期刊文献+
共找到676篇文章
< 1 2 34 >
每页显示 20 50 100
Balloon-based exposed payload designed for astrobiological research in Earth’s near space
1
作者 YanQiu Wang JianXun Shen +4 位作者 Chao Wang WeiNing Li GaoHong Wang Wei Lin YuanDa Jiang 《Earth and Planetary Physics》 EI CAS CSCD 2024年第6期878-889,共12页
Earth’s near space,located in the region between 20 and 100 km above sea level,is characterized by extreme conditions,such as low temperature,low atmospheric pressure,harsh radiation,and extreme dryness.These conditi... Earth’s near space,located in the region between 20 and 100 km above sea level,is characterized by extreme conditions,such as low temperature,low atmospheric pressure,harsh radiation,and extreme dryness.These conditions are analogous to those found on the surface of Mars and in the atmosphere of Venus,making Earth’s near space a unique natural laboratory for astrobiological research.To address essential astrobiological questions,teams from the Chinese Academy of Sciences(CAS)have developed a scientific balloon platform,the CAS Balloon-Borne Astrobiology Platform(CAS-BAP),to study the effects of near space environmental conditions on the biology and survival strategies of representative organisms in this terrestrial analog.Here,we describe the versatile Biological Samples Exposure Payload(BIOSEP)loaded on the CAS-BAP with respect to its structure and function.The primary function of BIOSEP is to expose appropriate biological specimens to the harsh conditions of near space and subsequently return the exposed samples to laboratories for further analysis.Four successful flight missions in near space from 2019 to 2021 have demonstrated the high reliability and efficiency of the payload in communicating between hardware and software units,recording environmental data,exposing sample containers,protecting samples from external contamination,and recovering samples.Understanding the effects of Earth’s near space conditions on biological specimens will provide valuable insights into the survival strategies of organisms in extreme environments and the search for life beyond Earth.The development of BIOSEP and associated biological exposure experiments will enhance our understanding of the potential for life on Mars and the habitability of the atmospheric regions of other planets in the solar system and beyond. 展开更多
关键词 earth’s near space biological sample exposure payload performance testing Mars analog AsTROBIOLOGY
下载PDF
Astronomic background of global huge earthquakes at beginning of 21st century
2
作者 Hu Hui Su You-Jin 《Applied Geophysics》 SCIE CSCD 2024年第3期423-432,616,共11页
Since the beginning of the 21st century,major earthquakes have frequently occurred worldwide.To explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is... Since the beginning of the 21st century,major earthquakes have frequently occurred worldwide.To explore the impact of astronomical factors on earthquakes,in this study,the statistical analysis method of correlation is used to systematically analyze the effects of astronomical factors,such as solar activity,Earth’s rotation,lunar declination angle,celestial tidal force,and other phenomena on M≥8 global earthquakes at the beginning of the 21st century.With regard to solar activity,this study focuses on the analysis of the 11-year and century cycles of solar activity.The causal relationship of the Earth’s rotation is not obvious in this work and previous works;in contrast,the valley period of the solar activity century cycle may be an important astronomical factor leading to the frequent occurrence of global earthquakes at the beginning of the 21st century.This topic warrants further study. 展开更多
关键词 M≥8.0 earthquake astronomical factors solar activity earth’s rotation lunar declination angle tidal force phenomena
下载PDF
Interrelationships between Length of the Day, Moon Distance, Phanerozoic Geodynamic Cycles, Tidal Dissipation and Earth’s Core: Review and Analysis
3
作者 Heinz-Jürgen Brink 《International Journal of Geosciences》 CAS 2024年第5期396-415,共20页
The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around... The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around the rotation axis of the spinning Earth during the growth of the core the rotation should have been accelerated. Controversially the tidal dissipation by the Moon, which is mainly dependent on the availability of open shallow seas and the kind of Moon escape from a nearby position, acts towards a deceleration of the rotating Earth. Measurements of LOD for Phanerozoic and Precambrian times open ways to solve questions concerning the geodynamical history of the Earth. These measurements encompass investigations of growth patterns in fossils and depositional patterns in sediments (Cyclostratigraphy, Tidalites, Stromatolites, Rhythmites). These patterns contain information on the LOD and on the changing distance between Earth and Moon and can be used as well for a discussion about the growth of the Earth’s core. By updating an older paper with its simple approach as well as incorporating newly published results provided by the geoscientific community, a moderate to fast growth of the core in a hot early Earth will be favored controversially to the assumption of a delayed development of the core in an originally cold Earth. Core development with acceleration of Earth’s rotation and the contemporaneous slowing down due to tidal dissipation during the filling of the ocean may significantly interrelate. 展开更多
关键词 Length of the Day Moon Distance Phanerozoic Geodynamic Cycles Tidal Dissipation earth’s Core
下载PDF
甘肃积石山 M_(s)6.2级地震的震害特征与启示 被引量:5
4
作者 王丽丽 王兰民 +5 位作者 卢育霞 许世阳 夏晓雨 盖海龙 池佩红 郭梅 《世界地震工程》 北大核心 2024年第1期58-71,共14页
2023年12月18日,甘肃省临夏回族自治州积石山保安族东乡族撒拉族自治县(35.70°N,102.79°E)发生了6.2级地震,震中烈度为VIII度。地震发生后,通过实地烈度评估与科学考察,对震区VI~VIII度区不同建(构)筑物与生命线工程的震害特... 2023年12月18日,甘肃省临夏回族自治州积石山保安族东乡族撒拉族自治县(35.70°N,102.79°E)发生了6.2级地震,震中烈度为VIII度。地震发生后,通过实地烈度评估与科学考察,对震区VI~VIII度区不同建(构)筑物与生命线工程的震害特点进行了统计分析;从抗震设计与施工管理、场地放大效应与地震次生灾害对建筑结构抗震性能的影响等角度,提出了此次地震的震害启示。结果表明:1)严重破坏和毁坏的建筑结构主要集中在老旧的土木结构、砖木结构和无设防或设防不规范的砖混结构。2)造成建筑结构破坏的主要原因是少量自建房抗震设计和施工的不规范、场地放大效应和地震次生灾害。3)优化和改良生土砌筑材料,改进纵横墙间的拉结措施,强化结构整体性是提高土木结构抗震的有效方法;普及“上下圈梁与构造柱”等基本抗震设防措施,规范水泥砂浆强度,提升农村工匠的施工水平,可有效提高砌体结构的整体性,避免房屋出现整体性垮塌;室内洗手间的墙体应该与房顶、纵横墙间建立有效联接,提高结构的抗震性能。4)孤突斜坡、河流高阶地与岸边为抗震不利地带。当建造用地极为匮乏,不得不选址在这些场地之上时,应该综合考虑场地的地形地貌特征、岩土体物理力学特性、水文地质条件、抗震设防目标、建筑结构类型等影响因素,做好地震灾害风险评估,根据评估结果进行科学设防。灾后重建过程中,应由政府统一规划选址、统一设计,规范施工。 展开更多
关键词 积石山6.2级地震 震害调查 场地放大效应 黄土液化流滑 震害特征
下载PDF
中强地震发震构造标志浅析——以2023年积石山M_(S)6.2地震为例
5
作者 张军龙 徐岳仁 +1 位作者 李文巧 陈峰 《地震》 CSCD 北大核心 2024年第1期226-234,共9页
地震地表破裂是地震发生的重要特征,是研究地震动力学、构造变形的重要手段。一般认为,M6 3/4以上的地震才会形成地表破裂。但近年来,也有M6.0左右的地震发生了地表破裂。本文旨在探讨中强地震地表破裂的识别方法。中强地震发震构造的... 地震地表破裂是地震发生的重要特征,是研究地震动力学、构造变形的重要手段。一般认为,M6 3/4以上的地震才会形成地表破裂。但近年来,也有M6.0左右的地震发生了地表破裂。本文旨在探讨中强地震地表破裂的识别方法。中强地震发震构造的识别具有一定的挑战性,主要表现在以下几个方面:(1)中强地震地表破裂的规模(位错量、宽度、长度和深度)较小,容易被黄土层厚覆盖,掩盖地表破裂的痕迹,不易识别;(2)非构造成因裂缝干扰,使得难以区分构造成因地表破裂。本文以2023年积石山M_(S)6.2地震为例,对中强地震构造成因破裂的识别标志进行了初步分析,提出了以下识别标志:(1)地表破裂几何展布和剖面形态,地震伴生的次生灾害(滑坡、崩塌、砂土液化等)的线性分布为识别发震构造提供参考和线索;(2)地表破裂沿破裂走向呈现稳定地穿越不同地貌单元,至少穿越一条沟谷等低凹地貌;(3)地表破裂在地质剖面上表现出稳定的产状;(4)地表破裂伴生构造形态,地表沿破裂发育雁列式褶皱(挤压鼓包)与张裂缝交替出现的现象。本文提出的识别标志为中强地震发震构造的识别提供了新的思路。 展开更多
关键词 青藏高原 拉脊山断裂带 2023年积石山M_(s)6.2地震 发震构造 地震地表破裂
下载PDF
O、S、Ce含量对U71MnG钢中Ce_(2)O_(3)和Ce_(2)O_(2)S夹杂物的影响
6
作者 王敏 刘香军 +1 位作者 杨昌桥 杨吉春 《稀有金属与硬质合金》 CAS CSCD 北大核心 2024年第2期45-49,共5页
我国稀土钢未实现大规模的生产,其主要原因是对稀土与钢中O、S等杂质元素的相互作用规律认识不足。考虑到Ce、O、S含量对钢中稀土夹杂物的影响缺少定量分析,使用FactSage 7.1软件计算U71MnG钢中不同含量O、S、Ce之间的相互作用关系及其... 我国稀土钢未实现大规模的生产,其主要原因是对稀土与钢中O、S等杂质元素的相互作用规律认识不足。考虑到Ce、O、S含量对钢中稀土夹杂物的影响缺少定量分析,使用FactSage 7.1软件计算U71MnG钢中不同含量O、S、Ce之间的相互作用关系及其对Ce_(2)O_(2)S、Ce_(2)O_(3)夹杂物析出量的影响。热力学计算结果表明,在U71MnG钢的成分体系下,随着Ce含量的增多,Ce_(2)O_(3)的析出量呈先增多后减少的趋势,m_(O)/m_(Ce)约为1/7.4时,Ce_(2)O_(3)的析出量最大;Ce_(2)O_(2)S的生成需要O、S、Ce共同作用,m_(O+S)/m_(Ce)约为1/3.7时,Ce_(2)O_(2)S析出量最大。试验钢夹杂物的SEM图像以及夹杂物颗粒数量统计结果显示,Ce含量为0.024%的试验钢中Ce_(2)O_(3)、Ce_(2)O_(2)S的个数大于Ce含量为0.016%的试验钢,钢中夹杂物析出规律与热力学计算结果一致。 展开更多
关键词 稀土夹杂物 热力学 Ce_(2)O_(2)s Ce_(2)O_(3)
下载PDF
Geochemical characteristics and growth suitability assessment of Scutellaria baicalensis Georgi in the Earth's critical zone of North China 被引量:1
7
作者 LI Xia WEI Xiao-feng +4 位作者 WU Jin YIN Zhi-qiang WAN Li-qin SUN Hou-yun AN Yong-long 《Journal of Mountain Science》 SCIE CSCD 2022年第5期1245-1262,共18页
Geochemical differentiation of soils has a series of consequences on plant and places pressure on the ecological environment.The quantitative evaluation of element migration in the Earth’s critical zone is a challeng... Geochemical differentiation of soils has a series of consequences on plant and places pressure on the ecological environment.The quantitative evaluation of element migration in the Earth’s critical zone is a challenging task.In this study,two demonstration study areas of Scutellaria baicalensis Georgi were selected,and multiple chemical weathering indexes,chemical loss fraction,mass migration coefficients and biological enrichment coefficient method were used to assess the ecological and geochemical suitability.The results show that for the element of Fe,Zn,Se,Cu,Co,Ni,Mo and Ge,the degree of weathering and soil maturation,were greater in the rhyolitic tuff area than in the Plagioclase gneiss area.In both research sites,the heavy metal level of samples in Scutellaria baicalensis Georgi did not exceed the standard limits.The plagioclase gneiss region’s surface soil environment was more alkaline,and the content of soil organic matter was lower,resulting in a higher bioenrichment intensity of Ge,Co,Cu,and Se elements in Scutellaria baicalensis Georgi than in the rhyolite-tuff area.The elements of Cd,Nb,Mo,Pb and As are considerably enriched in the soil of the plagioclase gneiss area but lost by leaching in the soil of the rhyolite tuff area,which is connected to the interplay of elemental abundance and human impact in the parent materials.This study provides a good example of how to assess growth suitability of Chinese medicinal materials in the Earth’s critical zone. 展开更多
关键词 earth’s critical zone Biogeochemistry characteristics Weathering mechanism Element migration Chinese medicinal materials Chengde
下载PDF
Possible Evolutionary Models in the Initially Hydride Earth Theory
8
作者 Kudryavtsev Pavel 《International Journal of Geosciences》 CAS 2023年第5期377-426,共50页
A modern view of the properties of chemical elements has confirmed the theory of the hot origin of the Earth. The next step in developing this theory was the hypothesis of the initial hydride Earth. In this work, we a... A modern view of the properties of chemical elements has confirmed the theory of the hot origin of the Earth. The next step in developing this theory was the hypothesis of the initial hydride Earth. In this work, we attempted to find additional evidence for this hypothesis and show additional effects that flow from it. The effect of the physical properties of atoms and ions on their behavior during the formation of the Earth was studied. The maximum contribution to the distribution of elements was made by those elements whose content in the original protoplanets of the disk was the maximum. Correlation dependence is obtained, which allows one to calculate the distribution of elements in the protoplanetary disk. It was shown that hydrogen was the main element in the proto substance located in the zone of the Earth’s formation. In this case, various chemical compounds formed, most represented by hydrogen compounds—hydrides. Since the pressure inside the Earth is 375 GPa, this factor forces the chemical compounds to adopt stoichiometry and structure that would not be available in atmospheric conditions. It is shown that many chemical elements at high pressure in a hydrogen medium form simple hydrides and super hydrides—polyhydrides with high hydrogen content. Pressure leads to a higher density of matter inside the planet. Given the possibility of forming polyhydrides, there is the possibility of binding the initially available hydrogen in an amount that can reach 49.3 mole%. Young Earth could contain about 10.7 mass% of hydrogen in hydrides, polyhydrides, and adsorbed form is almost twice higher than previous estimates. This fact additionally confirms the theory of the original hydride Earth. In hydrides, the occurrence of the phenomenon of superconductivity was discovered. Polyhydrides were shown as potential superconductors with a high critical temperature above 200 K. We, based on these data, hypothesized the presence of superconducting properties in the Earth’s core, which explains the presence of a magnetic field in the Earth, as well as the unevenness and instability of this field and the possibility of migration of the Earth’s poles. The fact that the Earth has a hydroid core causes its change in time due to the instability of hydrides. Arranged several possible models of the destruction of the Earth’s core. The calculations showed that both models give close results. These results give predictions that can be measured. The proposed models also made it possible to estimate the initial size of the Earth. Possible ways of further testing the hypothesis of the initial hydride Earth is shown. 展开更多
关键词 Theory of the Hot Origin of the earth Magnetic separation of Elements Atom Ionization Energy Hydrides Polyhydrides earth Expansion superconductivity of the earth’s Core
下载PDF
Remarks about External Forces Acting on Earth’s Rotation Axis
9
作者 Monica Zoe Ciobanu 《World Journal of Mechanics》 2023年第2期73-77,共5页
It is well known that a variation in the direction of Earth’s rotation axis is a real astronomical phenomenon, named nutation. It is interesting if a variation of this axis can take place only in intensity, in the si... It is well known that a variation in the direction of Earth’s rotation axis is a real astronomical phenomenon, named nutation. It is interesting if a variation of this axis can take place only in intensity, in the simplest theoretical case of only two rigid body dynamics. This paper presents two positions of the Moon during its monthly orbit, where a sudden variation of Earth’s rotation axis in intensity can take place. The duration of this phenomenon is limited in time, maybe an instant or a day, and then a vortex can appear. 展开更多
关键词 NUTATION Variation in Intensity of earth’s Rotation Axis Chandler’s Wobble
下载PDF
Topology Chemical Process Research on the Condensing and Growing Phase Multi Micro Oil Droplets Based on Hydrodynamics
10
作者 周毅 李旋旗 +1 位作者 张东翔 TAPACOB B B 《Journal of Beijing Institute of Technology》 EI CAS 2009年第1期84-88,共5页
The hydrodynamic research about the droplet condensing of the multi phase liquid state on the surface of the coal glass and water discusses the deepening process of convex shape curve and the formation of S shape, and... The hydrodynamic research about the droplet condensing of the multi phase liquid state on the surface of the coal glass and water discusses the deepening process of convex shape curve and the formation of S shape, and puts emphasis on describing the diagram formation method of the later. In the induction period the active diagram of the micro droplet is decided by pH value forming as convex shape diagram or S shape diagram. When pH value is above 4.0, the damage of convex shape diagram cannot be recovered, in that case produce S shape activity diagram. When pH value is equal to or above 12.0, the hard surface with alkali liquid state loses adhesion, so that the micro droplet condensing of the multi phase liquid state stops completely. The research result shows that the water cleaning conditions of getting rid of the oil micro droplets can be decided by the pH value. 展开更多
关键词 growing of micro oil droplet condensing of micro oil droplet topology chemical process convexshape diagram s shape diagram
下载PDF
Growing and Pruning Based Deep Neural Networks Modeling for Effective Parkinson’s Disease Diagnosis
11
作者 Kemal Akyol 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第2期619-632,共14页
Parkinson’s disease is a serious disease that causes death.Recently,a new dataset has been introduced on this disease.The aim of this study is to improve the predictive performance of the model designed for Parkinson... Parkinson’s disease is a serious disease that causes death.Recently,a new dataset has been introduced on this disease.The aim of this study is to improve the predictive performance of the model designed for Parkinson’s disease diagnosis.By and large,original DNN models were designed by using specific or random number of neurons and layers.This study analyzed the effects of parameters,i.e.,neuron number and activation function on the model performance based on growing and pruning approach.In other words,this study addressed the optimum hidden layer and neuron numbers and ideal activation and optimization functions in order to find out the best Deep Neural Networks model.In this context of this study,several models were designed and evaluated.The overall results revealed that the Deep Neural Networks were significantly successful with 99.34%accuracy value on test data.Also,it presents the highest prediction performance reported so far.Therefore,this study presents a model promising with respect to more accurate Parkinson’s disease diagnosis. 展开更多
关键词 Parkinson’s disease machine learning growing and pruning deep neural networks.
下载PDF
Earth: Review Article
12
作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期31-51,共21页
Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the ... Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the importance of protecting our world for future generations [1]. To provide the protection of our planet, we should explain Earth’s environmental challenges to the best of our knowledge in frames of contemporary Geophysics. This paper gives a short overview of the developed Hypersphere World-Universe Model (WUM) and pay particular attention to the principal role of Dark Matter (DM) in the Earth’s life. In this manuscript, we discuss different aspects of the Earth: a condition of Young Earth before the Beginning of life on It;Internal Structure;“The 660-km Boundary” that we named Geomagma;Random Variations of Earth’s Rotational Speed on a daily basis;Origin of Moon;Expanding Earth;Internal Heating;Faint Young Sun paradox;Geocorona and Planetary Coronas;High-Energy Atmospheric Physics. WUM proposed principally different ways to solve the problems of Internal Heating, Origin of the Moon, and Faint Young Sun paradox based on DM core of the Earth. The Model revealed the fact that the Sun Activity causes the Geomagma Activity and, as a consequence, Random Variations of Earth’s Rotational Speed by the varying Sun’s magnetic field. 展开更多
关键词 Internal structure 660-km Boundary Internal Heating Faint Young sun Paradox Origin of Moon Expanding earth Random Variations of earth’s Rotational speed
下载PDF
China's Energy Landscape Growing:Report
13
作者 Li Wenxin 《China Oil & Gas》 CAS 2017年第1期50-53,共4页
China’s slower economic growth and its economic transition and fuel mix will have a major impact on the global energy market in the next 20 years,according to the 2017 BP Energy Outlook released in Washington in earl... China’s slower economic growth and its economic transition and fuel mix will have a major impact on the global energy market in the next 20 years,according to the 2017 BP Energy Outlook released in Washington in early February of 2017.The report projects that China’s energy demand growth will slow down to 1.9 percent a year through the next 20 years to 2035,less than a third of China’s pace in the last 20 years of 6.3 percent a year.However,China will still consume more than a quarter 展开更多
关键词 China’s Energy Landscape growing:Report THAN DOWN MORE very Us
下载PDF
China's Electronic Publications Growing
14
《中国经贸画报》 1999年第5期95-95,共1页
China had 1,442 officially approvedelectronic publications by the end of 1998.The current number of electronic publishersin China is 64,and there are more than1,000 relatively big producers.In 1997,China produced 1025... China had 1,442 officially approvedelectronic publications by the end of 1998.The current number of electronic publishersin China is 64,and there are more than1,000 relatively big producers.In 1997,China produced 1025 sets 展开更多
关键词 THAN MORE China’s Electronic Publications growing
下载PDF
China's Exports Keeping Growing This Year
15
《China's Foreign Trade》 2001年第6期37-37,共1页
关键词 UsA China’s Exports Keeping growing This Year
下载PDF
BASF's Investment in China Growing Steadily
16
《China Oil & Gas》 CAS 2001年第2期60-62,共3页
关键词 BAsF’s Investment in China growing steadily In MDI
下载PDF
A Simple Mechanism for Generating a Geomagnetic Field
17
作者 Oleg Vladimirovich Styazhkin 《Open Journal of Applied Sciences》 2024年第9期2580-2591,共12页
On the basis of the ideal gas model, the polarization of charges in the mantle was obtained, a physical and mathematical model was constructed, and estimated calculations of the dipole mode of the Earth’s magnetic fi... On the basis of the ideal gas model, the polarization of charges in the mantle was obtained, a physical and mathematical model was constructed, and estimated calculations of the dipole mode of the Earth’s magnetic field were performed, taking into account the speed of its angular rotation, the parameters of density and temperature, the chemical composition, the ionization potential, the dielectric constant and the percentage of the main chemical compounds of the mantle substance. 展开更多
关键词 Physical Parameters of the earth’s Mantle Maxwell-Boltzmann statistics Phonon Gas Thermal Ionization Electron-Hole Polarization Electron-Hole Recombination earth’s Magnetic Field Dipole Mode of the Magnetic Field
下载PDF
China's growing role in IEC work
18
作者 Renzo Tani 《China Standardization》 2006年第6期2-,共1页
  Each year on 14 October, the members of the IEC, ISO and ITU celebrate World Standards Day, which is a means of paying tribute to the collaborative efforts of the thousands of experts worldwide who develop the vol...   Each year on 14 October, the members of the IEC, ISO and ITU celebrate World Standards Day, which is a means of paying tribute to the collaborative efforts of the thousands of experts worldwide who develop the voluntary technical agreements that are published as international standards.…… 展开更多
关键词 IEC China’s growing role in IEC work
下载PDF
Growing Investment in China's Education
19
作者 JJian Ping 《China's Foreign Trade》 1999年第4期44-44,共1页
关键词 growing Investment in China’s Education
下载PDF
China's Growing Demand For PVC
20
《China's Foreign Trade》 1999年第7期36-36,共1页
ChinawillneedmorepolyVinylchloride(PVC)in1999,ChinaLightindustryNewsreports.PVCisusedintheproductionofplasticsandplasticsheetingforagriculturaluse.IndusalanalystspredictariseinPVCdemandbecauseoftheincreaseduseoftheshe... ChinawillneedmorepolyVinylchloride(PVC)in1999,ChinaLightindustryNewsreports.PVCisusedintheproductionofplasticsandplasticsheetingforagriculturaluse.IndusalanalystspredictariseinPVCdemandbecauseoftheincreaseduseofthesheeting.TheexpansionofChina'slandco... 展开更多
关键词 China’s growing Demand For PVC
下载PDF
上一页 1 2 34 下一页 到第
使用帮助 返回顶部