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1.
Graeme Bristol 《Singapore journal of tropical geography》2002,23(3):348-362
This paper describes an exercise with children in the implementation of housing rights. Based on the argued opinion that housing rights cannot be exercised without participation and that participation without knowledge is pretence, a Kids and Architecture programme was initiated with a group of 40 children — displaced from homes in the Klong Toey slum in Bangkok — at a girls' home run by the Human Development Foundation (HDF). The programme, developed in two phases and involving students from the King Mongkut's University of Technology Thonburi (KMUTT), School of Architecture, set about to teach these children some of the elements of architecture so that they could participate in the design of their own housing. From this experiment a number of conclusions are drawn about the implementation of housing rights and about the teaching of architecture, both to children and architecture students. 相似文献
2.
对南极阿德雷岛企鹅栖息地粪土层进行210Pb测年,同时采用气相色谱-电子捕获检测器(GC-ECD)内标定量法测定了企鹅栖息地粪土混合地层和企鹅蛋卵中有机氯污染物含量,粪土混合地层中有机氯污染物最高浓度:表层PCBs为0.92ng/g,HCHs为0.42ng/g,DDTs在0.70ng/g,与非栖息地相比较,研究结果显示,通过鸟类活动的粪土混合地层(营巢和粪便)输入PCBs和OCPs含量比无鸟类生命途径的土壤相对要高。企鹅蛋卵样∑PCB在0.4-10.2ng/g,∑DDT2.4-10.3ng/g,HCB0.1-9.4ng/g,∑HCH0.1-0.5ng/g,总积蓄水平依次为:∑PCB>∑DDT>HCB>∑HCH。 相似文献
3.
MIL 090070陨石是2009年美国南极陨石搜寻项目(ANSMET)在南极横断山脉米勒山区(Miller Range)发现的一块月球陨石,属于斜长岩质月表角砾岩。它具有典型的碎屑结构,主要由岩屑、晶屑、玻屑和细粒基质组成。岩屑以复合斜长岩质岩屑和斜长岩岩屑为主,其次为辉长岩质斜长岩岩屑、辉长岩岩屑、辉长苏长岩岩屑、辉长岩质橄长岩岩屑和橄榄辉长岩岩屑等。晶屑有普通辉石、易变辉石、斜长石、尖晶石、石英和钛铁矿等矿物。玻屑主要为斜长石质的玻屑,呈细长或弯曲条状,多具裂纹。MIL 090070陨石的矿物组成主要为斜长石（86 vol%,An92—99）、橄榄石（6 vol%,Fo53—89）、辉石（7 vol%,En25—83Fs7—43Wo2—45）,以及少量的尖晶石、钛铁矿和石英等;其中,辉石有单斜辉石和斜方辉石二种。MIL 090070陨石中橄榄石和辉石的Fe-Mn值分布明显不同于地球、火星、金星和小行星的样品,基本落在月球岩石范围。MIL 090070陨石在多期次冲击和胶结作用下,岩屑的矿物成分和粒度不断变化,岩屑类型更多样,更复杂。基于MIL 090070陨石的岩石矿物学特征、碎屑类型及结构的特征等研究,可以进一步丰富我们对月球物质的形成及月岩—月壤演化过程的认识。 相似文献
4.
D. Bamford 《Geophysical Journal International》1977,49(1):29-48
Summary. Earlier interpretations of P n travel-times from the extensive quarry-blast observation scheme in western Germany — now supplemented by explosion data from the 1972 Rhinegraben experiment — have been checked and enhanced using the new MOZAIC time-term method. The large data set (762 travel times) continues to require a considerable anisotropy of upper-mantle P velocity. The resulting estimates of the overall velocity variation — probably 0.50–0.60 km/s about a mean value of 8.05 km/s, that is, 6 to 7 per cent anisotropy — and of the direction of the maximum velocity (close to 20° E of north) are reasonably reliable. However, the detailed form of the anisotropy is obscured by various limitations of the data.
These results allow a realistic assessment of the resolving power of refraction-based studies of velocity anisotropy in the lithosphere. It is concluded that though such studies are probably adequate if the measurement of in situ anisotropy is required within the context of a generalized discussion of lithospheric dynamics they are not appropriate if a detailed specification of the anisotropy is desired. 相似文献
These results allow a realistic assessment of the resolving power of refraction-based studies of velocity anisotropy in the lithosphere. It is concluded that though such studies are probably adequate if the measurement of in situ anisotropy is required within the context of a generalized discussion of lithospheric dynamics they are not appropriate if a detailed specification of the anisotropy is desired. 相似文献
5.
南极因其独特的自然环境成为潜在、重要的微生物资源库,是产生新型生物活性物质和先导化合物菌株的潜在种源地,南极微生物正在成为创新药物研究新的重要资源。虽然近年来对南极微生物次级代谢产物的研究逐渐增加,但与温带和热带微生物研究相比仍处于初级阶段。对从南极普里兹湾海洋沉积物中获得的两株枝孢霉属真菌Cladosporium sp. NJF4和NJF6进行次级代谢产物分离及结构鉴定,获得20个化合物。化合物结构类型包括甾醇(1)、倍半萜类(7—8)、生物碱类(9—14)、二酮哌嗪(2—5、15—17)、芳香酸(6、18—19)等,其中倍半萜类(7—8)为首次从枝孢霉属真菌中分离得到,以上研究将为丰富南极微生物次级代谢产物库奠定一定的研究基础。 相似文献
6.
K. P. Games 《Geophysical Journal International》1977,48(3):315-329
Summary. A new method for determining the magnitude of the palaeomagnetic field is described. The material used is adobe Sun-dried mud brick, and some of the magnetic properties of these bricks are described. The magnetization acquired by the mud in the higher coercive force region seems to be caused by shear strain (squeezing) alone. This magnetization is called an SRM. The method is tested on a modern adobe brick from Lima, and it is shown to be accurate and repeatable. The method may also be used to determine values of D and I , if the adobe brick is found in situ . Three results from old adobe bricks — two from Peru and one from Egypt — are presented and are compared with the world-wide average of published ancient VDM's. 相似文献
7.
北极海域楚科奇海和白令海表层沉积物的正构烷烃气相色谱图呈双峰群分布,楚科奇海正构烷烃分子组合特征高碳数峰群MH(主峰碳)在nC25-nC33、低碳数峰群MH在nC16-nC20范围;白令海高碳数峰群MH在nC25-nC27、低碳数峰群MH在nC17-nC22范围。两海域的OEP(奇偶优势指数)各为0.9-3.81、0.409-3.26;C-23/C+24比值为0.18-1.53、0.40-2.57之间;TABHC(陆/水生类脂物)比值在0.57-11.35、0.32-5.97之间。根据分子组合特征表明楚科奇海的陆源物质输入要比白令海大,而白令海的表层生产力又比楚科奇海高。本文将北极海域现代沉积过程中的正构烷烃分子组合特征与南极进行对比,同时又将高纬度海域与低纬度海域渤海、黄海、东海和南海进行对比,研究发现由高纬度北极到低纬度海域的陆源输入特征依次减弱,而海洋生物自身起源特征加强。不同纬度海域的表层沉积物中正构烷烃呈现出不同的分子组合差异,受到现代海洋沉积过程中物质来源、环境、气候诸多因素的影响。 相似文献
8.
本文利用 2 0 0 3年 2月我国第 1 9次南极考察队在南极普里兹湾到澳大利亚弗里曼特尔南印度洋断面上获得的XBT和XCTD数据 ,分析了该断面上层的水团分布和锋面的特征 ,并讨论了极锋以南表层的淡水输入和热量输入与海冰、降水及平流之间的关系。南极夏季表层水(AASSW)、亚南极表层水 (SASW)、亚热带表层水 (STSW)分布于温盐跃层之上的混合层中 ,由南向北依次分布。AASSW之下是向北延伸的温度最小值层 ,即冬季水 (WW) ,其下则是涌升的上层南极饶及深层水 (UCDW)。南侵的高温高盐的亚热带表层水 (STSW)之下是温度和盐度相对均匀的亚南极模式水 (SAMW)。本航次发现 ,在 63.5°S ,79.7°E的 60 0m以深有低盐水体 (相对其周围水体 )存在 ,核心盐度 34.5 8,位于 80 0- 90 0m水深之间。这是历次考察在该断面所不曾观测到的现象。断面上的锋面从南向北依次为南极陆坡锋 (ASF)、极锋 (PF)、亚南极锋 (SAF)和亚热带锋 (STF)。ASF位于 65°S以南的 1 0 0m以深 ,等温线和等盐线向南倾斜 ;PF位于 5 4°S ,90 .4°E ;SAF位于 45 .3°- 47.5°S ,1 0 2 .5°- 1 0 4 .4°E之间 ,深达整个测量深度 ,温度具有两个高梯度核心 ;首次在该断面观测到双STF结构 ,位于 41 .9°- 42 .6°S,1 0 6.7°- 1 0 7.3°E和 37.7°- 38 相似文献
9.
20世纪90年代以来,北极进入了以海冰快速减少为显著特征的快速变化时期。通过分析“波弗特流涡观测计划”在北冰洋加拿大海盆的4个站点上布放剖面观测系统所获得的2003—2011年的温度、盐度剖面观测数据,研究了加拿大海盆北极中层水的变化特征。在观测期间,加拿大海盆中央区中层水核心温度变化较小,楚科奇海台地区有明显下降特征,海盆中央区以北以及加拿大群岛陆坡边缘区核心温度呈持续升高趋势。北极中层水核心深度在4个站点都有不同程度的加深趋势,加深的程度和参与分析的表层淡水含量以及因海冰消失导致的风应力变化有一定的对应特征。4个站点表层(75—200 m)的热含量在无冰海域有明显的增长,在有冰海域热含量较稳定;加拿大海盆200—400 m和400—800 m深度范围内的热含量变化情况与中层水核心深度的变化情况一致,伴随着中层水核心深度加深至400 m乃至更深处,中层水的能量也逐渐下移,造成200—400 m水层能量普遍降低而400—800 m水层能量普遍增加。加拿大海盆4个观测站点因背景环境条件和所受影响的不同,造成了中层水的变化和响应趋势的差异。 相似文献
10.
Summary. Velocities of compressional waves are determined for central California rocks at pressures up to 0.7 GPa (7 kb) and temperatures up to 450°C. These data are used to interpret the seismic velocity structure of the crust in the California Coast Ranges. The seismic data on both sides of the San Andreas fault are consistent with the following model; besides some patches of surface sediments the upper 10—15 km of the crust on the northeast side consists predominantly of sedimentary and metasedimentary rocks of the Franciscan assemblage; the lower crust, of a thickness of 15—20 km, may be composed of gabbroic or other mafic rocks. Across the fault on the south-west side, the entire crustal section is probably a granitic complex similar to that exposed on the surface. The proposed model is shown to be consistent with the observed gravity anomaly. 相似文献
11.
从421株南极细菌中筛选出产超氧化物歧化酶南极细菌NJ062、NJ379、NJ522和NJ548。它们的最适生长温度在10-15℃之间,在0℃均能生长,属于嗜冷菌。4株南极嗜冷菌均含有一种类型的SOD同工酶。菌株NJ062的超氧化物歧化酶为Mn-SOD;菌株NJ379,NJ522和NJ548的超氧化物歧化酶均为Fe-SOD。它们所产的超氧化物歧化酶最适酶活温度大约在40-50℃,在0℃仍有较高的活性,为最高活性的20%-35%,热稳定性较差,属低温酶。通过16S rDNA序列对4株产低温超氧化物歧化酶的南极嗜冷菌NJ062、NJ379、NJ522和NJ548进行鉴定。结果表明,它们均属于细菌域(Bacteria)中的紫细菌类群(Proteobacteria)中的γ-亚群。其中菌株NJ062属于假交替单胞菌属(Pseudoalteromonassp.);NJ379属于希瓦氏菌属(Shewanellasp.);NJ522和NJ548属于海单胞菌属(Marinomonassp.)。 相似文献
12.
本文用MPN法测定楚科奇海和加拿大海盆表层沉积物中好气异养细菌(GAB)的含量,并对其地理学分布进行分析。结果表明,研究区GAB的检出率高达100%。4℃时GAB的含量范围、平均含量为4.00×102-2.40×106个.g-1、1.71×106个.g-1。25℃时GAB的含量范围、平均含量为2.40×105-2.40×107个.g-1、1.10×107个.g-1。无论是含量范围,还是平均含量,均是25℃时的培养结果大于4℃时的培养结果。GAB含量的地理分布趋势是随纬度增高,含量呈降低趋势。在经度变化上则为由东向西,含量呈降低趋势。对沉积物所处水深的分析,表明其在4℃培养得出来的GAB含量随水深增加有下降的趋势,25℃培养出来的GAB含量受环境影响较小,与水深变化关系不明显。 相似文献
13.
利用2012年9月1—6日采自马卡诺夫海盆3个站位和楚科奇深海平原1个站位的分层浮游动物样品,研究了浮游动物在0—1 000 m水层的垂直分布以及地理差异。结果表明,浮游动物在上层分布密集而在深层比较稀少。4个站位在0—50 m、50—100 m和100—200 m水层的平均丰度分别为265.0、360.7和231.2 ind·m-3,而在200—500 m和500—1 000 m的丰度只有64.4和36.9 ind·m-3。在数量上占优势的种类中,植食性为主的拟长腹剑水蚤(Oithona similis)、北极哲水蚤(Calanus glacialis)和极北哲水蚤(Calanus hyperboreus)集中在200 m以浅的水层。虽然在200m以下杂食性种类矮小微哲水蚤(Microcalanus pygmaeus)、隆剑水蚤(Oncaea spp.)和细长长腹水蚤(Metridia longa)的丰度明显降低,但是占浮游动物总丰度的比例却明显更高。两个调查海区浮游动物种类组成相似,但是楚科奇深海平原大型桡足类极北哲水蚤的丰度较高,而小型桡足类丰度较低?垂直分布上差异主要在于500—1 000 m水层,马卡诺夫海盆站位丰度为22.7—92.6 ind·m-3,而楚科奇深海平原只有1.6 ind·m-3。深海区浮游动物丰度的地理差异说明生物泵的作用存在空间异质性。类似地理差异产生的原因在于楚科奇深海平原存在数量较多的极北哲水蚤,它们在春季融冰前就上升到表层摄食冰藻,显著降低了有机物的垂直通量。 相似文献
14.
就目前认识,拉斯曼丘陵地区的所有基底和盖层岩石都卷入到了格林威尔期和泛非期高级变质和变形作用。泛非期高峰变质的时代大致在550—530 Ma,其造山晚期的花岗质岩浆作用遍及全区。我们观察到,中山站区石榴黑 云斜长片麻岩固相变质作用过程,主要是对早期锆石的重启、改造,例如,对早期岩浆锆石环带的模糊化,对锆石棱、角的溶蚀,甚至同位素体系的重启等,难以形成变质锆石（边）,退变或重启年龄平均值为522.7±6.6 Ma。峰期变质 之后侵位的花岗岩结晶年龄为545±9 Ma,意味着峰期变质应不晚于该年龄。泛非期的变形、变质作用及花岗岩可对早期“干”岩石进行某种程度的退变质改造,从而造成高级变质岩变质结构的复杂性。这种变质作用及有关的花岗岩活动似乎缘于陆块内部的活化,而不是不同陆块间的碰撞所致。 相似文献
15.
A. J. Harding 《Geophysical Journal International》1985,80(2):463-492
Summary. The transformation of a set of seismograms to the delay time-slowness, τ—p, domain is presented as a sequence of Fourier and Bessel transforms, For a horizontally layered medium, this sequence gives an exact cylindrical wave decomposition of the response to a point source; correctly compensating for the phase shifting and geometrical spreading associated with transmission through the Earth. The resultant τ—p map or 'slant stack' contains true amplitude and phase information. The spatial aliasing properties of the transformation, when applied to a dataset, are greatly improved by the use of only outgoing waves in the Bessel transform. This is equivalent to using Hankel functions rather than Bessel functions, and is justified by the absence of incoming waves from most datasets. The WKBJ approximation to the medium response enables predictions to be made about the shape and amplitude variation with slowness of truncation effects. Theoretically the τ—p transformation is reversible, thus the τ—p domain is a suitable one in which to perform filtering operations before seismogram reconstruction. 相似文献
16.
Sujata Ramachandran 《Singapore journal of tropical geography》2002,23(3):311-332
The remarkable ease with which the xenophobic tenor of the Hindu Right nationalist organizations or Sangh Parivar found favour with many privileged Indians in the early 1990s cannot be easily or comfortably discounted. Indeed, it even perniciously swayed a moderate secular central government led by the long dominant Congress Party. By mid–1992, when Sangh Parivar made the manifold dangers of the unsanctioned immigration by growing numbers of poverty–stricken Bangladeshi Muslim peasants their rallying cry, the lenient attitude of the Indian state towards these immigrants had hardened with astonishing rapidity. Unsettled by this sweeping tide of Hindu chauvinism, a hurriedly enforced "Action Plan" to locate and identify these undocumented immigrants was followed by brisk efforts under "Operation Pushback" to deport them from New Delhi — India's capital city and locus of bureaucratic, political and financial power. Haphazard and sporadic in implementation, Operation Pushback, while unmasking partisan dispositions coursing through the Indian bureaucracy, also exemplified Congress' belated attempts at redeeming its enervated standing. It is also worth noting that the highly circumscribed material realities of the Bangladeshi immigrants residing in Delhi's numerous slums made them easy targets of these perverse politics, and that subsequent opposition, internally and from neighbouring Bangladesh, to the gratuitous brutality displayed towards the first groups of deportees contributed to the Operation's abrupt truncation. 相似文献
17.
Summary. We report the results of our continuing efforts to compute theoretical seismograms for direct comparison with the experimental time series obtained with the long-period instruments of the WWSSN. The entire theoretical seismogram — body waves and surface waves — is generated for realistic sources buried in a radially heterogeneous, anelastic, spherical earth. The results described in Paper I (Nakanishi, Schwab & Knopoff) are extended to include the summation of 11 modes; for each, the dispersion, attenuation, and excitation are computed down to a minimum period of 1 s. Examples of the theoretical seismograms, and the comparison with experimental results are presented, The results of this comparison indicate that our first application of combined body- and surface-wave generation will concern the investigation of the intrinsic anelasticity in the upper mantle. The indicated technique for such an investigation is based on body waves simply crossing the region of high attenuation a few times in passing from focus to recording station, while a guided surface wave such as Sa , experiences this anelasticity over the entire propagation path. 相似文献
18.
根据 1 999年和 2 0 0 3年中国北极科学考察航次 ,从Canada海盆收集温、盐、深和营养盐浓度数据 ,用文献报道的低浓度1 2 9I和高浓度金属钡 (Ba)来指示太平洋源水、用相应的高浓度1 2 9I和低浓度Ba来指示大西洋源水 ,划分了该海盆物理化学特征的 4个水团。表层水 ( <40m)的盐度从 2 5至 31 .6;硝酸盐处于耗尽水平 ,而磷酸盐和硅酸盐处于最低水平。营养盐再生水大致位于 40- 2 0 0m ;盐度特征为 31 .6- 33.1 ;营养盐浓度一致增至最高 ;极大峰的盐度在 33.1附近 ,其位温则处于最低水平 (约 - 1 .5°C)。混合水 (深约 2 0 0- 385m)盐度从 33.1至 34.8;位温从局域最低升至整个水柱最高的 0 .5 0- 0 .65 7°C ;营养盐则逐渐降低。深层水深度变化较大 ( 385m至 1 90 0m以下海底 ) ;但其盐度变化较小 ( 34.8- 34.9) ;位温则从最高降低到 - 0 .4至 - 0 5 4°C ;营养盐均轻微增加。结合文献中对于营养盐极大的年际观测 ,1 2 9I、Ba与氯氟烃CFC 1 1的浓度及3H 3He示踪年龄的结果分析表明 ,营养盐再生水是无季节性变化的、高年龄 (约 8- 1 5年 )的太平洋源水 ;深层为大西洋源水 ;而混合水团即为上述 2大源水的混合层。硅酸盐和磷酸盐的强极大指示优势种硅藻及其再生主导太平洋源水。 相似文献
19.
武汉都市圈路网空间通达性分析 总被引：20，自引：1，他引：19
以武汉都市圈为例.通过距离算法、拓扑算法和空间句法模型,构建系列通达性数理模型.定量分析武汉都市圈路网发育的空间结构性规律:武汉都市圈路网整体发育水平和通达性格局保持高度相关性和一致性.空间差异显著;通达性遵循距离衰减律,空间收敛整体效应明显.呈现三大等级圈层和"中心-外围"结构:高等级路网发育不均衡.引起时空距离通达性圈发生"摄动"变形,呈西北-东南向倾斜的"Y"字形结构:拓扑连接等通达性圈更是出现"破碎化",交通轴线网络呈"轴一辐"式和"鱼骨刺"状空间伸展序:同时,路网发育的等级差异性也导致整个网络伺服效率和应对"拥堵"能力的低下,并形成沿长江东西向、沿京广南北向两条带状集成核.成为整个路网的第一等级交通轴线,控制整个都市圈网络连接性,强化交通轴线交汇处-武汉市的中心性优势:路网通达性这种等级空间格局与圈域城镇体系、交通设施和社会经济发展状况密切相关.尤其是与高速公路为代表的高等级路网发育水平,表现出复杂的共轭协调关系. 相似文献
20.
Cécile Duchêne Anne Ruas Christophe Cambier 《International journal of geographical information science》2013,27(9):1533-1562
Our research is concerned with automated generalisation of topographic vector databases in order to produce maps. This article presents a new, agent-based generalisation model called CartACom (Cartographic generalisation with Communicating Agents), dedicated to the treatment of areas of low density but where rubber sheeting techniques are not sufficient because some eliminations or aggregations are needed. In CartACom, the objects of the initial database are modelled as agents, that is, autonomous entities, that choose and apply generalisation algorithms to themselves in order to increase the satisfaction of their constraints as much as possible. The CartACom model focuses on modelling and treating the relational constraints, defined as constraints that concern a relation between two objects. In order to detect and assess their relational constraints, the CartACom agents are able to perceive their spatial surroundings. Moreover, to make the good generalisation decisions to satisfy their relational constraints, they are able to communicate with their neighbours using predefined dialogue protocols. Finally, a hook to another agent-based generalisation model – AGENT – is provided, so that the CartACom agents can handle not only their relational constraints but also their internal constraints. The CartACom model has been applied to the generalisation of low-density, heterogeneous areas like rural areas, where the space is not hierarchically organised. Examples of results obtained on real data show that it is well adapted for this application. 相似文献