MORAL GEOGRAPHY IN HIGH PLAINS HISTORY

ABSTRACT. When American society, through deliberate government action, intervenes to preserve the family farm as the locus of “good” human values and “authentic” environmental conditions, the result can be described as a moral geography. Nowhere is this clearer than in the protection of traditional farming on the High, or Great, Plains through federal funding and programs. Protection began during the Dust Bowl of the 1930s; federal support came to a close with the passage of the 1996 farm bill. These shifts deserve assessment of historic American interests in the protection of an agricultural institution and of a region at risk.     

柴达木盆地西部油族划分及成因研究

对柴达木盆地西部各油田的151个原油进行了分子地球化学分析,并选取伽马蜡烷/C30藿烷、升藿烷指数、甾烷C27/C29和三环萜烷/C30Hop四个参数作为变量进行SAS聚类分析。结合常规二维散点图法,柴西原油可以分为3个油族7个亚族：油族Ⅰ以强水体分层、强还原环境为特征,主要分布于西端的七个泉、红柳泉地区,该油族可以分为两个亚族,油亚族②相比于油亚族①具有更高的甾烷 C27/C29比值;油族Ⅱ主要分布于狮子沟、花土沟、跃进和南翼山油泉子地区,在七个泉、红柳泉等地区也有分布,以相对较强的水体分层、还原环境为特征;油族Ⅲ主要分布于东（南）部的切克里克、乌南、绿草滩、咸水泉、跃西和跃进Ⅱ号等地区,以水体分层变差、较还原环境为特征,该油族可以分为3个亚族,其中油亚族⑤则具有异常低的三环萜烷/C30Hop 比值,油亚族⑥具有异常高的甾烷 C27/C29比值,油亚族⑦则具有异常高的三环萜烷/C30Hop 比值。油族空间分布特征受下干柴沟组源岩有机相在空间上的变化制约,下干柴沟组源岩发育时期,自西向东地层沉积速率增大,水体的分层变差、还原性降低,导致陆源输入的增加以及有机质保存条件变差。     

青岛小珠山花岗岩岩石谱系单位划分及其主要特征

青岛小珠山花岗岩体为中生代偏碱性侵入岩,过去通称小珠山岩体,通过15万区域地质填图,将其划分为15个单元,划归为大店和崂山两个超单元.对各单元的岩石学、岩石化学、微量元素及稀土元素特征等进行了分析研究,认为应属A型花岗岩,为燕山晚期之产物.     

宜昌地区早志留世（Llandoverian）腕足类一新科Spinochonetidae (fam. nov.)及其意义

腕足类新科Spinochonetidae(fam.nov.)建立在宜昌地区志留系兰多维列统罗惹坪组下段中部(上埃隆阶)的Spinochonetes Rong,Xu et Yang(1974)和Spinolella(gen.nov.)两个属,以及一个属、种未定的分类单元的基础上。新科成员仅有从腹壳喙部伸出一根直的腹喙刺,这与Chonetoidea超科内的Strophochonetidae科以及Chonestrophiidae科众成员的铰合缘刺都是从腹壳铰合缘上伸出来的有着本质差别。另外,本文还对Spinochonetes以及它的属型种S.notata Rong,Xu et Yang(1974)进行重要图解和补充描述。与此同时,对Spinolella(gen.nov),以及S.minuta(gen.et sp.nov.)进行系统描述和对比。据目前所知,新科成员只分布于我国鄂西、黔东北、陕南和川北等地,属于上扬子台地的土族居民。因为Spinochonetidae(fam.nov.)属于腕足类独特的一个类型,演化快,贝体极小,保存精美,因此具有分类学、地层对比,以及恢复古环境等方面的重要意义。     

k=6,7,8,9的一类新几乎差族

C.Ding和J.Yin推广了几乎差集,定义了新的几乎差族的概念.通过有限域中分圆类的方法给出了几乎差族新的构造方法,并得到了k=6,7,8,9的一类新的几乎差族.     

The general solution of the HENON–HEILES problem

The general solution of the Henon–Heiles system is approximated inside a domain of the (x, C) of initial conditions (C is the energy constant). The method applied is that described by Poincaré as ‘the only “crack” permitting penetration into the non-integrable problems’ and involves calculation of a dense set of families of periodic solutions that covers the solution space of the problem. In the case of the Henon–Heiles potential we calculated the families of periodic solutions that re-enter after 1–108 oscillations. The density of the set of such families is defined by a pre-assigned parameter ε (Poincaré parameter), which ascertains that at least one periodic solution is computed and available within a distance ε from any point of the domain (x, C) for which the approximate general solution computed. The approximate general solution presented here corresponds to ε = 0.07. The same solution is further improved by “zooming” into four square sub-domain of (x, C), i.e. by computing sufficient number of families that reduce the density parameter to ε = 0.003. Further zooming to reduce the density parameter, say to ε = 10⁻⁶, or even smaller, although easily performable in both areas occupied by stable as well as unstable solutions, was found unnecessary. The stability of all members of each and all families computed was calculated and presented in this paper for both the large solution domain and for the sub-domains. The correspondence between areas of the approximate general solution occupied by stable periodic solutions and Poincaré sections with well-aligned section points and also correspondence between areas occupied by unstable solutions and Poincaré sections with randomly scattered section points is shown by calculating such sections. All calculations were performed using the Runge-Kutta (R-K) 8th order direct integration method and the large output received, consisting of many thousands of families is saved as “Atlas of the General Solution of the Henon–Heiles Problem,” including their stability and is available at request. It is concluded that approximation of the general solution of this system is straightforward and that the chaotic character of its Poincaré sections imposes no limitations or difficulties.     

Optical properties of dust from Jupiter family comets

To try to define specific physical properties of the dust of Jupiter-family comets (JFCs), we compare the light scattered by them. Amongst the more than 1000 JFCs, less than 200 are numbered, 40 of them being rather bright. In the present work we use data from the latter. In situ observations of three nuclei show low albedo surfaces. The albedo of the dust particles in the coma is low, with generally a red colour. The A(α)fρ product is a measure of cometary activity and secular changes. Images of different regions (jets and fans) give indications on the nucleus rotation and position of the emitting areas, as compared to the position of the rotation axis. Differences in physical properties between the particles in different regions are pointed out by differences in the linear polarization of the scattered light and by spectral variations in brightness and polarization. Jupiter family comets are considered as dust-poor comets. Tails and trails’ studies give an estimation of the size distribution of the particles. However the dust production rates depend on the largest particles (up to centimetre size), which are mainly observed in the trails where large dark compact particles are found. These dark particles are also responsible for the high polarization in the inner most coma of some comets. The meaning, in terms of physical properties, of the linear polarization is discussed through different examples such as 2P/Encke, 9P/Tempel 1 or the fragments of 73P/Schwassmann-Wachmann 3. Cometary outbursts and splitting events show that the properties of the dust ejected from the interior of the nucleus are similar to the ones of more active comets (new or with larger semi-major axis).     

Short-period Jupiter family comets after Stardust

The NASA Stardust mission has provided for laboratory study an extensive data set of cometary dust of known provenance (from comet 81P/Wild 2) yielding detailed insights into the composition of the comet. Combined with the results of data from other missions to short-period Jupiter family comets (JFC), this has greatly deepened the understanding of such objects. If depressions on the surface of comet 81P/Wild 2 are all taken as evidence of impact cratering, their number suggests a long occupancy in the outer region of the Solar System. The dust from comet 81P/Wild 2 has been shown to be heavily deficient in pre-Solar grains and rich in materials formed at high temperatures in the inner Solar System. Although it is too early to know if this is typical of JFC, it does argue for rapid and thorough mixing of materials in the disk on timescales related to comet formation, and may also suggest outward migration of small icy bodies after their formation. Thus, instead of providing mainly new knowledge of the pre-Solar materials expected to be rich in comets, Stardust and comet 81P/Wild 2 have instead focussed attention on large-scale transport processes during the critical period when cometary parent bodies were forming in the early Solar System.     

泰来草WOX转录因子的筛选与结构分析

WOX转录因子家族是植物中特有的一类转录因子家族,其主要参与调控干细胞多能性、侧生器官的发育、花器官的形成和胚发育等多种生物学功能,同时是一类比较古老的转录因子,因此也有以此为基准进行进化分析的研究。目前,WOX转录因子家族在大多数陆生植物和淡水生植物中被发现,在海洋植物中,这一类转录因子的研究尚较少。泰来草(Thalassia hemprichii)是一种热带区域常见的海洋单子叶植物,具有重要生态功能。本研究利用高通量测序技术获得泰来草的转录组信息,从中筛选获得了一个WOX基因(命名为ThWOX8),CDS序列全长597 bp,编码198个氨基酸,对其进行三维结构建模,显示其具有典型的HB结构,属于WOX转录因子家族中的中间分支。由于对海洋植物的WOX基因研究较少,本研究收集了93个位于中间进化支的WOX转录因子进行了同源比较分析和进化树分析,结果显示了泰来草与豆科和毛茛目莲科植物的亲缘关系较为接近,这可能暗示了泰来草在水生植物和陆生植物之间存在演化关系。鉴于泰来草是一种重要的潮间带植物,对于平衡海洋生态环境较为重要,深入研究泰来草WOX转录因子家族基因有助于我们进一步认识泰来草在进化中的关系,以及为针对性地改进泰来草的人工繁育提供理论依据。     

传统聚落景观基因的地理信息特征及其理解

传统聚落是民族传统文化遗产的重要组成部分,对社会经济和文化建设具有重要的价值。针对现有研究缺乏探讨传统聚落景观基因（简称景观基因）蕴藏的地理信息特征及理解方法,论文从以下方面开展了深入分析：① 地理信息包含了语义描述、几何形态、属性特征、维度、时空框架、尺度、要素相互关系（空间关联）、演化过程（存在状态）等属性;② 景观基因是一种特殊的文化因子,蕴含着丰富的哲理,是认识传统聚落特征的分析方法,也是文化符号的集合;③ 景观基因包含了空间定位、载体特征、历史与文化特征等丰富的地理信息。根据前述分析结果,论文从符号化、数据挖掘、谱系分析与空间格局制图等途径系统地探讨了景观基因地理信息特征的理解方法。论文认为：在地理时空大数据与地理服务日益深化发展的背景下,结合GIS原理探讨景观基因的地理信息特征对于延伸地理信息科学的内涵,深化传统聚落的地学认识,促进人文GIS的发展具有积极的意义,今后应该继续加强相关方法探索。