检索结果-南通市图书馆

Effects of ABA Content on the Development of Abscission Zone and Berry Falling After Harvesting of Grapes

Agricultural Sciences in china 2009年第1期8卷 59-67页

作者： ZHANG You-lin and ZHANG Run-guang College of Food Engineering and Nutritional Science,shaanxi normal university,xi’an {3.,P.R.{4. College of Food Engineering and Nutritional Science Shaanxi Normal University Xi'an 710062 P. R. China

The commodity price of grape reduces as berry falling after harvest. It is crucial to prevent grape from berry falling during storage. In this article, the structure change of grape cells in the abscission zone was observed, the ABA content and the activities of cellulase and polygalacturonase （PG） were measured, and the relationship of ABA and berry falling was investigated. The results suggest that cells in the abscission zone grow into a separation layer soon after the grapes are cut off. According to the level of development, we designed 6 grades to sort the different development stages. The grade 3.plays an important role in berry falling. ABA enhances the activities of cellulase and polygalacturonase, and accelerates the decomposition of cellulose and pectin, which determines the level of development of abscission zone and berry falling. If ABA ratio is less than 20 ng g-i flesh weight （FW）, the abscission zone is not developed to the grade 3. and the berry falling is effectively stopped. We treated grape bunches with nine plant growth regulators and two chemicals. The results indicated that 2,3.5-triiodobenzoic acid （TIBA） can （a） inhibit the generation of ABA significantly, （b） inactivate the activities of cellulase and PG, （c） delay the development of the grade 3.of abscission zone, and （d） stop berry falling. Indole acetic acid （IAA）, gibberellic acid （GA3., naphthalene acetic acid （NAA）, 6-benzylaminopurine （6-BA）, calcium chloride （CaCl2）, and potassium permanganate （KMnO4. caused similar results as TIBA. Chlorocholine chloride （CCC）, dimethyl amino succinamic acid （B9）, chloroethylphosphonic acid （CEPA） and exogenous ABA showed opposite effects.

关键词： grape phytohormone enzyme berry falling

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

A high-resolution late Pleistocene record of pollen vegetation and climate change from Jingning, NW china

引用

Science china Earth Sciences 2006年第2期49卷 154-162页

作者： LI Chunhai12, TANG Lingyu1, FENG Zhaodong3.4. ZHANG Hucai2, WANG Weiguo3.& AN Chenbang3.1. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, china 2. Nanjng Institute of geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, china 3. Environment and Resources College, Lanzhou university, Lanzhou 73.000, china 4. Beijing normal university, Beijing 100875, china Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China Nanjng Institute of geography and Limnology Chinese Academy of Sciences Nanjing China Environment and Resources College Lanzhou University Lanzhou China Beijing normal university Beijing China

With the support of 18 AMS-14. data, a high-resolution pollen record from the Suancigou section at Jingning, Gansu Province was established. Our results showed that the vegetation ex-perienced a series of changes characterized by the alternative growth and decline of forest and steppe components during the period from 4..2 to 11 ka B.P. in the Jingning area. Over the period of 4.―29 ka B.P. (MIS3., coniferous forests were flourishing, indicating a humid climate with the tem-perature being lower than that of the present. Since 23.ka B.P., the vegetation was dominated by steppe-desert steppe under a cold and dry condition, and entered the Last Glacial Maximum domi-nated by desert steppe. Several periods of the marked decrease in the arborous pollen content in Suancigou well corresponded to the North Atlantic Heinrich events, especially to Heinrich event 3. further supporting that the Heinrich events were well reflected by the pollen record in the Loess Pla-teau as well.

关键词： Western Loess Plateau, pollen record, climatic change, late Pleistocene.

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

The impacts of urbanization on soil erosion in the Loess Plateau region

引用

Journal of Geographical Sciences 2001年第3期11卷 282-290页

作者： SUN Hu, GAN Zhi-mao, YAN Jun-ping (Department of geography, shaanxi normal university, xi’an 710062,{3.) Department of geography Shaanxi Normal University

The accelerated urbanization has resulted in new soil erosion in the Loess Plateau region since the 1980s. A concept of urban erosion and its impacts on environment are discussed. The experimental studies and field investigations show that those loose silt and earth piles formed by urban construction can be eroded seriously: Under stormy rain, the amount of sediment from steep man-dumped slope is 10.8–12.2 times that of from uncovered slope land; the result of experiments with the wind tunnel also shows that the damage to the surface structure of dry loess can cause serious soil erosion by wind in some cities of the region. Even if in the urban built-up area, there are many loose sandy soil, mud and silt, which are washed into rivers by city’s ground flow in the rainy season. So, anthropogenically induced soil erosion has made soil erosion more serious around the urban areas. And the urban eroded environment has several characteristics such as fragility, complexity, seasonality and quick variability. Urban areas witness a quick economic growth and have more construction projects than rural areas, which brings more intensive changes of environments during a short period of time or adds some new elements to the erosion system. Therefore erosion has experienced more intensive impact by human activities. So, the possible impact of urbanization on erosion environment must be taken into consideration when designing or planning to exploit natural resources or to develop urban areas in the Loess Plateau.

关键词： the Loess Plateau urban erosion environment impacts characteristics

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

Organic solvent-and phase transfer catalyst-free oxidation of cyclohexanol to cyclohexanone with dilute H_2O_2

引用

Chinese Science Bulletin 2002年第24期47卷 2060-2062页

作者： WEI Junfa, SHI xianying, HE Diping & ZHANG MinSchool of Chemistry and Material Science, shaanxi normal university, xi’an 710062, china School of Chemistry and Material Science Shaanxi Normal University Xi'an China

The oxidation of cyclohexanol to cyclohexanone with 3.% aqueous hydrogen peroxide by using peroxotung-state complexes formed in situ from sodium tungstate di-hydrate and various bidentate organic ligands as the catalysts, without organic solvents, halide and phase transfer catalyst has been carried out. The influence of 13.ligands on the oxidation is investigated. The maximum yield of cyclohexanone is obtained when using 1,10-phenanthroline (96%) and oxalic acid (95%) as the ligand. Very high yields (around 90%) have also been obtained for the instances of using salicylic acid, 3.5-dibromosalicylic acid, and 8-hydro- xylquino-line as ligands. A research to improve the reaction condition using cheap oxalic acid as the ligand indicates that the optimum condition is that the reaction mixture with a molar ratio of cycohexanol:tungstate dihydrate:oxalic acid: 3.% H2O2=100:2:2:120 was stirred at 85-90℃ for 12 h.

关键词： cyclohexanol hydrogen peroxide catalytic oxidation peroxotungstate oxalic acid.

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

Study on sea water intrusion into palaeochannels on south coastal plain of the Laizhou Bay by the Bohai Sea

引用

Acta Oceanologica Sinica 2003年第1期22卷 69-74页

作者： Han Mei geography Department, Shandong normal university, Jinan 25001{3. china geography Department Shandong Normal University Jinan 250014 China

The palaeochannel evolution in the study region is divided into four stages by such methods as 14. dating. Sea water intrusion through palaeochannels has been studied as a focal point. Palaeochannels are the main passageways through which the sea water intrudes at a higher speed, through many means and in a changeable dynamic state.

关键词： Palaeochannel sea water intrusion south coastal plain of Laizhou Bay

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

Climate instability in the Yili region, xinjiang during the last glaciation

引用

Chinese Science Bulletin 2000年第17期45卷 1604-1609页

作者： YE Wei, DONG Guangrong, YUAN Yujiang & MA Yingjie1. xinjiang Institute of Ecology and geography, Chinese Academy of Sciences, Urumqi 83.011, china 2. Department of geography, Zhejiang {3. {4., Jinhua 3.1004. china 3. Institute of Desert Research, Chinese Academy of Sciences, Lanzhou 73.000, china 4. xinjiang Institute of Meteorological Research, Urumqi 83.002, china xinjiang Institute of Ecology and geography Chinese Academy of Sciences Urumqi China Department of geography Zhejiang Normal University Jinhua China Institute of Desert Research Chinese Academy of Sciences Lanzhou China xinjiang Institute of Meteorological Research Urumqi China

The climate is influenced by westerlies year in year out and the aeolian loess is widespread in the Yili region, the xinjiang Uygur Autonomous Region. Through the study of the loess section with a thickness of 21.5 m, much useful information about climatic change in this region during the last glaciation was gotten. Grain size analysis of loess samples in the section showed that the climatic change in the Yili region was of instability during the last glaciation and similar to those of the North Atlantic Ocean and Greenland. In correspondence with the Heinrich events, the percentage of the size fraction of loess with grain size less than 10 μm decreased in cold stadials in the Yili region. This result suggests that the westerly wind be strengthened during the cold periods. Compared with the stadials, the content of the loess with grain size less than 10 μm was increased in interstadials, which indicated that the strength of the westerly wind was weakened. It is obvious that the climate was instable

关键词： Yili region last glaciation climate instability.

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

Bio-screening and quantification of methyl paraben in vinegar and coconut juice separated by HPTLC

引用

Food Science and Human Wellness 2024年第3期13卷 1602-1607页

作者： Yisheng Chen xingjun xi College of Food Science and Engineering Shanxi Agricultural UniversityTaigu 030801China Insitute of Food Nutrition and Safety Shanxi Agricultural UniversityTaiyuan 030031China Institute of Agricultural Food Standardization China National Institute of StandardizationBeijing 100191China

As a widely used food preservative,methyl paraben was experimentally evidenced with serious hormonelike adverse ***,a high performance thin-layer chromatography platformed bioluminescent bioautography and image analysis for the selective quantification and confirmation of methyl paraben was proposed and validated in vinegar and coconut ***,the detectability of the bioautography to the analyte on different layer materials was estimated,revealing that normal silica gel was the best *** that,the liquid of sample extract and working solution were separated to overcome the background noises due to co-extracted *** separation result was then coupled to the optimized bioautography,enabling instant and straightforward screening of the targeted *** accurate quantification,bioluninescent inhibition pattern caused by the analyte was processed by image analysis,giving useful sensitivity(LOD>16 mg/kg),precision(RSD<10.1%)and accuracy(spike-recovery rate 76.9%-112.2%).Finally,the suspected result was confirmed by determining its MS fingerprint,further strengthening the reliability of screening.

关键词： High performance thin-layer chromatography Bio-screening Bioluminescence Image analysis Methyl paraben

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

Synthesis,crystal structure and thermal behavior of Rb(NTO)·H_2O

引用

Chinese Science Bulletin 2001年第1期46卷 45-49页

作者： HU Mancheng, GAO Shiyang, LIU Zhihong, SONG Jirong, xiA Shuping & YU Kaibei1. Institute of Applied Chemistry, shaanxi normal university, xi’an 710062, china 2. Department of Chemical Engineering, Northwest {3., xi’an 710069, china 3. Chengdu Branch of Chinese Academy of Sciences, Chengdu 61004., china Institute of Applied Chemistry Shaanxi Normal University Xi’an China Department of Chemical Engineering Northwest University Xi’an China Chengdu Branch of Chinese Academy of Sciences Chengdu China

The Rb(NTO) .H2O crystal has been synthesized by reaction of 3.nitro-l,2,4.triazole-5-one (NTO) with Rb2CO3.in aqueous solution. Its crystal structure has been determined. The crystal belongs to monoclinic system. Crystal structure data: space group P21/ n; a = 0.63. 0(1), b = 0.824.1(2), c =1.296 4.3. nm; β = 97.90(1)°; V = 0.669 9 (2) nm3. Z = 4. Dc= 2.3.6 g/cm3.μ = 7.3.5 nm-1, F(000) = 4.8. An eight coordinated compound is formed between Rb+ with oxygen atoms and nitrogen atoms. A layer structure is formed by coordination bonds and hydrogen bonds. The thermal decomposition mechanism of this coordination compound is discussed.

关键词： Rb-NTO coordination compound crystal structrue thermal decomposition.

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

Suspended sediment flux of river:Wavelet analysis in the Panlong basin of the Upper Red River (Honghe River),china

引用

Chinese Science Bulletin 2007年第A2期52卷 172-179页

作者： DING WenRong~(1,2+) ZHOU Yue~(1,3. L xixi~4.1 The Faculty of Environment Science and Engineering,Kunming university of Science and Technology,Kunming 650093.china 2 College of Tourism and {3. Science,Yunnan normal university,Kunming 650092,china 3.Yunnan university of Finance and Economics,Kunming 650221,china 4.Department of {3.,National university of Singapore 119260,Singapore The Faculty of Environment Science and Engineering Kunming University of Science and Technology Kunming China College of Tourism and geography Science Yunnan Normal University Kunming China Yunnan university of Finance and Economics Kunming China Department of geography National University of Singapore Singapore

这份报纸把小浪分析用于检验变化趋势，多时间规模变化，在上面的红河的 Panlong 盆的推迟的沉积流动(SSF ) 的周期、突然的变化特征，中国。结果显示 SSF 从 1951 ～ 1997 增加了，但是自从 1998，衰退了。SSF 的变化把多时间规模特征... 详细信息

这份报纸把小浪分析用于检验变化趋势，多时间规模变化，在上面的红河的 Panlong 盆的推迟的沉积流动(SSF ) 的周期、突然的变化特征，中国。结果显示 SSF 从 1951 ～ 1997 增加了，但是自从 1998，衰退了。SSF 的变化把多时间规模特征和变化在不同时间时期改变了。三周期的时间规模， 4. 7 和 22 年，被决定。22 年的周期的时间规模，是在三次规模之中的最明显的，通过整个研究时期延长了，而第 4.a 7 年的时间规模在某些时间时期仅仅是明显的。分别地有 27 次越过 4.年的时间规模，越过 7 年的时间规模的 16 次和越过 22 年的时间规模的 5 次的突然的变化。根据统计的聚会和气候数据分析，我们断定人的活动是导致了多时间规模的 SSF，而是特征的变化趋势的主要原因，周期、突然的变化被气候变化主要影响。

关键词：河流中国红河微波分析

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

Effect of Y_2Ba_4.uNbO_y on the Properties of Single Domain YBCO Superconductor by TSIG Process

引用

稀有金属材料与工程 2011年第S3期40卷 365-367页

作者： Song Fang, Yang Wanmin, Wang Miao, Li Guozheng, Wan Feng, Gao Ping, Liang Wei shaanxi normal university, xi’an 710062, china shaanxi normal Univ Dept Phys Xian 710062 Peoples R China

The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4.uWOx (GdW24.1) additions have been fabricated by TSIG process, the amount of GdW24.1 added to Y2BaCuO5 (Y211) is in the range from 0wt% to 8 wt%, but there is no other additions to the liquid source. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 14.to 25 N with the increasing of GdW24.1 addition from 0 to 4.wt%, and decreasing from 25 to 7 N with the increasing of GdW24.1 addition from 4.to 8 wt%, the largest levitation force is obtained when the GdW24.1 content is about 4.wt%. This is helpful for the fabrication of high quality YBCO bulk superconductors.

关键词： infiltration and growth YBCO single-domain Gd2Ba4.uWOx

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：