装配机器人位姿误差补偿的研究

在分析装配机器人位姿误差的基础上,提出了机器人位姿误差补偿模型,最后经实验表明本方法对提高装配机器人位姿精度十分有效。     

多因素影响下的机器人综合位姿误差分析方法

分析了影响机器人位姿精度的主要因素，将各种因素综合为机器人的结构参数误差和运动变量误差，充分考虑关节柔性和连杆柔性对机器人末端位姿精度的影响，建立了通用的机器人综合位姿误差分析模型，并编制了基于Matlab的Windows应用程序．该程序具有较强的通用性，适用于分析由机器人的各种静态误差以及关节柔性和连杆柔性所导致的平面和空间机器人末端执行器的综合位姿误差。     

并联6-SPS机构位姿误差分析

结合并联机构的特点，应用机器人微分关系建立了并联6-SPS机构位姿误差分析的正解模型，给定各结构参教误差即可得出主轴端的位姿误差．应用此模型可定量分析结构误差对主轴端位姿误差的影响．为并联机器人的精度综合提供了理论依据．     

并联6-SPS机构位姿误差分析

结合并联机构的特点,应用机器人微分关系建立了并联6 SPS机构位姿误差分析的正解模型,给定各结构参数误差即可得出主轴端的位姿误差.应用此模型可定量分析结构误差对主轴端位姿误差的影响.为并联机器人的精度综合提供了理论依据.     

并联机器人位姿误差分析

利用并联机器人的运动学反解模型,通过误差传递矩阵的求解来探讨机器人主要误差源与其位姿误差之间的关系,建立了并联机器人的位姿误差模型、并讨论了并联机器人主要误差源对位姿精度的影响,为实际误差的补偿与控制奠定了理论基础．     

主-从式手术机器人运动一致性分析

采用成熟的机器人误差理论建立了主-从手术机器人位姿误差模型,开发了基于MATLAB的位姿误差计算程序.采用蒙特卡罗法绘制了最大位姿误差图谱,对两种主手与三种从手机器人进行了仿真计算和运动一致性分析,给出了运动一致性条件,为进行主-从操作机器人精度设计提供了理论依据.     

基于熵不确定性概念的机器人位姿精度理论(Ⅲ)--机器人DH参数误差概率分布数学模型

基于熵不确定性概念的机器人位姿精度理论能够客观、有效地综合评价机器人位姿精度, 在对该理论的评价指标体系及其公式的前期研究的基础上, 本文首先分析机器人机构各随机误差源对DH参数的影响, 推导评价指标公式中非常关键的机器人DH参数误差概率分布的数学模型, 促进基于熵不确定性概念的机器人位姿精度理论的发展.     

关节间隙对机器人末端执行器位姿误差的影响

影响机器人末端执行器位姿的因素很多,其中关节间隙的影响历来为人们所关注。本文讨论了关节间隙对机器人末端执行器位姿误差的影响,推导出了由关节间隙引起的机器人末端执行器位姿误差的精确计算公式,且给出了算例,本文的工作为提高机器人的工作精度及有效地控制机器人,提供了理论依据。     

Stewart机器人的位姿误差分析

本文提出了一种分析Ｓｔｅｗａｒｔ机器人位姿误差的方法，即将各个关节引入的误差以及伺服定位误差对位姿误差的影响，都归算为杆件长度误差引起的位姿误差，并给出了按杆件长度误差计算位姿误差的关系式。     

基于熵不确定性概念的机器人位姿精度理论（Ⅲ）：机器 …

基于熵不确定性概念的机器人位姿精度理论能够客观、有效地综合评价机器人位姿精度,在对该理论的评价指标体系及其公式的前期研究的基础上,本文首先分析机器人机构各随机误差源对ＤＨ参数的影响,推导评价指标公式中非常机器人ＤＨ参数误差概率分布的数学模型,促进基于熵不确定性概念的机器人位姿精度理论的发展。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.