山东苍山5.2级地震前地震活动特征

从小震活动的时空分布以测震学参数的变化出发，分析了苍山地震前地震活动的异常特下，研究结果表明，苍山５．２级地震前出现了地震活动的图像和几种中，短期测震学参数，异常，但无明显短临信息的前震活动。     

Combining CLUE-S and SWAT models to forecast land use change and non-point source pollution impact at a watershed scale in Liaoning Province,China

Non-point source （NPS） pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent （CLUE-S） and Soil and Water Assessment Tool （SWAT） models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen （TN） and total phosphorus （TP） were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. How- ever, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effec- tively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.     

1997～1998年伽师强震群小地震震源机制解系统聚类分析

用P、S波最大振幅比法计算1997~1998年伽师强震群MS2.5~3.7小地震震源机制解,对小地震震源机制解进行系统聚类分析。结果表明,伽师小地震主要以走滑和正断层为主,与该时段发生的伽师6级强震具有相似的断错性质。1997年伽师小地震主压应力P轴方位为北东或近南北向,与1997~1998年6级强震主压应力P轴方位一致。1997年4月6日6.4级和1998年8月2日6.1级两次6级正断层地震前出现地震空段现象。     

PHYSICAL PROCESS BASED SOIL EROSION MODEL IN A SMALL WATERSHED IN THE HILLY LOESS REGION

ＰＨＹＳＩＣＡＬＰＲＯＣＥＳＳＢＡＳＥＤＳＯＩＬＥＲＯＳＩＯＮＭＯＤＥＬＩＮＡＳＭＡＬＬＷＡＴＥＲＳＨＥＤＩＮＴＨＥＨＩＬＬＹＬＯＥＳＳＲＥＧＩＯＮ１ＣＡＩＱｉａｎｇｇｕｏ２ＡＢＳＴＲＡＣＴＡｐｈｙｓｉｃａｌｐｒｏｃｅｓｂａｓｅｄｐｅｒｓｔｏｒｍ...     

多环芳烃在小白洋淀挺水植物中的分布、组成及其影响因素

利用GC-MS测定了端村小白洋淀5个采样点三种主要挺水植物(荷花、蒲草和芦苇)中16种优控多环芳烃(PAHs)的含量,分析了其分布与组成特征及其影响因素。结果表明:(1)16种优控多环芳烃总量(PAH_(16))在三种挺水植物中的平均干重含量范围为82.5-448.6ng/g(dw),七种挺水植物组织荷叶、荷茎、蒲叶、蒲茎、蒲根、苇叶与苇根中PAH_(16)的平均干重含量分别为448.6ng/g(dw)、129.3ng/g(dw)、292.6ng/g(dw)、166.8ng/g(dw)、82.5ng/g(dw)、141.5ng/g(dw)和90.0ng/g(dw),这些数据表明同种植物的叶中PAHs含量最高、茎中次之、根中最低;PAHs各组份在七种挺水植物中的含量具有显著的正相关关系,反映了PAHs在植物组织中的分布模式极为相似.(2)七种挺水植物组织中,均以低环PAHs为主,中环PAHs次之,高环PAHs很低,其百分比范围分别为66.2%(荷叶)-89%(蒲茎)、10.2%(蒲茎)-32.6%(荷叶)和0.6%(蒲叶)-3.7%(苇根);菲、荧蒽、萘、芴、芘和屈6种PAHs组分在挺水植物组织中的平均百分含量较高,分别为35.3%、15.5%、12.1%、11.7%、9.2%和5.2%,占PAH_(16)的89%.3)PAHs在挺水植物中的含量与植物含脂率具有显著的正相关关系,与PAHs组分的辛醇-水分配系数(K_(ow))以及辛醇-大气分配系数(K_(oa))具有显著的负相关关系.     

King Canute muses in the South Seas: Why aren’t Pacific Islands transitioning to low carbon sea transport futures?

Transition to low carbon sea transport is a logical response to the extreme dependency of the Pacific Islands region on imported fossil fuel, its significant vulnerability to the effects of climate change and the critical shipping needs of Pacific Island countries (PICs). Building on previous work in low carbon sea transport in the Pacific, this paper further considers the barriers to achieving such transition by assessing, through a ‘post-Paris Agreement’ lens, the Intended Nationally Determined Contributions (INDCs) submitted by PICs and contrasting these to the near total lack of investment and planning for low carbon transition in the transport sector with the parallel occurrence in the electricity sector where ~USD 2 billion of donor investment is deployed or queued despite electricity using only ~20% of fossil fuel across the region. Consistent with recent international studies, inadequate and inappropriate financing and policy have been identified as dominant transition barriers for low carbon sea transport development in PICs. This paper further examines the regional level barriers to policy development, and finds them inhibited by the silo nature of the major regional actors. The implications that the Paris Agreement has for climate financing to support the essential research and capacity development needed to underpin a successful low carbon sea transport transition strategy at any useful scale and speed are also considered in this paper.     

大型直剪与小型直剪对软弱夹层强度试验参数取值关系的研究

岩体中软弱夹层是控制岩体稳定的重要边界条件。准确、合理的选取其力学参数对大坝建基面的选取及未来坝基抗滑稳定性具有重大意义。对于深部难以取得大量试样的软弱夹层的工程地质性质的评价, 通过室内小型直剪获得的抗剪强度试验参数,然后再根据小剪和大剪之间的关系进行修正, 确定软弱夹层的抗剪强度参数,具有显著的经济价值和工程意义。     

Accumulation of terrestrial organic carbon on an active continental margin offshore southwestern Taiwan: Source-to-sink pathways of river-borne organic particles

Sediment samples (213 sites) collected from the tectonic-active continental margin, offshore southwestern Taiwan were analyzed for grain sizes, organic carbon, nitrogen and carbon isotopic composition to obtain mass accumulation rate of terrestrial organic carbon and carbon budget to evaluate fate of terrestrial organic carbon from small mountainous rivers on the continental margin offshore southwestern Taiwan. Terrestrial organic carbon accumulation rates range from 0.29 to 45.6 g C m⁻² yr⁻¹ with a total accumulation budget of 0.063 Mt yr⁻¹, which accounts for less than 13% of total river particulate organic carbon loads exported from the adjacent rivers, the Gaoping (a.k.a., Kaoping), Erhjen and Tsengwen rivers. This low burial efficiency of terrestrial organic carbon demonstrated that a majority of river-borne particles together with organic materials was moved away from the study area.For the river-borne particles from the Gaoping river, a pair of depocenters in the upper slope flanking the Gaoping submarine canyon are the locations where the maximum TC_org accumulation rate were observed which hold up to 45% (0.016 Mt yr⁻¹) of the calculated accumulation found in the study region. On the other hand, the occurrence of higher-fraction terrestrial organic carbon in the upper and middle Gaoping submarine canyon suggests that a majority of particulate organic carbon of the Gaoping river was transported directly into the deep-sea basin through the Gaoping submarine canyon. Our results demonstrated that active margin with narrow shelf and slope is not an efficient sink for the large amount of terrigenous organic carbon supplied by the small rivers, but, a transient environment for these river derived particles.     

Ecological quality assessment of small estuaries from the Portuguese coast based on fish assemblages indices

The importance of establishing the ecological quality of estuarine systems has been widely acknowledged and led to the development of several fish community-based multimetric indices. Nevertheless, a question rose about the accuracy of these tools when natural disturbance is acting upon the organization of the systems’ communities. Four multimetric indices were used to examine their ability to differentiate the ecological status of five small estuarine systems (southern Portugal), and also to test if they reflected the level of anthropogenic pressures. Fish assemblages from Mira, Odeceixe and Aljezur (in the Southwest coast), Gilão and Bensafrim (in the South coast) estuaries were sampled seasonally for one year, and anthropogenic sources of pressure were identified and quantified. We found that although the applied indices provided information on ecological condition differentiation among systems, they are unable to explain different classes of ecological status in systems with equivalent pressure levels.     

应用高分辨CT（HRCT）扫描弥补腔隙诊断之不足

目的:应用高分辨CT^*(HRCT)扫描方法,增加对头颅腔隙梗塞诊断的可靠性。材料和方法:对临床疑有腔隙的病人,在基底节区及可疑部位加用HRCT扫描,遇到腔隙病灶与像素颗粒难以区分时在相同层面或上下1~2mm处做HRCT扫描。结果:有489例常规CT正常的病例中发现了腔隙灶,在遇到的502例不易诊断的可疑病灶中,经HRCT确诊的真正腔隙灶300例,伪腔隙(像素)202例,同时发现HRCT对正常脑组织结构的显示要较常规CT优越得多。结论:HRCT不仅能提高腔隙性梗塞的检出率,还能辨伪腔隙,是弥补常规CT对腔隙诊断不足的较好手段。