吹扫捕集-气相色谱／质谱法测定土壤中挥发性有机化合物

建立了吹扫捕集-气相色谱/质谱技术测定土壤中挥发性有机化合物的方法,对标准模拟样品的基体选择、吹扫捕集条件、色谱条件等实验条件进行了考察。结果表明,方法检出限为0.20~0.60μg/kg,精密度(RSD,n=7)为2.78%~9.89%,基体加标平均回收率为81.5%~115.2%。方法准确可靠,用于批量样品的实际分析,检测结果良好。     

Geologic Characteristics of Gas Reservoirs in West Sichuan Foreland Basin

The foreland basin in West Sichuan is a tectonic unit that has undergone multi-periods tectonic movements of Indosinian-Yanshanian-Himalayan. Since late Triassic, it has been in a passive subsidence environment controlled by basin margin mountain systems and by the compression with abundant sediment sources. With the complex geologic setting, the main geologic characteristics of natural gas reservoir are listed as following： （1） Source rocks are coal-bearing mud and shale series with high to over maturity, and long and progressive hydrocarbon generation-displacement period. The key accumulation period is middle-late Yanshanian epoch. （2） There are three gas-bearing systems vertically, each of which has different reservoir mechanism, main-controlled factors and distribution law, so the exploration thoughts and techniques are also different. （3） Undergoing multi-period generation-migration-accumulation, oil and gas have encountered multi-period modification or destruction, and gas accumulation overpass multiple tectonic periods. So the trap type is complicated and dominated by combination traps. Because the main accumulation period of natural gas is early and the reservoir encountered the modification of strong Himalayan movement, there is great difference in the fullness degree of gas reservoirs and complicated gas-water relation. （4） Reservoir is tight to very tight, but reservoirs of relatively high quality developed under the super tight setting. （5） The key techniques for oil and gas exploration in west Sichuan foreland basin are the prediction of relatively favorable reservoirs, fractures and gas bearing; and the key techniques for oil and gas development are how to improve the penetration rate, reservoir protection and modification.     

领域陷阱与中国在缅甸北部的跨国禁毒实践

非法毒品不仅给国家安全和社会稳定带来新的挑战,也促使地理学者深入研究并揭示毒品贸易背后的地缘政治因素和经济社会问题。目前,中国已经成为缅甸北部“金三角”核心区域毒品的主要市场之一,基于中国政府恪守和平共处五项基本原则,无法对盘踞在“金三角”的毒贩进行有效的打击和根除。面对跨国毒贩,中国政府陷入了John Agnew提出的“领域陷阱”。如何在尊重缅甸国家主权的前提下实施有效的跨国禁毒,以维护中缅边境的安全和云南的社会稳定?本文借助政策报告和深度访谈资料,揭示毒品贸易的非传统安全属性,并且分析中国在缅甸北部的禁毒实践——采取武装威慑与替代种植。前者针对毒贩和跨国毒品集团,后者主要面向缅北依赖罂粟种植的农民。两种实践策略针对不同群体,相辅相成,标本兼治,不仅在缅甸领土主权和中缅边境安全之间找到了平衡,也为中国政府克服“领域陷阱”,建构了有效的跨国管制机制。本文丰富了地理学者对于领土主权、地缘政治以及边境安全的探讨,可为中国西南边境共建“一带一路”提供有益借鉴。     

白云深水区东部重力流水道岩性圈闭特征分析

白云深水区东部在早中新世时期处于两种沉积相带的交汇处:古珠江三角洲物源体系深水重力流水道砂岩沉积和东沙隆起台地生物礁物源体系碳酸盐岩峡谷水道沉积。层序地层学、沉积学、构造学研究表明,在白云深水区东部21.0Ma陆架坡折带下方,早期低位体系域发育的条带状优质重力流水道砂岩可以作为岩性圈闭的主力储层;晚期海进体系域大型碳酸盐岩、泥岩充填的峡谷水道,切割了下部早期低位体系域的重力流水道砂体,起到了有效的侧封作用,从而形成了重力流水道岩性圈闭,实际钻井资料证实该岩性圈闭为工业油气藏。     

Social-ecological feedbacks lead to unsustainable lock-in in an inland fishery

This interdisciplinary paper presents an empirical analysis of techno-institutional lock-in in a regional fishery, in the Logone floodplain in the Far North Region of Cameroon. In the Logone floodplain, one fishing technique is spreading exponentially even though it is changing the social, hydrological and ecological dynamics of the system in ways that are largely considered problematic by local communities. We use a complex systems framework to analyze large hydrological and socio-economic datasets. Results show how social-ecological feedbacks foster the spread of the technique and contribute to the process of lock-in. The lock-in leads to a resistance to change despite awareness of the technique’s impact, a situation that may also be described as a social-ecological trap. We identify and explain four kinds of positive feedback loops relating to socio-economic, behavioral, demographic and hydrological processes, respectively. We also identify possible solutions that consider the complexity of the feedback loops across multiple dimensions of the floodplain system.     

宽频地震处理技术在南海某工区的应用

在海洋地震勘探中产生的鬼波会抑制低频分量,造成频域的陷波点,降低地震记录的分辨率,使地震记录的同相轴发生混叠甚至产生假的同相轴。笔者采用FK域水平电缆压制鬼波法,将地震数据进行FK变换,对维纳滤波求取反褶积算子投影到FK域,并对二者进行褶积,将结果 FK反变换回时间域。鬼波压制后的模型数据频带得到了有效拓宽,低频、高频信息均得到了加强。鬼波压制后的实际数据目的层频带从12~60 Hz拓宽到8~75 Hz,三亚组能量与合成记录匹配较原始数据更好。     

川西什邡地区隐伏断层活动性及其对流体的控制作用

利用遥感地质解译、土壤微量元素分析、土壤氡气测量以及野外露头观察等手段,在什邡湔氐地区识别出22条隐伏断层。它们按走向可分为北北西向、北东东向和近东西向3组。受关口断层推覆上升的影响,隐伏断层普遍具张扭性,活性较好,含水破碎带发育。从油气水文地球化学和地下水的活动规律来探讨该区断裂和盖层、地下水的配置关系,认为本区油气保存条件总体较差,但在单斜带局部区域寻找水动力圈闭气藏以及在云西—徐家场鼻状背斜上勘探深层气藏仍然有一定的潜力。     

Vertical profiles of aeolian sand mass flux

Vertical profiles of the horizontal mass flux of blown sand are investigated experimentally using a passive vertical array in a wind tunnel. Considering lower sampling efficiency of the sand trap in the near-bed region, this investigation is complemented by the measurements of the longitudinal profiles of mass flux made using a horizontal sand trap. The experiments were conducted with two test sands and five different stream velocities.In the upper part of the vertical profile, the measured data exhibit an exponential decay distribution with a positive deviation occurring in the near-bed region. The measured longitudinal profiles are similar to the measured vertical profiles. Linking both profiles and the modes of sand transport, it is possible that saltating sand grains give rise to the well-known exponential decay distribution of mass flux, and that creeping and reptating grains force a deviation from it. A simple equation applicable for both the vertical and the longitudinal sand mass flux variations is introduced and the parameters are estimated from experimental data.     

Composition and flight periodicity of adult caddisflies in New Zealand hill‐country catchments of contrasting land use

A total of 6085 adult Trichoptera (excluding Hydroptilidae) representing 12 families, 31 genera, and 56 species were collected by a combination of Malaise net and light trapping from July 1998 to July 1999 at three hill‐country sites of contrasting catchment land use (100% native forest, a pasture site with native forest headwaters, and 100% pasture) in the Waikato, northern New Zealand. Forty‐eight species of Trichoptera were collected from Malaise nets and 45 species from light traps. Eleven species of Trichoptera were only ever collected from the Malaise nets and seven species from only the light traps. At the native forest site, Malaise nets collected more species and taxa of conservation interest than did light traps, possibly reflecting diurnal activity or non‐attraction to light by some species. Several species of Trichoptera showed site specificity and most of these were found at the native forest site. Twenty‐eight species were active for at least 6 months of the year with at least four species active all year. A minimum overnight air temperature of at least 9°C was required to induce Trichoptera flight activity, but large‐scale flight activity may require temperatures greater than 14°C. Trichoptera with free‐living and net spinning larvae exhibited extended flight periods, and for three species examined there were bi‐modal activity peaks. Adult caddisflies with cased larvae which grazed on epilithic food resources generally had reduced flight periods and one species had a well‐defined, synchronous periodicity. These findings suggest flight periodicity may partly be a functional response to larval food availability.     

Direct impacts of commercial and recreational fishing on spiny lobster,Panulirus interruptus,populations at Santa Catalina Island,California, United States

The California spiny or red rock lobster, Panulirus interruptus, is an ecologically and economically important species that has been exploited since the 1800s. No previous study in California has assessed the impacts of the recreational or commercial lobster harvest. Before the 2003–04 commercial and recreational lobster seasons, we conducted a fishery‐independent trap survey at Santa Catalina Island to document the impact of the lobster fisheries on the size structure, abundance, and sex ratios of mature P. interruptus (>65 mm carapace length (CL)). We concurrently sampled a predominantly commercially fished area, a recreationally fished area, and a 23‐year‐old invertebrate no‐take (INT) reserve. Relative to the INT reserve, legal‐size lobsters in the recreational area were similar in CL, but 31% less abundant. Legal‐size lobsters in the commercial area were 8% smaller and 70% less abundant than those in the INT reserve. The sex ratio of legal‐size lobsters, although near 50:50 in the recreational and INT reserve areas, was male‐dominated (67:33) in the commercial area. Differences in CPUE and mean CL of sub‐legal lobsters in the recreational and commercial areas suggest that factors in addition to harvesting pressure may affect these populations. Total biomass of mature lobsters in the recreational and commercial areas was 92% and 45%, respectively, of biomass in the INT reserve. Fecundity in the recreational and commercial areas was 83% and 42%, respectively, of fecundity in the INT reserve. This study provides preliminary data for future ecological studies and fisheries management evaluations.