检索结果-南通市图书馆

Temporal variation of resource allocation between sexual and asexual structures in response to nutrient and water stress in a floating-leaved plant

引用

Journal of Plant Ecology 2013年第6期6卷 499-505页

作者： Fan Liu wen ying wu Tao Wan Qing feng Wang Yu Cheng Wei Li Key Laboratory of Aquatic Botany and Watershed Ecology Chinese Academy of SciencesWuhanHubei 430074China Hubei Key Laboratory of Wetland Evolution and Ecological Restoration Wuhan Botanical GardenThe Chinese Academy of SciencesWuhanHubei.430074China Key Laboratory of Southern Subtropical Plant Diversity Fairylake Botanical GardenShenzhen&Chinese Academy of ScienceShenzhenGuangdong 518004China Shenzhen Key Laboratory of Technologies for Industrial Water Conservation&Municipal Wastewater Resources ShenzhenGuangdong Province 518055China

Aims Adaptive plasticity of biomass allocation to different environmental stressors enables plants to maintain functional relationships among reproductive *** freshwater systems,water depth and nutrient content of sediments can have a major effect on biomass allocation in aquatic ***,the relative importance of these two stressors is unknown as it is the temporal variation of biomass allocation to the stressors during the growing *** information may be critical for understanding the tolerance of a plant to environmental *** Here,we used four levels of environmental stressors generated by deep and shallow water and high or low sediment nutrient content in a factorial experiment to investigate the biomass allocation responses of a floating macrophyte,Trapella sinensis,during the growing *** Findings The results showed that the lower sediment nutrient content inhibited biomass increase,whereas the lower water depth increased the sexual reproduction of the *** lower sediment content also led to a delay in flowering and compensated trade-offs among sexual reproduction and elongation and clonal reproduction during the growing *** results indicated that water depth affected the ratio of biomass allocation,whereas the sediment nutrient content affected biomass accumulation when the plants faced these two environmental factors *** temporal changes in allocation under lower sediment nutrient content underscored the importance of collecting data at different stages of growth when trying to interpret resource allocation,especially in resource-limited environments.

关键词： growing period resource allocation water depth sediment type

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

Broadband and perfect terahertz absorber based on multilayer metamaterial with cross-ring patterned structures

引用

Optoelectronics Letters 2025年第1期21卷 1-6页

作者： wen Jin LIU Zhanzhi wu Zhengwei PAN Yu ZHANG ying School of Science Xian Shiyou UniversityXi'an 710065China Shaanxi Key Laboratory of Measurement and Control Technology for Oil and Gas Wells Xi'an 710065China

Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and *** structure of the absorber is double absorption layers consisting of a chromium cross ring and eight isosceles right *** unique structure of the double absorbing layers excites the electric dipole multimode resonance,giving rise to high absorption ***,the influence of construal parameters on absorber behavior is also *** numerical results show that the absorption achieves over 90%ranging from 2.45 THz to 6.25 THz and 99%absorption in the range of 3.7—5.3 *** realization of broadband and perfect absorber is described using the impedance matching *** is obviously found that the absorber is insensitive to the high angle of incidence for both transverse electric(TE)and transverse magnetic(TM)*** with the former reports,this absorber has remarkable improved absorption efficiency and smaller *** terahertz absorber may be found applications in the fields of energy capture and thermal detection.

关键词： polarization absorber perfect

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 emission permit allocation and trading

引用

Journal of Environmental Sciences 1999年第4期11卷 468-473页

作者： CHEN wen\|ying, wu Zong\|xin (Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China) 清华大学核能技术设计研究院北京

Nowadays our earth is faced with grim challenge of global climate change. All countries should go into action jointly to mitigate climate change. Carbon emission permit allocation and trading are two important issues to realize global cooperation. In this paper two kinds of comprehensive carbon emission permit allocation methods not only considering equity but also efficiency were advanced. After the carbon permit price was determined, the trading situations in various regions or countries in the world and the global benefits gained from emission trading were expounded. Moreover, the impact of carbon emission permit trading on Chinas economy was analyzed.

关键词： climate change carbon permit allocation carbon permit trading comprehensive allocation method

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

Achieving further refinement of grain structure and improvement of mechanical properties in Al-12Si-4Cu-2Ni-1Mg alloy by Al-Ti-C-B master alloy addition and deep cryogenic treatment

引用

China Foundry 2025年第1期22卷 75-82页

作者： Lin-fei Xia wen-bo Li Zuo-shan Wei Yu-ying wu Xiang-fa Liu China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China Shandong Key Laboratory of Advanced Aluminum Materials and Technology Binzhou Institute of TechnologyBinzhou 256600ShandongChina

Near-eutectic Al-Si alloys are widely used in automotive manufacturing due to their superior wear resistance and high temperature *** of high Si content,the grain refinement of near-eutectic Al-Si alloy has been a problem for many *** this study,the effect of deep cryogenic treatment(DCT)on the microstructure and mechanical properties of Al-12Si-4Cu-2Ni-Mg alloy with addition of Al-Ti-C-B master alloy was fully *** show that the average grain size of the alloy is greatly reduced from 0.92 mm to 0.50 mm,and the eutectic Si and Al7Cu4Ni precipitates are spheroidized and refined in Al-12Si-4Cu-2Ni-Mg after DCT for 24 h and aging *** these changes of microstructures result in a significant increment of about 22.5%in elongation and a slight enhancement of about 6.8%in tensile ***,the refinement of microstructure also significantly improves the fatigue life of the alloy.

关键词： deep cryogenic treatment near-eutectic Al-Si master alloy microstructure mechanical properties

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

Further study on the synthesis of F-containing porphyrins and their catalytic activity on oxidation of cyclohexene

引用

Chinese Journal of Chemistry 1993年第5期11卷 464-471页

作者： HUANG,Wei-Yuan ying,Wei-wen MA,wu-Ping Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032 Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032

Reaction of tetrakis(p-allyloxyphenyl)porphyrin and perfluoroalkanesulfonyl bromides gives tetrakis(p-polyfluoroalkoxylphenyl)substituted *** yields are over 90%.The synthesis of the metal ion complexes of these F-containing porphyrins is also *** results on the study of the catalytic activity of the manganese(Ⅲ)complexes of various fluorinated porphyrins on oxidation of cyclohexene indicate that the introduction of R_F group into porphyrin contributes to the stability of the catalysts.

关键词： meta Further study on the synthesis of F-containing porphyrins and their catalytic activity on oxidation of cyclohexene

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

Berbamine selectively induces apoptosis of human acute promyelocytic leukemia cells via survivin-mediated pathway

引用

Chinese Medical Journal 2007年第9期120卷 802-806页

作者： ZHAO Xiao-ying HE Zhi-wen wu Dong XU Rong-zhen Department of Hematology Second Affiliated Hospital Zhejiang University College of Medicine Hangzhou 310009 China

Background Currently, resistance and relapse are still major problems in acute promyelocytic leukemia （APL） cases. Thus, new agents that override the resistance are crucial to the development of curative therapies for APL. In this study, we investigated the effects of berbamine on the proliferation of APL cell line NB4 and its possible mechanisms. Methods NB4 cells were treated with berbamine at different concentrations （0-64 μg/ml） for 72 hours. MTT assay was used to determine proliferation inhibition of NB4 cells. Cell apoptosis was evaluated by both flow cytometry （FCM） and morphological examination. PML/RAR-α and survivin mRNAs were measured by nested-RT-PCR and RT-PCR, respectively. Activated-caspase 3 was determined by FCM. Results Berbamine greatly inhibited the proliferation of NB4 cells in dose- and time-dependent manners, and its IC50 value was 3.86 μg/ml at 48 hours. Both morphological observations and FCM results showed that berbamine induced apoptosis of NB4 cells with concomitant increase of activated caspase-3 and decrease of survivin mRNA. After treatment with berbamine at 8 μg/ml for 48 hours, the percentage of apoptotic cells increased from 2.83% to 58.44% （P〈0.01）, and the percentage of cells with activated-caspase 3 elevated from 2.06% to 70.89% （P〈0.01）, whereas, level of survivin mRNA was reduced to 38.24% of control （P〈0.01）. However, no significant change was observed in PML/RAR-α mRNA.Conclusions Berbamine induces caspase-3-dependent apoptosis of leukemia NB4 cells via survivin-mediated pathway, suggesting that berbamine may be a novel potential agent against APL with a mechanism distinct from that of all-trans retinoic acid （ATRA） and arsenic trioxide （ATO）.

关键词： acute promyelocytic leukemia NB4 cells berbamine apoptosis survivin

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

Nanostructured ZnO/BiVO_(4)I-scheme heterojunctions for piezocatalytic degradation of organic dyes via harvesting ultrasonic vibration energy

引用

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 488-497页

作者： Yiling Li Xiaoyao Yu yingjie Zhou Yao Lin ying wu Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004China

BiVO_(4)porous spheres modified by ZnO were designed and synthesized using a facile two-step *** resulting ZnO/BiVO_(4)composite catalysts have shown remarkable efficiency as piezoelectric catalysts for degrading Rhodamine B(RhB)unde mechanical vibrations,they exhibit superior activity compared to pure *** 40wt%ZnO/BiVO_(4)heterojunction composite displayed the highest activity,along with good stability and *** enhanced piezoelectric catalytic activity can be attributed to the form ation of an I-scheme heterojunction structure,which can effectively inhibit the electron-hole ***,hole(h+)and superoxide radical(·O_(2)^(-))are proved to be the primary active ***,ZnO/BiVO_(4)stands as an efficient and stable piezoelectric catalyst with broad potential application in the field of environmental water pollution treatment.

关键词： piezoelectric catalytic heterojunction dye degradation ultrasonic vibration

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

Tuning the ion-dipole interactions between fluoro and carbonyl(EC)by electrolyte design for stable lithium metal batteries

引用

Chinese Chemical Letters 2025年第1期36卷 579-584页

作者： Guihuang Fang ying Liu Yangyang Feng ying Pan Hongwei Yang Yongchuan Liu Maoxiang wu Faculty of Metallurgy and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Ethylene carbonate(EC)is the conventional and promising solvent to achieve high energy lithium metal ***,the innate low energy level of lowest unoccupied molecular orbital(LUMO)in EC makes it incompatible with lithium metal,causing uncontrolled lithium growth and low Coulombic efficiency(CE).Herein,we introduced bis(2,2,2-trifluoroethyl)carbonate(TFEC),a carbonate with a strong electron-withdrawing effect(-CF_(3)),which enhances the stability of EC at electrode interface by reducing ion-dipole interactions between Li^(+)and *** the interaction between Li and EC weakens,TFEC and more PF_(6)^(-)anions coordinate with Li^(+),promoting the formation of contact ion pairs(CIPs)and aggregates(AGGs),thereby increasing the inorganic composition within the solid electrolyte ***,the distinct solvated sheath structure favors the decomposition of fluorinated solvents and PF_(6)^(-)anions,forming inorganic-rich electrode-electrolyte interfaces(SEI and CEI),thereby ensuring high stability for both the Li anode and high-voltage ***,when applied in the full-cell Li||LiMn_(0.8)Fe_(0.2)PO_(4),it displays consistent cycling performance,exhibiting minimal capacity decay with a retention rate of 62.5%after800 cycles,substantially surpassing that of cells using base electrolytes(29.8%).

关键词： Lithium-ion batteries LiMn_(0.8)Fe_(0.2)PO_(4) High-voltage Solvation structure Ethylene carbonate Bis(2,2,2-trifluoroethyl)carbonate

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

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

引用

Science China Chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu wen-Qiang Xu ying-Tong Di Man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu ying Zeng Yun-Dong wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines(Chinese Academy of Sciences) Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical OncogenomicsPeking University Shenzhen Graduate SchoolShenzhen 518055China Shenzhen Bay Laboratory Shenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Microbial Metabolism School of Life Sciences&BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical UniversityGuiyang 550014China Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest ChinaKunming Institute of BotanyChinese Academy of SciencesKunming 650201China Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical SciencesBeijing 100730China

In the intricate process of natural product biosynthesis,a metabolon can enhance metabolic flux by associating sequential enzymes.A fungal metabolon,comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G,is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide *** notoamide E as a substance,Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation,followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium ***,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol *** provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

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

Heavy metal stress strengthens the stability and complexity of microbial molecular ecological networks in Sanyang wetland sediments

引用

Journal of Oceanology and Limnology 2025年第1期43卷 103-118页

作者： Shengwei wu Huixi ZOU Nan LI Xiufeng YAN wen LIU College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China Institute for Eco-environmental Research of Sanyang Wetland Wenzhou UniversityWenzhou 325035China Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province School of Environmental&Resource SciencesZhejiang Agriculture and Forestry UniversityHangzhou 311300China

Pollution from heavy metals(HMs)(Cd,As,Cr,and Ni,etc.)has become a serious environmental issue in urban wetland ecosystems with more and more *** studies conducted in agricultural soils,rivers,and lakes demonstrated that microbial communities exhibit a response to HM ***,little is known about the response of microbial communities to HM pollution in urban wetland *** examined how heavy metals affect the stability of the microbial networks in the sediments of Sanyang wetland,wenzhou,*** environmental parameters,including HMs,TC(total carbon),TN(total nitrogen),TP(total phosphorus),S,and pH,varied profoundly between moderately and heavily polluted areas in shaping microbial ***,the microbial community composition in moderately polluted sites correlated significantly(Pying levels of HM pollution.

关键词： heavy metal(HM) urban wetland microbial networks network stability

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：