植被作用下土壤抗剪强度和径流侵蚀力的耦合效应

利用野外径流小区动态监测和人工模拟降雨试验,阐明了草被和灌木的减流减沙效应,从力学层面揭示了坡面侵蚀产沙的过程机理。结果表明,与裸地相比,野外坡面草地和灌木地径流量分别减少28.1%~56.5%和85.7%~100%、产沙量分别减少84.9%~90.7%和98.5%~100%;在人工模拟降雨强度下,草地和灌木地径流量分别减少51.9%~90.9%和61.7%~80.6%、产沙量分别减少93.6%~99.2%和95.5%~99.2%;植被具有明显的增强土壤抗剪强度的作用,不同植被坡面抗剪强度与剪切面上的法向压力成正比,且符合库仑定律;不同下垫面条件下土壤黏聚力与坡面径流量和侵蚀产沙量呈显著的负相关关系,随着黏聚力的增大,径流量和侵蚀产沙量呈下降趋势;草地和灌木地坡面侵蚀临界径流切应力分别为裸地的2.64~3.16倍和2.44~3.18倍,建立了不同被覆坡面临界径流切应力与土壤抗剪强度和黏聚力的关系。研究结果对定量评价植被减蚀作用和深化土壤侵蚀力学过程有一定的参考意义。     

中国装备制造业产学研合作创新网络初探

产学研合作是区域创新的主要途径和重要来源.以中国装备制造产业为例,基于中国知识产权局1985-2012年间的合作发明专利数据,借助SPSS,UCINET,ArcGIS等定量分析工具,对中国装备制造产业合作网络的创新主体结构,空间结构及其演变,创新合作的空间尺度的影响因素进行了分析.研究发现,民营企业,高校在中国装备制造产业创新网络中的地位不断上升,数量不断增加,且已经成为重要的创新源泉;市域空间合作成为发达地区城市产学研创新合作最重要的空间单元,国家空间是欠发达地区城市产学研创新合作的主要空间载体;理工科高校等科技资源的空间集聚态势是导致创新网络层级特征的主要因子,科技资源富集的行政中心如直辖市,省会城市等发达城市成为最重要的资源集聚地,创新源泉和创新合作对象.     

Safety Assessment of Buried Pipeline during Pile Driving Vibration in Offshore Engineering

To assess the impact of pile driving on adjacent submarine pipelines during the reconstruction of a pier berth, the local damage model of submarine pipelines is established to explore the safety thresholds of the particle peak velocity and horizontal displacement. The results are analyzed and adjusted by the existing standards and the corresponding literatures. Then, a three-dimensional numerical model is presented to assess the feasibility of the construction of piles by the obtained safety limits, in which the nonlinear behavior of the soil and stress–seepage coupling analysis are considered. After the construction, the safety of submarine pipelines is rechecked by the measured value of the particle peak velocity and horizontal displacement. Meanwhile, the propagation law of vibration, the horizontal displacement of underground soil, and the pore pressure during pile driving are explored. The results indicate that the construction of piles of 2# mooring pier did not cause damage to adjacent submarine pipelines. However, the construction of piles of 1# mooring pier which is nearer may cause damage to submarine pipelines.     

Pharmacokinetics and acetylation of sulfamethoxazole in turbot <Emphasis Type="Italic">Scophthalmus maximus</Emphasis> after intravascular administration

The pharmacokinetic profiles and sulfamethoxazole (SMX) acetylation process in turbot reared at 18°C were investigated. Either SMX (parent drug) or its acetylized metabolite, N₄-acetylsulfamethoxazole (AcSMX), was administered intravascularly to turbot at a dosage of 50 mg/kg BW. Serum concentrations of the parent drug and its metabolite were both measured by HPLC, and the changes in concentration over time were analyzed in two- and non-compartment models because SMX treatment produced multiple peaks. The results demonstrated that the elimination half-life of the parent drugs, SMX and AcSMX, were 159.2 and 5.9 h, respectively. The apparent volume of distribution was 0.2 and 0.8 L/kg, and the clearance was 0.038 and 0.222 L/(h·kg), for SMX and AcSMX, respectively. SMX acetylation in turbot was 2.8%, and the deacetylation of AcSMX was 0.2%. These findings may be useful in optimizing SMX dosage regimens in turbot aquaculture.     

中国南部及邻区能源资源成矿区带数据集

能源矿产是国家安全和经济发展的战略资源,加强我国及周边地区油气和煤等能源资源的研究和开发利用意义重大。依据板块构造和大陆动力学以及油气与煤成藏地质学理论,以深部构造控制盆—山发育、盆—山耦合和热动力系统控制成矿的研究工作思路,应用70个油气田、471个煤田的基础地质资料,从沉积盆地发育的区域地质特征、成矿地质条件和成矿单元诸多方面,在地理信息系统（GIS）平台上提示了该区板块构造格局与能源资源的时空分布规律。中国南部及邻区能源资源可划分为3个成矿域,每个成矿域又可进一步划分为成矿省、含矿区（盆地）、矿田聚集区带、矿田（油气田）五个级别的成矿区域。数据集由构造带（断裂带和造山带）类型和时代、盆地类型和时代、能源矿产资源类型和丰度、成矿区带等元数据组成。该数据集是在区域大地构造研究的基础上,结合沉积盆地能源矿产（石油、天然气、煤）资源评价资料,综合分析成矿区带特征,利用地理信息系统（GIS）建立的一套完整的数据库,不仅是对中国南部及邻区区域地质认识和沉积盆地能源资源勘查工作成果的集成,而且为国家科学地引导地质找矿工作部署提供理论基础。     

渝东北地区五峰组—龙马溪组页岩气地质特征及其勘探方向探讨

渝东北地区五峰组—龙马溪组暗色泥页岩沉积厚度介于30.92~164.47m之间,其中在朝阳镇咸池剖面及田坝一带厚度最大,往研究区东西两侧具有减薄的趋势。全区总有机碳含量平均3.32%,中部(平均3.93%)和西部(平均3.59%)相对东部(平均2.77%)具有更高的有机质丰度。有机质以I型腐泥型为主,西部个别剖面及东部栗子坪一带夹少量Ⅱ_1—Ⅱ_2型干酪根,其成熟度普遍处于高成熟—过成熟阶段,呈现自北向南升高的趋势。石英、脆性矿物含量普遍较高(尤其是中西部区块),黏土矿物较低,更易产生储气裂缝及利于后期压裂。储层特征方面,中部地区泥页岩具有更高的孔隙度和较低的渗透率,同时比表面积也相对更高,以有机质孔隙为主。中部区块田坝—朝阳—文峰一带含气性最好,结合页岩厚度、总有机碳含量分布、储层条件及构造保存条件分析,本区中部区块田坝—朝阳—文峰一带具有更好的页岩气勘探前景,是该区下一步勘探的重点区域。     

Rainfall threshold determination for flash flood warning in mountainous catchments with consideration of antecedent soil moisture and rainfall pattern

Flash flood disaster is a prominent issue threatening public safety and social development throughout the world, especially in mountainous regions. Rainfall threshold is a widely accepted alternative to hydrological forecasting for flash flood warning due to the short response time and limited observations of flash flood events. However, determination of rainfall threshold is still very complicated due to multiple impact factors, particular for antecedent soil moisture and rainfall patterns. In this study, hydrological simulation approach (i.e., China Flash Flood-Hydrological Modeling System: CNFF-HMS) was adopted to capture the flash flood processes. Multiple scenarios were further designed with consideration of antecedent soil moisture and rainfall temporal patterns to determine the possible assemble of rainfall thresholds by driving the CNFF-HMS. Moreover, their effects on rainfall thresholds were investigated. Three mountainous catchments (Zhong, Balisi and Yu villages) in southern China were selected for case study. Results showed that the model performance of CNFF-HMS was very satisfactory for flash flood simulations in all these catchments, especially for multimodal flood events. Specifically, the relative errors of runoff and peak flow were within?±?20%, the error of time to peak flow was within?±?2 h and the Nash–Sutcliffe efficiency was greater than 0.90 for over 90% of the flash flood events. The rainfall thresholds varied between 93 and 334 mm at Zhong village, between 77 and 246 mm at Balisi village and between 111 and 420 mm at Yu village. Both antecedent soil moistures and rainfall temporal pattern significantly affected the variations of rainfall threshold. Rainfall threshold decreased by 8–38 and 0–42% as soil saturation increased from 0.20 to 0.50 and from 0.20 to 0.80, respectively. The effect of rainfall threshold was the minimum for the decreasing hyetograph (advanced pattern) and the maximum for the increasing hyetograph (delayed pattern), while it was similar for the design hyetograph and triangular hyetograph (intermediate patterns). Moreover, rainfall thresholds with short time spans were more suitable for early flood warning, especially in small rural catchments with humid climatic characteristics. This study was expected to provide insights into flash flood disaster forecasting and early warning in mountainous regions, and scientific references for the implementation of flash flood disaster prevention in China.     

Geological Controls on the CBM Productivity of No.15 Coal Seam of Carboniferous–Permian Taiyuan Formation in Southern Qinshui Basin and Prediction for CBM High-yield Potential Regions

Coalbed methane (CBM) resources in No.15 coal seam of Taiyuan Formation account for 55% of the total CBM resources in southern Qinshui Basin (SQB), and have a great production potential. This study aims at investigating the CBM production in No.15 coal seam and its influence factors. Based on a series of laboratory experiments and latest exploration and development data from local coal mines and CBM companies, the spatial characteristics of gas production of No.15 coal seam were analyzed and then the influences of seven factors on the gas productivity of this coal seam were discussed, including coal thickness, burial depth, gas content, ratio of critical desorption pressure to original coal reservoir pressure (RCPOP), porosity, permeability, and hydrogeological condition. The influences of hydrological condition on CBM production were analyzed based on the discussions of four aspects: hydrogeochemistry, roof lithology and its distribution, hydrodynamic field of groundwater, and recharge rate of groundwater. Finally, a three-level analytic hierarchy process (AHP) evaluation model was proposed for predicting the CBM potentials of the No.15 coal seam in the SQB. The best prospective target area for CBM production of the No.15 coal seam is predicted to be in the districts of Panzhuang, Chengzhuang and south of Hudi.     

川滇黔邻区龙马溪组页岩气富集主控因素与勘探方向

中国的页岩气资源评价必须立足于中国主要陆块的地质条件与构造演化特点之上,对于不同层系、不同地区的页岩气选区评价,也必须抓住关键因素。川滇黔邻区的五峰组-龙马溪组富有机质页岩发育,但保存条件较渝东南地区更为复杂。印支期以来,该区经历了多期次构造应力场转换,断裂、褶皱发育,因此,建立针对性的页岩气选区评价参数体系是该区页岩气勘探走出困局的当务之急。本文在分析该区已有页岩气钻井成效的基础上,立足于扬子海相层系页岩气勘探应是基于保存条件的"连续型甜点区"的选区评价基本思路,结合前人研究成果,系统梳理出一套评价指标体系。该体系涵盖5大因素(区域盖层、直接盖层、底板条件、页岩层自身条件、构造改造强度)、4个等级、17个选区评价参数。另外,根据已有相关钻井数据,总结提出了5个页岩气层评价表征参数(含气量、孔隙度、电阻率、氮气组分含量和压力系数)。根据该指标体系,对川滇黔邻区的主要构造单元进行了梳理分析,优选出5个有利区,提出了各有利区的首选可能突破点。本研究对复杂构造区页岩气有利区带优选具有一定的指导意义。     

A modified three-dimensional ionospheric tomography algorithm with side rays

The three-dimensional ionospheric tomography (3DCIT) algorithm based on Global Navigation Satellite System (GNSS) observations have been developed into an effective tool for ionospheric monitoring in recent years. However, because the rays that come into or come out from the side of the inversion region cannot be used, the distribution of the rays in the edge and bottom part of the inversion region is scarce and the electron density cannot be effectively improved in the inversion process. We present a three-dimensional tomography algorithm with side rays (3DCIT-SR) applying the side rays to the inversion. The partial slant total electron content (STEC) of side rays in the inversion region is obtained based on the NeQuick2 model and GNSS-STEC. The simulation experiment results show that the algorithm can effectively improve the distribution of GNSS rays in the inversion region. Meanwhile, the iteration accuracy has also been significantly improved. After the same number of iterations, the iterative results of 3DCIT-SR are closer to the truth than 3DCIT, in particular, the inversion of the edge regions is improved noticeably. The GNSS data of the International GNSS Service (IGS) stations in Europe are used to perform real data experiments, and the inversion results show that the electron density profiles of 3DCIT-SR are closer to the ionosonde measurements. The accuracy improvement of 3DCIT-SR is up to 56.3% while the improvement is more obvious during the magnetic storm compared to the case of a calm ionospheric state .