An integrated method for calculating DEM-based RUSLE LS

The improvement of resolution of digital elevation models (DEMs) and the increasing application of the Revised Universal Soil Loss Equation (RUSLE) over large areas have created problems for the efficiency of calculating the LS factor for large data sets. The pretreatment for flat areas, flow accumulation, and slope-length calculation have traditionally been the most time-consuming steps. However, obtaining these features are generally usually considered as separate steps, and calculations still tend to be time-consuming. We developed an integrated method to improve the efficiency of calculating the LS factor. The calculation model contains algorithms for calculating flow direction, flow accumulation, slope length, and the LS factor. We used the Deterministic 8 method to develop flow-direction octrees (FDOTs), flat matrices (FMs) and first-in-first-out queues (FIFOQs) tracing the flow path. These data structures were much more time-efficient for calculating the slope length inside the flats, the flow accumulation, and the slope length linearly by traversing the FDOTs from their leaves to their roots, which can reduce the search scope and data swapping. We evaluated the accuracy and effectiveness of this integrated algorithm by calculating the LS factor for three areas of the Loess Plateau in China and SRTM DEM of China. The results indicated that this tool could substantially improve the efficiency of LS-factor calculations over large areas without reducing accuracy.     

Jurassic-Cretaceous Boundary Strata of the Somanakamura Group in NE Japan and their Correlation with Coeval Terrestrial Deposits in China

Defining the Jurassic-Cretaceous boundary is a controversy in stratigraphic study of the world. It has been widely accepted that this boundary can be defined at the bottom of Berriasian in Tethys, with the appearance of the ammonite Berriasella jacobi dating to ca. 145 Ma. However, it is difficult for the widespread terrestrial deposits in China to correlate with the international standard of marine facies. The Somanakamura Group in Japan is represented by a succession of marine-continental transitional strata. It provides a bridge of marine and nonmarine stratigraphic correlation. The ammonite and radiolarian fossils preserved in this group suggest an age from Bajocian to early Valanginian. The J-K boundary was defined in or atop the Tomizawa Formation of the group according to the ammonite data. The present authors study the fossil spores and pollen newly found from the Tomizawa and Koyamada formations. Three assemblages have been recognized. They are Assemblage 1 (Cyathidites-Classopollis) from the upper part of the Tomizawa Formation, Assemblage 2 (Cyathidites-Jiaohepollis) from the lower part of the Koyamada Formation, and Assemblage 3 (Cyathidites-Spheripollenites-Ephedripites) from the middle to upper part of the Koyamada Formation. With the reference of ammonite evidence, the J-K boundary can be defined between Assemblage 1 and Assemblage 2. This palynological J-K boundary can be correlated with that of terrestrial sequence in China. However, local biostratigraphy imply that the continental J-K boundary in China is of 135 or 137 Ma age. It has a considerable discrepancy from the marine standard. Biogeographically, the distribution pattern of spores and pollen in southern China is in accordance with that in the Somanakamura Group, which parallels the Tuchengzi Formation in northeastern China. By the palynological correlation between the Somanakamura Group and the strata in southern China, and then with the sequence in northeastern China, it is suggested that the continental J-K boundary is located in the Tuchengzi Formation.     

1971—2014年玉门市旅游气候舒适度评价分析

利用玉门市1971—2014年逐日气温、相对湿度、平均风速和日照时数等气象观测资料,运用温湿指数、风寒指数、着衣指数和人体舒适度指数4种旅游气候舒适度评价指数,计算玉门市旅游舒适度指数,确定了玉门市旅游气候舒适期及天数;构建综合舒适度指数模型,并对各指数进行了突变检验。结果表明,玉门市较舒适期为4月下旬中期至9月下旬末,约160 d;舒适期为5月中旬至9月中旬,约124 d。其中,5、6、8月最适宜旅游,7、9月为适宜旅游,11月—次年的3月,由于气候寒冷,不适宜旅游。玉门市的温湿指数舒适期天数从1983年开始明显增多;风寒指数舒适期天数从1990年开始明显增多;着衣指数舒适期天数从1991年开始明显增多;人体舒适度指数舒适期天数从1986年开始明显增多。     

海州湾及邻近海域大泷六线鱼的生长、死亡和最适开捕体长研究

根据2011年海州湾及邻近海域的底拖网调查资料,对大泷六线鱼(Hexagrammos otakii)的群体结构、体长-体重关系、生长、死亡和资源利用状况进行初步研究。结果表明:大泷六线鱼渔获群体体长范围为44~292mm,优势体长组为54~74mm,平均体长为88mm;体重范围为0.35~574.3g,优势体重组为10g,平均体重为17.94g;体长-体重关系为W=4.23×10-6 L3.31(R2=0.978 6,n=1 514)。应用FiSATⅡ软件中的ELEFANⅠ方法估算的von Bertalanffy生长方程参数L∞、K和t0分别为328mm、0.36a-1和-0.43a;应用FiSAT软件中变换体长渔获曲线法求得总死亡系数Z为2.06,自然死亡系数M和捕捞死亡系数F分别为0.62和1.44,开发率E为0.70。Beverton-Holt单位补充量渔获量模型分析表明,在现行捕捞死亡系数F=1.44、YW/R取最大值时对应的开捕年龄为1.83a。现阶段大泷六线鱼资源已处于过度开发状态,考虑拐点年龄、临界年龄、繁殖和经济效益等综合因素,建议将海州湾大泷六线鱼最适开捕规格定为体长191mm。     

哈萨克斯坦北特鲁瓦油田石炭系碳酸盐岩储层测井评价

哈萨克斯坦北特鲁瓦油田石炭系碳酸盐岩储层受沉积作用、构造作用和差异成岩作用等影响,储层岩性复杂、储集空间多样、基质物性较差、测井响应复杂,使得该类储层在岩性识别、储层参数计算和流体性质识别等方面遇到了许多困难.针对北特鲁瓦油田复杂碳酸盐岩储层测井评价中存在的问题,在大量岩心观察、薄片分析的基础上,通过碳酸盐岩储层最优化...     

CT导引T胸部病变穿刺活检体会

目的：研究CT导向胸部病灶穿刺活检的方法及应用价值，材料与方法：83例中，脑内病变70例，纵膈病变10例，胸壁及胸膜病变3例，穿刺针为肺活检针，共穿93针，结果：穿刺成功率为100％，取材病理检验效果，理想占80．7％，可行占13．3％，总可靠率为94．－％，不可靠6．0％，结论：精确的定位，熟练的技术及病人的良好配合可提高穿刺成功率和取材的可靠性。     

热带气旋干湿特征的对比分析

热带气旋属于热带天气系统，由于其生成地及生命史的大部分时间基本都在洋面或海面上，所以就其自身来说，有着充分的水汽资源，但在它的移动路径中，随着环境场的不断变化，其影响地区也并不是都有很强的降水产生，针对这一问题，引入了干湿热带气旋概念，并选取了３个较为典型的个例，对它们的天气形势及物理量场作了对比分析，得到了些有有益的结果。     

铈异常(Ce~0)和轻稀土分异(La/Nd)的双对数图解的旋转变换

本文在分析现行的铈异常定义及其表示方法优缺点的基础上 ,提出用铈值 (Ce0 )来表示单个岩石 (或水体 )中铈的异常特征 ,用 L a/ N d比值来表示其轻稀土分异特征。根据Ce0 和 L a/ N d比值分别等于 Ce/ N d和 L a/ Ce的商和积 ,提出 Ce0 - L a/ N d和 Ce/ N d- L a/Ce两种双对数图之间 ,存在一种简单直观和定量的 4 5°角旋转变换关系 ,为解释岩石 (或水体 )中铈异常、轻稀土分异的成因和演化定量规律提供了一种严谨而又方便的途径     

松辽盆地南部长岭断陷营城组火山岩系储层固体沥青的地球化学特征以及成因分析

松辽盆地南部长岭断陷深层营城组广泛分布火山岩系储集层,天然气成藏条件优越,具有较好的勘探前景.根据长岭断陷Ysl井与D2井营城组火山岩储层固体沥青的显微特征、抽提物中饱和烃与芳烃组成特征以及储层流体包裹体均一化温度等资料,分析探讨储层固体沥青的来源、成藏期次及成因机制.结果表明,研究区储层固体沥青为无定形状,无荧光特征,充填于岩石的缝隙之中,其抽提物饱和烃中正构烷烃分布呈单峰态前峰型分布,nC21-/nC22 大于1,奇偶优势不明显,成熟度偏高,Pr/Ph小于1,β-胡萝卜烷、孕甾烷与升孕甾烷以及伽玛蜡烷指数丰度值低;芳烃化合物中菲、惹烯、荧蒽、芘与屈相对丰度高,缺少卡达烯、花、联苯、萘等化合物,三芴化合物中硫芴、芴的相对丰度高,与饱和烃生标指示特征具有较好的匹配性.这些特征反映研究区储层固体沥青生源母质为低等生物或者藻类,高等植物贡献少,形成于微成水的还原环境.营城组火山岩储层中含烃类盐水包裹体均一化温度分布范围为126℃～130℃与146℃～160℃,石英矿物裂隙的液态烃类包裹体的成藏期为嫩江期,与固体沥青的成藏期相近.根据储层抽提物生物标志物分布及天然气地球化学特征综合分析,研究区储层固体沥青为营城组源岩生成的原油热蚀变作用的产物,有气洗作用的影响.     

Spatio-temporal differences and factors influencing intensive cropland use in the Huang-Huai-Hai Plain

This study developed a comprehensive system to evaluate the intensity of cropland use and evolution of cropland use in the Huang-Huai-Hai Plain. Delphi-entropy methods were adopted to determine the weight of the index, and the GeoDetector model was established to explore the influencing factors. The results are summarized as follows: (1) The intensity of inputs, degree of utilization, and production increased continuously, but the intensity of continuous conditions experienced an overall decline followed by a rebound towards the end of the study period. The number of counties with high and moderately high intensity increased by 56.8% and 14.6%, respectively, from 1996 to 2011. The number of counties with moderately low and low intensity declined by 35.9 % and 11.9 %, respectively. Areas with significant increases in intensity were mainly distributed in northeast Hebei Province, northwest Shandong Province, and north Jiangsu Province. The intensity is high in northern Jiangsu and Anhui; the output effect remained above moderate intensity mainly near Beijing, Tianjin, Tangshan, and counties in the suburbs of Shijiazhuang. (2) Natural disasters, elevation, slope, and road networks were the main factors influencing the intensity of cropland use in this region, with influence values of 0.158, 0.143, 0.129, and 0.054, respectively. Areas with moderately high and high levels of intensity were distributed in low-lying areas. Uneven distribution of precipitation, seasonal drought, and flood disasters can directly affect the stability index of croplands and reduce the intensity of cropland use. Developed road networks are associated with moderately high intensity. Our results suggest recommendations such as promoting agricultural intensification and large-scale management, promoting the construction of road networks, improving early warning systems for drought and flood disasters, and promoting moderate and intensive use of arable land, and focusing on restoration and sustainable use of cropland.