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991.
Joseph W. Dauben 《Archive for History of Exact Sciences》2008,62(2):91-178
In December and January of 1983–1984, archaeologists excavating the tomb of an ancient Chinese provincial bureaucrat at a
Western Han Dynasty site near Zhangjiashan, in Jiangling county, Hubei Province, discovered a number of books on bamboo strips,
including inter alia works on legal statutes, military practice, and medicine. Among these was a previously unknown mathematical work on some
200 bamboo strips, the
Suan shu shu, or Book of Numbers and Computations. Based upon other works found in the tomb, especially a copy of the
Er nian lü ling (Laws and Decrees of the Second Year (of the reign of empress Lü, i.e. Lü Hou)), archaeologists have dated the tomb to ca. 186 BCE (Lü Hou’s regency lasted from 188 to 180 BCE). The Suan shu shu, as the earliest yet discovered work devoted specifically to mathematics from ancient China, has stirred considerable interest
among Chinese historians of science. The translation and commentary offered here draw extensively on the works cited in Sect.
3 below. Several appendixes devoted to specific issues related to translating the Suan shu shu, including its title and the problem of determining English equivalents for various commodities that arise in the text, may
be found in Appendix II.
An erratum to this article can be found at 相似文献
992.
Gituru Wahiti Robert 《武汉大学学报:自然科学英文版》2007,12(2):337-342
Outcrossing rate in a natural population of Caldesia grandis was estimated by the dominant random amplified polymorphism DNA (RAPD) marker using 10 open-pollinated progeny arrays of 24 individuals. The multilocus outcrossing rate estimated based on all 25 RAPD loci was 0.872 ±0.033 and the single-locus outcrossing rate was 0.795 ±0.032. Multilocus estimates did not differ significantly from the single-locus estimates. The fixation index, F, in the progeny estimated from RAPD data was -0.142 ±0.000. The estimates of multilocus outcrossing rates (t_m) and single-locus outcrossing rates (t_s) obtained from MLDT clearly indicate that outcrossing is predominant in the open-pollinated C. grandis population. An empirical analysis suggests that 15 should be the minimum number of dominant marker loci necessary to achieve robust estimates of t_m. 相似文献
993.
Participatory Sustainability Impact Assessment: Scientific Policy Advice as a Social Learning Process 总被引:3,自引:3,他引:0
Manuel Gottschick 《Systemic Practice and Action Research》2008,21(6):479-495
This paper deals with the development of scientific policy advice by providing a methodology to foster a social learning process.
The methodology, called participatory Sustainability Impact Assessment (pSIA), aims to structure complex problem situations,
to clarify interests and basic assumptions, to interpret scientific studies, to develop impact assessment, and to explore
sensitivity of uncertainty and lack of information. In pSIA workshops the participants are supposed to build conceptual models
with different modelling methods, like System Dynamics, Value Chain Analysis, and Morphological Analysis. A case study is
presented that describes a workshop series with political as well as academic actors, applying the pSIA approach to an impact
assessment of Economic Partnership Agreements between the European Union and the Eastern and Southern Africa Region.
相似文献
Manuel GottschickEmail: URL: www.agchange.de |
994.
ZHANG Tao ZOU Xuecheng ZHAO Guangzhou SHEN Xubang 《武汉大学学报:自然科学英文版》2007,12(3):491-495
A 3.5 times PLL clock frequency multiplier for low voltage different signal (LVDS) driver is presented. A novel adaptive charge pump can automatically switch the loop bandwidth and a voltage-controlled oscillator (VCO) is designed with the aid of frequency ranges reuse technology. The circuit is implemented using 1st Silicon 0.25 μm mixed-signal complementary metal-oxide-semiconductor (CMOS) process. Simulation results show that the PLL clock frequency multiplier has very low phase noise and very short capture time . 相似文献
995.
Belgacem BETTAYEB Imed KACEM Kondo H.ADJALLAH LOSI-ICD CNRS FRE Universitéde technologie de Troyes France 《系统科学与系统工程学报(英文版)》2008,17(4):446-459
This article investigates identical parallel machines scheduling with family setup times. The objective function being the weighted sum of completion times, the problem is known to be strongly NP-hard. We propose a constructive heuristic algorithm and three complementary lower bounds. Two of these bounds proceed by elimination of setup times or by distributing each of them to jobs of the corresponding family, while the third one is based on a lagrangian relaxation. The bounds and the heuristic are incorporated into a branch-and-bound algorithm. Experimental results obtained outperform those of the methods presented in previous works, in term of size of solved problems. 相似文献
996.
Zhaozhi ZHANG Nan JIANG 《系统科学与复杂性》2007,20(4):486-491
Most cipher systems designed thus far are binary-valued or integer-valued cipher systems. Their security relies on the assumption that one-way functions exist. Though the existence of one-way functions has not been proved yet, most cryptographic researchers believe that one-way functions exist. In addition, many candidates for one-way functions have been proposed. Therefore, the key step for developing real-valued cipher systems is to define real one-way functions and to propose candidates for them. In this paper, based on computational complexity theory over the real field, we give two definitions of real one-way functions; one is for digital one-way functions and the other is for general one-way functions. Candidates for these two classes of one-way functions are also proposed. Moreover, we present two examples to demonstrate that the candidates for both digital one-way functions and general one-way functions can be applied to construct secure real-valued cipher systems. 相似文献
997.
探讨采用真空波导及反常波模式(X模)微波输入技术,以避免微波石英窗口的污染,并研究了这种微波耦合模式装置中等离子体的放电特性. 相似文献
998.
黑加仑色素的分离及组成初步鉴定 总被引:1,自引:0,他引:1
利用纸层析对黑加仑色素进行分离,并进行分析鉴定,初步推测黑加仑色素4个组分分别为矢车菊素-3-芸香糖苷(Cy-3-rut)、飞燕草素-3-芸香糖苷(Dp-3-rut)、矢车菊素-3-葡萄糖苷(Cy-3-glu)、飞燕草素-3-葡萄糖苷(Dp-3-glu). 相似文献
999.
宋仁 《五邑大学学报(自然科学版)》1998,(4)
通过对框架分析的各种手算和电算方法的综合分析和比较,根据手算和电算对分析方法的不同要求提出选择计算方法的的原则和方案。同时对土木工程各专业的结构分析课程提出一些内容更新和优化的建议。 相似文献
1000.
旅游景区开发规划环境影响评价研究——以锦屏山旅游规划为例 总被引:2,自引:0,他引:2
旅游业作为我国的朝阳产业,必将在国民经济和社会发展中发挥越来越重要的作用.但随着我国旅游产业规模迅速扩张,旅游活动带来的环境问题也日益突出.本文以章丘市锦屏山旅游规划为例,采用矩阵法对旅游规划的环境影响进行识别;在环境影响识别的基础上,运用情景分析法和环境承载力分析法,预测并评价了锦屏山旅游规划实施后4种情景下对环境的影响. 相似文献