Origin of the Mushroom Stone Forest at the southeastern foot of the Little Sangpu Mountain in eastern Guangdong,China: A palaeo-sea-level indicator or not?     

LI Jian-cheng  WANG Wei  ZHENG Yan-ming 《山地科学学报》2019,(3)

The Mushroom Stone Forest, which consists of granite boulders looking like mushrooms with flared sidewalls, is located in eastern Guangdong China, and is a famous scenic spot that draws many tourists each year. The Mushroom Stone Forest has been traditionally recognized as a collection of wave erosion landforms and used for the reconstruction of palaeo-sea-level changes along the coastal areas of eastern Guangdong in previous coastal researches. By combining in situ measurements of the aspect,vertical profile and height of boulder sidewalls,palaeo-coastal wave direction estimation, rock density determination, major elemental analysis, and petrographic thin section analysis, this paper presents an alternative origin for the Mushroom Stone Forest.Our results suggest that wave or wind erosion cannot offer a satisfactory explanation for the formation of the Mushroom Stone Forest; The boulders that make up the Mushroom Stone Forest originated from the corestones in the granite weathering crusts of the Little Sangpu Mountain; When the debris of the weathering crust was removed, the corestones are perched on rocky outcrops or half-buried by weathering debris beneath the natural land surface;The flared sidewall (concave vertical profile) of the boulders is a particular form developed in the foot zone of a half-buried boulder through increased chemical weathering beneath the land surface. A recent exposed half-buried boulder found in the study area provides convincing evidence to support this argument. Sea water reached the foot of the Sangpu Mountain during the Holocene transgression, but it merely provided a mechanism to erode the weathering debris from the bottom of the mushroom rocks and enhanced salt weathering that created tafoni on the boulders. These findings demonstrate that the boulders of the Mushroom Stone Forest are not sea stacks and cannot be served as a palaeo-sea-level indicator.  相似文献   

Detecting and attributing vegetation changes in Taihang Mountain,China   总被引：1，自引：0，他引：1  

HU Shi  WANG Fei-yu  ZHAN Che-sheng  ZHAO Ru-xin  MO Xiong-guo  LIU Liang-mei-zi 《山地科学学报》2019,(2)

Attributing vegetation changes provide fundamental information for ecosystem management,especially in mountainous areas which has vulnerable ecosystems. Based on the Normalized Difference Vegetation Index(NDVI) data, the spatial-temporal change of vegetation was detected in Taihang Mountain(THM) from 2000 to 2014. The topographical factors were introduced to interpret the response of vegetation variation to climate change and human activities. Results showed that the avegaged NDVI during growing season showed a single-peak curve distribution, with the largest value(0.628) among 1600-1800 m. A significant greening trend was detected in THM, with the largest increasing rate(0.0078 yr~(-1)) among the elevation of1600-1800 m and slope gradient between 3~5°. The partial correlation and multiple correlation analyses indicated that vegetation variation in more than81.8% pixels of the THM was mainly impacted by human activities. In the low elevation zones less than1000 m, increasing precipitation is the principle factor promoting vegetation restoration, whereas in the high elevation zones of THM, temperature is the restricted factors impacting vegetation variation.Considering the dramatic climate change in the future,further studies should be conducted to explore inherent mechanism of vegetation growth to dynamic environment changes.  相似文献   

不同植被盖度沙质草地生长季土壤水分动态   总被引：2，自引：1，他引：1  

王明明  刘新平  李玉霖  车力木格  罗永清  孙珊珊  魏静 《中国沙漠》2019,39(5):54-61

水分是干旱半干旱沙地生态系统最大的限制因子,研究植被盖度和土壤水分之间的关系有助于沙地生态恢复和保护。基于生长季科尔沁沙质草地不同植被盖度下土壤水分动态和降水的观测试验,分析了沙质草地植被盖度和土壤水分的耦合关系。结果表明：在土壤剖面上土壤水分存在明显的分层结构,依次为水分剧变层（0~40 cm）、缓变层（40~100 cm）和稳定层（100~180 cm）;植被盖度对土壤水分有很大影响,不同植被盖度下土壤含水量存在显著差异,土壤水分与盖度之间呈倒“V”型关系,土壤水分状况在28%的盖度下最优;不同的植被盖度下土壤水分对降水的响应也存在差异,在13%盖度下响应最敏感,28%和46%的盖度下响应微弱,后二者的土壤水分也相对稳定。在沙地生态恢复建设过程中合理的植被盖度配置可提高降水利用效率,并能使土壤水分和植被达到一种良好的平衡状态,从而有利于生态系统的稳定。  相似文献   

桂枝法联合盐酸多奈哌齐治疗血管性痴呆30例临床观察          下载免费PDF全文

王启芝  陈炜  李媛媛 《应用海洋学学报》2019,35(8):1-3

目的：观察桂枝法联合盐酸多奈哌齐治疗血管性痴呆的临床疗效。方法：采用单盲、随机、平行对照试验的设计方法,将60例血管性痴呆患者分为治疗组和对照组,每组各30例。对照组采用盐酸多奈哌齐治疗,治疗组在对照组的基础上加用桂枝法化裁的阳化汤治疗。观察治疗前后2组患者的简易智能量表（MMSE）、日常生活功能（ADL）评分的变化。结果：治疗后治疗组的显效率和总有效率分别为36.7%和80.0%,对照组分别为26.7%和63.3%,2组比较,差异有统计学意义（P<0.05）;且治疗组治疗后MMSE和ADL评分均明显高于对照组（P<0.05）。结论：桂枝法联合盐酸多奈哌齐治疗血管性痴呆效果显著,优于单用盐酸多奈哌齐治疗。  相似文献   

降低受信仪行程开关返程误差方法的分析          下载免费PDF全文

刘威  吴建萍 《数字海洋与水下攻防》2019,2(2):71-78

由于受信仪的行程开关返程误差较大,导致了运行、射界范围的控制精度不高。 针对返程误差偏大实际问题,研究了受信仪的行程开关工作原理,建立了其工作过程数学模型,采用复合形法开展了参数优化设计。 依据 PDCA 程序,应用因果图分析方法获得影响误差的主要因素,并逐一采取相应的解决措施。 经过验证,其实现了凸轮行程开关的返程误差减小到 0. 5°以下,提高了发射装置运行、射界范围的控制精度,达到了预期的目标。  相似文献   

复方清痹片糖衣片改薄膜衣片质量标准研究          下载免费PDF全文

刘会  唐伟  彭艳梅 《应用海洋学学报》2019,35(11):142-144

目的：研究复方清痹片糖衣片改薄膜衣片的质量标准。方法：将原由滑石粉、糖浆、川蜡等辅料包糖衣片改为由胃溶型薄膜包衣预混剂包薄膜衣片,对薄膜衣片质量标准进行研究,对赤芍、防己、黄柏、甘草等进行薄层鉴别研究,并对赤芍中芍药苷进行含量测定方法学研究。结果：赤芍、防己、黄柏、甘草薄层鉴别斑点清晰,专属性强;芍药苷在2.9858～29.8584μg/ml之间有良好的线性关系,平均回收率98.33%,RSD%为1.70%。结论：糖衣片改薄膜衣片工艺可行,质量控制可靠、准确,可用于复方清痹片的质量控制。  相似文献   

基于DPPH-HPLC-Q-TOF-MS/MS技术的安化黑茶发酵前后抗氧化活性物质基础研究          下载免费PDF全文

周卿意骏  贺炜  张水寒 《应用海洋学学报》2019,35(8):146-151

目的：建立基于高效液相色谱串联四级杆飞行时间质谱技术（HPLC-Q-TOF-MS/MS）的安化黑茶抗氧化活性成分快速筛选和鉴别的方法,并对安化黑茶生茶及熟茶的抗氧化活性成分分别进行检测和分析。方法：采用Inertsil ODS-2C_{18色谱柱（250mm×4.6mm,5μm）反相HPLC梯度洗脱法分离各主要成分,在负离子模式下,利用四级杆-飞行时间串联质谱对各主要活性成分进行检测;进而在安化黑茶生茶及熟茶乙酸乙酯及正丁醇部位分别加入适量1,1-二苯基-2-苦基苯肼（DPPH）作为实验组,避光室温反应30min后经液质联用分析,并与不加入DPPH的空白组物质进行比较,快速发现其活性成分;并采用对照品、文献比对、质谱裂解规律分析鉴定生茶、熟茶的抗氧化活性成分。结果：依据质谱裂解规律及文献检索,从安化黑茶生茶乙酸乙酯部位中共鉴定出32个抗氧化活性成分,从生茶正丁醇部位中共鉴定出28个抗氧化活性成分;从熟茶乙酸乙酯部位中共鉴定出31个抗氧化活性成分,从熟茶正丁醇部位中共鉴定出26个抗氧化活性成分。结论：利用DPPH-HPLC-Q-TOF-MS/MS技术快速筛选和鉴别安化黑茶中抗氧化活性成分的有效方法,为其质量控制及物质基础研究提供了技术支持。  相似文献}   

Spatio-temporal variability of small fishes related with environmental factors in a typical domestic tap water lake,Eastern China     

CAI Xingwei  YE Shaowen  LI Wei  FAN Hourui  LI Zhongjie  ZHANG Tanglin  LIU Jiashou 《海洋湖沼学报（英文）》2019,(1):278-289

The knowledge of prey small ?sh stock, distribution and abundance is necessary to guide stocking of piscivorous ?sh for the biomanipulation in domestic tap water lakes. This study describes the current status of small ?sh community in Kuilei Lake(China), and examines the spatial and seasonal variations of the community in relation to key environmental factors. Based on submerged macrophyte cover and water depth, the lake was divided into ?ve major habitats:(1) macrophyte covered shallow habitat of water depth< 2.00 m,(2) uncovered or less-covered shallow habitat(2.00 m–3.50 m),(3) uncovered medium shallow habitat(3.50 m–5.00 m),(4) uncovered medium deep habitat(5.00 m–6.50 m) and(5) uncovered deep habitat(6.50 m–8.50 m). The abundance and composition of small ?sh were monitored by benthic fykenet sampling from April 2013 to January 2014. A total of 2881 individuals belonging to 5 families and 21 species were collected. Based on their abundance(accounted for 88.96% of the total) and occurrence(more than 33.33%), Acheilognathus chankaensis, Acheilognathus macropterus, Microphysogobio microstomus,Pseudorasbora parva and Rhinogobius giurinus were recognized as dominant small ?sh species. The results of correlation analysis identi?ed that species richness( Sr), Shannon-Wiener diversity index( H′)and Margalef′s richness index( D) were signi?cantly negatively correlated with water depth, but positively correlated with biomass of submerged macrophytes.Redundancy analysis(RDA) revealed that the spatial distributions of most small ?shes were negatively associated with water depth. The details of these ?ndings are bene?cial to understanding the adaptation of the small ?shes in degraded environments, and to developing suitable biomanipulation strategies for the management of ?sh resources and water quality in the lakes along the lower reach of the Changjiang(Yangtze) River basin.  相似文献   

Relationships between body weight and other morphological traits in young sea cucumbers Apostichopus japonicas     

ZHAN Yaoyao  ZHANG Weijie  GE Chen  LIN Kai  LI Guang  SONG Jian  CHANG Yaqing 《海洋湖沼学报（英文）》2019,(2):759-766

Correlation, multiple regression, and path analyses were used to investigate the relationships between body weight and three other morphological traits in juvenile Japanese sea cucumbers Apostichopus japonicus . We measured live body weight (BW), body length (BL), numbers of papillae (NP), and numbers of tube feet (NF) at 60, 80, 100, and 130 days post-hatching (dph). We calculated path correlation coefficients, correlation indices ( R 2 ), and coefficients of determination with BW as the dependent variable and the other morphological traits as independent variables. The coefficient of variation for BW was high across all age groups, and all measured morphological traits were significantly correlated ( P < 0.01). BL had the greatest direct eff ect on BW across all age groups (60 dph, 0.526;80 dph, 0.404;100 dph, 0.620;and 130 dph, 0.681), while NF had the greatest indirect eff ect on BW across all age groups (60 dph, 0.528;80 dph, 0.452;100 dph, 0.666;and 130 dph, 0.603). Regression analyses between morphological traits and BW indicated that R 2 was greater than 0.85 only in the 100-dph specimens. The indirect eff ects of the other measured morphological traits on BW were age-dependent. The optimal regression equations, as determined with stepwise regression, were, for 60-dph specimens: BW 60 =10 (-3.04+0.092BL+0.014NP+0.014NF)( R 2 =0.632);for 80-dph specimens: BW 80 =10 (- 3.035+0.056BL+0.017NP+0.02NF)( R 2 =0.686);for 100-dph specimens: BW 100 =10 (- 3.742+0.069BL+0. 633 · lg (NP)+0. 464 · lg (NF))( R 2 =0.893);and for 130-dph specimens: BW 130 =10 (- 2.472+0.065BL+0.012NP)( R 2 =0.774). Our work clarified the correlation between various morphological traits and body weight of a commercially-important sea cucumber species ( A . japonicus ). Our predictive models for body weight might be useful for the aquaculture and selective breeding of A . japonicus . These models might also provide theoretical support for the indirect selection of traits that are difficult to select directly.  相似文献   

航行体近水面滑跳运动试验研究          下载免费PDF全文

孙士明  陈玮琪  王宝寿  郁伟  何振民  季锦梁 《数字海洋与水下攻防》2019,2(2):79-83

航行体近水面滑跳运动是近年来跨介质航行体研究的热点问题之一,针对航行体水面滑跳运动现象开展研究。 首先设计了适宜滑跳的航行体构型,通过数值仿真方法确定航行体的主要技术参数,发现航行体滑跳过程对于重心位置非常敏感;然后,针对设计的构型,开展水面自由滑跳试验,试验表明本文设计的模型可以在近水面稳定滑跳,验证了滑跳运动方式的可行性。 工作可为后续跨介质航行体设计提供技术参考。  相似文献