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511.
为探讨在粉土及粉质黏土中桩端阻力随贯入深度的变化规律,通过在试验桩P1的桩端安装轮辐压力传感器,以及在试验桩P1、P2距桩端200 mm处安装光纤光栅(FBG)传感器,采用两种不同的测试技术全程监测了两根闭口预应力高强度混凝土(PHC)管桩现场贯入过程中的桩端阻力。试验结果表明:桩端阻力与土层的变化密切相关,土层越硬,桩端阻力越大,当桩端从粉质黏土层进入粉土层时,桩端阻力明显增大,粉土中的桩端阻力达到粉质黏土层的2倍;整个贯入过程中,同一土层不同位置的差异性对桩端阻力也存在较大影响,在距离地面1.50 m处,P1和P2桩FBG传感器桩端阻力的差值达到了89.29 kN,而在距离地面3.50~4.50 m处,两桩的桩端阻力则相差较小。 相似文献
512.
Sang Heon Lee Jongseong Ryu Dabin Lee Jung-Woo Park Jae-Il Kwon Jingping Zhao 《地理信息系统科学与遥感》2019,56(5):794-810
Phytoplankton size classes (hereafter, PSCs) were derived from satellite ocean color data using a present phytoplankton abundance-based optical algorithm in the northern Bering and southern Chukchi Seas to characterize the spatial and seasonal variations of the different PSC and investigate the contributions of small phytoplankton to the total phytoplankton biomass. The comparison results showed that the phytoplankton abundance-based method approach could reasonably classify the three PSCs (pico-, nano-, and micro phytoplankton). The satellite maps of the dominant PSCs were derived using long-term satellite ocean color data. The general spatial distribution showed that the large (micro-) phytoplankton were dominant in the coastal waters and the west side of the Bering strait, while the small size (nano- or pico-) phytoplankton were dominant in the open ocean waters. Nano- and microphytoplankton were dominant in May and October in most of the study area, while pico-phytoplankton were dominant in the summer months in the open ocean waters. The annual variation in small phytoplankton dominance had a strong positive relationship with the annual mean sea surface temperature (SST), which is consistent with the increasing dominance of small phytoplankton biomass as water temperature increases. Microphytoplankton have an apparent increasing trend in the southeastern Chukchi Sea but slightly decreasing trends in Chirikov and St. Lawrence Island Polynya (SLIP). In contrast, there were increasing trends in picophytoplankton in Chirikov and SLIP, which seems to be related to increasing annual SST. It is crucial to monitor changes in dominant groups of phytoplankton community in the Bering and Chukchi Seas as important biological hotspots responding to the recent changes in environmental conditions. 相似文献
513.
琼胶酶是作用于琼胶的水解酶,在食品、化妆品和制药工业中有广泛的应用。本文建立了一种基于诱导模式和甘油补料优化的高细胞密度和高产β-琼胶酶策略,同时可以较好的控制乙酸盐产量。首先,在诱导前期采用不同的比生长速率(μ)的甘油指数补料策略。结果表明,低的比生长速率(μ=0.2)是细胞生长和β-琼胶酶产生的最佳条件。其次,研究了诱导阶段诱导温度和诱导物浓度对细胞生长和β-琼胶酶产生的影响。当异丙基-β-d-硫代半乳糖苷(IPTG)诱导时,在20℃下0.8mmol/L的IPTG诱导策略对β-琼胶酶的产生效果最佳。采用1.0g/(L·h)的乳糖连续补料策略诱导培养,β-琼胶酶活性达到112.5U/mL,是目前报道的产量最高的β-琼胶酶。此外,β-琼胶酶能直接酶解龙须菜粉,产生新琼寡糖,水解产物为新琼胶四糖(NA4)和新琼胶六糖(NA6)。本文的研究为β-琼胶酶的工业化生产和应用提供了较好的理论依据。 相似文献
514.
Sangil Kim Suk Hyun Youn Hyun-Ju Oh Sun Kyeong Choi Yun Hee Kang Tae-Hoon Kim Hyuk Je Lee Kwang-Sik Choi Sang Rul Park 《Ocean Science Journal》2018,53(3):595-600
We conducted testing to determine whether stipe length is a useful indicator of reproductive maturity in the kelp Ecklonia cava, a species that plays a pivotal role in ecosystem functioning and services in subtidal areas. Approximately 100 sporophytes with stipes of various lengths were collected during the fertile period (July–November, 2013). We investigated the relationships between stipe length and other morphological characteristics to determine whether stipe length could indicate the age of reproductive maturity. Primary blade length, longest blade length, thallus height, and total length showed significant relationships with stipe length. The length of the primary and longest blades gradually declined as stipe length increased above 125 mm. Zoosporangial sori were found on the blades of more than 70% of individuals with stipes longer than 125 mm, but on only 8% of individuals with stipes less than 125 mm long. Stipe length therefore seems to be an acceptable proxy for reproductive maturity. Another factor to consider, however, is that all specimens with zoosporangial sori, regardless of stipe length, had a dry weight of 80 g or more; thus, individual biomass may also be an important parameter influencing the initiation of reproduction. 相似文献
515.
Huabin Mao Xiujun Sun Chunhua Qiu Yusen Zhou Hong Liang Hongqiang Sang Ying Zhou Ying Chen 《海洋学报(英文版)》2021,40(10):167-175
Latent and sensible heat fluxes based on observations from a Black Pearl wave glider were estimated along the main stream of the Kuroshio Current from the East China Sea to the east coast of Japan, from December 2018 to January 2019. It is found that the data obtained by the wave glider were comparable to the sea surface temperature data from the Operational Sea Surface Temperature and Sea Ice Analysis and the wind field data from WindSat. The Coupled Ocean Atmosphere Response Experiment 3.0 (COARE 3.0) algorithm was used to calculate the change in air-sea turbulent heat flux along the Kuroshio. The averaged latent heat flux (LHF) and sensible heat flux (SHF) were 235 W/m2 and 134 W/m2, respectively, and the values in the Kuroshio were significant larger than those in the East China Sea. The LHF and SHF obtained from Objectively Analyzed Air-Sea Fluxes for the Global Oceans (OAFlux) were closer to those measured by the wave glider than those obtained from National Centers for Environmental Prediction (NCEP) reanalysis products. The maximum deviation occurred in the East China Sea and the recirculation zone of the Kuroshio (deviation of SHF >200 W/m2; deviation of LHF >400 W/m2). This indicates that the NCEP and OAFlux products have large biases in areas with complex circulation. The wave glider has great potential to observe air-sea heat fluxes with a complex circulation structure. 相似文献
516.
为了探明南海北部海陆过渡带的深部地壳结构,我们在香港外海域进行了一次海陆地震联洲的实验,利用固定地震台网远距离接收海上气枪信号,接收距离远达200多km,并利用此次实验的测线1剖面模拟得到了海陆过渡带的深部地壳速度结构.速度结构模型表明:研究区海陆过渡带的地壳结构非均匀性较明显,由陆至海沉积层有一个突然增厚的特点;莫霍面深度约为26~29 km,上地壳P波速度约为5.5~6.4 km/s,下地壳P波速度为6.5~6.9 km/s.在担杆列岛往海方向有一个低速破碎带,其上地壳P波速度为5.2~6.1 km/s,下地壳P波速度为6.2~6.4 km/s,结合野外地质调查的结果,推测它可能为滨海断裂带.在担杆列岛往陆方向香港和深圳之间的研究区域,莫霍面有较大起伏,可能与此处发育的海丰断裂有关. 相似文献
517.
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519.
Bhavya P. S. Kim Bo Kyung Jo Naeun Kim Kwanwoo Kang Jae Joong Lee Jae Hyung Lee Dabin Lee Jang Han Joo HuiTae Ahn So Hyun Kim Yewon Min Jun-Oh Kang Min Gu Yun Mi Sun Kang Chang Keun Lee Sang Heon 《Ocean Science Journal》2019,54(1):1-14
Ocean Science Journal - Biochemical composition of phytoplankton is a key indicator of the physiological and nutritional status of phytoplankton. A balanced biochemical pattern represents a healthy... 相似文献
520.