检索结果-南通市图书馆

Journal of Environmental sciences 2008年第12期20卷 1445-1452页

作者： GUO Xuelian LU Xianguo TONG Shouzheng DAI Guohua College of urban and Environmental sciences Northeast Normal University Changchun 130024 China Northeast institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130012 China

The litterbag method was used to study the decomposition of wetland plant root in three wetlands along a water level gradient in the Sanjiang Plain,Northeast *** wetlands are Calamagrostis angustifolia(***),Carex meyeriana(***)and Carex lasiocarpa (***).The objective of our study is to evaluate the influence of environment and substrate quality on decomposition rates in the three *** material was used as a standard substrate to evaluate environmental *** native to each we...

关键词： wetland plant root decomposition environment quality substrate quality Sanjiang Plain

Direct Photolithography of WO_(x)Nanoparticles for High‑Resolution Non‑Emissive Displays

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第3期17卷 297-309页

作者： Chang Gu Guojian Yang Wenxuan Wang Aiyan Shi Wenjuan Fang Lei Qian Xiaofei Hu Ting Zhang Chaoyu Xiang Yu‑Mo Zhang Laboratory of Optoelectronic Information Technology and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Hangzhou Bay Laboratory of Advanced Nano‑Optoelectronic Materials and Devices Qianwan Institute of CNITECHNingbo 315336People’s Republic of China Smart Materials for Architecture Research Lab Innovation Center of Yangtze River DeltaZhejiang UniversityJiaxing 314100People’s Republic of China University of Science and Technology of China Hefei 230026People’s Republic of China State Key Lab of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012People’s Republic of China

High-resolution non-emissive displays based on electrochromic tungsten oxides(WOx)are crucial for future near-eye virtual/augmented reality interactions,given their impressive attributes such as high environmental stability,ideal outdoor readability,and low energy ***,the limited intrinsic structure of inorganic materials has presented a significant challenge in achieving precise patterning/pixelation at the micron ***,we successfully developed the direct photolithography for WOx nanoparticles based on in situ photo-induced ligand *** strategy enabled us to achieve ultra-high resolution efficiently(line width3600 cycles),as well as promising applications in electronic logos,pixelated displays,flexible electronics,*** success and advancements presented here are expected to inspire and accelerate research and development(R&D)in high-resolution non-emissive displays and other ultra-fine micro-electronics.

关键词： Electrochromic Direct photolithography WOx nanoparticles In situ photo-induced ligand exchange High-resolution displays

Land Use Changes in Northeast China Driven by Human Activities and Climatic Variation

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2009年第3期19卷 225-230页

作者： WANG Zongming LIU Zhiming SONG Kaishan ZHANG Bai ZHANG Sumei LIU Dianwei REN Chunying YANG Fei Northeast institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China College of urban and Environmental sciences Northeast Normal University Changchun 130024 China

Human-induced land use/cover change (LUCC) forms an important component of global environmental change. Therefore, it is important to study land use/cover and its change at local, regional and global scales. In this paper we conducted the study of land use change in Northeast China, one of the most important agricultural zones of the nation. From 1986 to 2000, according to the study results obtained from Landsat images, widespread changes in land use/cover took place in the study area. Grassland, marsh, water body and woodland decreased by 9864, 3973, 1367 and 10,052km2, respectively. By comparison, paddy field, dry farmland, and built-up land expanded by 7339, 17193 and 700km2, respectively. Those changes bore an interactive relationship with the environment, especially climate change. On the one hand, climate warming created a potential environment for grassland and marsh to be changed to farmland as more crops could thrive in the warmer climate, and for dry farmland to paddy field. On the other hand, the changed surface cover modified the local climate. Those changes, in turn, have adversely influenced the local environment by accelerating land degradation. In terms of socio-economic driving forces, population augment, regional economic development, and national and provincial policies were confirmed as main driving factors for land use change.

关键词： land use change remote sensing climate warming Northeast China

Ring-Opening Polymerization of Lactide Catalyzed by Bimetallic Salen-Type Titanium Complexes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2017年第5期35卷 640-644页

作者： Ranlong Duan Zhi Qu Xuan Pang Yu Zhang Zhiqiang Sun Han Zhang Xinchao Bian Xuesi Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun Jilin 130012 China changchun institute of urban Planning & Design Changchun Jilin 130033 China

Three kinds of bimetallic Schiff base titanium complexes with different substituent moieties on organic ligands were ***-opening polymerizations （ROP） of lactides were carried out by using these titanium complexes as *** polymerization data and kinetic studies showed that complex 1a had the highest activity and complex 2a had the lowest activity for ROP of ***,all these three newly synthesized bimetallic titanium complexes showed higher polymerization activity and better molecular weight control than their monometallic counterparts reported in our previous work.

关键词： salen-type titanium complex catalysis ring-opening polymerization

X-RAY CRYSTALLOGRAPHIC STRUCTURE OF Meta-AND Para-DIMETHYL ESTER OF PYROMELLITIC ACID

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

Chinese Journal of Polymer Science 1997年第1期15卷 40-49页

作者：黄文溪刘天西高连勋张欣徐纪平丁孟贤 changchun institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022

The polycrystalline powder of para- and meta-dimethyl ester of pyromellitic acid (PMDE) have been prepared by fractional crystallization, and their crystal structures have been determined by Wide-Angle X-ray Diffraction (WAXD). Both p-PMDE and m-PMDE was found to be orthorhombic crystal system, and their unit cell parameters a = 0.840 nm, b = 0.707 nm, c = 1.136 nm and a = 1.032 nm; b = 0.835 nm, c = 0.714 nm, respectively. Space group all belongs to P-mmm. p-PMDE has two molecules per unit cell with crystal density 1.388 g . cm(-3), while m-PMDE has two molecules per unit cell with crystal density 1.522 g . cm(-3). Indices of crystal diffraction peaks are also detailed in the present work. The difference in crystal structures between p-PMDE and m-PMDE has thus been used to explain the curing behavior of isomerically pyromellitic dianhydride-based poly(amic ester)s.

关键词： WAXD orthorhombic polyimide aromatic diester-diacids

Efficient and simple synthesis of B_(2)O_(3)-Al_(2)O_(3)nanocomposites assisted by deep eutectic solvent for production of 5-hydroxymethylfurfural from glucose

在线全文

学校读者我要写书评

暂无评论

Nano Research 2025年第1期18卷 236-248页

作者： Yuchen Wang Kai Rong Shanlei Chang Youxing Fang Shaojun Dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China College of Chemistry Jilin UniversityChangchun 130012China

The catalytic conversion of glucose to high valueadded platform chemical 5-hydroxymethylfurfural(HMF)is a promising biorefinery process,and alumina-boria catalysts are considered to be green and mild solid acid catalysts for this catalytic ***,compared to the common synthesis methods with complicated steps,we reported a simple and efficient strategy to prepare B_(2)O_(3)-Al_(2)O_(3)nanocomposites by calcining cost-effective glucose-urea deep eutectic solvent(DES)solution containing the *** prepared B_(2)O_(3)-Al_(2)O_(3)nanocomposites exhibited an open three-dimensional skeleton and two-dimensional porous lamellar substructure,endowing them with a high specific surface area(228.27 m2/g).The introduction of boron changed the ratios of different aluminum species(AlⅣ,AlⅤ,and AlⅥ)and borate species(BO3 and BO4),thus further affecting the acidity and the types of acid sites of the *** prepared B_(2)O_(3)-Al_(2)O_(3)bifunctional acid catalysts possessing abundant Lewis acid sites and adjustable Brønsted acid sites showed complete glucose conversion and 55.38%of HMF yield under the optimum *** study proposed a concise method to synthesize alumina-boria solid acid catalysts assisted by glucose-urea *** hope to extend the application and prospect of this efficient and simple synthesis strategy.

关键词： 5-hydroxymethylfurfural(HMF) deep eutectic solvent glucose alumina-boria acid catalyst

THE INFLUENCE OF HEAT TREATMENT ON STRUCTURES OF THE AGGREGATED STATE OF POLYAMIDE-1010

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

Chinese Journal of Polymer Science 1996年第4期14卷 318-323页

作者：张宏放杨宝泉莫志深 changchun institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022

The structural parameters of the aggregated state of polyamide (PA)-1010 annealed at various temperatures were computed by means of the desmearing intensity from Smalt Angle X-ray Scattering (SAXS) measurements and by using the concept of the distance distribution function. The results indicated that the structural parameters of the aggregated state were strongly dependent upon heat treatment conditions and the maximum values of the structural parameters were obtained for the samples annealed at T = 175 degrees C. The particle size Z annealed at different temperature was ranged between 8.1-12.8nm, and the values of the distance distribution function P-max(Z) were obtained when Z = 4.0-6.8 nm. Using one dimension electron density correlation function (1D EDCF) method long period (L) and thickness of the lamellar (d(0)) were estimated and were found to increase with the increase of the degree of crystallinity.

关键词： polyamide-1010 SAXS heat treatment structure of aggregated state

Economic Transformation Capacities and Developmental Countermeasures of Coal-resource-based Counties of China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2010年第2期20卷 184-192页

作者： WANG Shijun JIANG Lili College of urban and Environmenal sciences Northeast Normal University Changchun 130024 China

In China,the economic systems of many small-scale resource-based regions are confronted with realizing sustainable development through economic transformation. This paper,taking 37 coal-resource-based counties in China as objects,evaluates the economic transformation capacities of the counties by principal component analysis (PCA). Based on the comprehensive principal component values of >1,0–1 and <0,the economic transformation capacities of the counties are classified into strong,common and weak grades. Then,the paper proposes the developmental countermeasures according to different transformation capacities. For the counties with strong transformation capacities,it is crucial to make scientific positioning and rationally exploite resources in view of the developing characteristics and modes of those counties; as for the counties with common transformation capacities,the preparation and perfection of basic transformation conditions are still important aspects; as for the counties with weak transformation capacities,shifting from ″passive transfromation″ to ″active transformation″ in light of resources conditions is necessary.

关键词： coal-resource-based county economic transformation capacity development countermeasure

Stability of Mo/Si Multilayer Structure Used in Bragg-Fresnel Optics

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1998年第7期15卷 522-524页

作者： LE Zi-chun CAO Jian-lin LIANG Jing-qiu PEI Shu YAO Jin-song CUI Cheng-jia LI Xing-lin changchun institute of Optics and Fine Mechanics Chinese Academy of SciencesChangchun 130022 institute of Atomic and Molecular Physics Jilin UniversityChangchun 130023 changchun institute of Applied Chemistry Chinese Academy of SciencesChangchun 130022

The thermal and chemical stabilities of Mo/Si multilayer structure used in Bragg-Fresnel optics were studied to get optimal technological parameters of pattern ***/Si multilayers were annealed at temperature ranging from 360 to 770 K,treated with acetone and 5‰NaOH solution,and characterized by small-angle x-ray diffraction technique as well as x-ray photoelectron spectroscopy and Olympus microscopy.

关键词： Mo/Si Fresnel optics

Cultural Landscape Evolution of Traditional Agricultural Villages in North China——Case of Qianzhai Village in Shandong Province

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

Chinese Geographical Science 2008年第4期18卷 308-315页

作者： FANG Yangang LIU Jisheng College of urban and Environment sciences Northeast Normal University Changchun 130024 China

Agricultural village is an important rural type in China. The evolution process and mechanism of its cultural landscape are different from those of the industrialized village. The paper focuses this theme by a case study of Qianzhai Village of Qufu City, Shangdong Province. In the case of Qianzhai Village, the evolution of its settlement has experienced three stages: mechanical expansion, sprawling expansion and hollowing, and recentralization. The land- scape evolution of residents' houses has undergone three phases: traditional quadrangle house, one-storied house and multistoried house. The evolution of its land use has experienced three stages: circled stratification, fragment and intensive use, and concentration and extensive use. We can see that the main driving factors of cultural landscape evolu- tion of agricultural village are the changes of rural population, society, economy and culture, which are influenced by the change of urban-rural relation, the national modernization process and economic development, the reform of family planning and land system, and the changes in governmental policies. In the future, the modernization, ecological trend, and individualization for residents' houses of agricultural villages in China will develop step by step. The recentralization of settlement and the scaled, sustainable, intensive land use are likely to be the trends of agricultural villages in China.

关键词： agricultural village rural cultural landscape landscape evolution sustainable development Qianzhai Village Shandong Province China