Key Technology of Cutting and Moving Large Spherical Tank

This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construction quality of field assembly and welding in the process of spherical tank moving and loading.

GERBER TECHNOLOGY LAUNCHES FIRST OF NEW SERIES OF CUTTING SOLUTIONS

Precision, Productivity and Performance def ine the GERBERcutter? Z7Tolland, Conn., USA – Gerber Technology, a business unit of Gerber Scientific, Inc. (NYSE: GRB), and the world leader in providing innovative integrated software and hardware automation systems to

Fracture mechanics analysis on Smart-Cut~ technology.Part 1:Effects of stiffening wafer and defect interaction

In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator （SOI） wafers of high uniformity in thickness. Using integral transform and Cauchy singular integral equation methods, the mode-I and mode-II stress intensity factors, energy release rate, and crack opening displacements are derived in order to examine several important fracture mechanisms involved in the Smart-Cut process. The effects of defect interaction and stiffening wafer on defect growth are investigated. The numerical results indi- cate that a stiffener/handle wafer can effectively prevent the donor wafer from blistering and exfoliation, but it slows down the defect growth by decreasing the magnitudes of SIF＇s. Defect interaction also plays an important role in the splitting process of SOI wafers, but its contribution depends strongly on the size, interval and internal pressure of defects. Finally, an analytical formula is derived to estimate the implantation dose required for splitting a SOI wafer.

Fracture mechanics analysis on Smart-Cut~technology.Part 2:Effect of bonding flaws

In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that the bonding flaws with large size are prone to cause severe deviation of defect growth, leading to a non-transferred area of thin layer when splitting. In a practical Smart-Cut process where the internal pressure of bonding flaws is very small, large interfacial defects always promote defect growth in the splitting process. Meanwhile, increasing the internal pressure of the bonding flaws decreases the defect growth and its deviation before splitting. The mechanism of relaxation of stiffener constraint is proposed to clarify the effect of bonding flaws. Moreover, the progress of the splitting process is analyzed when bonding flaws are present. After splitting, those bonding flaws with large size and high internal pressure are vulnerable for the blistering of the thin film during high-temperature annealing.

Generalized equation for calculating rock cutting efficiency by pulsed water jets

One of the promising methods for rock cutting technology is the use of high-speed water jets.In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment,pulsed water jets are basically used to increase the rock cutting efficiency.However,there are no mature recommendations for selection of rational parameters,and the relationship between indicators of rock cutting efficiency and parameters of pulsed water jet is still not established.In this context,we aimed at developing a generalized equation for calculating rock cutting efficiency,in which all the major parameters in consideration of rock cutting process are included.Then,a calibration of the rational parameters of rock cutting by pulsed water jets was conducted.The results are likely helpful for increasing productivity and reducing energy consumption.

Exploring the silvicultural and economic viability of gap cutting in Mediterranean softwood plantations

Gap cutting consists of the removal of all trees growing on a small surface, varying in size from 200 to 600 m2. In Italy, gap cutting has been successfully tested for introducing the natural regeneration of native species into softwood plantations, thus ac- celerating the transition towards climax hardwood stands. Depending on plantation types and conditions, gap cutting should be start- ed at an age between 70 and 80 years and the system should include at least 12 to 15 gaps, in order to produce enough wood to cover costs. Generally, natural regeneration is firmly established within 5-7 years from treatment. Gap cutting also offers superior results to selection thinning, the latter producing about 35% less value and incurring 25% to 30% more costs. As for all regeneration cuts, the success of gap cutting depends on wildlife control in order to prevent extensive damage to the regeneration.

The status and prospects of in situ grain harvesting technology and its machine system

Two main types of in situ grain harvesttng machine are introduced. The comparison of their working principles and advantages are given. The limitations and prospects for stripper header are discussed.

A survey of digital paper-cutting

Paper-cutting is one of the most fantastic Chinese folk arts. With the aid of computers, digital paper-cutting has become a popular topic in the field of NPR research. This paper will make a comprehensive survey of related references in four as- pects-image-based paper-cutting, paper-cutting based on computer graphics, paper architectures and paper-cutting animation and it shows that the imitation of the masters＇ artistic styles of paper-cutting will be the trend of future study.

基于Pro/E&VERICUT的曲面加工仿真及优化

论文通过Pro/E软件定义不同切削类型,利用CAM技术生成曲面加工工艺的走刀轨迹和G代码。利用VERICUT仿真该曲面加工过程,对比分析不同切削方式下的加工质量。然后,用恒定体积法优化切削参数,并以连杆外形曲面为实例进行验证,分析结果表明优化后仿真效果更好。实际生产过程中,采用该方法可以有效选择合适的加工程序及切削参数达到提高生产效率的目的。

基于VERICUT的水轮机叶片五轴联动数控加工仿真技术研究

针对五轴联动数控加工水轮机叶片存在的技术难点,采用仿真技术加以解决。首先说明了仿真技术的发展历史和功能特点,然后介绍了VERICUT软件的结构和用途。根据黑箱控制原理,创造性地提出了仿真函数概念,并根据加工使用的数控系统条件,给出了仿真函数的求解流程以及软件的操作方法。最后以某型号水轮机叶片的加工过程为例,实际进行了仿真,通过对仿真结果的分析,说明了仿真过程中容易遇到的问题及其解决方法。

Fuel-Cut策略对WLTC循环排放及油耗影响

基于一辆搭载1.4 L增压乘用车,通过WLTC循环工况测试,分别对比研究了Fuel-Cut策略,对整车试验循环排放及油耗的影响。研究发现,怠速起停技术(STT)、减速断油技术(DFCO)和换挡断油技术(CFCO)均能够改善油耗,使得油耗分别降低1.34%、1.67%和1.13%,但对CO、NOX、HC及NMHC排放都会产生一定恶化。

Smart cut智能截割技术的应用实践

主要介绍了JOY公司7LS8型采煤机的Smart cut智能截割技术在神东矿区大柳塔煤矿7 m大采高52304综采自动化工作面的应用情况及使用方法,并简述了Smart cut智能截割技术适用条件及应用前景。

A new technique for high-fidelity cutting technology for hydrate samples

Designing a high-fidelity cutting device is one of the difficulties in hydrate samples pressure-holding transfer.Due to the limitations of the existing mechanical system,there is much damage to the cut surface of hydrate samples,with many chips produced,which seriously affects the quality of samples.In this paper,a new cutting device utilizes two servo motors to achieve a high degree of automation.Using the Archimedes spiral,it achieves low disturbance of the cut surface and provides accurate control of the process.In addition,due to the operation of the sample long-stroke push unit,cutting hydrate samples of any length with almost no chips within a short cutting time can be achieved.Laboratory and sea tests have achieved all design requirements of the equipment and strongly demonstrate its benefit and stability.It is concluded that this new high-fidelity cutting technology is practically efficient.The physical state of the hydrate can be maintained to the greatest extent,and thus the new equipment provides significant support for the exploration and development of hydrate resources.

Final Cut Pro 6中的视频技术质量控制方法

电视节目制作环节,需要诸多技术以及设备的动力支撑,其中的Final Cut Pro 6为重要代表,若想使技术应用指标正常并提高节目制作质量,就要对传输、制作以及播送等各个环节进行把控,重视视频技术质量控制工作,以此为根本,将Final Cut Pro 6技术的运用优势予以全面体现,进而为节目的规范制作打下良好铺垫,满足标清数字录制带录制的技术要求,最大程度的增强节目播出效果,也为节目的持续性发展注入充足的动力。

Smart-cut方法制备GeOI材料的Ge表面腐蚀研究

通过H离子注入Ge晶圆退火起泡动力学研究,对实现晶圆Ge在氧化硅上层转移后的Ge表面(Ge OI)采用湿法化学腐蚀研究,使其能进一步改善表面质量(即粗糙度),同时去除由于H离子注入Ge所造成的表面非晶层。通过氨水、H2O2、去离子水混合溶液在室温下对被转移Ge层腐蚀,采用原子力显微镜(AFM)和透射电子显微镜(TEM)检测。实验证实,湿法化学腐蚀方法能显著降低表面粗糙度,并去除制备Ge OI过程中所造成的非晶层,从而得到晶格质量完好的表面。

基于Cut-and-Choose技术的安全多方计算

Cut-and-Choose技术是密码学中一种被广泛使用的密码学工具,对安全多方计算协议的设计起着重要的作用.其主要思想是一方在协议中构造多份混淆电路,另一方要求打开其中一部分电路进行检查,若检查通过则计算剩余的电路,决定电路的最终输出.在早期工作中,Cut-and-Choose技术主要应用于恶意模型下的安全两方计算,并由此产生了许多优秀的工作.尽管该技术在隐蔽安全模型中的工作也很早提出,但在当时并没有引起太多的关注.近年来,随着学者对于隐蔽敌手的深入研究,Cut-and-Choose技术以及基于该技术的思想也开始被用于实现公开可验证的隐蔽安全协议,涌现出一些代表性的工作.首先介绍了Cut-and-Choose技术在恶意安全模型和隐蔽安全模型中的研究进展;其次重点介绍其应用于公开可验证隐蔽安全模型中的研究成果;最后通过对该领域的研究成果进行详细的总结与分析,并指出后续可能的发展方向.

油气井井下切割技术发展现状及趋势

油气开发后期,退役井数量急剧增加,完井修井作业中套管磨损、卡钻等问题突出,退役经济耗费显著增加。为最大限度减少卡钻和退役经济耗费,有必要开展新型套管切割技术及装备的研发与应用。首先,总结了现阶段井下管柱切割技术的主要类型、工作原理和配套装备,包括机械切割、磨料射流切割、聚能切割、化学切割、电弧切割以及激光切割;对比机械切割、磨料射流切割以及特种切割方式的技术发展现状和趋势,分析上述切割方式的工程应用及优缺点;在此基础上,提出面向高效套管切割工程需求的主要切割技术及工具。结合目前切割技术及工具的发展现状,对未来井下管柱切割技术给出优化割刀性能、加强磨料射流切割的控制、研制新型切割工具及切割工具智能化等建议。

科研反哺教学在林木育种学教学中的探索与实践

林木育种学是高等农林院校林学专业的一门骨干课程,是以遗传进化理论为指导,研究林木优良品种选育、繁殖原理和技术的学科。其最高目标是选育林木优良品种,为林业生产提供最基本、最优质、最高效的生产资料,是林业的命脉和促进林业产业发展的原动力,在生态文明和美丽中国建设中发挥着越来越重要的作用。为了使学生更容易理解和掌握林木育种学的理论知识,深化科教融合,推进创新型人才培养,完善协同育人机制,在林木育种学授课过程中,通过将理论知识与生产实践相联系,将科技前沿贯穿于课堂教学,并以科研平台辅助实验教学的方式进行教学改革,不仅丰富了教学内容,激发了学生的学习热情,加深了对理论知识的理解,而且还利于学生良好科研素养的培养及创新能力的提高。

聚四氟乙烯材料切削工艺和应用研究进展

聚四氟乙烯(polytetrafluoroethylene,PTFE)因其优异的物理化学性能而成为生产制造电子通信、航空航天等领域关键零部件的重要材料。相比模压烧结工艺,切削工艺能够更高效地加工结构较为复杂的PTFE零部件。然而,PTFE材料具有韧性强、回弹性高、导热性差和线膨胀系数大等特点,使得其切削加工质量难以保证,在一些特殊领域,对PTFE零部件的表面洁净度更是有极高的要求,这些都对PTFE材料的切削工艺提出了新的挑战。从PTFE材料的基础力学和物理化学等特性出发,总结了PTFE材料的切削加工性;结合聚合物切削理论及其研究方法分析了PTFE材料的切削去除机理;阐述了PTFE及其复合材料的车、铣、钻等切削加工工艺;最后概述了PTFE材料切削工艺在相关重要领域的应用现状,并从材料性能研究、基础切削理论研究、切削工艺探索等方面总结了现有研究和应用中存在的问题,对未来研究的发展趋势和研究重点进行了展望。

卷烟生产过程中焦油稳定性关键影响因素研究

为探索卷烟生产过程各因素对卷烟焦油稳定性的影响,采用单因素试验方法,分析切丝宽度、切丝水分、烟丝混合均匀度、梗丝加工工艺、烟支重量及劈刀盘规格对卷烟焦油批内均匀性和批间稳定性的影响。方差分析及T检验结果表明,切丝宽度不同对卷烟焦油的批间稳定性有显著性影响,试验范围内,随着切丝宽度的增加,批间焦油量减小;试验范围内,切丝水分、烟丝混合均匀度及梗丝加工工艺影响卷烟焦油的批内均匀性;烟支重量不同对卷烟焦油批间稳定性有显著性影响,随着烟支重量增加,焦油量增大;重量稳定的前提下,劈刀盘规格不同影响烟支密度的均匀性,从而影响卷烟焦油的批间稳定性和批内均匀性。