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Global CO_(2) concentration change induced by“trigger-connectors”model,especially since about 24 Ma?A preliminary hypothesis
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作者 LI Leyi CHANG Hong 《地球环境学报》 CSCD 2024年第4期545-565,共21页
Background,aim,and scope The tectonic uplift of the Cenozoic Tibetan Plateau has produced a chain effect,which is an excellent location for Earth system science research,and its uplift process,mechanism and environmen... Background,aim,and scope The tectonic uplift of the Cenozoic Tibetan Plateau has produced a chain effect,which is an excellent location for Earth system science research,and its uplift process,mechanism and environmental effects are the hot spot and frontier of the current research.The“Tibetan Plateau uplift-weathering-CO_(2) concentration-global climate change”model was put forward by Raymo and Ruddiman to interpret the Late Cenozoic climate change.However,there are still some questions suspended,such as does the weathering of the Tibetan Plateau have the ability to control the global climate?How to explain the modern-like global CO_(2) concentration starting at about 24 Ma?Here,a short space was taken to present a brainstorm about the above questions on account of existing geological pieces of evidence.Materials and methods In this paper,we integrate the formation and evolution of the Yangtze River and Pearl River,the origin and development of the Asian inland aridification-monsoon system,the Cenozoic tectonic uplift process of the Tibetan Plateau,and the westerly winds to discuss and analyze the relationship between the Cenozoic CO_(2) concentration changes and the uplift of the Tibetan Plateau and why the CO_(2) concentration similar to the present was formed at about 24 Ma.Results Similar correspondence of the surface uplift history of Xizang,other global mountains,and the declining CO_(2) concentration could support the theory Tibetan Plateau weathering inf luences CO_(2) concentration.Starting from 24 Ma,the most important character was the uplift and erosion of Xizang and Himalaya,collaborating with Ocean Iron Fertilization(OIF)together as an entity to control the atmospheric CO_(2) concentration because the great Asian rivers,Asian monsoons,and westerlies connected Xizang and surrounded seas together through materials transportation.Discussion Paleogeographic reconstructions from 40 Ma to 20 Ma illustrate that the main topographic change occurred in the Andes,Cordillera orogenic belt,and Xizang.We comprise a comprehensive set of evidence from independent data,which correspond temporally with the tipping point(about 24 Ma)of the atmospheric CO_(2) and we noticed that modern-like Asia monsoon,inland aridity,Asian great rivers,and climate zone formed at about 24 Ma and also there are tectonic activities for the Andes and Rockies.We raised the possibility that the modern-like atmospheric CO_(2) concentration at about 24 Ma was caused by the above geological factors.Here the rivers,monsoon,and westerlies are termed as“connectors”.In addition,these Asian rivers originated from Xizang,the monsoon,and inner Asian aridification are strongly a function of the uplift and growth of Xizang,thus,Xizang here is named as“trigger”.The distinct character of“trigger-connectors”model is that this not only takes the monsoon,westerlies,and the global great rivers into consideration but also expands the range which inf luences atmospheric CO_(2) concentration,from local points to a vast area since about 24 Ma,such as from Tibetan Plateau to Asia,including surrounded seas,after about 24 Ma.However,because the opening of the Late Oligocene-Early Miocene Antarctic periphery straits is highly coincident with the onset of modern-like global atmospheric CO_(2) concentration,we are forced to consider that they also had a significant impact on the reduction of atmospheric CO_(2) concentrations at this time.Conclusions“Trigger-connectors”was put forward to explain the Cenozoic CO_(2) variation,especially modern-like global CO_(2) concentration since about 24 Ma.Recommendations and perspectives Here we use the“trigger-connectors”model to explain the formation of modern-like CO_(2) concentrations starting at about 24 Ma,but there are still some problems.The most important premise for the“trigger-connectors”model is the constructed Cenozoic CO_(2) concentration record is reliable,which is the foundation of our hypothesis.In the future,potential improvements should focus on topographic reconstructions of Xizang and the global mountains.Here we have concentrated on Xizang in the considered timeslices but still,pay less attention to other global orogenic belts.Collaborations with geologist experts in those regions could provide valuable feedback to evaluate their potential role of them in CO_(2) evolution.What is more,considerable progress may be achieved with the addition and consideration of more and new geological data. 展开更多
关键词 Tibetan Plateau CO_(2) concentration WEATHERING trigger-connectors
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Zn^(2+)和TiO_(2)合金化过程中不同成分占比对薄膜结构和光催化性能的影响
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作者 肖文悦 董小硕 +4 位作者 买买提热夏提·买买提 牛娜娜 李国栋 朱泽涛 毕杰昊 《物理学报》 SCIE EI CAS CSCD 北大核心 2024年第18期121-130,共10页
使用溶胶-凝胶法在单晶硅衬底上制备一批不同Zn^(2+)成分调节的TiO_(2)薄膜,观测Zn^(2+)和TiO_(2)合金化过程中光学和光催化性能的变化.X射线衍射光谱仪用于观测在合金化过程中薄膜的晶体结构变化并追踪ZnTiO_(3)化合物的形成.扫描电子... 使用溶胶-凝胶法在单晶硅衬底上制备一批不同Zn^(2+)成分调节的TiO_(2)薄膜,观测Zn^(2+)和TiO_(2)合金化过程中光学和光催化性能的变化.X射线衍射光谱仪用于观测在合金化过程中薄膜的晶体结构变化并追踪ZnTiO_(3)化合物的形成.扫描电子显微镜、原子力显微镜用于观测合金化过程中因TiO_(2)晶格对Zn^(2+)溶解度有限而导致薄膜表面出现大量孔洞的现象.X射线光电子能谱和光学带隙用于观测Zn^(2+)与TiO_(2)合金化过程中电子结构层面的变化.最后,通过降解亚甲基蓝(MB)溶液,表明少量Zn^(2+)掺杂完全溶解在TiO_(2)中,并破坏TiO_(2)结晶质量.在Zn^(2+)的成分占比继续提高至15%的过程中,XPS峰形拟合结果验证了TiO_(2)对Zn^(2+)的溶解度有限,导致薄膜出现大量孔洞结构,薄膜的活性比表面积得以提升,同时Zn^(2+)可以有效地捕获光生e^(-)/h^(+).为了继续观察Zn^(2+)浓度对TiO_(2)的影响,将Zn^(2+)的浓度提升至40%,观察Zn^(2+)与TiO_(2)合金化过程中的现象.表明化合物ZnTiO_(3)的出现可以充当e^(-)/h^(+)的复合中心以及TiO_(2).占比的大幅下降导致合金化之后的薄膜光催化效率逐渐下降. 展开更多
关键词 TiO_(2) Zn^(2+) 光催化 带隙 表面
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Plasma-assisted aerogel interface engineering enables uniform Zn^(2+)flux and fast desolvation kinetics toward zinc metal batteries
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作者 Zijian Xu Zhenhai Shi +7 位作者 Zhan Chang Fan Feng Zhuanyi Liu Dongkun Chu Jianguo Ren Zi-Feng Ma Suli Chen Tianxi Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期29-38,I0002,共11页
The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)... The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)interface engineering was proposed as efficient ion transport modulator that can simultaneously regulate uniform Zn^(2+)flux and desolvation behavior during battery operation.The PAG with ordered mesopores acted as an ion sieve to homogenize Zn deposition and accelerate Zn^(2+)flux,which is favorable for corrosion resistance and dendrite suppression.Importantly,the plasma-assisted aerogel with abundant hydrophilic groups can facilitate the desolvation kinetics of Zn^(2+)due to the multiple hydrogen-bonding interaction with the activated water molecules,thus accelerating the Zn^(2+)migration kinetics.Consequently,the Zn/Zn cell assembled with PAG-modified separator demonstrates stable plating and stripping behavior(over 1400 h at 1 mA cm^(-2))and high Coulombic efficiency(99.8%at1 mA cm^(-2)after 1100 cycles),and the Zn‖MnO_(2)full cell shows excellent long-term cycling stability and maintains a high capacity of 154.9 mA h g^(-1)after 1000 cycles at 1 A g^(-1).This study provides a feasible approach for the large-scale fabrication of aerogel functionalized separators to realize ultra-stable Zn metal batteries. 展开更多
关键词 Zn metal batteries Aerogel interface Plasma Zn^(2+)migration kinetics Dendrite growth
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基于不同荧光发色基团的Zn^(2+)荧光探针的研究进展
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作者 毛申 彭云佩 +4 位作者 刘聪聪 刘瑶 王琦 梁笑 王新潮 《理化检验(化学分册)》 CAS CSCD 北大核心 2024年第4期433-439,共7页
荧光光谱法具有灵敏度高、选择性好、检出限低以及操作简单等特点,设计合成特异性识别和检测Zn^(2+)的荧光探针对化学、生物学、临床医学等研究具有十分重要的意义。以近年来文献报道的Zn^(2+)荧光探针为例,综述了基于不同荧光发色基团... 荧光光谱法具有灵敏度高、选择性好、检出限低以及操作简单等特点,设计合成特异性识别和检测Zn^(2+)的荧光探针对化学、生物学、临床医学等研究具有十分重要的意义。以近年来文献报道的Zn^(2+)荧光探针为例,综述了基于不同荧光发色基团的Zn^(2+)荧光探针的作用机制、应用与发展前景,为Zn^(2+)荧光探针研究提供了参考(引用文献44篇)。 展开更多
关键词 Zn^(2+) 荧光探针 荧光发色基团 研究进展
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Uniform deposition of ultra-thin TiO_(2) film on mica substrate by atmospheric pressure chemical vapor deposition: Effect of precursor concentration 被引量:2
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作者 Ming Liu Ying Li +4 位作者 Rui Wang Guoqiang Shao Pengpeng Lv Jun Li Qingshan Zhu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第8期99-107,共9页
The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pre... The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pressure chemical vapor deposition(APCVD) was investigated. The precursor concentration significantly affected the deposition and morphology of TiO_(2) grains assembling the film. The deposition time for fully covering the surface of mica decreased from 120 to 10 s as the TiCl_(4) concentration increased from 0.38%to 2.44%. The grain size increased with the TiCl_(4) concentration. The AFM and TEM analysis demonstrated that the aggregation of TiO_(2) clusters at the initial stage finally result to the agglomeration of fine TiO_(2) grains at high TiCl_(4) concentrations. Following the results, it was suggested that the nucleation density and size was easy to be adjusted when the TiCl_(4) concentration is below 0.90%. 展开更多
关键词 Chemical vapor deposition TiO_(2)thin film Nucleation reaction Precursor concentration Pearlescent pigment
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Spatial Inhomogeneity of Atmospheric CO_(2) Concentration and Its Uncertainty in CMIP6 Earth System Models
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作者 Chengjun XIE Tongwen WU +7 位作者 Jie ZHANG Kalli FURTADO Yumeng ZHOU Yanwu ZHANG Fanghua WU Weihua JIE He ZHAO Mengzhe ZHENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第11期2108-2126,共19页
This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospher... This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospheric carbon dioxide(CO_(2))concentration.The multi-model ensemble mean(MME)can reasonably simulate the increasing trend of CO_(2) concentration from 1850 to 2014,compared with the observation data from the Scripps CO_(2) Program and CMIP6 prescribed data,and improves upon the CMIP5 MME CO_(2) concentration(which is overestimated after 1950).The growth rate of CO_(2) concentration in the northern hemisphere(NH)is higher than that in the southern hemisphere(SH),with the highest growth rate in the mid-latitudes of the NH.The MME can also reasonably simulate the seasonal amplitude of CO_(2) concentration,which is larger in the NH than in the SH and grows in amplitude after the 1950s(especially in the NH).Although the results of the MME are reasonable,there is a large spread among ESMs,and the difference between the ESMs increases with time.The MME results show that regions with relatively large CO_(2) concentrations(such as northern Russia,eastern China,Southeast Asia,the eastern United States,northern South America,and southern Africa)have greater seasonal variability and also exhibit a larger inter-model spread.Compared with CMIP5,the CMIP6 MME simulates an average spatial distribution of CO_(2) concentration that is much closer to the site observations,but the CMIP6-inter-model spread is larger.The inter-model differences of the annual means and seasonal cycles of atmospheric CO_(2) concentration are both attributed to the differences in natural sources and sinks of CO_(2) between the simulations. 展开更多
关键词 CMIP6 Earth System Models the simulation of atmospheric CO_(2)concentration spatial inhomogeneity UNCERTAINTY
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Influence of high concentration Zn^(2+) on floatability of sphalerite in acidic system 被引量:2
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作者 Ting-sheng QIU Guo-dong LI +2 位作者 Xiao-bo LI Hua-shan YAN Chen LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第7期2128-2138,共11页
The influence of high concentration Zn^(2+) on the floatability of sphalerite in an acidic system was investigated via flotation experiments,zeta potential measurements,contact angle measurements,and X-ray photoelectr... The influence of high concentration Zn^(2+) on the floatability of sphalerite in an acidic system was investigated via flotation experiments,zeta potential measurements,contact angle measurements,and X-ray photoelectron spectroscopy.The results indicated that Zn^(2+) was adsorbed on the sphalerite surface and a Zn-hydroxyl complex was formed at a pH of 4 and a Zn^(2+) concentration of 4×10^(-2) mol/L.The zeta potential increased and the contact angle decreased from 84.80°to 36.48°,strongly inhibiting the floatability of sphalerite.When S^(2−) or Cu^(2+) activator was used alone,sphalerite was not activated after Zn^(2+) was adsorbed,and its contact angle did not change significantly.However,by using a combination of S^(2−) and Cu^(2+) activators,its floatability was realized after Zn^(2+) adsorption.This result was attributed to the removal of the Zn-hydroxyl complex on the surface of sphalerite by S^(2-).After this removal,Cu^(2+) was adsorbed on the sphalerite surface to form a Cu_(2)S·S^(0) hydrophobic film. 展开更多
关键词 acidic system high concentration Zn^(2+) SPHALERITE FLOTATION
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Effects of Concentration and Freeze-Thaw on the First Hydration Shell Structure of Zn^(2+) Ions 被引量:3
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作者 王文华 赵林 +3 位作者 阎波 谭欣 齐云 贺博 《Transactions of Tianjin University》 EI CAS 2011年第5期381-385,共5页
To investigate the effects of salt concentration and freeze-thaw (FT) on the first hydration shell of Zn2+ ions in Zn(NO_3)_2 aqueous solutions, extended X-ray absorption fine structure (EXAFS) spectroscopy was used t... To investigate the effects of salt concentration and freeze-thaw (FT) on the first hydration shell of Zn2+ ions in Zn(NO_3)_2 aqueous solutions, extended X-ray absorption fine structure (EXAFS) spectroscopy was used to examine Zn K-edge EXAFS spectra of Zn(NO_3)_2 aqueous solutions with various concentrations before and after FT treatment. The influences of salt concentration and freeze-thaw on the structural parameters of the first hydration shell of Zn2+ ions, including hydration number, Zn-O distance and thermal disorder, were analyzed. The results show that Zn2+ ions have 3.2―6.8 nearest oxygen neighbors with the Zn-O distance being 0.202―0.207 nm. In highly concen-trated solutions, Zn2+ ions are hydrated with four water molecules in a tetrahedral form. The dilution of Zn(NO_3)_2 aqueous solutions increases the number of water molecules in the first hydration shell of Zn2+ ions to six with their octahedral arrangement. Both the hydration number in the first hydration shell of Zn2+ ions and the degree of thermal disorder increase when the FT treatment is operated in Zn(NO_3)_2 aqueous solutions. 展开更多
关键词 EXAFS Zn (NO3)2 aqueous solution first hydration shell hydration number concentration FREEZE-THAW
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THE .EFFECT OF TRIPTERYGIUM WILFORDH (TWH) SYRUP ON THE CONCENTRATIONS oF Zn^2+ AND Cu^2+ IN MOUSE TESTIS TISSUES
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作者 WULi JIATai-He HAOXiao-Dong LIXiang-Fu WANGXiao-Xu 《Journal of Reproduction and Contraception》 CAS 1989年第1期143-143,共1页
关键词 雷公藤 ZN^2+ CU^2+ 睾丸 生殖能力
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Effects of Controlled Atmospheres with High_O_2 or High_CO_2 Concentrations on Postharvest Physiology and Storability of "Napoleon" Sweet Cherry 被引量:27
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作者 姜爱丽 田世平 徐勇 《Acta Botanica Sinica》 CSCD 2002年第8期925-930,共6页
Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) +... Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively. 展开更多
关键词 sweet cherry physiological properties quality STORABILITY high O(2) concentrations high CO(2) concentrations
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STRUCTURAL RESPONSE OF SOYBEAN LEAF TO ELEVATED CO_2 CONCENTRATION 被引量:26
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作者 林金星 胡玉熹 《Acta Botanica Sinica》 CSCD 1996年第1期31-34,共4页
The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dra... The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dramatic change,while stomatal density decreased with increasing CO 2 concentration.Under SEM,no epicuticular wax was observed on both abaxial and adaxial sides of the control group as well as on adaxial side of the treatment group.However,leaf surface of abaxial side was noticed to be densely covered with microasterisk epicuticular wax when they were exposed to CO 2 enriched environment.The epicuticular wax deposition was present in equal abundance on both stomatal and nonstomatal areas.Furthermore,leaf thickness increased significantly due largely to the origin of an extra layer of palisade in the treatment group.The results confirmed that CO 2 enrichment might enhance cell division and induce greater quantity of epicuticular wax. 展开更多
关键词 SOYBEAN Foliar structure CO 2 concentration
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Effects of Ca^(2+)concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii 被引量:6
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作者 方升佐 候常英 洑香香 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第1期46-50,共5页
The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii wer... The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii were studied under controlled conditions. The types ofHoagland nutrient solution with three Ca^(2+) concentrations levels (200, 400 and 600 μg·g^(-1))and a control (without Ca^(2+)) were designed to culture Pteroceltis tatarinowii. After 6 months,contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and barkwere analyzed. The results indicated that Ca accumulations content in the root, leaf and bark hadpositively relation with Ca^(2+) concentrations (200, 400, 600 μg · g^(-1)), and the order of theCa content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g^(-1) Ca^(2+) concentrations was 5.5 times as high as that of the control, and about 1.4 times ashigh as that of the root treated in 200 and 400 μg/g Ca^(2+) concentrations respectively. On thecontrary, K and Mg contents in the root, leaf and bark were negatively related to Ca^(2+)concentrations, especially in the bark, and their accumulation trend followed the order ofleaf>root>bark. K content in the bark treated with 600 μg ·g^(-1) Ca^(2+) concentrations was 39.3%of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 μg ·g^(-1)and 400 μg ·g^(-1) Ca^(2+) concentrations respectively; Mg content in the bark treated with 600μg ·g^(-1) Ca^(2+) concentrations was 23.4% of that of the control, and was 27.1% and 35.4% ofthat of the bark treated with 200 and 400 μg·g^(-1) Ca^(2+) concentrations respectively. Comparedwith the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca^(2+)concentrations and their contents were in the order: root>leaf>bark. Based on the results of thisstudy, the experiment has been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil. 展开更多
关键词 pteroceltis tatarinowii hoagland nutrient solution Ca^(2+) concentrations mineral element COMPONENT
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Zn^(2+)/Zn和Fe^(3+)/Fe^(2+)的电化学行为及其在液流电池中的应用
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作者 彭海泉 赵丽娜 胡显龙 《中国资源综合利用》 2023年第7期1-3,共3页
锌铁液流电池采用成本低廉的锌、铁元素作为活性物质,有望成为下一代高性价比储能电池。本文利用循环伏安法测试锌、铁离子在碳毡电极表面的电化学活性,计算Zn^(2+)/Zn与Fe^(3+)/Fe^(2+)的扩散系数与反应速率常数。结果表明,锌离子与铁... 锌铁液流电池采用成本低廉的锌、铁元素作为活性物质,有望成为下一代高性价比储能电池。本文利用循环伏安法测试锌、铁离子在碳毡电极表面的电化学活性,计算Zn^(2+)/Zn与Fe^(3+)/Fe^(2+)的扩散系数与反应速率常数。结果表明,锌离子与铁离子在多孔碳毡上具有良好的电化学性能,可以作为锌铁液流电池的活性物质。充放电测试结果表明,锌铁液流电池的充放电性能良好,它具有较高的电流效率、电压效率和能量效率。 展开更多
关键词 Zn^(2+)/Zn Fe^(3+)/Fe^(2+) 液流电池 电化学行为 充放电性能
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Effects of Doubled_CO_2 Concentration on Ultrastructure, Supramolecular Architecture and Spectral Characteristics of Chloroplasts from Wheat 被引量:1
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作者 左宝玉 张泉 +2 位作者 姜桂珍 白克智 匡廷云 《Acta Botanica Sinica》 CSCD 2002年第8期908-912,共5页
Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architect... Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat. 展开更多
关键词 chloroplast wheat ( Triticum aestivum ) doubled_CO 2 concentration ultrastructure and supramolecular architecture absorption spectra low temperature (77 K) fluorescence emission spectra
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RELATIONSHIPS OF STARCH CONCENTRATION WITH SPECIFIC LEAF WEIGHT AND MINERAL CONCENTRATIONS IN POTATO LEAVES UNDER VARIED CO_2 AND TEMPERATURE 被引量:2
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作者 曹卫星 Theodore W.Tibbitts 《Acta Botanica Sinica》 CSCD 1997年第12期1118-1125,共8页
Foliar concentrations of starch and major nutrients N, P, K, Ca, and Mg along with specific leaf weight (SLW) were determined in the potato (Solanun tuberosum L.) cvs "Denali", "Norland "'and &... Foliar concentrations of starch and major nutrients N, P, K, Ca, and Mg along with specific leaf weight (SLW) were determined in the potato (Solanun tuberosum L.) cvs "Denali", "Norland "'and "Russet Burbank" grown for 35 days under the CO2 concentrations of 500, 1 000, 1 500 and 2 000 mol mol-1 at both 16 and 20℃ air temperature. The starch concentration, pooled from the three cultivars, increased with increasing CO2 concentration at both 16 and 20℃,, and was consistently higher at 16℃ than at 20℃. The SLW (g m-2) was positively related to the foliar starch concentration on the basis of leaf area or dry weight. The concentrations of N, P, Ca, and Mg in leaves were negatively related to starch concentration under 14% starch on a dry weight basis. Above 14%, there was no significant relationship between nutrient and starch concentrations . The similar patterns were seen when the SLW and nutrient concentrations were expressed on a starch-free basis. In contrast, the leaf concentration of K was not closely related to the starch concentration. The results indicated that the changes in SLW and concentrations of N, P, Ca, and Mg in potato leaves only partially resulted from the changed starch concentration. 展开更多
关键词 CO_2 concentration Temperature Specific leaf weight Starch concentration Mineral concentration POTATOES
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Prediction of SO_2 Concentration in Urban Atmosphere Based on B-P Neural Network 被引量:1
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作者 姚建 王丽梅 袁野 《Meteorological and Environmental Research》 CAS 2010年第11期9-11,14,共4页
Base on the principle and method of B-P neural network,the prediction model of SO2 concentration in urban atmosphere was established by using the statistical data of a city in southwest China from 1991 to 2009,so as t... Base on the principle and method of B-P neural network,the prediction model of SO2 concentration in urban atmosphere was established by using the statistical data of a city in southwest China from 1991 to 2009,so as to forecast atmospheric SO2 concentration in a city of southwest China.The results showed that B-P neural network applied in the prediction of SO2 concentration in urban atmosphere was reasonable and efficient with high accuracy and wide adaptability,so it was worthy to be popularized. 展开更多
关键词 B-P neural network SO2 concentration in urban atmospheric Prediction model China
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连续识别Zn^(2+)和草甘膦荧光探针的合成与应用 被引量:2
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作者 喻艳超 陈心仪 +3 位作者 巴新宇 李艳萍 刘洋 曾运波 《精细化工》 EI CAS CSCD 北大核心 2023年第1期56-62,共7页
以2-巯基苯并噻唑为原料,设计合成了一种结构简单的苯并噻唑类荧光探针2-[2-(苯并噻吩-2-基亚甲基)肼基]苯并噻唑(简称NSS),并通过FTIR、HRMS、^(1)HNMR、^(13)CNMR对其结构进行了表征。荧光光谱表明,在二甲基亚砜中,探针NSS实现了Zn^(... 以2-巯基苯并噻唑为原料,设计合成了一种结构简单的苯并噻唑类荧光探针2-[2-(苯并噻吩-2-基亚甲基)肼基]苯并噻唑(简称NSS),并通过FTIR、HRMS、^(1)HNMR、^(13)CNMR对其结构进行了表征。荧光光谱表明,在二甲基亚砜中,探针NSS实现了Zn^(2+)的“关-开”型检测,具有响应时间短(30 s)、特异性强、抗干扰性强等优点。探针NSS荧光强度与Zn^(2+)浓度(0~11μmol/L)呈现良好的线性关系,检出限达19.1 nmol/L,并与Zn^(2+)形成物质的量比为1∶1的络合物。同时,络合物NSS-Zn^(2+)对草甘膦呈现特异性的荧光猝灭响应,猝灭率达99.4%,检出限16.0 nmol/L(2.71 ng/mL),且不受其他有机磷农药的干扰。 展开更多
关键词 苯并噻唑 荧光探针 Zn^(2+) 草甘膦 连续识别 功能材料
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基于改进INFO-Bi-LSTM模型的SO_(2)排放质量浓度预测 被引量:1
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作者 王琦 柴宇唤 +2 位作者 王鹏程 刘百川 刘祥 《动力工程学报》 CAS CSCD 北大核心 2024年第4期641-649,共9页
针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进IN... 针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进INFO-Bi-LSTM模型)。采用Circle混沌映射和反向学习产生高质量初始化种群,引入自适应t分布提升INFO算法跳出局部最优解和全局搜索的能力。选取改进INFO-Bi-LSTM模型和多种预测模型对炉内外联合脱硫过程中4种典型工况下的SO_(2)排放质量浓度进行预测,将预测结果进行验证对比。结果表明:改进INFO算法的寻优能力得到提升,并且改进INFO-Bi-LSTM模型精度更高,更加适用于SO_(2)排放质量浓度的预测,可为变工况下的脱硫控制提供控制理论支撑。 展开更多
关键词 炉内外联合脱硫 烟气SO_(2)质量浓度 INFO算法 Bi-LSTM神经网络 Circle混沌映射 自适应t分布
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换热器T2紫铜管在水线部位的腐蚀机理研究
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作者 李超 王长罡 董俊华 《装备环境工程》 CAS 2024年第5期103-108,共6页
目的基于对换热器中T2紫铜管因受残留水作用而出现泄漏降压现象的研究,分析换热器T2紫铜管在水线部位的腐蚀机理。方法通过T2紫铜管的润湿试验,对腐蚀样品进行宏观和微观形貌观察,对点蚀坑部位的腐蚀产物进行EDS和XPS等表征手段分析,探... 目的基于对换热器中T2紫铜管因受残留水作用而出现泄漏降压现象的研究,分析换热器T2紫铜管在水线部位的腐蚀机理。方法通过T2紫铜管的润湿试验,对腐蚀样品进行宏观和微观形貌观察,对点蚀坑部位的腐蚀产物进行EDS和XPS等表征手段分析,探究腐蚀产物的成分和结构,从而推导出反应机理。结果铜管水线上部位和下部位都以均匀腐蚀为主,但是颜色有所差异。水线部位以点蚀为主,肉眼即可见排成直线的斑点状腐蚀坑,腐蚀产物的颜色主要为黑色和绿色。根据表征分析结果可知,腐蚀体系中含有HCO_(3)^(-)和SO_(4)^(2-)。腐蚀产物的组成有,内层Cu_(2)O,外层CuO,水线部位和水线以下部位铜管表面还有一层CuCO_(3)Cu(OH)_(2)膜。结论根据腐蚀产物的元素分析可知,在HCO_(3)^(-)和SO_(4)^(2-)共同存在的环境中,铜具有很高的点蚀敏感性,T2紫铜管很容易发生局部腐蚀,加之氧浓差电池的作用,水线部位铜管发生严重的点蚀以致穿孔失效。 展开更多
关键词 T2紫铜管 水线 点蚀 HCO_(3)^(-)和SO_(4)^(2-) 局部腐蚀 氧浓差电池
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Effects of Ca2+concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii 被引量:4
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作者 方升佐 候常英 洑香香 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第1期46-50,94,共页
The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were... The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were studied under controlled condi-tions. The types of Hoagland nutrient solution with three Ca2+ concentrations levels (200, 400 and 600 靏g-1) and a control (without Ca2+) were designed to culture Pteroceltis tatarinowii. After 6 months, contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and bark were analyzed. The results indicated that Ca accumulations content in the root, leaf and bark had positively relation with Ca2+ concentrations (200, 400, 600 靏g-1), and the order of the Ca content in the three components was root】leaf】bark. Ca content in the root treated with 600 靏g-1 Ca2+ concentrations was 5.5 times as high as that of the control, and about 1.4 times as high as that of the root treated in 200 and 400 靏/g Ca2+ concentrations respectively. On the contrary, K and Mg contents in the root, leaf and bark were negatively related to Ca2+ concentrations, especially in the bark, and their accumulation trend followed the order of leaf】root】bark. K content in the bark treated with 600 靏g-1 Ca2+ con-centrations was 39.3% of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 靏g-1 and 400靏g-1 Ca2+ concentrations respectively; Mg content in the bark treated with 600 靏g-1 Ca2+ concentrations was 23.4% of that of the control, and was 27.1% and 35.4% of that of the bark treated with 200 and 400 靏g-1 Ca2+ concentrations respectively. Com-pared with the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca2+ concentrations and their contents were in the order: root】leaf】bark. Based on the results of this study, the experiment has been useful for providing academic bases in improving the bark quality of Pteroceltis tatarinowii on non-limestone soil. 展开更多
关键词 Pteroceltis tatarinowii Hoagland nutrient solution Ca2+ concentrations Mineral element COMPONENT
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