酶活性的影响。结果表明：萌芽期和坐果期土壤水分含量为田间持水量的55%～60%、施肥配比为N∶P∶K=2∶5∶3的水肥处理能有效促进叶面积增加，提高光合速率，是较好的水肥处理组合；转色期和采收后需维持正常含水量和适当增施钾肥可提高光合速率；土壤水分含量为田间持水量的55%～60%、施肥配比为N∶P∶K=2∶5∶3的水肥处理无核白鸡心葡萄硝酸还原酶活性较高，能有效促进氮肥的吸收利用；水分胁迫处理使谷氨酰胺合成酶活性先升高后降低，且使谷丙转氨酶活性升高。在生长期中轻度水分胁迫、适当增施钾肥能明显提高硝酸还原酶、谷氨酰胺合成酶与谷丙转氨酶活性，提高氮肥的转化利用。     

The Decisive Network: Producing Henri Cartier-Bresson at Mid-Century

Henri Cartier-Bresson’s photobook The Decisive Moment (1952) popularised the notion that the best photographs are made by the patient and gifted photographer who captures a fleeting moment with just one click of the shutter, creating an image with internal geometry and balance. The book solidified Cartier-Bresson’s reputation as an artist working with a camera and it encouraged scholars, curators, and hobbyists to understand photography as the product of trained individual vision and talent. Yet the book’s emphasis on personal vision also deflected attention away from the collective efforts and infrastructure necessary to promote Cartier-Bresson’s practice as art. By shifting our attention to the decisive network of magazine editors, book publishers, printers, and curators who helped Cartier-Bresson onto a highly orchestrated road to fame at mid-century, this article considers the ways in which collective work is central to the material and social history of photography, and how these realities challenge the decisive moment’s paradigm of individual and inspired creation.     

基于并行结构的相位恢复算法在全息激光投影中的应用

全息激光投影技术相比传统图像显示技术有突出的优势。作为全息激光投影技术的关键图像处理算法——相位恢复算法,算法的收敛速率和精度都有待提高,在实际计算中它们的效果不够理想,甚至不能保证迭代过程总收敛到正确解。基于此,本文提出了基于并行结构的相位恢复算法(PGSGA)。该方法思路是对多个初值进行并行运算,不断"筛"出最优结果来对GS算法进行加速。仿真实验证明,该算法在收敛速率和恢复的灰阶图像质量等方面具有优越性。     

一种基于单片机及CPLD测试平台的设计与实现

文章介绍可编程计数器/定时器M82C54和高速异步双端口RAM IDT7130的性能特性.利用单片机80C196KB及上述芯片设计并实现测试平台,给出测试平台的接口电路,并阐述了它的实现原理.     

MasterCAM9.0自动生成加工程序后置处理的探讨

MasterCAM是数控加工应用比较广泛的软件.由于数控系统厂家生产的数控系统的代码标准不同,使得MasterCAM用通用后置生成的程序不能直接应用于数控加工.文章就如何解决MasterCAM后置处理问题做了一些初步的探讨,较好地解决了在实际加工中的应用问题.     

美国GS400SS型手弧焊机工作原理及工艺性能的研究分析

分析了美国GS400SS手弧焊机主电路及控制电路的工作原理及特点,并将该焊机同AX7—500型弧焊发电机、ZS—300型磁放大器式整流焊机的工艺性能进行对比工艺试验。试验表明:该焊机具有焊接规范稳定,引弧性能好,飞溅小等特点。     

Functionalization of carbon nanomaterials for advanced polymer nanocomposites: A comparison study between CNT and graphene

The allotropes of carbon nanomaterials (carbon nanotubes, graphene) are the most unique and promising substances of the last decade. Due to their nanoscale diameter and high aspect ratio, a small amount of these nanomaterials can produce a dramatic improvement in the properties of their composite materials. Although carbon nanotubes (CNTs) and graphene exhibit numerous extraordinary properties, their reported commercialization is still limited due to their bundle and layer forming behavior. Functionalization of CNTs and graphene is essential for achieving their outstanding mechanical, electrical and biological functions and enhancing their dispersion in polymer matrices. A considerable portion of the recent publications on CNTs and graphene have focused on enhancing their dispersion and solubilization using covalent and non-covalent functionalization methods. This review article collectively introduces a variety of reactions (e.g. click chemistry, radical polymerization, electrochemical polymerization, dendritic polymers, block copolymers, etc.) for functionalization of CNTs and graphene and fabrication of their polymer nanocomposites. A critical comparison between CNTs and graphene has focused on the significance of different functionalization approaches on their composite properties. In particular, the mechanical, electrical, and thermal behaviors of functionalized nanomaterials as well as their importance in the preparation of advanced hybrid materials for structures, solar cells, fuel cells, supercapacitors, drug delivery, etc. have been discussed thoroughly.