1951~2013年华北地区极端降水事件的变化

利用华北地区90个气象站点1951~2013年逐日降水量资料,计算了8个极端降水指数,采用滑动平均、线性回归、Mann\|Kendall非参数检验和Morlet小波分析等方法,分析了华北地区极端降水事件的变化规律。结果表明:华北地区近63 a连续干旱日数(CDD)呈明显的增加趋势,连续5 d降雨量、连续湿日、年总降雨量趋于减少并通过0.05显著性检验,其他4个极端降水指数都表现为减少趋势且不显著。各极端降水指数与年总降水量(PRCPTOT)有很好的相关性,除连续干旱日数与之呈负的弱相关性以外,其他指数均呈较强的正相关性。在近63 a的时间尺度上各项极端降水指数都存在2～4 a显著周期,多数指数也存在8 a、16 a和32 a的周期。在时间转折上,连续湿日(CWD)的突变点时间较早,发生于1964年。从空间分布来看,京津冀地区及山西大部是极端降水指数变化最为显著的区域,连续干旱日数增加,其他指数均呈现减小趋势。
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东营凹陷北带深层Es下4盐下段轻质油地球化学特征及油源探讨

根据饱和烃、轻烃、双金刚烷的分析资料,全面剖析了东营凹陷北带E_s^下₄盐下段轻质油的地球化学特征。研究发现,轻质油Pr/Ph值为0.7,略呈植烷优势,轻烃中以正烷烃占优势,异构烷烃相对较少,2-甲基己烷/3\|甲基己烷的比值大于1,表征油源岩为还原的湖相沉积,生源母质较好。经轻烃指纹对比,结合双金刚烷成熟度指标分析认为,轻质油来自于E_s^下₄盐下段烃源岩。进一步表明东营凹陷深层E_s^下₄盐下段将成为勘探重要的潜力区带。     

浅谈陕北地区窑洞建筑的通风设计策略

窑洞是陕北地区的特色建筑形式,它不仅是当地传统文化和人文精神的结晶,而且符合绿色生态和可持续发展的要求。该文以陕北地区传统窑洞为研究对象,通过文献数据分析和实地调研两种方式,提出了陕北地区传统窑洞建筑的通风设计策略,旨在探索传统窑洞建筑改造的新方式。     

慢城发展模式与规划布局——以晋北中部城镇群为例

慢城可被理解为是对传统城市发展模式和生活方式的回归与升华,探索一种更为人性化和具有人文主义精神的新型城市发展模式与现代生活方式。慢城发展模式可分为自然发展型、自上而下的政府主导型、自下而上的组织联盟型和综合发展型四类。慢城规划布局的内容层次体系包括慢核、慢城(慢岛)、慢区三个层次。这三个层次通过网络化的慢行系统形成有机、紧密的联系,从而共同组成一个完整的区域"慢城系统"。     

Supercritical carbon dioxide extraction of polyunsaturated fatty acids from Northern shrimp (Pandalus borealis Kreyer) processing by-products

This study investigated the potential of Northern shrimp (Pandelus borealis Kreyer) by-products as a source of omega-3 polyunsaturated fatty acids (ω-3 PUFAs). The by-products (heads, shell and tail) of processing accounted for approximately 50–60% of the catch. Supercritical CO₂ extraction (SFE) of the by-products at 35 MPa and 40 °C generated a deep red oil, rich in ω-3 PUFAs, specifically 7.8 ± 0.06% eicosapentaenoic acid (EPA) and 8.0 ± 0.07 % docosahexaenoic acid (DHA).     

Establishment and Development of Bolt Net Support System of Coal Mine Roadway in Mining Area of Northern Anhui

近几年,在我国煤矿支护中,煤巷锚网支护取得了大面积推广应用,该技术比传统的架棚支护有着很多优点,节约了大量的人财物,减轻了职工的劳动强度,大大提高了劳动生产率。煤巷锚网支护体系在皖北矿区已全面推广,煤巷锚网支护率已达到90％以上。着重介绍锚网支护体系在皖北矿区的发展历程及顶板控制的成功经验。     

苏北盆地海州群火山岩地球化学特征及其大地构造学意义

苏北盆地元古代晚期的海州群中发育大量火山岩,以石英角斑岩为主,细碧岩次之,角斑岩类稀少,属于细碧岩—石英角斑岩组合类型。海州群火山岩富碱、富钠,具双峰值特征,该岩系的主量元素、微量元素和稀土元素地球化学特征表明,它形成于非造山张性环境,为裂陷槽,是与晚元古代罗迪尼亚超大陆裂解有关的岩浆作用的产物。      

黔北地区构造特征与下寒武统页岩气储层裂缝研究

裂缝发育程度是页岩气储层的主控因素之一,而裂缝的形成与构造特征密切相关。在对黔北地区构造特征分析的基础上,对该区下寒武统牛蹄塘组黑色页岩地层的裂缝特征及分布进行了研究。认为黔北地区褶皱、断裂发育复杂,褶皱整体以隔槽式为主,断裂是在多个走向断裂体系相互切割、联合下形成的,各断裂体系的主形成期具有差异性;构造裂缝是下寒武统黑色页岩层段的主要裂缝类型,而且以水平缝与低角度缝所占比例大。裂缝发育区的分布主要受到断裂带的控制,其中以北东向和北北东向断裂体系的控制作用最为显著,裂缝发育区多位于断裂带的末端、拐点处、不同走向断裂带相交处和相同走向的断层夹持带等应力集中部位。其次,在背斜的高陡部位,也有利于裂缝的形成。     

西藏北喜马拉雅马扎拉金锑矿床地质特征及成矿作用

马扎拉金锑矿床位于西藏北喜马拉雅金锑成矿带.阐述了马扎拉金锑矿床矿床地质特征、金的赋存状态以及矿床地球化学特征,并对矿床成矿作用进行了探讨.研究结果表明,马扎拉金锑矿床严格受构造及层位的控制,金主要以裂隙金、包裹金和晶隙金3种形式赋存在黄铁矿、辉锑矿、石英及方解石中;流体包裹体类型主要为气液二相包裹体和含CO2三相包裹...     

Influence of climate parameters and management of permanent grassland on biogas yield and GHG emission substitution potential

In many regions of Europe, grassland is no longer needed for fodder production as it is not economically viable. However, due to the important role it plays in soil carbon storage, it is imperative that grassland should be maintained. The energetic use of its biomass could be an alternative means of generating income from grassland.The aim of this study is to identify the best permanent grasslands management systems for CHP production with regard to maximizing biogas yields, energy use efficiency and greenhouse gas mitigation potential.A long-term field trial was established in 1994 and managed under various nitrogen fertilizer level regimes and cutting frequencies until 2007. Annual dry matter yields ranged between 9.1 t ha⁻¹ and 10.8 t ha⁻¹.Based on these data the methane yields for the different cutting regimes were calculated. The highest methane yield of 288.4 L kg⁻¹ oDM was calculated for a yearly cutting regime of four cuts.Energy and CO₂ balances were calculated to assess the energy efficiency and the global-warming potential of power generation in a CHP plant using biogas produced from the different grassland management systems. The highest net energy yield (48.52 GJ per hectare per year) was calculated for a two-cut regime. Furthermore, the highest CO₂ equivalent reduction potential was also documented for a cutting frequency of two cuts per year. In this case a CO_2eq mass reduction of 5.1 t per hectare per year could be achieved compared to fossil fuel (consisting of a German power mix and natural gas components) reference systems.