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银杏受精的形质变化及其种胚生长发育的候周期观察
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作者 于钊妍 李芳弟 +3 位作者 Muhammad Ali 汪贵斌 曹福亮 郭起荣 《中南林业科技大学学报》 CAS CSCD 北大核心 2023年第7期170-178,200,共10页
【目的】探究银杏种实受精时的内、外部形态变化;观察种胚发育的结构及数量变化规律。【方法】在7月中旬银杏种实形态建成后,以5 d为周期连续采样,观察其受精前、中、后期的外种皮颜色变化;制作系列石蜡切片,使用光学显微镜和电子显微... 【目的】探究银杏种实受精时的内、外部形态变化;观察种胚发育的结构及数量变化规律。【方法】在7月中旬银杏种实形态建成后,以5 d为周期连续采样,观察其受精前、中、后期的外种皮颜色变化;制作系列石蜡切片,使用光学显微镜和电子显微镜观察种胚结构的内部变化。统计分析不同时期“圆球胚、小子叶胚、大子叶胚、近成熟胚、完全成熟胚”5种类型种胚比例。【结果】五天一候的频度观察发现,银杏外种皮由绿转黄是受精的外部形质标志;外种皮由圆润变得缩皱,是胚胎开始发育的外部形态指标。8月中旬完成受精,形成合子;9月初,种胚肉眼可见,此时绝大多数为圆球胚和小子叶胚;9月下旬,小子叶胚占比最多(85%);到10月中旬,大子叶胚占比数量上升(63%);至11月上旬,近成熟胚占比为71%;到翌年1月下旬,57%已达完全成熟胚阶段。【结论】采用气象候周期采样频度,辅以光镜、电镜显微技术,首次获得了银杏在受精以及种胚始育时段种实的外部形质变化高精图;以候周期统计了种胚发育过程中相应的各种胚类型的数量比例。在研究过程中,新发现银杏种胚的子叶表面已经具气孔,中部具螺纹管胞,胚轴具维管束;首次大数据统计获得约1.5%的银杏种实有双胚发育现象,这些研究结果丰富了对银杏生殖发育的认识。 展开更多
关键词 形质变化 种胚发育 裸子植物受精 候周期 银杏
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Holocene Climate Cycles in Northwest Margin of Asian Monsoon 被引量:1
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作者 LI Yu WANG Nai'ang +2 位作者 LI Zhuolun ZHOU Xuehua ZHANG Chengqi 《Chinese Geographical Science》 SCIE CSCD 2012年第4期450-461,共12页
In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we invest... In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we investi- gated the absolutely dated Holocene records in Zhuye Lake for detecting the Holocene climate cycles. Totally, 14 14C dates and 6 optically simulated luminescence (OSL) dates are obtained from the QTH01 and QTH02 sections. The proxies of grain-size, total organic carbon content (TOC), C/N and 813C are used for wavelet analysis, and the results show obvious -256, -512 and -1024-year climate cycles, which are consistent with the Holocene millennial and cen- tennial scale climate cycles in the typical Asian summer monsoon domain. In different parts of the Zhuye Lake, the Holocene sediments show variable climate cycles that are affected by the lake basin topography. In the Zhuye Lake, the Holocene climate cycles are mainly correlated with the solar-related Asian summer monsoon variability and the North Atlantic ice-rafting events. 展开更多
关键词 HOLOCENE climate cycle Asian monsoon wavelet analysis Zhuye Lake
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Carbon Footprint Analysis for Baby Strollers
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作者 Yu Ang Luo Yifan 《Chinese Journal of Population,Resources and Environment》 2012年第4期16-21,共6页
The increasing awareness of climate change has led organizations to demand a standard procedure to measure and communicate greenhouse gas(GHG) emissions linked to their products or services.The publicly available spec... The increasing awareness of climate change has led organizations to demand a standard procedure to measure and communicate greenhouse gas(GHG) emissions linked to their products or services.The publicly available specification PAS 2050 has been developed in response to broad community and industry desire for a consistent method-carbon footprint for assessing the life cycle GHG emissions of goods and services.Specifically,this paper illustrates the implementation of carbon footprint for a baby stroller in accordance with PAS 2050.A fial value of 321 kg per one stroller including package was calculated.Moreover,the study led to identify raw materials production of the stroller as the main source of GHS emissions where efforts need to focus for emission reduction opportunities.This case study is hoped to be a starting point for organizations to benefit from the increasing application of carbon footprint assessment. 展开更多
关键词 baby stroller carbon footprint greenhouse gas emis- sions life cycle PAS 2050
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Atmospheric Equilibrium Tide Theory
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作者 张德宇 《Marine Science Bulletin》 CAS 2004年第2期28-33,共6页
Based on the equilibrium tide theory of the seawater, a model of long- period variations in air pressure with the lunar motion is derived to advance the climatic tide concept and formulate the climatic tide formula, w... Based on the equilibrium tide theory of the seawater, a model of long- period variations in air pressure with the lunar motion is derived to advance the climatic tide concept and formulate the climatic tide formula, which provides useful leads for predicting the heavy meteorological catastrophe in Shandong area, even in China, as well as in the whole world. 展开更多
关键词 air pressure long period variations MODEL climatic tide atmospheric equilibrium tide
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Mean Sea Level Changes near Weizhou Island from 1969 to 2010
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作者 ZHENG Zhaoyong LI Guangxue +1 位作者 TANG Chaolian ZHOU Xiong 《Journal of Ocean University of China》 SCIE CAS 2014年第3期369-374,共6页
Tidal data from Weizhou, Zhapo, and Shanwei stations between 1969 and 2010 and from five gauging stations in the western Pacific Ocean provided by PSMSL, and the global mean sea level data recorded between December 19... Tidal data from Weizhou, Zhapo, and Shanwei stations between 1969 and 2010 and from five gauging stations in the western Pacific Ocean provided by PSMSL, and the global mean sea level data recorded between December 1992 and December 2010 by TOPEX and Jason satellites were compiled and analyzed. The results show that the perennial mean sea level near Weizhou Island is 211.7 cm(relative to the water gauge zero), and the relative mean sea level rising rate is 2.2 mm yr-1 from 1969 to 2010, which is consistent with the relative mean sea level rising rate recorded at other gauging stations in the western Pacific regions and with the global mean sea level rising rate. The absolute mean sea level rising rate at Weizhou Island is 3.0 mm yr-1 from 1993 to 2010, also conforming with the global mean sea level rising rate(3.1±0.4 mm yr-1) during the same time period. The highest annual tide level at Weizhou Island has a rising rate of 4.6 mm yr-1 and shows a 20-year quasi-periodic variation from 1966 to 2010. The primary cause of the mean sea level rising is global warming. 展开更多
关键词 CLIMATOLOGY mean sea level change global climate change Weizhou Island
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Economic Competition for High Profits from Antarctic Living Resources in Their Protection Area
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作者 Ryszard Jacek Traczyk 《Journal of Environmental Science and Engineering(A)》 2016年第1期1-58,共58页
Since 1790, Antarctic living resources were becoming subjects of competition among the exploiters to be first in obtaining the maximum profit from them. This led to subsequent extinction of valuable species from fur s... Since 1790, Antarctic living resources were becoming subjects of competition among the exploiters to be first in obtaining the maximum profit from them. This led to subsequent extinction of valuable species from fur seals and next penguins, large through small whales, industrial demersal fish, further to pelagic species and now toothfish, crabs and krill. Catch proportions of their numerous and biomass decrease. The biomass of South Georgia Icefish estimated for 40 years in spide of decreasing trend has one of the largest components-the oscillations with periods of 3 years or 4 years. Their models explain large biomass fluctuations in the years 1975 to 1981 with amplitudes ±15 × 10^3 tonnes around average 20 ×10^3 tonnes and further decline up to 2005 season with oscillation ±4 ×10^3 tonnes around average 5 × 10^3 tonnes. For future season, 2016 model predicts a little increase of the biomass oscillation at level of 8 × 10^3 tonnes with reduced amplitude 2 × 10^3 tonnes. Slowly increase density of adult fish was also reported for target similar and close related mackerel icefish. Additional references for biomass levels help reduce the risk of further depletion biomass of Pseudochaenichthys georgianus which already declined to 75%. As global warming promote phytoplankton growth, replacing krill fishery by algae farms can save unique Antarctic heritages. 展开更多
关键词 Maximum profits from resources fish biomass age of icefish Antarctic fish krill.
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The Impacts of Two Milk Packages on Climate Change in the Life Cycle Perspective
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作者 Sara Toniolo Anna Mazzi Monia Niero Alessandro Manzardo Antonio Scipioni 《Journal of Food Science and Engineering》 2013年第7期371-378,共8页
Several food companies are implementing effective strategies to evaluate the environmental impacts of their products or processes and to estimate the greenhouse gases emissions (GHG) using a life cycle approach. Par... Several food companies are implementing effective strategies to evaluate the environmental impacts of their products or processes and to estimate the greenhouse gases emissions (GHG) using a life cycle approach. Particularly, a sector which can play an important role to reduce the impact on the environment through the life cycle thinking is the beverage packaging. In this context, the aim of this study was to use the life cycle assessment (LCA) method to investigate the consistency of the preference order across two alternative beverage packages through the application of two impact assessment methods, namely the IPCC 2007 which is focused on the GHG emissions estimation and the EcoIndicator 99 which considers several environmental categories including impact on climate change. The results showed that the life cycle approach employment was a useful strategy to investigate the consistency of the preference order across two beverage packages, especially, whether the results are made more reliable by the utilization of primary data. The investigation on climate change conducted on two level, initially, the quantification of the GHG emissions and secondly the estimation of the related diseases and mortality, demonstrated that the laminated carton presents lower impacts than the high-density polyethylene (HDPE) bottle. 展开更多
关键词 Greenhouse gases emissions life cycle assessment beverage packaging.
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Environmental Assessment of AI-Hilla City Wastewater Treatment Plants
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作者 Mohammad A. Alanbari Hind Q. Alazzawi +1 位作者 Nadhir A. A1-Ansari SvenKnutsson 《Journal of Civil Engineering and Architecture》 2015年第6期749-755,共7页
Iraq is one of the countries that is suffering from water shortage problems and, for this reason, wastewater treatment plants become a necessity to minimize this problem. In this study, the impact of A1-Hilla WWTP (w... Iraq is one of the countries that is suffering from water shortage problems and, for this reason, wastewater treatment plants become a necessity to minimize this problem. In this study, the impact of A1-Hilla WWTP (wastewater treatment plant) on the environment has been studied. This was achieved using SimaPro software package. This software is a powerful tool for analyzing the environmental impact on products during their whole life cycle. A huge amount of knowledge about the environment is built into the program and database, enabling to analyze a product with a minimum of specialized knowledge. The results of LCA (life cycle assessment) showed that the impact and damage on the environment by A1-Hilla WWTP was 41 bad points for each 1 m3 of treated wastewater. The most environmental impacts potentially were global warming, respiratory inorganics and non-renewable energy. The study also showed that most of the effects were the result of the use of cement, steel and electricity consumption. 展开更多
关键词 SimaPro environmental impact life cycle assessment wastewater treatment plant A1-Hilla.
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Sedimentary records of environmental evolution in the Sanmen Lake Basin and the Yellow River running through the Sanmenxia Gorge eastward into the sea 被引量:26
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作者 王苏民 吴锡浩 +4 位作者 张振克 蒋复初 薛滨 童国榜 田国强 《Science China Earth Sciences》 SCIE EI CAS 2002年第7期595-608,共14页
A series of independent faulted basins developed in the present middle reaches of the Yellow River during late Cenozoic, among which the Sanmen Lake Basin is located in the east edge of the Loess Plateau, a transition... A series of independent faulted basins developed in the present middle reaches of the Yellow River during late Cenozoic, among which the Sanmen Lake Basin is located in the east edge of the Loess Plateau, a transitional zone between the second and third macromorphological step of China. The thick strata of the Sanmen Group deposited in the large basin. The Sanmen Group is a perfect place for the study on paleoenvironmental change, tectono-climatic cycles as well as the formation and evolution of the Yellow River. In this paper, the paleoenvironmental changes, regional tectonic movement and the evolutionary process of the Sanmen Lake Basin during the past 5 Ma were reconstructed based on the analysis of paleomagnetic stratigraphy, pollen, TOC and carbonate content from the Huangdigou outcrop near the Sanmenxia Reservoir, Pinglu County, Shanxi Province. The sedimentary records from the outcrop indicate that the basin was first formated by fault activity at about 5.4 MaBP, and after the strong tectonic movement at 3.6 MaBP the lake enlarged and the rainfall of summer monsoon increased. There was no great climatic transition near 2.6 MaBP, corresponding to the bottom age of loess in the Loess Plateau. After Olduvai event (about 1.77 MaBP) the Picea and Abies were presented in the sediments, which indicates a colder climate. The tectonic movement at 1.2 MaBP caused the light angular discordance between the upper and lower Sanmen Group. The sedimentary records show a cold and wet climate during the prosperous periods of loess accumulation such as L15, L9, L6. The tectonic intensification periods of the Sanmen Basin correspond with the tectonic movements in the Qinghai-Xizang Plateau chronologically. The earliest age of the outflow from the Paleo-Sanmen Lake or the partly cutting off of the Sanmenxia Gorge was about 0.41- 0.35 MaBP. The age of cutting thoroughly the Sanmenxia Gorge by the Yellow River and the disappearance of the Paleo-Sanmen Lake was about 0.15 MaBP, which symbolized the formation of the present Yellow River and had an important influence on the environmental and morphological evolution in the middle and lower reaches of the Yellow River. 展开更多
关键词 Sanmen Basin sedimentary records formation of the Yellow River environmental evolution tectono-climatic cycles
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Coherent variations of the obliquity components in global ice volume and ocean carbon reservoir over the past 5 Ma 被引量:4
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作者 TIAN Jun 《Science China Earth Sciences》 SCIE EI CAS 2013年第12期2160-2172,共13页
The Milankovid theory stresses that the summer insolation in the high northern latitudes that is dominated by the precession cycle controls the glacial/interglacial cycles in global climate change. If the climate syst... The Milankovid theory stresses that the summer insolation in the high northern latitudes that is dominated by the precession cycle controls the glacial/interglacial cycles in global climate change. If the climate system responds linearly to the external insolation forcing, the precession cycle of 23 or 19 ka should dominate the variations in the climatic proxy records. I per- formed spectral and evolutive cross spectral analyses on the high resolution benthic ~80 and oa3C records from the South China Sea and the North Atlantic, the proxies of global ice volume and ocean carbon reservoir respectively. I found that the obliquity instead of the eccentricity or the precession is the most marked cycle in the global ice volume and ocean carbon res- ervoir variations over the past 5 Ma. The analysis further reveals that only at the obliquity band instead of the eccentricity or the precession band does the global ice volume and ocean carbon reservoir display consistently high coherency and stable phase relationship over the past 5 Ma. The consistently positive or near-zero phases of the benthic -o^SO relative to the benthic ff3C at the obliquity band suggest that the global carbon cycle is involved in the polar ice sheet growth as an important internal feedback, not a determinative driving factor. The obliquity instead of the precession or the eccentricity takes the dominant role of driving the global climate change during the Pliocene and Pleistocene. 展开更多
关键词 global ice volume ocean carbon reservoir OBLIQUITY 5 Ma
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The Fountain for Development
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作者 Shi Yongming 《Beijing Review》 2016年第19期20-21,共2页
China and neighboring countries start new cooperation pattern in the Lancang-Mekong River regionThe strongest El Ni?o weather cycle on record has exacerbated drought in the Mekong River area since the end of last year.
关键词 cooperation drought weather cycle record downstream neighboring ASEAN likely mutual
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Stochastic dynamic simulation of the 100-kyr cycles in climate system
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作者 DUAN MingKeng ZHOU XiuJi 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第3期420-428,共9页
Based upon the stochastic resonance theory,the formation mechanism of 100-kyr cycles in climate system is numerically studied in the perspective of stochastic dynamics.In this study,firstly we combine the idealized al... Based upon the stochastic resonance theory,the formation mechanism of 100-kyr cycles in climate system is numerically studied in the perspective of stochastic dynamics.In this study,firstly we combine the idealized albedo model with the geological evidence and observation in climate system to construct a new albedo model.Secondly,a bistable nonlinear system is constructed by introducing the albedo model into zero-dimensional energy balance model.Finally,based on this new system,with the solar radiation cycles and stochastic perturbation simultaneously taken into account,the variation of 100-kyr cycles is analyzed by numerical simulations.The results show that,when the noise intensity reaches a certain value,the stochastic resonance can be triggered.However,the noise intensity in this level does not exist in the actual climate system.In order to explain the formation mechanism of 100-kyr glacial-interglacial cycles forced by the weak solar radiation cycles,besides the solar radiation stochastic perturbation,the stochastic dynamic effects of the other "non-solar" radiation stochastic perturbation in the climate change processes should also be considered.The stochastic dynamic simulations taking the two types of stochastic perturbation into consideration show that,when the two types of appropriately observable stochastic perturbation are introduced,the stochastic resonance also can be generated.In this situation,the contribution rate of solar radiation stochastic perturbation is about 38%,which proves the importance of solar radiation stochastic perturbation in the formation of 100-kyr climate cycles. 展开更多
关键词 solar radiation climate change stochastic dynamics stochastic resonance energy balance model
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