Study on the high precision acoustic measurement techniques for determining temperature field around seafloor hydrothermal vent

This paper presents the basis of acoustic method used for temperature field measurement of seafloor hydrothermal vent and two techniques of the parabolic interpolation and the bending compensation of propagation paths of acoustic signal are introduced. Experimental research is performed to exactly rebuild the temperature field around hot springs on the floor of Qiezishan Lake, Yunnan, China. The accuracy of the travel time estimation has been improved based on the aforementioned technique and method. At the same time, by comparison of the results of temperature field with different means, the max absolute error, the maximum relative error and the root mean square error are given. It shows that the technique and the method presented in the paper can be applied to the temperature field measurement detector around the seafloor hydrothermal vent. It also has a good accuracy.     

Airborne geometry correction method for marine multispectrum data without attitude information

Marine airborne multispectrum scanner (MAMS) onboard the China marine surveillance plane can be used to survey marine environment, resources and disaster and provide the technical support for high-frequency, high-efficiency and high-resolution remote sensing monitoring for the coastal management. MAMS did not have the IMU/POS equipment, so it brought severe challenge for the geometry correction. One airborne geometry correction method is introduced for marine multispectrum data without the attitude information. First, it is the coarse geometry correction, which simulates the roll angle and pitch angle of plane according to the ideal flying model; the second step is the precise geometry correction by using the SPOT orthogonal projected data as the reference of registration, based on maximization of alignment metric method. With the validation, relative error of coarse correction is 81.42 m compared with SPOT data, and 11.3 m for precise correction. This method provides the high precision localization information for the oceanic remote sensing and application, and establishes the foundation for monitoring the marine resource and environment.     

Accumulation and exploration of gas hydrate in deep-sea sediments of northern South China Sea

The large deep-sea area from the southwestern Qiongdongnan Basin to the eastern Dongsha Islands,within the continental margin of northern South China Sea,is a frontier of natural gas hydrate exploration in China.Multiform of deep-sea sedimentations have been occurred since late Miocene,and sediment waves as a potential quality reservoir of natural gas hydrate is an most important style of them.Based on abundant available data of seismic,gravity sampling and drilling core,we analyzed the characteristics of seismic reflection and sedimentation of sediment waves and the occurrence of natural gas hydrate hosted in it,and discussed the control factors on natural gas hydrate accumulation.The former findings revealed the deep sea of the northern South China Sea have superior geological conditions on natural gas hydrate accumulation.Therefore,it will be of great significance in deep-sea natural gas hydrate exploration with the study on the relationship between deep-sea sedimentation and natural gas hydrate accumulation.     

Ecological effects of co-culturing sea cucumber Apostichopus japonicus (Selenka) with scallop Chlamys farreri in earthen ponds

Monthly changes in sedimentation and sediment properties were studied for three different culture treatments: sea cucumber monoculture (Mc), sea cucumber and scallop polyculture (Ps-c) and scallop monoculture (Ms). Results indicated that the survival rate of sea cucumber was significantly higher in Ps-c cultures than in Mc cultures. Sea cucumber yield was 69.6% higher in Ps-c culture than in Mc culture. No significant differences in body weight and scallop shell length were found between Ps-c and Ms cultures. The mean sedimentation rate of total particulate matter (TPM) was 72.2 g/(m2 d) in Ps-c cultures, with a maximum of 119.7 g/(m2 d), which was markedly higher than that of Mc (mean value). Sedimentation rates of organic matter (OM), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in Ps-c cultures were also significantly higher than those in Mc cultures. TOC and TN contents of sediment increased rapidly in the first 5 months in Ms cultures and remained at a high level. TOC and TN contents in Mc and Ps-c cultures decreased during sea cucumber feeding seasons and increased during sea cucumber dormancy periods (summer and winter). The study demonstrates that co-culture of sea cucumber and scallop in earthen ponds is an alternative way to alleviate nutrient loads and improve water quality in coastal aquaculture systems. Moreover, it provides the additional benefit of an increased sea cucumber yield.     

Characteristics and variations of the picophytoplankton community in the Arctic Ocean

Picophytoplankton are responsible for much of the carbon fixation process in the Arctic Ocean, and they play an im- portant role in active microbial food webs. The climate of the Arctic Ocean has changed in recent years, and picophytoplankton, as the most vulnerable part of the high-latitude pelagic ecosystem, have been the focus of an increasing number of scientific studies. This paper reviews and summarizes research on the characteristics of picophytoplankton in the Arctic Ocean, including their abundance, biomass, spatial distribution, seasonal variation, commtmity structure, and factors influencing their growth. The impact of climate change on the Arctic Ocean picophytoplankton community is discussed, and future research directions are considered.     

Preliminary investigations on Arctic microalgae by joint aDDlication of fluorescent instruments

In vivo fluorescence has a wide application in analyzing microalgae, including assessing phytoplankton biomass, rates of primary production and physiological status. This study describes a preliminary investigation on the joint application of the three kinds of fluorescence analysis in the physiological study of microalgae. Flow cytometry and fluorescence spectrometry were used to obtain the in vivo static fluorescence information of pigments, and a Pulsed-Amplitude-Modulation chlorophyll fluorometer was used to detect the dynamic fluorescence of chlorophyll. The validity of the joint application was proved by analyzing two labora- tory cultured Arctic microalgae, Pseudo-nitzschia delicatissima （Bacillariophyceae） and Thalassiosira sp. The higher value of minimum fluorescence yield in dark-adapted state （Fo）, actual photochemical efficiency of PSll （ФPSII）, and electron transport rate （ETR） exhibited positive results in a higher cell abundance and chlorophyll a content of P. delicatissima; whereas higher fl-carotene content of Thalassiosira sp. played an important role in the protection of photosynthesis.     

相同养殖条件下青、红刺参体壁营养成分的比较研究

研究同一养殖池塘内青、红刺参(Apostichopus japonicus)体壁的营养组成与含量。结果表明:青刺参和红刺参体壁中水分含量、出皮率和干品灰分含量差异显著(P<0.05),粗蛋白、总糖分和粗脂肪含量差异不显著(P>0.05)。青、红刺参体壁均含有18种氨基酸,各种氨基酸含量无显著差异(P>0.05)。在检出的10种主要脂肪酸中,青刺参体壁中MUFA-16∶1(十六碳烯酸)和SFA-20∶0(二十碳酸)的含量显著高于红刺参(P<0.05),AA(二十碳四烯酸)的含量显著低于红刺参(P<0.05)。青、红刺参体壁均含有VB1、VB2、VB3、VB9、VB12、VC和VE等7种维生素,红刺参的VB3含量显著高于青刺参(P<0.05)。红刺参类胡萝卜素总量显著高于青刺参(P<0.05)。在检测的微量元素中,红刺参Zn、Cu和Se含量均显著高于青刺参(P<0.05)。研究表明,红刺参的综合营养品质优于青刺参。     

A new approach to measurement of regional inequality in particular directions

Regional inequality is a core issue in geography,and it can be measured by several approaches and indexes.However,the global inequality measures can not reflect regional characteristics in terms of spatiality and non-mobility,as well as correctly explore regional inequality in particular directions.Although conventional between-group inequality indexes can measure the inequality in particular directions,they can not reflect the reversals of regional patterns and changes of within-group patterns.Therefore,we set forth a new approach to measure regional inequality in particular directions,which is applicable to geographic field.Based on grouping,we established a new index to measure regional inequality in particular directions named Particular Direction Inequality index(PDI index),which is comprised of between-group inequality of all data and between-group average gap.It can reflect regional spatiality and non-mobility,judge the main direction of regional inequality,and capture the changes and reversals of regional patterns.We used the PDI index to measure the changes of regional inequality from 1952 to 2009 in China.The results show that:1) the main direction of China’s regional inequality was between coastal areas and inland areas;the increasing extent of inequality between coastal areas and inland areas was higher than the global inequality;2) the PDI index can measure the between-region average gap,and is more sensitive to evolution of within-region patterns;3) the inequality between the northern China and the southern China has been decreasing from 1952 to 2009 and was reversed in 1994 and 1995.     

新疆奇台绿洲农田灌溉前后土壤水盐时空变异性研究

对比研究了新疆奇台县绿洲农田灌溉前后土壤水盐的时空变异特征。结果表明,灌溉前,剖面各层土壤含水量较低（18.43%～20.30%之间）,且呈中等（偏弱）变异性。大水漫灌后1周,除40～60 cm和100～120 cm土层外,其他层土壤含水量均变为弱变异性;剖面平均土壤含水量升高6.90%,脱盐率达11.37%,其中,表层（0～20 cm）土壤水分增加率（50.93%）及脱盐率（27.14%）最大,底层（100～120 cm）土壤水分增加率（26.59%）及脱盐率（-4.76%）最小。灌后3周,剖面平均含水量减少3.64%,其中,表层（0～20 cm）失水率（28.84%）最大;剖面平均脱盐率降为9.63%,0～60 cm土层平均脱盐率（7.58%）减小,而60～120 cm土层脱盐率（11.01%）增大。除20～40 cm土层外,其他层含水量变异性均与灌前一致,说明含水量已接近灌前水平。至灌后第3周,各层含盐量、剖面平均盐分（中等变异性）及平均水分（弱变异性）含量的变异性未变,但其变异系数均在减小;剖面平均含水量的空间自相关性由中等转为强烈,变程一直增大,而平均含盐量均具有强烈的空间自相关性,变程先增大后减小。