检索结果-南通市图书馆

Regulating the electronic structure of Ir single atoms by ZrO_(2)nanoparticles for enhanced catalytic oxidation of formaldehyde at room temperature

引用

Chinese Chemical Letters 2024年第7期35卷 200-205页

作者： Shiqi Peng Yongfang Rao Tan Li Yufei Zhang Jun-ji Cao Shuncheng Lee Yu Huang key laboratory of Aerosol Chemistry&Physics State Key Laboratory of Loess and Quaternary Geology(SKLLQG)Institute of Earth EnvironmentChinese Academy of Sciences(CAS)Xi’an 710061China School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Environmental Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China School of Environment and Energy South China University of TechnologyGuangzhou 51006China School of Environmental and Municipal Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100190China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong KongChina CAS Center for Excellence in quaternary Science and Global Change Xi’an 710061China

Developing low-loading single-atom catalysts with superior catalytic activity and selectivity in formaldehyde(HCHO)oxidation at room temperature remains ***,ZrO_(2)nanoparticles coupled low-loading Ir single atoms in N-doped carbon(Ir_(1)-N-C/ZrO_(2))was *** optimal Ir_(1)-N-C/ZrO_(2)with 0.25 wt%Ir loading delivers the high HCHO removal and conversion efficiency(>95%)at 20℃,which is higher than that over Ir_(1)-N-C with the same Ir *** specific rate can reach 1285.6 mmol gIr^(-1)h^(-1),surpassing the Ir based catalysts reported to *** functional theory calculation results and electron spin resonance spectra indicate that the introduction of Zr O_(2)nanoparticles modulate the electronic structure of the Ir single atoms,promoting O_(2)activation to·O_(2)^(–).Moreover,the Ir-C-Zr channel is favorable for the dissociation of·O_(2)^(–)to active oxygen atom(*O),and further accelerates the transformation of HCHO and intermediates(dioxymethylene and formates)to CO_(2)and H_(2)*** work provides a facile strategy to design low-loading single-atom catalysts with high catalytic activity toward HCHO oxidation.

关键词： ZrO_(2)nanoparticles Ir single atoms Electronic structure Formaldehyde Catalytic oxidation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Carbon isotopic composition of modern soil and paleosol as a response to vegetation change on the Chinese loess Plateau

引用

Science China Earth Sciences 2005年第1期48卷 93-99页

作者： LIU Weiguo NING Youfeng AN Zhisheng WU Zhenghai LU Huayu CAO Yunning state key laboratory of loess and {4. geology IEE Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology IEE Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology IEE Chinese Academy of Sciences Xi'an 710075 China Northwest Sci-Tech University of Agriculture and Forest Yangling 710000 China State Key Laboratory of Loess and Quaternary Geology IEE Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology IEE Chinese Academy of Sciences Xi'an 710075 China

The relationship between the carbon isotopic composition of paleosols and paleovegetation on the loess Plateau is still unclear. One of the main reasons is that we are short of knowledge about the characteristics of the carbon isotopic composition of modern soil in this area. A preliminary investigation of the carbon isotopic compositions of the modern soil and the loess/paleosol sequence on the loess Plateau shows that the carbon isotopic composition of modern soil is consistent with the distribution of modern plants on the loess Plateau, where the ecosystem is dominated by a mixture of C4.and C3 plants. Comparing theδ13C values of modern soil and loess-paleosol sequences from the Xunyi profile, we conclude that C3 plants dominated the landscape during loess sediment stages, while C4.plants expanded during paleosol stages.

关键词： modern soil, paleosol, carbon isotope, paleovegetation, loess Plateau.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research and development on mechanism of removal of indoor volatile organic compounds by plants

引用

地球环境学报 2024年第4期15卷 583-595页

作者： LI Fangwei CUI Long CHENG Yan XUE Yonggang HUANG Yu School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China key laboratory of Aerosol Chemistry and Physics State Key Laboratory of Loess and Quaternary GeologyInstitute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China CAS Center for Excellence in quaternary Science and Global Change Xi’an 710061China

Background,aim,and scope Owing to the rapid development of modernisation and urbanisation,living standards have gradually ***,the widespread use of high-energy-consuming indoor appliances and furniture has made indoor environments a primary environmental problem affecting human *** building syndrome(SBS)and building-related illness(BRI)have occurred,and indoor air conditions have been extensively *** indoor pollutants include CO,CO_(2),volatile organic compounds(VOCs)(such as the formaldehyde and benzene series),NOx(NO and NO_(2)),and polycyclic aromatic hydrocarbons(PAHs).VOCs have replaced SO_(2)as the“The Fourteenth Five-Year Plan”urban air quality assessment new *** VOCs can cause diseases such as cataract,asthma,and lung *** protect human health,researchers have proposed several indoor air purification technologies,including adsorption,filtration,electrostatic dust removal,ozonation,and plant ***,each technology has drawbacks,such as high operating costs,high energy consumption,and the generation of secondary waste or toxic *** degradation of VOCs as a bioremediation technology has the characteristics of low cost,high efficiency,and sustainability,thereby becoming a potential green solution for improving indoor air *** study introduces the research status and mechanism of plant removal of indoor VOCs and provides an experimental basis and scientific guidance for analysing the mechanism of plant degradation of *** and methods This study reviews studies on the harm caused by indoor pollutants to human health and related sources,mainly investigating the degradation of indoor formaldehyde,BTEX(benzene,toluene,ethylbenzene,and xylene)plant mechanisms,and research *** Plants can remove VOCs via stomatal and non-stomatal adsorption,interfoliar microbial,rhizosphere microbial,and growth ***,toluene,and xylene(BTX)are adsorbed by pores,hydrox

关键词： plants VOCs removal mechanism indoor air purification microorganism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Changes in grain-size and sedimentation rate of the Neogene Red Clay deposits along the Chinese loess Plateau and implications for the palaeowind system

引用

Science China Earth Sciences 2005年第9期48卷 1452-1462页

作者： WEN Lingjuan LU Huayu QIANG Xiaoke state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China

The wind system responsible for transporting dust onto the Chinese loess Plateau during the late Miocene and Pliocene is still unknown and recent investigations highlight many controversies. This report aims to investigate spatiotemporal changes in grain-size and sedi- mentation rate of the Neogene Red Clay deposits in north China and to explore palaeoclimatic changes during the late Miocene and Pliocene, in particular the palaeowind system that trans- ported dust. Samples were collected from eight Red Clay sections on the loess Plateau. Meas- urement and analysis show that there is a clear southward decrease in the mean grain-size index and in the coarse particle fraction (>20 μm). At Jiaxian site on the northern loess Plateau, the average mean grain-size is around 20 μm, while at Lantian site in the south, the mean is around 9 μm. The coarse particle fraction >20 μm makes up 24.4. and 5.6%, at the two sites respec- tively. This distinct diversity of grain-size in the aeolian Red Clay deposit between the north and south indicate that the palaeodust was transported mainly by northerly low-level winds. The grain-size variations in the Red Clay deposits can also be divided into three stages (the lower, the middle and the upper interval): grain-size of the lower stage is significantly coarser than that of the middle stage, but finer than that of the upper stage. As a consequence, the intensity of pa- laeowind and desiccation of the dust source region during the late Miocene and Pliocene can be divided into three stages: 6.2―5.4.Ma, 5.4.3.5 Ma and 3.5―2.6 Ma. Strength of the palaeowind during the middle stage (5.4.3.5 Ma) is weaker than that of the previous and subsequent stages and the intensity of palaeowind during the latest stage (3.5―2.6 Ma) is stronger than that of the early time (6.2―5.4.Ma). Variations in the sedimentation rate of the Red Clay deposit can also be divided into three stages: the earlier, the middle and the later interval. The sedimentation rate of

关键词： Red Clay deposit, grain size, atmospheric circulation, the late Miocene and the Pliocene, Chinese loess Plateau.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Global CO_(2)concentration change induced by“trigger-connectors”model,especially since about 24.Ma?A preliminary hypothesis

引用

地球环境学报 2024年第4期15卷 545-565页

作者： LI Leyi CHANG Hong state key laboratory of loess and {4. geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China Xi’an Institute for Innovative Earth Environment Research Xi’an 710061China Yunnan key laboratory of Earth System Science Yunnan UniversityKunming 650500China CAS Center for Excellence in quaternary Science and Global Change Xi’an 710061China

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 ***“Tibetan Plateau uplift-weathering-CO_(2)concentration-global climate change”model was put forward by Raymo and Ruddiman to interpret the Late Cenozoic climate ***,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 *** 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.*** 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)*** 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 *** Paleogeographic reconstructions from 4. Ma to 20 Ma illustrate that the main topographic change occurred in the Andes,Cord

关键词： Tibetan Plateau CO_(2)concentration weathering trigger-connectors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ecophysiological responses of winter wheat seedling to aerosol wet deposition of Xi'an area, China

引用

Journal of Environmental Sciences 2010年第11期22卷 1786-1791页

作者： Yiping Chen state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China.

Aerosol leads to 30% reduction in solar radiation reaching the earth’s surface, and a similar reduction in crops yield for both wheat and rice. To determine the effect of aerosol wet deposition on crops, aerosol samples were collected in September, 2006 at Xi’an urban suburb （34.4. N, 109 4. E）, and wheat seedlings were treated with aerosol of different concentrations in laboratory conditions. Changes in physiological and biochemical parameters of wheat seedlings were measured. In comparison with the control, the activities of superoxide dismudase （SOD） and catalase （CAT） and the concentration malondialdehyde （MDA） and oxidized glutathione （GSSG） of wheat seedlings increased progressively with increasing concentrations of added aerosol, while the opposite trend was seen for the activities of nitric oxide synthase （NOS）, the concentrations of glutathione （GSH） and nitric oxide （NO）, and the ratio of GSH/GSSG. When the seedlings were treated with the aerosol of 1 and 2 mg/L, the coleoptile elongation, shoot elongation and biomass accumulation were increased, the effect at treatment of 2 mg/L was most significant. However, aerosol treatments with rates of 3 and 4.mg/L resulted in a decrease in coleoptile elongation, shoot elongation and biomass accumulation in seedlings, and significant effect was for the treatment of 4.mg/L. Hence, lower concentrations of aerosol wet deposition were in favor of crops growth, but its higher concentrations could result in deleterious effects for crops and decreased crops growth.

关键词： aerosol deposition environment pollution air pollution ecotoxicological testing aerosol risk assessment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Distribution of branched glycerol dialkyl glycerol tetraethers in soils on the Northeastern Qinghai-Tibetan Plateau and possible production by nitrite-reducing bacteria

引用

Science China Earth Sciences 2016年第9期59卷 1834-1846页

作者： SUN ChiJun ZHANG ChuanLun LI Fu Yan WANG HuanYe LIU WeiGuo state key laboratory of Marine geology Tongji University Department of Earth and Planetary Sciences Northwestern University state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences

Branched glycerol dialkyl glycerol tetraethers （bGDGTs） are ubiquitous and abundant in soils, but their sources remain elusive. Recent studies demonstrate that the distributions of bGDGTs are sensitive to various environmental factors. In an effort to understand how and to what extent soil moisture （expressed as soil water content （SWC） or mean annual precipita- tion （MAP）, pH and temperature may impact the distribution of bGDGTs, and to shed more light on the biological sources of bGDGTs in cold and arid regions, we investigated the distribution of bGDGTs as well as bacterial 16S rRNA gene and func- tional genes involved in the N cycle （including amoA, nirS and nirK） in 4. surface soil samples from around Lake Qinghai and east of Qaidam Basin on the Northeastern Qinghai-Tibetan Plateau. We found that lower soil moisture reduced the fractional concentrations of cyclic bGDGTs and thus the cyclisation ratio of branched tetraethers （CBT） index correlated negatively with SWC and MAP, suggesting that soil moisture is an important factor controlling bGDGT distributions in soils in this add and semi-add region. Two subgroups of bGDGTs were assigned on the basis of cluster analysis, and bGDGT indices behaved dif- ferently in the two groups, hinting at different biosynthetic mechanisms for bGDGTs under different environmental conditions. Real time PCR results showed that nirS and nirK genes correlated significantly with the concentration of bGDGTs, suggesting that the nirS- or nirK-encoding bacteria involved in denitrification might potentially be an additional biological source for soil bGDGTs （besides Acidobacteria）. Moreover, our results also support the application of new indices based on 5-methyl bGDGTs and 6-methyl bGDGTs in reconstructing past temperature and pH variations in this region.

关键词： bGDGTs Soil water content CBT nirS- or nirK-encoding bacteria Real time PCR Cluster analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structure and functional heterogeneity of soil microbial communities in different farmland types on the loess Plateau

引用

地球环境学报 2024年第4期15卷 653-664页

作者： XU Chen SU Cuicui CHEN Yiping MA Jifu WU Junhua JIANG Yao state key laboratory of loess and {4. geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China University of Chinese Academy of Sciences Beijing 100049China Xi’an Institute for Innovative Earth Environment Research Xi’an 710061China

Background,aim,and scope Soil microbes are important drivers of nutrient transformation and energy f *** forest land for agricultural use may have profound effects on soil properties and microbial ***,the response of soil microbial communities to soil reclamation in the dryland agroecosystem is less ***,it is necessary to investigate the changes of soil microbial communities driven by land use conversion to promote nutrient cycling in reclaimed *** and methods Based on the metagenomic technique,we evaluated the microbial composition and function of the newly created farmland(NF)after reclamation with two types of traditional farmland(slope farmland(SF),checkdam farmland(CF))on the loess Plateau,and explored the response of nutrient cycling function to dominant genera and soil *** The results showed that Proteobacteria,Actinobacteria,and Acidobacteria were prevalent in the three types of *** with SF and CF,NF increased the relative abundance of Actinobacteria and Nocardioides,as well as genes related to amino acid metabolism and carbohydrate *** relative abundance of functional genes related to carbon and nitrogen cycling in the NF was higher than that in the traditional farmland(SF and CF).The relative abundance of nutrient cycling functional genes was positively correlated with dominant genera in the three types of *** for pH,soil physicochemical factors were negatively correlated with genes related to amino acid metabolism and carbon *** Previous studies have shown that the nutrient conditions of the soil may intensify the competition between the eutrophic and oligotrophic microbial *** long-term cultivation and fertilization,the soil properties of traditional farmland were significantly different from those of NF,leading to the differentiation of dominant microbial *** usually have functional redundancy to cope wi

关键词： metagenomics microbial function farmland nutrient cycling loess Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Late Miocene–early Pleistocene paleoproductivity variations of the Lop Nor in the Tarim Basin and its implications on aridification in Asian Interior

引用

Chinese Science Bulletin 2014年第28期59卷 3650-3658页

作者： Hong Chang Zhisheng An Weiguo Liu Feng Wu Xiaoke Qiang Yougui Song state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences

Extensive lacustrine deposits in the eastern Tarim Basin provide records of climate change influenced by the westerly winds and the Asian monsoon. To characterize the evolution of climate change in this region, we analyze elemental concentrations of barium(Ba) from the Ls2 drill core of Lop Nor, a paleo-lakebed located in the eastern Tarim Basin. Biogenic Ba concentrations from this drill core display a large-amplitude oscillation that generally follows a pattern similar to that of Artemisia content and ostracod assemblages, suggesting that is may serve as an index for climate change experienced in the basin. Our results indicate that biogenic Ba is especially sensitive to precipitation. All climatic proxies served in this study vary significantly over late Miocene to early Pleistocene time period. Strong aridification of eastern Tarim in the late Miocene to the early Pliocene may be attributed to a latitudinal shift in the westerly winds, which would have resulted in more moisture transported to southern and eastern Tibet. The growth of the Himalaya and Tibetan Plateau may have acted as an orographic barrier that blocked moisture sourced in the south from the northern margins of the plateau. We link weaker aridification in the late Pliocene to an increased intensity of the Indian Monsoon.

关键词：晚中新世早更新世亚洲季风塔里木河流域干旱化罗布泊古生产力塔里木盆地

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Geochronology of a surface core in the northern basin of Lake Qinghai: Evidence from ^(210)Pb and ^(137)Cs radionuclides

引用

Chinese Journal Of Geochemistry 2006年第4期25卷 301-306页

作者：徐海艾莉谭亮成安芷生 state key laboratory of loess and {4. geology Institute of Earth Environment Chinese Academy of Sciences

The radioactivities of 210Pb and 137Cs have been measured to estimate the dates of the sediments of a surface core （QH04.7-C-2） in the northern basin of Lake Qinghai. The sedimentation rate derived from 210Pb radioactivity correlates well with that inferred from （137）Cs radioactivity. The dates calculated from depth sedimentation rate （cm/a） are similar to those derived from mass accumulation rate （g·cm-2·a-1） between 0-5 cm, but are significantly different below 5 cm, which has been ascribed to the compaction of surface sediments during early diagenesis. The dates derived from mass accumulation rate are consistent with those calculated from the AMS 14. dating model. The precipitation-controlled indices based on the chronology data derived from mass accumulation rate are similar in trends to the precipitation reconstructed from tree rings in adjacent region, which further verifies the reliability of the geochronology data.

关键词：深度沉降率质量积累率青海湖表面核

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：