检索结果-南通市图书馆

NPP vulnerability of the potential vegetation of China to climate change in the past and future

Journal of Geographical Sciences 2017年第2期27卷 131-142页

作者： YUAN Quanzhi WU Shaohong DAI Erfu ZHAO Dongsheng REN Ping ZHANG Xueru key Lab of Land Resources Evaluation and Monitoring in Southwest Ministry of Education Sichuan NormalUniversity Chengdu 610068 China Institute of Geography and Resources Science Sichuan Normal University Chengdu 610101 China Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China key Laboratory of Land Surface Pattern and Simulation CAS Beijing 100104 China Chongqing Jiaotong University Chongqing 400074 China

Using the Integrated Biosphere Simulator, a dynamic vegetation model, this study initially simulated the net primary productivity（NPP） dynamics of China＇s potential vegetation in the past 55 years（1961–2015） and in the future 35 years（2016–2050）. Then, taking the NPP of the potential vegetation in average climate conditions during 1986–2005 as the basis for evaluation, this study examined whether the potential vegetation adapts to climate change or not. Meanwhile, the degree of inadaptability was evaluated. Finally, the NPP vulnerability of the potential vegetation was evaluated by synthesizing the frequency and degrees of inadaptability to climate change. In the past 55 years, the NPP of desert ecosystems in the south of the Tianshan Mountains and grassland ecosystems in the north of China and in western Tibetan Plateau was prone to the effect of climate change. The NPP of most forest ecosystems was not prone to the influence of climate change. The low NPP vulnerability to climate change of the evergreen broad-leaved and coniferous forests was observed. Furthermore, the NPP of the desert ecosystems in the north of the Tianshan Mountains and grassland ecosystems in the central and eastern Tibetan Plateau also had low vulnerability to climate change. In the next 35 years, the NPP vulnerability to climate change would reduce the forest–steppe in the Songliao Plain, the deciduous broad-leaved forests in the warm temperate zone, and the alpine steppe in the central and western Tibetan Plateau. The NPP vulnerability would significantly increase of the temperate desert in the Junggar Basin and the alpine desert in the Kunlun Mountains. The NPP vulnerability of the subtropical evergreen broad-leaved forests would also increase. The area of the regions with increased vulnerability would account for 27.5% of China.

关键词： climate change vulnerability potential vegetation net primary productivity IBIS China

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

不同含量的固体颗粒对喷嘴内空化流动特殊演化影响的研究

引用

Journal of Central South University 2023年第12期30卷 4197-4206页

作者：韩向东员康于方艳李超景建斌袁瑛琳冯淦 Norinco Group Testing and Research Institute Xi’an 710116China School of Civil Engineering Nanchang Institute of TechnologyNanchang 330044China State key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource&HydropowerSichuan UniversityChengdu 610065China

本文研究了不同含量的固体颗粒对喷嘴内空化流动特殊演化的影响。固体颗粒含量从1%变至6%,平均粒径从0.0015 mm增加至0.070 mm。修正适用于清水介质空化流动的Schnerr-Sauer空化模型用于含固体颗粒空化流动的数值模拟。结果表明:含固体... 详细信息

本文研究了不同含量的固体颗粒对喷嘴内空化流动特殊演化的影响。固体颗粒含量从1%变至6%,平均粒径从0.0015 mm增加至0.070 mm。修正适用于清水介质空化流动的Schnerr-Sauer空化模型用于含固体颗粒空化流动的数值模拟。结果表明:含固体颗粒空化流动的含汽量高于清水介质空化流动下的。不同含量的固体颗粒促进空化流动的演化。随着固体颗粒含量的增加,平均粒径的促进范围逐渐变小。研究含固体颗粒空化流动的流动参数与作用于固体颗粒上的力用于揭示机理。最大滑移速度与最小滑移速度的绝对值均高于清水介质空化流动下的。最大与最小湍动能均高于清水介质空化流动下的。含固体颗粒空化流动的混合动能高于清水介质空化流动下的。它们是降低压力促进空化流动发展的主导影响因素。计算所得的萨夫曼升力的量级是10^(−2),对空化流动的影响相对较弱,是次要影响因素。这些因素共同作用,促进喷嘴内含固体颗粒空化流动的特殊发展。

关键词：含固体颗粒空化流动固体颗粒含量含汽量滑移速度湍动能

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

Reflux extraction and analysis of polyethylene wax in soil

引用

Journal of Chongqing University 2014年第4期13卷 115-121页

作者：熊小莉 CHEN Cheng LUO Xue-gang College of Chemistry and Materials Science Sichuan Normal University School of Materials Science and Engineering Southwest University of Science and Technology Engineering Research Center for Biomass Materials Ministry of education

An efficient reflux extraction of polyethylene wax(PEW) in soil is presented, followed by molecular structure characterization methods to explore its degradation mechanism. To more realistically simulate the actual degradation of PE film powders in soil, low density PE(M=5 000) powders, being used as simulated PEW residue sample, were uniformly mixed with soil and then recovered by reflux extraction with decahydronaphthalen(decalin) at 90 ?C for 60 min. The average recovery of PEW from fortified soils was 96.5% with the developed reflux extraction procedure. The recovered PEW residue samples were characterized by infrared spectroscopy(IR), element analysis(EA), X-ray fluorescence(XFR), and high-temperature gel permeation chromatography(GPC). The results from spectra analysis show that there were no significant changes in molecular structures and molecular mass distribution of PEW samples after the reflux extraction, which demonstrate the reliability of this method. These results also indicate that the reflux extraction procedure and analytical methods of characterization could serve as a novel measurement technique to evaluate the degradation of low-density PE powders in soil over time.

关键词： polyethylene wax ·reflux extraction decalin soil biodegradation

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

Surface wave attenuation based polarization attributes in time-frequency domain for multicomponent seismic data

引用

Applied Geophysics 2018年第1期15卷 99-110,149页

作者： Kong Xuan-Lin Chen Hui Hu Zhi-Quan Kang Jia-Xing Xu Tian-Ji and Li Lu-Ming Geomathematics key Laboratory of sichuan Province Chengdu University of Technology Chengdu 610059 China Exploration and Production Research Institute Sinopec Southwest Company Chengdu 610041 China Multi-wave Seismic Technology key Laboratory of SINOPEC Group Chengdu 610041 China

In the paper, we propose a surface wave suppression method in time-frequency domain based on the wavelet transform, considering the characteristic difference of polarization attributes, amplitude energy and apparent velocity between the effective signals and strong surface waves. First, we use the proposed method to obtain time-frequency spectra of seismic signals by using the wavelet transform and calculate the instantaneous polarizability at each point based on instantaneous polarization analysis. Then, we separate the surface wave area from the signal area based on the surface-wave apparent velocity and the average energy of the signal. Finally, we combine the polarizability, energy, and frequency characteristic to identify and suppress the signal noise. Model and field data are used to test the proposed filtering method.

关键词： Vector seismic trace polarization time-frequency domain surface wave denoising

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

Hydrogen-incorporated vanadium dioxide nanosheets enable efficient uranium confinement and photoreduction

引用

Nano Research 2022年第4期15卷 2943-2951页

作者： Huanhuan Liu Jia Lei Jiali Chen Ye Li Changyao Gong Shangjie Yang Yamin Zheng Ning Lu Yan Liu Wenkun Zhu Rong He State key Laboratory of Environment-friendly Energy Materials National Co-innovation Center for Nuclear Waste Disposal and Environmental SafetySichuan Civil-military Integration InstituteSouthwest University of Science and TechnologyMianyang 621010China College of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China

Photocatalytic reduction of U(VI)represents a novel and effective manner for the removal of U(VI)pollutant from radioactive ***,we successfully incorporated hydrogen into VO_(2)nanosheets,which strengthened the interaction between VO_(2)and U(VI),thereby achieving a highly active and stable photocatalyst for U(VI)*** the increase of H content in hydric VO_(2)(H_(x)-VO_(2))nanosheets,the bandgap shrank from 2.29 to 1.66 eV,whereas the position of conduction bands remained more negative than the reduction potential of U(VI)/U(IV)(0.41 V ***).When irradiated by simulated sunlight,the U(VI)removal efficiency over H0.613-VO_(2)nanosheets reached up to 95.4%within 90 min,which largely outperformed 28.3%of pristine VO_(2)*** mechanistic study demonstrated that the hydroxylated surface gave rise to the balanced O confinement sites in VO_(2)(011),leading to the stabilized adsorption configuration and increased binding strength of UO_(2)^(2+)on H_(x)-VO_(2)nanosheets.

关键词： VO_(2)nanosheets hydroxylated surface confinement photoreduction uranium

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

Optimization of Fermentation Process for the Production of Bacteriocins from Lactic Acid Bacteria

引用

Agricultural Biotechnology 2015年第2期4卷 50-53页

作者： Zhiping ZHAO Li ZHANG Yanrong REN Xia ZHANG Xin NIE School of Chemistry and Pharmaceutical Engineering Sichuan University of Science & Engineering department of Biological and Chemical Engineering Chongqing University of Education

[Objective]This study aimed to improve the yield of bacteriocins from lactic acid bacteria by optimizing the fermentation process for production of bacteriocins from lactic acid bacteria.[Method]By single-factor analysis,fermentation temperature,seed age,inoculation volume,fermentation duration and fermentation media p H were optimized to determine the best fermentation *** inhibitory zone of bacteriocins from lactic acid bacteria was analyzed with oxford cup method,based on which the fermentation process was evaluated.[Result]The optimal fermentation process was optimized：fermentation temperature 37℃,seed age 14 h,inoculation volume 2%,fermentation duration 48 h,fermentation media p H 5.0.[Conclusion]Under the optimized fermentation conditions,the yield of bacteriocins from lactic acid bacteria was improved significantly.

关键词： fermentation Bacteria lactic inoculation optimizing inoculated contained ammonium antibacterial dissolved

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

Mechanisms of MYB-bHLH-WD40 Complex in the Regulation of Anthocyanin Biosynthesis in Plants

引用

Agricultural Biotechnology 2015年第3期4卷 5-8,13页

作者： Xin NIE Yang ZHAO Li ZHANG Yi TANG Juan WANG Zhiping ZHAO School of Chemistry and Pharmaceutical Engineering Sichuan University of Science & Engineering Institute of Pharmaceutical Engineering Technology and Application Sichuan University of Science & Engineering

Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisive role in the biosynthesis of anthocyanins. Studies have shown that the transcriptional levels of an- thocyanins are mainly regulated by MYB-bHLH-WD40 ternary complex. This paper summarized the structure characteristics of MYB-bHLH-WD40 ternary complex and its regulatory role in anthocyanin biosynthesis pathway, focusing on the regulation mechanism of several important model plants by MYB-bHIM-WD40 complex.

关键词： Anthocyanins Transcriptional regulation Biosynthesis MYB-bHLH-WD40 Ternary complex

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

Analysis on the Stability of Dendrobium Polysaccharides in Simulated Beverages

引用

Agricultural Biotechnology 2015年第4期4卷 70-71,76页

作者： Jing YUAN Li ZHANG Zhiping ZHAO School of Chemistry and Pharmaceutical Engineering Sichuan University of Science & Engineering

[ Objective ] This study aimed to investigate the stability of Dendrobium polysaccharides in simulated beverages, thus providing theoretical basis for further development of Dendrobium beverages. [ Method] The prepared simulated Dendrobium juice beverages and extracted Dendrobium polysaccharides were added into wine and Chinese liquor and treated under different pH, temperature and light conditions to determine changes in Dendrobium polysaccharide content. [ Result] Dendrobium polysaccharides exhibited high stability in beverages under neutral pH, room temperature, dark conditions. [ Conclusion] Dendrobium polysaccharides can be used for the development of Dendrobium beverages.

关键词： Dendrobium polysaccharides Beverages Stability

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

雷公藤红素抑制食管癌细胞转移及其机制

引用

生理学报 2015年第3期67卷 341-347页

作者：徐佳伍春莲西华师范大学西南野生动植物资源保护省部共建教育部重点实验室南充637009 西南大学三峡库区生态环境与生物资源省部共建国家重点实验室重庆400715

雷公藤红素是从传统中药雷公藤中提取分离得到的一种醌甲基三萜,具有抗炎、免疫抑制及抗肿瘤等药理活性。本文探讨雷公藤红素对食管癌细胞粘附、迁移及侵袭的影响。用MTT法检测不同浓度的雷公藤红素对食管癌细胞ECA-109粘附的影响;用划... 详细信息

雷公藤红素是从传统中药雷公藤中提取分离得到的一种醌甲基三萜,具有抗炎、免疫抑制及抗肿瘤等药理活性。本文探讨雷公藤红素对食管癌细胞粘附、迁移及侵袭的影响。用MTT法检测不同浓度的雷公藤红素对食管癌细胞ECA-109粘附的影响;用划痕实验测定不同浓度雷公藤红素对ECA-109细胞迁移的影响;用Transwell实验测定不同浓度雷公藤红素对ECA-109细胞侵袭的影响;用实时荧光定量PCR及Western blot实验检测不同浓度的雷公藤红素对ECA-109中整联蛋白家族及Wnt信号通路的影响。结果显示:雷公藤红素以剂量依赖的方式抑制ECA-109的粘附、迁移及侵袭,抑制整联蛋白β1、β4、αv基因和蛋白的表达,并抑制Wnt信号通路中β-Catenin、LRP6蛋白的表达。研究结果表明雷公藤红素能通过抑制Wnt信号通路和整联蛋白的表达来抑制食管癌细胞的转移。

关键词：雷公藤红素食管癌转移整联蛋白 Wnt信号通路

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

Atom-economic macrocyclic amphiphile based on guanidinium-functionalized selenacrown ether acting as redox-responsive nanozyme

引用

Chinese Chemical Letters 2023年第4期34卷 266-270页

作者： Bo Li Qiangqiang Xu Xin Shen Tiezheng Pan Jie Shang Yan Ge Zhenhui Qi Sino-German Joint Research Lab for Space Biomaterials and Translational Technology Synergetic Innovation Center of Biological Optoelectronics and Healthcare Engineering(BOHE)Shaanxi Provincial Synergistic Innovation Center for Flexible Electronics&Health Sciences(FEHS)School of Life SciencesNorthwestern Polytechnical UniversityXi’an 710072China

Control of self-assembly is significant to the preparation of supramolecular materials, but the control of hydration, responsiveness, dimension, catalysis of macrocyclic amphiphiles in an atom-economic manner is still a great challenge. The herein presented 527 Da low-molecular-weight macrocyclic amphiphile was fabricated by utilizing the selenium-containing crown ether as a hydrophobic motif together with guanidinium group as the hydrophilic moiety. The resulting benzo[21]crown-7 based macrocyclic amphiphile readily forms a redox-responsive solid nanoparticles in water, which can further interconnect into wrinkled pattern on-surface, as well as exhibits as a nanozyme for catalyzing disulfid bond formation. The present work highlights the great potential of guanidinium-and selenium-containing crown ethers for the control of functional assemblies.

关键词： Selenium Guanidinium Macrocycle amphiphile Crown ether Molecular assembly Winkled surface Nanozyme

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：