刍议交换类型的演进及其交易性质变化

本文基于生产增长的内在机制,分析生产增长对生产率的要求及追求资本收益率的生产对生产率的强制性提高,指出这种生产实质是借贷关系中的交换,并在此基础上探讨了交换类型的历史演进及其交易性质的变化。

小学课堂表扬话语的规训诉求及其认识

小学课堂中教师对儿童表扬的次数越来越多,儿童的表现却越发拘谨、身体越发约束。通过观察小学的课堂表扬活动,采用话语分析方法,以考察表扬的意义是如何在课堂情境中发生变化的。研究发现,表扬是要求的一种“折中形式”,遵循的是“优绩理念”,围绕的是“知识中心”。教师所假设的主张通过语义关系句合理化。教师在表扬儿童时需要纠正认识偏差,使表扬具备真实性、多元性和开放性。

交换机故障发生的类型以及分析方法

文章根据作者的工作实践,总结了交换机故障的发生原因,并对常用的查找故障的方法进行了归纳总结。

大规模实时图形编辑中可交换复制数据模型一致性维护

CRDT(交换复制数据类型)已经被提出作为协作文本编辑中的新的替代机制.但是,基于CRDT的实时图形编辑系统一致性维护方法系统在以前的文献中很少被研究.本文提出了一种新颖高效的CRDT算法,并且把图形之间的存在的位置条件的约束关系,用动态规则库标识,把图形操作分为基本操作和预定义关系操作,并且给出相关解决方案.该算法集成了智能和大规模协作的不同类型的图形操作.首先,该算法在交换复制模型框架下保证协同用户的收敛和维护操作意图.其次,基于CRDT的新颖的算法,维护实时协同编辑下共享图形文档的一致性并给出了实例证明以及合理的案例分析.第三,理论上分析所提出算法的时间复杂度低于现有技术OT算法的时间复杂度.第四,实验评估表明,该算法优于现有的OT算法.同时本文开发了Web平台下的在线协同图形编辑系统Co-Drawing,进一步验证了所写算法的可行性.

交换机故障分析与维护处理探讨

为保障通信网络的畅通和交换机安全、稳定的运行,在交换机出现故障后应当迅速地作出分析处理,找出故障原因和故障点,对故障进行排除,但要能快速、准确的对故障进行分析定位,就必须了解交换机发生的故障类型以及较高的故障分析和维护处理水平。

支持操作意图一致性的实时协同编辑算法综述

有别于传统分布式系统,实时协同编辑系统强调自然和谐的人人交互和人机交互,允许不同地点的协同用户同时编辑同一共享对象.为了给协同用户提供良好的响应性,实时协同编辑系统有必要采用全复制式体系结构,但又给共享对象的一致性维护问题带来巨大挑战,这一直是协同计算学科的研究热点.近年研究重点逐步从结果一致性发展到操作意图一致性.该文以操作意图一致性为主线,对支持操作意图一致性的实时协同编辑算法进行深入和全面的比较、分析和总结.首先,以Lamport事件偏序关系为起点,对协同编辑系统的因果关系、简单并发关系和偏并发关系概念进行整理.同时,给出实时协同编辑系统中全序关系的分类,操作的全序和操作对象的全序.在对全序关系和优先级进行剖析的基础上,阐述了实时协同编辑系统中的三类一致性模型:CC(Causality-preservation,Convergence)模型、CCI(Causality-preservation,Convergence,Intention-preservation)模型和CA(Causalitypreservation,Admissibility)模型.特别地,文中按照因果一致性、结果一致性和操作意图一致性的分类,给出操作意图一致性的维护路线图.然后,分别综述了各类实时协同编辑算法的研究进展和现状,包括OT(Operational Transformation)算法、AST(Address Space Transformation)算法和CRDT(Commutative Replicated Data Type)算法.进一步,文中给出了各类操作意图一致性算法的基本原理和执行框架,并基于一个代表性协同工作场景和算例对典型算法进行详细解析.接下来,文中从操作意图一致性、支持操作意图一致性的典型算法、操作转换函数和算法时间复杂度这4个关键方面对实时协同编辑算法进行归纳和对比.最后对全文小结,并指出为了进一步发展实时协同编辑系统,未来还需要在优先级策略、算法伸缩性、复杂操作语义类型、粗粒度操作对象以及选择性撤销机制等方面深入开展一些研究工作.

Effect of Simulated N Deposition on Soil Exchangeable Cations in Three Forest Types of Subtropical China

The effects of simulated nitrogen(N)deposition on soil exchangeable cations were studied in three forest types of subtropical China.Four N treatments with three replications were designed for the monsoon evergreen broadleaf forest (mature forest):control(0 kg N ha-1 year-1),low N(50 kg N ha-1 year-1),medium N(100 kg N ha-1 year-1)and high N(150 kg N ha-1 year-1),and only three treatments(i.e.,control,low N,medium N)were established for the pine and mixed forests.Nitrogen had been applied continuously for 26 months before the measurement.The mature forest responded more rapidly and intensively to N additions than the pine and mixed forests,and exhibited some significant negative symptoms,e.g.,soil acidification,Al mobilization and leaching of base cations from soil.The pine and mixed forests responded slowly to N additions and exhibited no significant response of soil cations.Response of soil exchangeable cations to N deposition varied in the forests of subtropical China,depending on soil N status and land-use history.

Thermal performance analysis of borehole size effect on geothermal heat exchanger

Thermal performance was the most important factor in the development of borehole heat exchanger utilizing geothermal energy. The thermal performance was affected by many different design parameters, such as configuration type and borehole size of geothermal heat exchanger. These eventually determined the operation and cost efficiency of the geothermal heat exchanger system. The main purpose of this work was to assess the thermal performance of geother^nal heat exchanger with variation of borehole sizes and numbers of U-tubes inside a borehole. For this, a thermal response test rig was established with line-source theory. The thermal response test was performed with in-line variable input heat source. Effective thermal conductivity and thermal resistance were obtained from the measured data. From the measurement, the effective thermal conductivity is found to have similar values for two- pair type （4 U-tubes） and three-pair type （6 U-tubes） borehole heat exchanger systems indicating similar heat transfer ability. Meanwhile, the thermal resistance shows lower value for the three-pair type compared to the two-pair type. Measured data based resistance have lower value compared to computed result from design programs. Overall comparison finds better thermal performance for the three-pair type, however, fluctuating temperature variation indicates complex flow behavior inside the borehole and requires further study on flow characteristics.

Comparative Structural and Spectroscopic Characterization of M^ILn^IIITiO4 Ion-exchanged Phases,with M^I： Na, H, K

In this paper, a comparative study of the XRD characterization and FTIR spectroscopic behavior of some M^ILn^IIITiO4 phases with M^I： Na, H, K and Ln^III, the trivalent lanthanides elements： Sm, Eu, Er and Yb is reported. The H and K- oxides were obtained by ion-exchange from NaLnTiO4. These ternary oxides belong to the K2NiF4 structural type, with the M^I and Ln^III cations distributed in an ordered way on the K-sub lattice. The FTIR spectra of the materials were analyzed by comparison with structurally related materials. A close relationship with the parent NaLnTiO4 was found.

Soil indicators for eco-geographic regionalization:A case study in mid-temperate zone of eastern China

Eco-geographic regional system is formed by division or combination of natural features based on geographic relativity and comparison of major ecosystem factors(including biological and non-biological) and geographic zonality.In previous studies, soil types were often taken as a basis for soil regionalization.However, the quantitative characteristics of soil indicators are fitter than the qualitative ones of soil types for modern regionalization researches.Based on the second China's national soil survey data and the provincial soil resource information, by principal analysis and discriminant analysis, this paper discusses the appropriate soil indicators as the complement of eco-geographic region indicator systems and the relationships between these soil indicators and soil types in regionalization.The results show that five indicators are used in eco-geographic zonality in mid-temperate zone of eastern China which are organic matter content, cation exchange capacity, pH, clay content and bulk density in topsoils.With a regression-kriging approach, the maps of soil indicators in mid-temperate zone of eastern China are compiled with a resolution of 1 km in every grid and the indicative meanings of these soil indicators are discussed.By cluster analysis it is proved that these soil indicators are better than the soil types and soil regionalization in delineating eco-geographic regions.

移动协同编辑中基于CRDT的序列转换算法

为高效地处理移动协同编辑中用户积累的大量本地操作,实现移动协同编辑系统的高响应性,提出一种支持序列转换的可交换复制数据类型(commutative replicated data type,CRDT)算法.首先,提出一个移动协同编辑的总体框架,支持多个移动终端离线或在线地协同编辑共享文档副本;然后,提出一个支持序列转换的移动协同编辑算法,可以实现离线操作中多个首尾连接的顺序插入操作的自动转换和操作效果的合并,维护移动协同编辑中共享文档副本的一致性.相关实验表明所提出的算法在响应性和功耗方面优于典型的一致性维护方法.