智能工业电导仪误差来源及分析

通过对智能工业电导仪误差来源的分析探讨，使读者进一步了解智能工业电导仪的特性，了解其误差的来源及误差的补偿原理，有助于智能工业电导仪的正确使用和推广。     

大山口水文站不同雨量器降雨量误差分析

通过对JDZ-1型固态雨量存储仪与20cm口径普通雨量器平行观测分析,找出了JDZ-1型固态雨量存储仪采集降水数据产生误差的原因。并提出了切实可行的解决方法,提高了该仪器在使用中的精度,同时也证明我区普遍推广使用JDZ-1型固态雨量存储仪来采集降水数据是能够代表客观实际的。     

高精度电压测量回路的研究

对电容式电压互感器与电磁式电压互感器的计量误差进行了分析,提出了一种新的电压互感器二次回路压降补偿方法,采用该方法的二次回路压降补偿装置与进行过空载补偿的电容式电压互感器或电磁式电压互感器配合使用时,可使整个电压测量回路的计量误差非常小.     

三维姿态测量系统的安装误差

研究了倾角仪相对于电荷耦合器件的倾斜安装误差的标定方法和补偿技术.运用旋转矩阵描述了传感器之间的相对位置关系,并由此定义了3个安装误差参数,通过旋转矩阵的复合变换推导了测角系统因倾斜安装倾角仪而造成的测量误差的表达式,采用蒙特卡罗方法分别分析了3个安装误差参数对系统测量误差的影响,最后给出了3个安装误差参数的标定方法并进行了基于高精度三轴转台的安装误差补偿实验.实验证明所提方法有效地减小了倾角仪的倾斜安装误差对角度测量的影响,使系统获得了更高的测量精度.     

谐波对平均值原理仪表测量的影响分析

非线性负载的广泛应用,导致电力系统中的谐波日益严重.电力系统中使用的交流电压表和电流表通常采用整流式仪表,其工作原理是对电网电压和电流的平均值响应,利用平均值和有效值的比例关系从而得出信号的有效值.由于是按50 Hz标准正弦波设计,当电网电压中有高次谐波或者负荷电流中有高次谐波时,必然会影响其正常工作.因此采用平均值原理的仪表测量非正弦周期信号电压和电流的有效值,存在原理性的误差.基于其工作原理,定量分析不同谐波下的误差及一定谐波含量下误差的大小.通过分析结果,建议采用真有效值原理的电压表和电流表.     

降水现象仪误差及故障分析

该文通过对DSG4型降水现象仪数据与人工平行观测数据的对比分析,找出降水现象仪的误差因子,并分析误差因子的产生原因和误差作用程度,并简要分析DSG4型降水现象仪的日常维护及故障分析处理。     

波纹腹板H型钢梁柱端板螺栓连接节点抗弯性能

提出了一种波纹腹板H型钢梁与普通H型钢柱采用端板螺栓连接的节点构造.基于高强螺栓抗拉性能的刚性端板模型和T形连接件理论,提出波纹腹板H型钢梁柱端板螺栓连接节点的设计方法.进行了2个波纹腹板H型钢梁柱端板螺栓连接节点的静力试验,并使用商用有限元分析软件ABAQUS建立节点的有限元模型,将设计弯矩下的高强螺栓最大拉力的试验结果与有限元计算结果进行对比,证明了高强螺栓拉力计算公式的可靠性;通过对比设计弯矩和有限元计算的端板屈服弯矩,证明了端板厚度计算公式的合理性.     

压力型和拉力型锚杆承载性状对比试验研究

基于现场试验,对比研究了压力型、拉力型锚杆的承载性状.研究结果表明,压力型、拉力型锚杆的破坏形式为锚固段砂浆体与岩土层间的粘结滑移破坏,两者的极限承载力主要取决于锚固段与周围岩土体的粘结力.在相同条件下,压力型锚杆极限承载力标准值较之拉力型锚杆提高了近70%.张拉荷载与锚头位移的关系具有明显的非线性特征,采用双曲线模型进行拟合,具有较好的吻合性.采用高强钢筋作为杆体材料的压力型锚杆的承载性状较之于普通拉力型锚杆有明显改善.     

基于动态可修调误差放大器的高精度Buck-Boost转换器设计方法

传统的修调方案是通过改变电阻反馈网络的反馈系数来对系统的输出电压进行修调，这种针对于特定输出电压下的反馈电阻修调的方法无法保证配置不同输出电压时的精度. 针对上述问题，本文通过分析环路的工作特点，从固定工作点的误差放大器入手，提出基于动态修调误差放大器电流的高精度Buck - Boost转换器设计方法. 基于0.18 μm BCD工艺对提出的方法进行了具体电路设计与物理实现验证.结果表明，修调电流可以将输出电压±40 mV的输出电压误差降低到±1.83 mV，输出电压精度可以达到0.045 7 %；在输出电压误差满足≤5 mV时，满修调时可实现最大误差62.83 mV的修调.相较于传统结构，修调电压的精度受PVT变化影响较小，极大地改善了系统的输出精度，该方法已在一款Buck - Boost型转换器中得到成功应用.      

基于新型前馈补偿的电压源型逆变器研究

研究了三相电压源型逆变器输出电压控制,分析了逆变器的非线性扰动和等效滞环继电器模型,提出了补偿量在线可调的前馈补偿控制系统模型.利用搜索控制器(SC),在给定电压不变条件下,通过消除不同开关频率定子电流基波幅值的差,在线确定由死区、电力半导体器件导通关断时间产生的脉宽误差.将功率开关和续流二极管通态电阻视为负载阻抗的一部分,将导通阀值产生的逆变器输出电压误差折算为等效的脉宽误差,并进行了补偿.最后利用合众达DSP F28335模拟器进行了实验,比较了脉宽误差补偿前后得到的定子电流波形,结果表明,该方法有效地消除了脉宽误差,抑制了死区效应.     

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.     

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.     

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.     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-