东北地区城市群组的格局、过程及城市流强度

根据城市群、城市组群及城市群组的内涵指出中国东北地区目前存在辽中南、吉林中部、哈大齐三个城市群组。按照其形成发展过程和现状特征,辽中南已经发育成为成熟的城市群,而吉林中部和哈大齐尚处于城市群发育的中间阶段,即城市组群阶段,从而在东北地区形成了"一群二组"的空间结构框架。通过对东北地区城市群组外向功能量和城市流强度的计算发现,群组内部尚未出现主要外向服务部门区位熵均大于1的城市,与国内发达城市群的发展水平相距较远。未来发展应该围绕城市群组的组织结构、网络化发展模式、职能分工与功能互补、发展关系协调等方面进一步调控和优化。     

Paleomagnetic Excursions Recorded in the Yanchi Playa in Middle Hexi Corridor, NW China Since the Last Interglacial

Paleomagnetic determinations on lithologieal profiles of two paralleled long drillin gcores covering the past 130 kyr B.P., GT40 and GT60,from the Yanchi Playa in the arid Northwestern China indicate that a series of pronounced paleomagnetic excursions have been documented. By correlating our results with published regional and worldwide reports 4 excursion events out of 10 apparent reversal signals (labeled from GT-1 to GT-10) were identified as excursion events coeval with the Mono Lake Event (28.4 kyr-25.8 kyr), Laschamp Event (43.3 kyr-40.5kyr), Gaotai Event (82.8 kyr-72.4 kyr) and the Blake Event (127.4 kyr-113.3 kyr), respectively. GT-9 correlates with the above-mentioned Gaotai Event,GT-7 and GT-6 correspond to two stages of the Laschamp Event and GT-5 to the Mono Lake Event. It is noteworthy that the so-called Gaotai Event has not been reported as a pronounced paleomagnetic excursion in the Northwestern China. Every magnetic excursion event corresponds to paleointensity minima, anteceding those established abrupt paleoclimatic change events, such as the Younger Drays and the Heinrich Events (H1-H6). Here, we tentatively propose that these geomagnetic excursions/reversals can be viewed as precursors to climate abruptness. During the transitional stages when the earth‘s magnetic field shifted between a temporal normal and a negative period, the earth‘s magnetic paleointensity fell correspondingly to a pair of minima. Although more precise chronology and more convincing rock magnetic parameter determinations are essentially required for further interpretation of their intricate coupling mechanism, these results may have revealed, to some extent, that the earth‘s incessantly changing magnetic field exerts an strong influence on the onset of saw-tooth shaped abrupt climate oscillations through certain feedback chains in arid Central Asia or even North Hemispheric high latitude regions.     

地震计灵敏度的对比测量法

本文提出一种地震计灵敏度的对比测量法, 该方法将被测地震计和一台校准过的地震计比邻、 平行摆放, 共同记录地振动数据, 通过对比分析两台地震计的输出信号, 计算被测地震计的灵敏度。 与振动台测量法相比, 该方法成本低, 与电测法相比, 不需已知地震计的标定常数, 是一种简单易行、 精度高的地震计灵敏度测量方法。     

大别山北缘地质找矿中遥感方法的研究

本项工作着重探讨在植被覆盖、地质背景十分复杂的地区，利用遥感信息寻找金矿及其它多金属矿的方法。即从地层岩系、构造及构造交叉部位、蚀变带这三个方面，进行地质找矿专题信息特征提取方法的研究。最后，通过信息提取及影像综合特征，进行遥感地质制图，圈定找矿有希望的地段。     

三种凡纳滨对虾池塘养殖模式环境因子变化和养殖效益的分析

研究了3种凡纳滨对虾池塘养殖模式环境因子变化情况和对养殖效益的分析。实验分为3种不同的养殖模式:对虾单养组、鱼虾混养A组、鱼虾混养B组。结果表明:pH变化范围在8.40~9.06之间,其中对虾单养组pH较之两组鱼虾混养组略高,最高值达9.06;COD变化范围在101~211之间,其中对虾单养组COD较之两组鱼虾混养组略高,范围在132~211之间;氨氮和亚硝酸盐氮浓度为对虾单养组>鱼虾混养A组>鱼虾混养B组;异养菌数目和弧菌数目,随着养殖的进行呈现逐渐增加的趋势,最大值分别为对虾单养组1.1×106 CFU/mL、2.0×103 CFU/mL,鱼虾混养A组1.45×106 CFU/mL、1.80×103 CFU/mL,鱼虾混养B组1.20×106 CFU/mL、1.56×103 CFU/mL;养殖效益上,总产值、纯利润、亩利润、投入产出比均呈现出鱼虾混养B组>鱼虾混养A组>对虾单养组。由此可见,凡纳滨对虾和鱼类混养,可以在保证水质的前提下,提高凡纳滨对虾养殖规格,提高投入产出比,增加养殖效益,是一种相较于凡纳滨对虾单独养殖优越的养殖模式;而不同规格和数量的鱼类和不同数量凡纳滨对虾的混养,又会产生不同的养殖效益。     

2000—2015年柴达木盆地植被覆盖度时空变化及其与环境因子的关系

基于MODIS-NDVI、DEM和气象数据,分析柴达木盆地2000—2015年植被覆盖度(FVC)时空变化特征,并与降水、温度、日照时数、相对湿度、蒸散量和海拔进行相关、偏相关或叠加分析,探讨FVC与各环境因子的关系。结果表明:FVC整体自东南向西北内陆呈半环状递减,FVC集中在20%以下,人类活动及径流等打破植被地带性规律;2000—2015年FVC明显改善,广泛分布于盆地中西部地区,2001—2002年年际变化最显著;FVC与降水、相对湿度以正相关为主,与温度关系不显著,与日照时数和蒸散量主要为负相关,降水对FVC贡献最大,温度通过影响蒸散量等间接影响FVC,而土壤蒸发对蒸散量的影响大于植物蒸腾;FVC与等高线空间分布较吻合,FVC在2 800~2 900 m和4 600~4 700 m出现两个峰值,4 700 m以上FVC迅速降低。     

The petrogenesis and implications of deformed late Caledonian–early Hercynian granites in the Wuyi area,South China

Precambrian basement rocks have been affected by Caledonian thermal metamorphism. Caledonian‐aged zircon grains from Precambrian basement rocks may have resulted from thermal metamorphism. However, Hercynian ages are rarely recorded. Zircon U–Pb Sensitive High Resolution Ion Microprobe (SHRIMP) dating reveals that zircon ages from the Huyan, Lingdou, and Pengkou granitic plutons can be divided into two groups: one group with ages of 398.9 ±5.3 Ma, 399 ±5 Ma, and 410.2 ±5.4 Ma; and a second group with ages of 354 ±11 Ma, 364.6 ±6.7 Ma, and 368 ±14 Ma. The group of zircon U–Pb ages dated at 410–400 Ma represent Caledonian magmatism, whereas the 368–354 Ma ages represent the age of deformation, which produced gneissosity. The three plutons share geochemical characteristics with S‐type granites and belong to the high‐K calc‐alkaline series of peraluminous rocks. They have (⁸⁷Sr/⁸⁶Sr)_i ratios of 0.710 45–0.724 68 and εNd(t) values of ?7.33 to ?10.74, with two‐stage Nd model ages (T_DM2) ranging from 1.84 Ga to 2.10 Ga. Magmatic zircon εHf(t) values range from ?3.79 to ?8.44, and have T_DMC ages of 1.65–1.93 Ga. The data suggest that these granites formed by partial melting of Paleoproterozoic to Mesoproterozoic continental crust. A collision occurred between the Wuyi and Minyue microcontinents within the Cathaysia Block and formed S‐type granite in the southwest Fujian province. The ca 360 Ma zircon U–Pb ages can represent a newly recognized period of deformation which coincided with the formation of the unified Cathaysia Block.     

利用Abel-Poisson径向基函数模型化局部重力场

多种类型高分辨率重力场数据的不断增加,使得在局部范围内精化重力场模型成为了可能。本文采用Abel-Poisson核将重力场量表示成有限个径向基函数线性求和的形式,对局部区域的多种重力场数据进行联合建模。为了提高运算速度,运用了基于自适应精化格网算法的最小均方根误差准则(RMS)来求解径向基函数平均带宽。以南海核心地区为例,联合两种不同类型、不同分辨率的重力场资料(大地水准面起伏6'×6'、重力异常2'×2'),构建了局部区域高分辨率的重力场模型。所建模型表示的重力场参量达到了2'×2'的分辨率,对原始的重力异常数据(2'×2')拟合的符合程度达到±0.8×10-5m/s2。结果表明,利用径向基函数方法进行局部重力场建模,避免了球谐函数建模收敛慢的问题,有效提高了模型表示重力场的分辨率。     

青藏铁路沿线不同类型挡沙墙阻沙率

基于风洞试验对青藏铁路沿线不同类型防沙措施防沙效果进行模拟研究,探讨了不同类型挡沙墙的防沙效果。结果表明：挂板式、轨枕式和箱式挡沙墙输沙率随高度基本呈递增缓变型趋势,最大输沙率低于20%;铃铛式和高立式聚乙烯（PE）网挡沙墙随高度呈递减陡降型趋势,距地表6~8 cm处为转折点,转折点以上输沙率随高度增大急剧减小,转折点以下输沙率随高度变化较为平缓,最大输沙率低于50%。随着风速的增大,各挡沙墙的阻沙率呈递减趋势：挂板式和轨枕式挡沙墙对风速的敏感性最弱,整体阻沙效果较优,可大范围推广;箱式挡沙墙对风速的敏感性较弱,建议在风速18 m·s^-1以下的地区使用;PE网挡沙墙防沙效果对风速的敏感性最强,建议在风速10 m·s^-1以下的地区使用。     

北祁连山西段早元古代变质火山岩的地球化学特征及其构造背景

产于北大河群的早元古代火山岩是北祁连山西段最主要的三期火山岩之一,其地球化学特征表明,该期火山岩的原岩为具有双峰式组合的拉斑玄武岩和中酸笥凝灰岩。两者具有完全不同的稀土分布型式,前者以极低的富集轻稀土为特征,而后者以强烈富集轻稀土的特征;基性火山岩的微量元素分布曲线指示了其形成了裂陷槽环境。结合Ｎｄ同位素特征以及区域２得出本区早元古代变质火山岩形成于裂陷槽环境。