Distribution of the indigenous microorganisms and mechanisms of their orientational activation in Daqing Oilfield

The distribution of indigenous microorganisms was surveyed in Block 1 of Daqing Oilfield. Based on this survey, the indigenous microorganisms in the formation water were activated with different activator systems at the simulated stratum ecological environment. The changes of the number of bacteria of various physiological groups were determined during the process of activation. Also changes of pH value and composition of gas productions were analyzed at the end of culturing. The results showed that the selected block formation water contained a great number of saprophytic bacteria, hydrocarbon-oxidizing bacteria, fermentative bacteria, methane-producing bacteria and sulfate-reducing bacteria. Under the conditions that the growth of sulfate-reducing bacteria was controlled the block had the potential to enhance oil recovery by activating beneficial bacteria. The growth of sulfate-reducing bacteria can be inhibited through the activation of nitrate-reducing bacteria. The number of nitrate-reducing bacteria reached 10⁶–10⁷ cells/mL, but sulfate-reducing bacteria reached only 0–45 cells/mL in A system. Methane-producing bacteria can be activated by C, D activators. The relative content of biological methane in the light hydrocarbon gas reached 80% in C, D systems. B activator was conducive to the propagation of acid-producing bacteria, so that the pH value of the culture medium decreased from 7.5 to around 5.0. Hydrocarbon-oxidizing bacteria can be activated by various activator systems. There was low molecular light hydrocarbon in gas production according to the analysis of gas chromatograph. According to the content of methane and the number of methane-producing bacteria, methane only can be generated through activating methane-producing bacteria. By choosing different activator systems, various populations of indigenous microorganisms can be activated accordingly.     

长江三峡库区梯田稳定性分析与对策*──以鄂西秭归县为例

三峡库区历史上就是滑坡、崩塌作用强烈的地带,在调查分析秭归县滑坡、崩塌对梯田稳定性的影响的基础上,探讨了四种不稳定梯田培坎的特征、性质和现状,提出了利用优势植物固土护坎等相应的对策。     

The electromagnetic and gravitational-wave radiations of X-ray transient CDF-S XT2

Binary neutron star(NS)mergers may result in remnants of supra-massive or even stable NS,which have been supported indirectly by observed X-ray plateau of some gamma-ray burst(GRB)afterglows.Recently,Xue et al.(2019)discovered an X-ray transient CDF-S XT2 that is powered by a magnetar from merger of double NS via X-ray plateau and following stepper phase.However,the decay slope after the plateau emission is slightly larger than the theoretical value of spin-down in electromagnetic(EM)dominated by losing its rotation energy.In this paper,we assume that the feature of X-ray emission is caused by a supra-massive magnetar central engine for surviving thousands of seconds to collapse into a black hole.Within this scenario,we present the comparisons of the X-ray plateau luminosity,break time,and the parameters of magnetar between CDF-S XT2 and other short GRBs with internal plateau samples.By adopting the collapse time to constrain the equation of state(EOS),we find that three EOSs(GM1,DD2,and DDME2)are consistent with the observational data.On the other hand,if the most released rotation energy of magnetar is dominated by GW radiation,we also constrain the upper limit of ellipticity of NS for given EOS,and its range is[0.32-1.3]×10^-3.Its GW signal cannot be detected by Advanced LIGO or even for more sensitive Einstein Telescope in the future.     

�Ľ�����Ⱥ�㷨���GPS�̻�������ģ���ȵ��о�

????????????????????????????????????????????????IPSO??????????????·?????IPSO????????????????????????????б????????????????????????????????????????????????PSO?????????????????????????????????????????????????LAMBDA????????????????????·??????п??????????????????????????????????ü????     

基于学籍地址和地理编码的乡村小学教育资源空间可达性分析

基于“学籍信息中的家庭地址承载了学生空间位置”这一假设,通过学籍信息收集了湖南省株洲县小学生的家庭地址,借助高德开放平台提供的地理编码和POI搜索服务,获得到了株洲县小学生的空间位置和分布,并基于最短路径分析和高斯型两步移动搜索法分析了株洲县小学教育资源的空间可达性及其特征,尝试为区域教育资源的空间均衡性分析与规划配置提供新的数据源和方法借鉴。结果表明：① 基于学籍地址和地理编码技术能够较准确地获取株洲县小学生的空间分布。② 株洲县小学生就近入学距离的最大值、平均值和中位数分别为11.83 km、2.10 km和1.81 km,就近入学距离小于2.0 km的学生仅占55.46%,为株洲县兼顾公平和效率的教育资源配置工作带来了挑战。③ 株洲县北部城镇地区因学校数量较多,平均就近入学距离较小,教育资源的空间可达性普遍较高,且空间差异小,均衡性好;而东南部的乡村地区,平均就近入学距离较大,教育资源的空间可达性普遍较低,且空间差异大。④ 基于情景分析,在不造成局地生源稳定性问题的前提下,新增3所学校后,东南部地区的平均就近入学距离和教育资源的空间可达性有很大的改善,龙潭镇和龙门镇的平均入学距离由3784 m和3520 m降低到3116 m和2636 m,教育资源的空间可达性分别由0.0492和0.0982提高到0.0762和0.1496。     

��Ͽ����ˮλ��ϫ�����뺬ˮ�������ϵ�о�

???????????????????????????????????????????λ??????????????????????????????????????????????????????????￡????λ????仯???????????????????????????????????????????????????????????????仯??????????????????????????????????????????й??     

介绍一个新建立的岩石地层单位——陈刘组

陈刘组为新建立的岩石地层单位，代表广西早三叠世盆地滨岸相带沉积类型。层型剖面位于贵港市陈刘村附近。层型定义指位于龙潭组与板纳组之间的沉积序列，岩性为灰绿、紫红色泥岩、粉砂细砂岩夹少量火山岩及碳酸盐岩，含菊石、双壳类、牙形石等化石，厚３５９ｍ。     

东北黑土区保护性耕作的发展现状与成效研究

东北黑土区承担着国家粮食安全“稳压器”的重要责任。然而,由于长期超负荷开发利用导致黑土日益退化,黑土资源的永续利用受到严重制约。理论与实践证明,保护性耕作是保护黑土地、推动黑土耕地质量和耕作效益绿色增长的发展模式。综述了保护性耕作的基本内涵及其在东北黑土区的发展现状与技术概况,从保护性耕作在土壤保持、保墒效益、结构改善、固碳培肥和土壤生物多样性增加、节本增效等方面系统评估了东北黑土区实施保护性耕作后的生态与经济效益,提出黑土区实施保护性耕作存在的问题与未来发展方向,以促进黑土地保护与利用协调发展、推动保护性耕作高质量跨越式发展。     

黄河北岸兰州段丘陵区土壤生态化学计量与空间变异北大核心CSCD

为探究黄河北岸兰州段丘陵区土壤碳、氮、磷含量及化学计量比的空间变异特征,基于12个样地数据,采集1 m剖面内不同发生层土壤进行土壤含水率(SWC)、pH、有机碳(SOC)、全氮(STN)和全磷(STP)的测定。分析了研究区土壤碳、氮、磷含量及其生态化学计量特征在植被和土层上的差异及空间变异特征。结果表明:(1)研究区SOC、STN、STP均值分别为4.53、0.74、0.13 g·kg^(-1),C∶N、C∶P、N∶P均值分别为7.85、55.17、8.40;(2)研究区SOC、STN、C∶N和N∶P的块基比C_(0)/(C_(0)+C)<0.25,主要受气候、植被、地形等自然因素影响;STP、C∶P则C/(C+C)>0.75,主要受退耕还草等人为因素影响;(3)研究区土壤整体受到氮限制,与此同时有机碳更为匮乏,磷则在短期内不会成为限制因子。在黄河流域兰州段北岸丘陵区北岸的生态治理与恢复中,应重视有机肥和氮肥的配置与施加,同时需减少人为干扰,这对于植被的快速恢复与养分的固定具有重要意义。     

天津市服务业利用外商投资的实证分析

服务业的发展是促进全球经济增长的重要力量,发达国家普遍呈现出产业结构高级化特征。利用外商投资可以促进中国服务业的发展,是加快经济发展的有效手段。通过对天津市服务业发展以及服务业利用外商直接投资现状的分析,对服务业外商直接投资与经济增长的关系进行了实证研究。研究结果表明:服务业外商直接投资不仅促进了天津经济的增长,同时,还对资本积累、产业结构、技术水平、就业程度及人力资本产生了不同程度的促进作用;技术水平进步、就业水平的提高、人力资本的提升又将带动天津经济增长。天津市应发挥现代服务业发展的优势,发挥天津自贸区的区位优势和政策优势,积极承揽国际服务外包。