河岸带潜流层温度示踪流速计算方法

为揭示低温水影响下的河岸带潜流层的温度场和流场分布特性,利用野外水温水位实时监测试验,研究河岸带潜流层温度场在不同季节、不同空间位置上的分布特性,并利用水温资料计算获得地下水流速。结果表明:河岸带潜流层温度场在夏季和冬季分别呈现出"上暖下冷"和 "上冷下暖"的温度分层现象;通过对温度示踪方法的4种计算方法进行分析比较,得到Hatch相位法计算的地下水流速具有较高的准确性,在2014年12月15—31日时段内流速大小为1.03×10-4~7.96×10-4m/s,在空间上,断面深度增加,地下水流速降低,且不同深度流速曲线接近平行。     

Active Characteristics and Paleoearthquakes in the West Kalpin Nappe Since the Holocene,SW Tianshan Mountain

the Kalpin nappe is an important multiple thrust system. It is important to study the Cenozoic tectonic of the Tianshan Mountain. Holocene active characteristics and paleoearthquake of the Kalpin nappe can be used to evaluate the neotectonic of this area. In this paper, we accurately measured the fault scarp in the front of three thrust-fold faults and analyzed paleoearthquake events in the trenches of the Kalpin nappe. Using the ¹⁰Be exposure age, we obtained those geomorphic surface ages and paleoearthquake times. The result showed that the slip rates of the west Kalpintag fault, aozitag fault and the tuoketag fault were 1.45(+1.68/-0.44) mm/a, 0.81(+0.35/-0.19) mm/a and (0.3±0.05) mm/a, respectively since the Holocene. The slip rate indicated that the increased activity transferred from back-row fault to front-row fault and accorded with the piggy-back propagation model in the Tianshan Mountain. Displacements and recurrence intervals of paleoearthquakes was similar to the slip rate characteristics. It also showed paleoearthquakes in the front row fault were stronger than paleoearthquakes of the back row fault. The strong paleoearthquake which caused the highest surface rupture happened in the Kalpintag fault. The interval of paleoearthquakes was about 4 ka and the displacement of every paleoearthquake was about 3 m in the west Kalpintag fault; the interval of paleoearthquakes was about 2 ka and the displacement of every paleoearthquake was about 1m in the aozitag fault; the tuoketag fault ruptured only one paleoearthquake since 7 ka. The Piqiang tear fault was the tectonic result of different shortening rate between the west Kalpin system and the east Kalpin system. The shortening rate of west Kalpin system was obviously stronger than the east Kalpin system. The huge separation distance was near 20 km between the east and the west back-row fault. Because the slip rate of system transferred to the front-row fault in the piggy-back propagation model, the separation distance (~4 km) between the east and the west front-row fault was increasing.     

黄河三角洲滨海湿地演化过程中的碳埋藏效率及其控制因素

2007年在黄河三角洲布设了一口浅钻ZK4,孔深28.3 m,对获取的岩心样品进行了详细的沉积学观测及含水量、有机碳、总碳和营养成分的实验室分析测试。通过ZK4孔的地层分析,将其划分为7种沉积环境,揭示了滨海湿地地质演化过程。并利用AMS14C测年方法,结合黄河改道的历史记录,运用历史地理学和沉积地质学综合分析的方法对黄河三角洲沉积环境进行了年代划分,并计算了黄河三角洲不同沉积环境沉积物的沉积速率和碳的加积速率。结果表明:总碳和有机碳与除硫和磷元素以外的各营养成分都呈良好的线性相关;碳、氮、磷的加积速率与沉积物的沉积速率呈极显著正相关关系(R0.89,p0.01),沉积物的沉积速率是碳、氮、磷的加积速率的主控因素;虽然现代黄河三角洲沉积物有机碳浓度较低(1%),但由于沉积物的高沉积速率,现代黄河三角洲沉积物有机碳的平均加积速率达到2878.23 g/(m2·a),远高于世界其他高有机碳浓度的湿地,因此是很好的碳汇地质体。     

东北大三江盆地群早白垩世存在统一湖盆的沉积学证据

大三江盆地群位于黑龙江省东部,中生代以来经历了多期构造运动,形成现今各自分割的10余个残余盆地。由于缺乏关键性证据,前人对大三江地区早白垩世是否存在统一湖盆存在争议。本次研究通过野外地质调查和钻井岩心观察,认为盆地总体缺乏边缘相沉积,并且主要以三角洲平原亚相和滨浅湖亚相为主。古水流恢复和重矿物特征显示,研究区主要存在西部和西北部、东部以及东南部三大物源体系,并且平面上具有由四周向中心汇聚的特征。地震资料反射特征显示下白垩统具有典型的断陷-坳陷复合结构,坳陷时期地层由各盆地中心至边部未出现明显的地层减薄现象,现今的盆地边界断裂多为后期对盆地进行改造、破坏的逆冲断裂。这些证据都是对大三江地区早白垩世存在统一湖盆的有力支撑。本研究不仅能为大三江盆地群原型盆地的恢复提供重要依据,也将为东北盆地群油气资源远景评价和进一步的勘探部署提供参考。     

Influence of anthropogenic pressure and seasonal upwelling on coral reefs in Nha Trang Bay (Central Vietnam)

The growing coastal development, dredging and dumping activities, overfishing and expansion of marine cage culture in Nha Trang Bay (NTB) of Central Vietnam since the beginning of the 2000s have resulted in a dramatic decrease of live coral cover. Surveys conducted in April–May 2013 and the same period in 2014 revealed that with an increase in distance from the outer part of the bay towards the mainland, the rivers’ influxes and dredged areas, coral cover decreased from 75% to 0.6% and species richness from 63 to 5, while the abundance of macroalgae increased from 0% to 56%. These changes correlate with differences in the concentration of suspended sediments on the same gradient. The abundance of the crown‐of‐thorns starfish Acanthaster planci and of the echinoid Diadema setosum significantly increased between the first estimation in 1998 and the survey in 2014, from 0 to 1.7 individuals (ind.) per 100 m^?2 and from 50.8 to 94.5 ind. per 100 m^?2, respectively, contributing to coral loss and intensive bioerosion of the reef framework in the bay. The large sizes of adult colonies of tabulate Acropora on the remote stations with negligible sedimentation and eutrophication loads were inconsistent with the assumptions that temperature‐induced coral bleaching or cyclones could be the major impacts in Nha Trang Bay. Analysis of the 16‐year thermal history of the bay did not reveal any instances in which the coral thermal bleaching threshold had been exceeded up to the present study. Seasonal upwelling, which occurs annually in the vicinity of Central Vietnam, may contribute to mitigation of thermal anomalies within NTB and to the maintenance of healthy coral communities on the remote reefs with relatively low anthropogenic impact.     

使用多普勒超声成像比较栉孔扇贝与虾夷扇贝循环生理特征

将先进的多普勒超声成像技术运用于栉孔扇贝(Chlamys farreri)和虾夷扇贝(Patinopecten yessoensis)循环生理学的研究中,首次量化了扇贝心率(HR)、血流加速度(ABF)、收缩峰值速度(PS)、舒张末期速度(ED)、血液最大瞬时血流量(Max-IBF)、血液最小瞬时流量(Min-IBF)、收缩期与舒张期流速比(S/D)和阻力指数(RI)等指标,对比了两种不同耐温性扇贝的循环生理指标差异。结果表明,两种扇贝HR、ABF、PS、ED、Max-IBF、Min-IBF与水温均呈正相关;在10—25°C间,栉孔扇贝和虾夷扇贝HR范围分别为16—39、14—31次/min,ABF范围分别为1.75—15.84、0.99—7.41cm/s2,PS范围分别为3.54—8.09、2.32—8.85cm/s,ED范围分别为1.51—3.15、1.09—4.23cm/s,Max—IBF范围分别为0.051—0.193、0.137—0.316m L/s、Min—IBF范围分别为0.025—0.072、0.022—0.131m L/s、RI范围分别为0.49—0.69、0.42—0.54,S/D范围为2.28—2.83、1.75—2.12。同一温度下栉孔扇贝的HR、ABF、PS、ED指标水平均高于虾夷扇贝,Max-IBF、Min-IBF水平均低于虾夷扇贝;两种扇贝RI和S/D指标均在一定范围内波动。研究显示,虾夷扇贝在较低的心脏和血流搏动节律下保持了高效的血液流通,从而以相对较少的能量消耗维持了其机体代谢对血液循环的需求,这也与其冷水性的生态习性相适应。     

黑潮延伸体上游中尺度涡场的年代际振荡及其相关机制

黑潮延伸体上游区域的中尺度涡场的涡动能和涡特征尺度存在显著地年代际振荡,和黑潮延伸体路径的年代际变化有很好的相关性。当黑潮延伸体路径比较稳定时,其上游区域涡动能比较高,涡特征尺度比较大,反之相反。通过对黑潮延伸体上游区域的中尺度涡场进行集合分析发现:当黑潮延伸体处于稳定状态时,上游涡场几乎是各向均匀地,有轻微的径向伸长;而当黑潮延伸体处于不稳定状态时,上游的中尺度涡场有显著地纬向伸长。对与中尺度涡场的产生相关的线性斜压不稳定和正压不稳定进行了计算分析,结果显示,线性斜压不稳定不是控制中尺度涡场年代际变化的机制,而正压不稳定对中尺度涡场的年代际变化有积极的贡献。不稳定产生的中尺度涡之间存在非线性涡-涡相互作用。     

温度、盐度和光照对浒苔生长和光合作用的影响

Intensive Pyropia aquaculture in the coast of southwestern Yellow Sea and its subsequent waste, including disposed Ulva prolifera, was speculated to be one of the major sources for the large-scale green tide proceeding in the Yellow Sea since 2007. It was, however, unclear how the detached U. prolifera responded and resumed growing after they detached from its original habitat. In this study, we investigated the growth and photosynthetic response of the detached U. prolifera to various temperature, salinity and irradiance in the laboratory. The photosynthetic rate of the detached U. prolifera was significantly higher at moderate temperature levels(14–27°C)and high salinity(26–32), with optimum at 23°C and 32. Both low(14°C) and highest temperature(40°C), as well as low salinity(8) had adverse effects on the photosynthesis. Compared with the other Ulva species, U. prolifera showed higher saturated irradiance and no significant photoinhibition at high irradiance, indicating the great tolerance of U. prolifera to the high irradiance. The dense branch and complex structure of floating mats could help protect the thalli and reduce photoinhibition in field. Furthermore, temperature exerted a stronger influence on the growth rate of the detached U. prolifera compared to salinity. Overall, the high growth rate of this detached U. prolifera(10.6%–16.7% d~(–1)) at a wide range of temperature(5–32°C) and salinity(14–32) implied its blooming tendency with fluctuated salinity and temperature during floating. The environmental parameters in the southwestern Yellow Sea at the beginning of green tide were coincident with the optimal conditions for the detached U. prolifera.     

放养密度对大杂交鲟生长性能的影响及生理应答机制

为探讨放养密度对鱼类生长及生理应答机制的影响规律和作用,作者以大规格大杂交鲟(达氏鳇(Huso dauricus)♀×施氏鲟(Acipenser schrenckii)♂)为实验材料,研究了平均初始体质量约为243 g/尾,放养密度分别为6(SD1组)、9(SD2组)、12(SD3组)、15 kg/m3(SD4组)条件下,不同放养密度处理70 d后的实验鱼生长性能变化及生理应答机制。结果显示,放养密度对大杂交鲟肥满度影响不显著,SD2组鱼类具有最大的特定生长率和生长效率,随着放养密度增加,日增质量显著降低(P0.05),特定生长率和生长效率下降。测定了血液甲状腺素(T4)、三碘甲腺原氨酸(T3)和皮质醇水平变化,发现放养密度能引起大杂交鲟3个血液生理指标发生显著改变;随着养殖时间推移,T3和皮质醇浓度显著升高,T4浓度显著下降(P0.05)。这些结果说明神经内分泌活动的变化引起大杂交鲟血液生理指标变化,进而影响实验鱼生长性能。因此,在该养殖条件下推荐的养殖密度为9 kg/m3。     

曹妃甸近岸及周边海区碎屑矿物组成特征及其环境意义

为探讨曹妃甸近岸及周边海区沉积物碎屑矿物组成特征以及曹妃甸大规模围填海工程对其影响,作者对2013年10月采自曹妃甸及周边海区的表层沉积物样品采用轻重矿物分离的方法进行了鉴定。结果表明:大规模围填海工程在改变曹妃甸岸线形态的同时也改变了其冲淤环境,使得碎屑矿物组分在大规模围填海前后发生一定变化。研究区的沉积物整体以轻矿物为主,平均含量为97.83%,其中曹妃甸近岸平均含量为95.57%;重矿物平均含量为2.17%,其中曹妃甸近岸平均含量为4.43%。研究区的重矿物优势矿物主要有普通角闪石、绿帘石和自生黄铁矿,其中普通角闪石所占比例在曹妃甸近岸达到最高值(36.41%);轻矿物的优势矿物主要有石英、斜长石和风化碎屑,其中石英所占比例也在曹妃甸近岸达到最高值(62.72%)。研究发现,曹妃甸近岸沉积物碎屑矿物相对含量增加而重矿物基本不变,这在一定程度上揭示了大规模人工围填海工程对曹妃甸近岸及周边海区沉积环境的影响。