Theory of the halftone process I. The penumbra theory

A method of calculating the tone reproduction curve of a halftone from the light distribution behind the halftone screen, or vice versa, is described. The actual light distribution is found to check satisfactorily with the distribution calculated from geometrical optics, i.e., penumbra theory, when coarse screens and abnormally short screen distances are used, except in the regions of very low light intensity. With fine screens and normal screen distances, both dot shape and tone reproduction differ markedly from the calculated results and can only be explained by the effects of diffraction.     

专利视角下的美国空军核心技术演化分析

[目的/意义]通过对美国空军公布的专利进行研究,揭示其不同阶段的重点研究方向,更好地把握技术变化,为相关决策提供参考。[方法/过程]引入时间维度将主题模型生成的"文档—主题"分布转换为"年份—主题"分布,结合t-SNE降维并可视化来划分时间段。采用专利分类号与技术领域的映射关系和社会网络分析方法做粗粒度的技术领域演化及可视化分析,并综合运用LDA和JS散度对其中某一技术领域做细粒度的技术主题演化与可视化分析。[结果/结论]将美国空军公布的1958—2019年的专利划分为7个时间段,得到技术领域演化河流图以及"测量"技术领域的技术主题演化桑基图。结果表明该方法可以较好地识别美国空军不同阶段的核心技术演化过程,是从专利的角度研究国防技术发展趋势的一次积极探索。     

关于槽鳞贝母和蒲圻贝母的分类等级

F. sulcisquamosa is slightly different from F. unibracteata in pollen morphology and differs external-morphologically from the latter in lacking trellised spots inside tepals. There- fore the former is reduced to a variety of the latter. F. puqiensis is found very similar to F. thunbergii both in pollen morphology and gross morphology. The former is different fromthe latter in geographical distribution and thus reduced to a variety of the latter.     

On the generalized Zipf distribution. Part I

This article is concerned with a class of informetric distribution, a family of skew distributions found to describe a wide range of phenomena both within or outside of information sciences and referred to as being of Zipf-type. A generalization of Zipf distribution (a size-frequency form of the Zipf’s law), named the generalized Zipf distribution, is introduced. Two main characterizations of the generalized Zipf distribution are obtained based on the proportionate hazard rate and truncated moments. Finally, some asymptotic properties of the generalized Zipf distribution are investigated.     

聚集还是分散：中美创新活动区域分布比较

 在中国 “增强自主创新能力,建设创新型国家”的战略背景下,以中国作为发展中国家的典型代表和美国进行创新活动区域分布的比较,为中国以及其他发展中国家的创新活动区域分布提供建议。以发明专利为创新活动指标,基于来自中国国家知识产权局和美国专利商标局网站的数据,本文运用排序—频度、集中度和排序分类等方法对中美创新的区域分布进行了比较。研究结果表明中国发明专利增长率较快,变化幅度较大,美国相对平稳;中国发明专利地区分布差异大于美国,中美两国创新活动分布均呈现区域集聚的态势,并且具有从中部地区向沿海地区聚集的趋势。     

獐牙菜属植物的起源, 散布和分布区形成

本文根据植物类群的系统发育和地理分布统一的原理，讨论了獐牙菜属植物的起源、散布和分 布区的形成。獐牙菜属包括11组16系154种，间断分布在亚洲、欧洲、北美洲和非洲。中国西南部- 喜马拉雅地区汇集了大多数种类、不同演化水平的类群以及形形色色的特有类群，成为该属的多样化 中心和多度中心。该属的原始类群和外类群也集中分布在中国西南山地，极有可能是该属的起源地。该 属的分布区类型中出现了各式的间断分布，根据有该属植物分布的大陆间及大陆与岛屿间分离和连接 的时间推测，该属的起源时间至少不会晚于晚白垩纪，也许更早，可追溯到中白垩纪。通过分类群间亲 缘关系和现代分布分析，显示出该属植物从起源地向周围和一定方向散布，形成了三个主要散布途径。在散布过程中植物本身也发生演化和就地特化，形成新的类群。     

浙江降水量场时空分布变化的特征

应用EOF方法对浙江省38个气象观测站43年（1961．1～2003．12）的月、季降水量距平场的时空分布变化进行统计分析,结果表明：浙江省降水量场的空间分布主要有南北分布型和东西分布型,春、冬季节以南北分布为主,夏、秋季节以东西分布为主。冬季降水场的空间分布尺度比夏季大;夏季降水场空间分布的年际变化比冬季大。秋季降水场空间分布变化的显著周期为9～14年,冬季降水场空间分布变化的显著周期为3．5～4．7年,而春季和夏季降水场空间分布则无显著周期存在。     

黄河上游兰西城市群人口时空特征多维透视

明确区域人口时空演化特征,有助于推动人口高质量集聚。本文以多源数据为基础,采用人口重心、标准差椭圆、人口分布结构指数、人口-土地一致性系数、空间自相关分析和GIS空间统计分析等方法,从城市群整体、县、乡（镇）和栅格尺度对兰州—西宁城市群人口时空特征进行分析,得出以下结论：①兰西城市群人口呈现规模小、流动性弱、城镇化水平低、人口和城镇化率小幅缓慢增长等基本特点。②人口重心略微西移,人口分布“西北—东南”走向的空间格局基本稳定,呈“核心—外围”式空间结构,兰州、西宁和临夏是3个人口集聚中心,其中兰州市显现出人口集聚的“虹吸效应”。甘青两片人口分布格局存在差异,甘肃片区人口密度中南部高、北部低,青海片区人口以西宁为中心向其他县域“圈层”递减。③海拔是影响兰西城市群人口垂直分布格局的主要地形因素,人口分布的高程梯度效应和河谷盆地集聚指向明显,人口主要集中在海拔低于2400 m的中海拔河谷盆地内。多尺度、多视角的研究结论及相应的对策建议,可为区域人口空间优化布局提供科学依据。     

国产酸脚杆属与印度板块漂移

 In this paper, the present writer has discussed the lemurian intercontinental discontinuous distribution of the genus Medinilla of Melastomataceae between Tropical Asia and Tropical Africa. It appears to be that the genus was first brought to Eurasia continent from Africa continent as a result of Indian Plate drift. Therefore we conjecture that the genus probably occurred in Upper Cretaceous and its birthplace is probably in  the southern part of Gondwanaland.      In addition, we have reduced the genus Pseudodissochaeta M. P. Nayar published in 1969, because in this taxon the extra-ovarial chambers may go down to the middle or to the base of the ovary, as in other genera of Melastomataceae. Besides, no differences in pollen have been found between the taxon and the genus Medinilla.     

淫羊藿属(小檗科)花瓣的演化和地理分布格局的研究

淫羊藿属的种数与60年前大不相同，现在已知约有50种。该属种类间断地分布于日本至北非 的阿尔及利亚之间的广大地区，这一分布格局表明了该属的古老性质。它们在欧亚大陆的分布极不均 匀，约有80％的种类产于中国中部至东南部，而且根据花瓣的演化分析结果表明，只有中国的淫羊藿属 植物具有连续不断的演化过程。由此可见，中国中部至东南部成为北半球淫羊藿属植物的汇集中心是 有充分根据的。淫羊藿属种类基本上是林地草本植物，常生于水青冈林下，为林下草本层的优势种，而 且该属的分布格局与第三纪植物属——水青冈属在欧亚大陆的分布格局极为相似，说明淫羊藿属植物 在早第三纪时期已广泛分布于北半球。中新世时期由于中亚地区气候变干，加之印度板块向欧亚大陆 俯冲并引起喜马拉雅山脉隆起，致使中亚地区进一步干旱，水青冈属和淫羊霍属植物随之消失，进而导致其东亚—地中海、西亚间断分布格局的形成。     

沙棘的生态地理分布及其植物地理学意义

沙棘hippophae rhamnoides subsp．sinensis是分布于我国境内的一个亚种，是沙棘属中的原始类群。沙棘的分布区大体呈西南—东北走向，从西藏东北部起，经黄土高原，直至大兴安岭西南角。本文通过对分布区与各生态因子等量线相似性比较，并结合野外考察，探讨了沙棘对各生态因子的耐性限度、最适值以及限制因子。研究发现，沙棘灌丛不仅有一个比较稳定的分布区，而且受大的气候带的控制，表现出明显的水平地带性规律，其分布与我国的三大地理气候区分异规律相一致，正处在我国三大植被区的过渡地带。因而，沙棘的分布可以作为我国三大植被区分界的一个标志，这打破了以往认为灌丛没有明显水平地带性规律的概念。另外，本文还就沙棘分布区与建立人工沙棘园及我国种植制度区划和植树造林之间的关系进行了讨论。     

女蒿属的分类研究

 The present paper is an attempt to propose a preliminary taxomomic treatment of the genus Hippolytia Poljak. and to analyse the geographical distribution of its com- posite elements.      This small genus with 17 species is divided  into  2  sections,  namely,  section Anthodesma Shih and section Hippolytia. Anthodesma is a small section with 3 species and is characterized by fascicled corymbs, campanulate and nitid involucres, rigidly herbaceous phyllaries, and undershrubs, while Hippolytia consisting of 14 species is characterized by corymbose inflorescence or glomerules or compund heads, cuneate and unpolished involucres, herbaceous phyllaries with pitch black margines.      There are 12 species of Hippolytia in China, of which 3 are proposed as new in the present paper.      Regarding the distribution pattern of Hippolytia, it is noteworthy to note that its range of distribution forms a more or less U-shape as shown in map 2. It may be seen that Hippolytia distributes in Central Asia-Sino-Himalaya-Median Asia. Section Antho- desma Shih occurs in central Asia, while section Hippolytia in the whole Himalayan region and northern Meridional Ranges and Median Asia.      There seems to be no center of species concentration within the total range of Hippolytia, whose species are localized in distribution, for example, H. desmantha Shih is known only from Qinghai provence (Yu-Shu-Hsien), H. alashanensis (Ling) Shih is restricted to Ninghsia and central part of Kansu provence.  It is interesting to note that H. yunnanensis (J. F. Jeffrey) Shih and H. longifolia (Wall.) Shih are referred to as vicarious species.  The localization of the  species  distribution  and  the  obvious discontinuity of morphological characters between species indicate a remarkable geogra- phical influence on the species formation of Hippolytia.       Hippolytia is an alpine genus of temperate zone of Asia, in which 64 per cent of species occurs at high elevations of above 3300m. altitude, 30 per cent of species are distributed in middle elevations of above 2200m. altitude.  The life forms are micro- undershrubs, erect perennial herbs, glomerule stemless herbs or stemless herbs. It is very possible that its geographical origin and development may be linked up with occurance of desert steppe, especially of alpine meadow vegetations in the northern temperate zone of Asia.      With regard to the geographical elements to which each species of Hippolytia belongs, it seems to indicate that H. trifida (Turcz.) Poljak., H. alashanensis (Ling) Shih and H. desmantha Shih belong to the geographical elements of central Asia, while H. yunnanensis (J. F. Jeffrey) Shih, H. glomerata Shih, H. tomentosa (DC.) Tzvel., H. senecionis (Bess.) Poljak. H. longifolia (Wall.) Shih, H. kennedayi (Dunn) Ling, H. syncalathiformis Shih, H. gossypina (Hook. f. et Thoms.) Shih and H. nana (C. B. Clarke) Shih to Himalayan elements, and H. darvasica (C. Winkl.) Poljak., H. megacephala (Rupr.) Poljak,, H. herderi (Rgl. et Schmalh.) Poljak. to Median Asia, H. delavayi (W. W. Smith) Shih to North-West-Yunna.       

中美高校科技成果转化收益分配机制比较研究

高校科技成果转化收益分配问题是各国法律和政府政策关注的焦点。论文以中美两国一流高校为研究对象,从科技人员收益占比以及大学支配资金的分配模式两个角度,归纳并比较两国高校科技成果转化收益分配机制。研究发现两者存在明显差异:中国高校对科技人员的奖励力度要明显高于美国;美国高校以内部激励为主,而中国高校主要使用内部激励与外部激励相结合的方式。两国高校科技成果转化发展阶段和发展模式的差异是造成收益分配机制不同的主要原因。建议:现阶段中国高校科技成果转化收益分配政策一方面仍然要坚持政府主导型发展模型下的收入分配方式,但另一方面,应适当地向市场型发展模式下的收入分配方式转变。     

三尖杉属的研究

The genus Cephalotaxus contains a small number of species. It is adequately appreciated as a newly discovered cancerresistant medicament for the alkaloids obtai- ned from its branches leaves and barks are of curative effect.      This paper deals with the classificatory revision based on the morphological featu- res,  with the reference to the anatomical characters of leaves,  types of alkaloids and pollen morphology observed.  Two new combinations are proposed,  and 4 species and varieties are reduced in the paper. The genus Cephalotaxus is thus suggested to consist of 2 sections and 9 species.  The trees occur in East Asia and the north of Indo-China, with 88% found in China where is the distribution centre and refuge of the genus. The genus in discussion is of unique morphological features which are distinctly dif- ferent from these of Amentotaxus,  Cephalotaxaceae,  containing a single genus of Ce- phalotaxus,  is closely related to Taxaceae,  and therefore the Cephalotaxaceae is best placed in the Taxinieae of Coniferales.     

我国网络信息资源利用中的知识产权保护研究论文定量分析

通过对新千年网络信息资源利用中的知识产权保护研究论文的统计，从论文主题分布、论文的作者（核心作者、核心单位、合著情况）、论文的时空分布（论文产出量及年代分布、论文产出期刊源及分布）等对中国期刊网2000年1月-2004年7月间发表的网络信息资源利用中的知识产权保护研究论文进行定量分析。     

市场经济条件下收入分配公平问题探析

从界定收入分配公平的含义出发,分析了我国收入分配的现状,结果表明我国收入分配存在不公平现象。通过分析我国市场经济与收入分配不公平之间的关系,发现市场经济的收入分配制度本身能够产生收入分配差距,从而导致收入分配不公平,且市场经济不健全所产生的非市场因素也能导致收入分配不公平,然而,这只能解释一小部分收入分配不公平的现象。     

中国落新妇属的研究

The Astilbe Buch.-Ham.  ex D. Don was founded in  1912.  There are now 18 species throughout the world. USSR, Thailand, Indonesia, Bhutan, Nepal d Kashan- mir each has only 1 species; Korea, Philippines and USA each has 2; India 3; Japan 6; and China 7 (including 3 endemics and 1 new variety). And northeast China, north China and northwest China each has 2;  central China and southwest China  each 4; eastern  China 5. Thus the distribution centre of this genus seems  to be in the region  covering Japan and eastern, central, and southwest China.       This genus is divided into two sections: Sect. Simplicifoliae Engl.  and Sect. Astilbe. Sect. Simplicifoliae may be considered as the primitive one because it has 5 ordinary petals. This section consists of about 10 species: 5 in  China (east China 4; southwest China 3; ce- ntral China, north China and northeast China each 2; Northwest China 1), 5 in Japan, 2 in Korea, 1 in Philippines and India each. According to the distribution of this section, the author suggests that the centre of origin of this genus be in the  forested  parts  from Japonthrough east China to southwest China.     

朱缨花属在我国的自然分布

In this paper, natural distribution of the genus Calliandra Benth.  and anew record species, Calliandra umbrosa, from China are reported.     

我国乳制品业的集中度、布局与绩效分析

分析了我国乳制品业的集中度与布局及其对绩效的影响,结果显示,乳制品业的集中度较低,但呈不断上升的态势;乳制品业的布局已经由资源导向型向市场导向型转变,提高乳制品业的集中度及合理的布局将会改善其绩效水平。     

综合区域环境影响下的农村居民点空间分布变化及影响因素分析

农村居民点空间分布变化对农村地域景观变化具有重要影响。本文应用GIS空间分析以及景观指数的定量分析方法,以河南巩义市为研究区域,分析了综合区域环境影响下的农村居民点空间分布变化特征。结果表明：①随着农村经济社会发展,农户居住用地总面积及相应的占地比重有较大幅度增加;②现有农村居民点分布扩展表现出规模集中化和局部分散化并存的现象;③外部调控因素对聚居斑块的作用力度不断增强,农户聚居空间形态逐步向规则化的方向发展;④农村居民点空间扩展由地理位置偏僻、交通不便利、居住环境条件差的区域逐渐向地势相对平缓、交通基础设施相对优越、经济发展环境较好地方集中,表现出较为明显的区位集中指向。规模化、集约化和空间区位的合理化应是今后农村居民点整合发展的主要趋势。