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Changes of nutrient concentrations and N:P:Si ratios and their possible impacts on the Huanghai Sea ecosystem 被引量:15
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作者 FU Mingzhu WANG Zongling +2 位作者 PU Xinming XU Zongjun ZHU Mingyuan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第4期101-112,共12页
To investigate the impacts of nutrient concentrations and N:P:Si ratios on the ecosystem of the Huanghai Sea (Yellow Sea), the current status and long-term variation of nutrients concentrations and ratios as well ... To investigate the impacts of nutrient concentrations and N:P:Si ratios on the ecosystem of the Huanghai Sea (Yellow Sea), the current status and long-term variation of nutrients concentrations and ratios as well as phytoplankton community structure in the Huanghai Sea were collected and analyzed. The results reveal great annual and seasonal fluctuations in the nutrient concentrations and N:P:Si ratios during 1998-2008 with no clear pattern observed in the whole region. Yet on a seasonal scale of spring and in the coastal regions such as the Jiaozhou Bay and Sanggou Bay, the increase of DIN concentration and N:P ratio as well as the decrease of phosphate and sili- cate concentrations and Si:N ratios were relatively significant. Many pelagic ecosystem changes have occurred concurrent with these changes of the nutrient regime, such as the recent increase of primary production, changes of phytoplankton chlorophyll a biomass and abundance, an increase of eutrophication, and occurrence of HABs. In addition, new trends in the variation of nutrients seem to be developing in some particular transect such as 36N, which suggests that long-term and systematic ecosystem monitoring in the Huanghai Sea is necessary. 展开更多
关键词 nutrient concentration and ratio long-term variation Huanghai Sea ecosystemresponse
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Improving photoreduction of CO2 with water to CH4 in a novel concentrated solar reactor 被引量:2
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作者 Sisi Han Yinfei Chen +1 位作者 Stéphane Abanades Zekai Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第4期743-749,共7页
COphotoreduction is an attractive process which allows the storage of solar energy and synthesis of solar fuels. Many different photocatalytic systems have been developed, while the alternative photo-reactors are stil... COphotoreduction is an attractive process which allows the storage of solar energy and synthesis of solar fuels. Many different photocatalytic systems have been developed, while the alternative photo-reactors are still insufficiently investigated. In this work, photoreduction of COwith HO into CHwas investigated in a modified concentrating solar reactor, using TiOand Pt/TiOas the catalysts. The TiOand Pt/TiOsamples were extensively characterized by different techniques including powder X-ray diffraction(XRD), Nadsorption/desorption and UV–vis absorption. The catalytic performance of the TiOand Pt/TiOsamples in the gas phase was evaluated under unconcentrated and concentrated Xe-lamp light and nature solar light with different concentrating ratios. Various parameters of the reaction system and the catalysts were investigated and optimized to maximize the catalytic performance of COreduction system. Compared with the normal light irradiation, the TiOand Pt/TiOsamples show higher photocatalytic activity(about 6–7 times) for reducing COinto CHunder concentrated Xe-lamp light and nature solar light. In the range of experimental light intensity, it is found that the concentration of the light makes it suitable for the catalytic reaction, and increases the utilization efficiency of the TiOand Pt/TiOsamples while does not decrease the quantum efficiency. 展开更多
关键词 CO2 photoreduction CH4 Concentrating solar reactor Concentrating ratio
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Influence of the concentration ratio of nitrogen to phosphorus on the growth and interspecies competition of two red tide algae 被引量:2
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作者 KANG Yanyu LIANG Junrong +5 位作者 GAO Yahui LIN Rongcheng GAO Hua XING Xiaoli MA Jie LUO Qiaoqi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2007年第5期107-115,共9页
The growth and interspecies competition of two red tide algal species Thalassiosira pseudonana Hasle et Heimdal and Gymnodinium sp. were studied under different concentration ratios of nitrogen to phosphorus, and the ... The growth and interspecies competition of two red tide algal species Thalassiosira pseudonana Hasle et Heimdal and Gymnodinium sp. were studied under different concentration ratios of nitrogen to phosphorus, and the algal hatch culture experiments were conducted. The physiological and biochemical indexes were measured periodically, including the maximum comparing growth rate, relative growth rate, average double time and chlorophyll a concentration. The results showed that when the concentration ratio of nitrogen to phosphorus was 16: 1, the maximum comparing growth rate, relative growth rate and chlorophyll a concentration of Thalassiosira pseudonana all reached the highest,and average double time was the shortest. This implied that the optimal concentration ratio of nitrogen to phosphorus of Thalassiosira pseudonana is 16: 1. When the concentration ratio of nitrogen to phosphorus was 6:1, the maximum comparing growth rate, relative growth rate and the chlorophyll a concentration of Gymnodinium sp. reached the highest, and average double time was the shortest, so the optimal concentration ratio of nitrogen to phosphorus of Gymnodinium sp. is 6: 1. From the growth curves as indicated both in the cell density and the chlorophyll a concentration, it is suggested that the influence of concentration ratio of nitrogen to phosphorus on the chlorophyll a concentration and the cell density are almost the same. Different concentration ratios of nitrogen to phosphorus had weak influence on community succession and the competition between the two algae. Gymnodinium sp. may use the phosphorus in vivo for growth, so it is important to pay attention to the concealment of phosphorus, in order to avoid the outbreak of red tide. On the basis of the importance of nitrogen and phosphorus and the ratio of their concentration, the possible outbreak mechanism of red tide of the two algae was also discussed. 展开更多
关键词 concentration ratio of nitrogen to phosphorus Thalassiosira pseudo nana Gymnodinium sp. red tide
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Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake, digestibility, plasma metabolites, ruminal fermentation and fecal microflora of male Chinese Holstein calves 被引量:7
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作者 XIA Chuan-qi Aziz-Ur-Rahman Muhammad +4 位作者 NIU Wen-jing SHAO Tao-qi QIU Qing-hua SU Hua-wei CAO Bing-hai 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第2期415-427,共13页
Twenty-eight male, weaned Chinese Holstein calves((156.8±33.4) kg) were used to investigate the effects of dietary forage to concentrate ratio(F:C) and forage length on nutrient digestibility, plasma metab... Twenty-eight male, weaned Chinese Holstein calves((156.8±33.4) kg) were used to investigate the effects of dietary forage to concentrate ratio(F:C) and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement: whole-length forage(WL) with low F:C(50:50); WL with high F:C(65:35); short-length forage(SL) with high F:C(65:35); and SL with low F:C(50:50). Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size(-50% particles 〉19 mm). Dry matter intake(DMI) and organic matter(OM) intake was increased by increasing both F:C(P〈0.01) and forage length(FL)(P〈0.05), while acid detergent fiber(ADF) and neutral detergent fiber(NDF) intakes were only increased by increasing the F:C(P〈0.01). The digestibility of NDF was increased as the FL increased(P〈0.01), and it was also affected by interaction between F:C and FL(P〈0.05). Cholesterol(CHO)(P〈0.01), leptin(LP)(P〈0.05), and growth hormone(GH)(P〈0.01) concentrations in plasma were increased as dietary F:C increased. A significant increase in plasma triglyceride(TG)(P〈0.01), insulin(INS)(P〈0.05), and GH(P〈0.01) levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F:C diets were significantly lower than those in high F:C treatment(P〈0.05). Increasing the F:C enhanced ruminal acetic acid(P〈0.05) and acetic acid/propionic acid(P〈0.01). Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F:C groups(P〈0.05). Lower fecal scores(higher diarrhea rate) were observed in calves fed with SL hay compared to WL hay(P〈0.05). Denatured gradient gel electrophoresis(DGGE) bands and richness index(S) were significantly affected by the interaction between F:C and FL(P〈0.05), under high F:C, band numbers and richness index from WL group were higher than that from SL group(P〈0.05), whereas there were no differences between WL andSL groups under low F:C(P〉0.05). Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F:C(65:35) diet is suitable for weaned calves. 展开更多
关键词 forage to concentrate ratio forage length nutrient digestibility plasma metabolites ruminal fermentation fecal microflora male Holstein calves
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Spatial-temporal Pattern Evolution of Manufacturing Geographical Agglomeration and Influencing Factors of Old Industrial Base:A Case of Jilin Province,China 被引量:6
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作者 LI Linshan MA Yanji 《Chinese Geographical Science》 SCIE CSCD 2015年第4期486-497,共12页
The primary object of this paper is to examine the spatial-temporal pattern evolution of manufacturing geographical agglomeration of the old industrial base.Industrial spatial agglomeration index and concentration rat... The primary object of this paper is to examine the spatial-temporal pattern evolution of manufacturing geographical agglomeration of the old industrial base.Industrial spatial agglomeration index and concentration ratio are used in this paper.Multiple linear regression models are also applied to try to explore the internal driving mechanisms on manufacturing geographical agglomeration.The results show that:1) the manufacturing agglomeration degree of Jilin Province is increasing gradually.The spatial polarization structure is visible;and the central region is the agglomeration area,in addition,the manufacturing industries of Changchun Proper present a trend of dispersion;2) the structure of manufacturing industries has changed,and the concentration ratio of labor-intensive manufacturing industry is declining,while the proportions of technology-intensive and capital-intensive manufacturing industry are relatively rising;3) marketing level,location accessibility,labor resources,capital,science and technology innovation capability,scale economy and the level of globalization affect manufacturing agglomeration with different degree.There are significant differences of the effects about employment,technology,the quality of residents and the export-oriented market on the industrial concentration ratio;4) in the future,the impact of policy and institution,export-oriented market and quality of resident on manufacturing geographical agglomeration pattern will be more profound. 展开更多
关键词 old industrial base manufacturing geographical agglomeration industrial spatial agglomeration index concentration ratio Jilin Province China
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Lateral displacement of silty clay under cement-fly ash-gravel pile-supported embankments: Analytical consideration and field evidence 被引量:5
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作者 张崇磊 蒋关鲁 +1 位作者 刘先峰 王智猛 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1477-1489,共13页
Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankme... Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankments was proposed. In order to validate the proposed method, a full-scale high-speed railway embankment(HSRE) with four instrumented subsections over medium compressibility silty clay was constructed in three stages. The soil profile, construction procedure and monitoring of settlements and lateral displacements of the four test sections were described. The field deformation analysis results show that 1) the combined reinforcement of CFG piles and geosynthetic layer perform well in terms of reducing lateral displacements; 2) the development of lateral displacements lags behind the increase of fill load, which can be attributed to the vertical load transfer mechanism of the pile foundation; and 3) pile length has a dominant effect on the stress distribution proportion between piles and surrounding soils. The comparison between predicted and experimental results suggests that the proposed analytical solution and the back analysis-based method are capable of reasonably estimating the lateral deformation and the stress concentration ratio, respectively, if the appropriate soil elastic modulus is chosen. 展开更多
关键词 piled-supported embankment silty clay lateral displacement field test stress concentration ratio
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Characterization of the Growth,Chlorophyll Content and Lipid Accumulation in a Marine Microalgae Dunaliella tertiolecta under Different Nitrogen to Phosphorus Ratios 被引量:3
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作者 SONG Donghui XI Bo SUN Jing 《Journal of Ocean University of China》 SCIE CAS 2016年第1期124-130,共7页
Microalgal lipids are regarded as main future feedstock of biofuels for its higher efficiency of accumulation and sus- tainable production. In order to investigate the effect of various nitrogen to phosphorus ratios o... Microalgal lipids are regarded as main future feedstock of biofuels for its higher efficiency of accumulation and sus- tainable production. In order to investigate the effect of various nitrogen to phosphorus ratios on cells growth, chlorophyll content and accumulation of lipids in Dunaliella tertiolecta, experiments were carried out in modified microalgal medium with inorganic nitrogen (nitrate-nitrogen) or organic nitrogen (urea-nitrogen) as the sole nitrogen source at initial N:P ratios ranging from 1:1 to 32:1. The favorable N:P of 16:1 in the nitrate-N or urea-N medium yielded the maximum cell density and specific growth rate. Decrease in chlorophyll content were observed at the N:P of 4:1 in both nitrate-N and urea-N cultures. It was also observed that the maximum lipids concentration was obtained at the N:P of 4:1 in both nitrate and urea nutrient medium. The lipid productivity and lipid content of cultures in the urea-N medium at the N:P of 4: lwere markedly higher than those from cultures with other N:P ratios (p〈 0.05). The results of this work illustrate the possibility that higher ratios of nitrogen to phosphorus have enhancing effect on cells growth of D. tertiolecta. Conversely, higher lipid accumulation is associated with a decrease in chlorophyll content under lower ratios of nitro- gen to phosphorus. The results confirm the hypothesis of this study that a larger metabolic flux has been channeled to lipid accumu- lation in D. tertiolecta cells when the ratios of nitrogen to phosphorus drop below a critical level. 展开更多
关键词 Dunaliella tertiolecta lipid accumulation ratios of nitrogen and phosphorus concentration
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Concentration Changes of Medroxyprogesterone Acetate in Serum and Milk in Lactating Woman Who Used Depo Geston~
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作者 Su-hua FANG Dan-li SUN +1 位作者 Hai-ying JIANG Hong-ying LUO 《Journal of Reproduction and Contraception》 CAS 2004年第3期157-162,共6页
Objective To determine the concentration changes of medroxyprogesterone acetate (MPA) in serum and milk in the Chinese lactating women who used Depo Geston Methods Ten postpartum and breastfeeding women received an ... Objective To determine the concentration changes of medroxyprogesterone acetate (MPA) in serum and milk in the Chinese lactating women who used Depo Geston Methods Ten postpartum and breastfeeding women received an injectable contraceptive of Depo Geston (depo medroxyprogesterone acetate, DMPA, 150 mg/ampoule). Serum and milk samples were collected in the 1^st, 2^st, 4^th, 6^th, 8^th 10^th and 12^th week after contraceptive injection. The concentrations of medroxyprogesterone acetate (MPA) in serum and milk were determined by radioimmunoassay. Results The highest MPA concentration in serum was observed at the 1^st week and then the level of serum MPA decreased obviously at the 2^na and 4^th week. After the 4^th week, the decline of serum MPA level slowed down. The concentration of milk MPA reached the highest level at 1^th week. But at the 2^nd week the average level of MPA in milk dropped by half The MPA concentration in the milk was changed in the range of 5.2-8.3 ng/mL in the following 10 weeks. During observation, the average ratios of concentration and area under curve (AUC) in milk/serum were both 0.55. There was a wide variation in MPA concentrations and ratios of milk/serum between subjects. Conclusion MPA concentrations maintained a certaim level at the 12^th week after DMPA injection. However, whether mather's intake of DMPA during feeding period has effect on children's growth, espcially pubertal growth, deserves further studies. 展开更多
关键词 depot medroxyprogesterone acetate (DMPA) injectable contraceptive duration of lactation MPA concentration and ratio in serum/milk
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Effect of Corn Stalks Treated with Carbonylamines in Different Concentrate and Forage Rations and Nitrogen Conditions on Rumen Fermentation in Vitro
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作者 LU Guang-lin LI Dong-feng YANG Lian-yu 《Animal Husbandry and Feed Science》 CAS 2011年第3期9-12,共4页
[ Objective] To investigate the effects of concentrate/roughage ratios and nitrogen levels on in-vitro rumen fermentation of urea-treating corn stalk. [ Method] The concentrate/roughage ratios were 7: 3, 5:5 and 3:... [ Objective] To investigate the effects of concentrate/roughage ratios and nitrogen levels on in-vitro rumen fermentation of urea-treating corn stalk. [ Method] The concentrate/roughage ratios were 7: 3, 5:5 and 3: 7. The crude protein levels were 11% and 14%. The in-vitro culture time was 2, 4, 6 and 48 h. [ Result] The pH value of broth decreased significantly with the decline in the proportion of roughage ( P 〈 0.01 ) and with the increase in the crude protein levels (P 〈 0.05). The ammonium nitrogen concentration and acetic acid/propionic acid ratio of the fermen- ted products decreased with the increase in the crude protein levels and proportion of concentrate in diet. The diet with concentrate/roughage ratio of 5:5 and crude protein level of 14% had significantly higher digestibility of dry matter and organic matter than other diets ( P 〈 0.05). The digesti- bility of organic matter increased gradually with the increasing proportion of concentrate and crude protein level. With the increase in the proportion of concentrate, the microbial protein levels increased remarkably, while the acetic acid/propionic acid ratio declined. [ Conclusion] The concentrate/ roughage ratios and nitrogen levels affect rumen fermentation and microbial growth during in-vitro culture. However, the best supplementary feeding results of urea-treatinq corn stalks can be obtained when the concentrate/rouahaae ratio is below 5:5 and the crude protein level is 14%. 展开更多
关键词 Concentrate/roughage ratio Nitrogen level DIET Rumen fermentation
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Effect of Concentrate to Roughage Ratio on Cost Effective Growth Performance of Brahman Crossbred Calves
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作者 Mohammad Mahbubur Rashid Khan Shahidul Huque +2 位作者 Mohammad Azharul Hoque Nathu Ram Sarker Abul Kashem Fazlul Haque Bhuiyan 《Journal of Agricultural Science and Technology(A)》 2015年第4期286-295,共10页
An experiment was conducted to evaluate the growth performance and cost per gain of Brahman × local crossbred bull calves receiving three diets with varying concentrate to roughage ratio (C:R) of 75:25, 65:3... An experiment was conducted to evaluate the growth performance and cost per gain of Brahman × local crossbred bull calves receiving three diets with varying concentrate to roughage ratio (C:R) of 75:25, 65:35 and 55:45 on dry matter (DM) basis. Twelve bull calves (aging 11.5 ±1.2 months and 170.8 ± 13.0 kg live weight) divided into three equal groups were fed on three diets. The diets were balanced to 14.5% crude protein (CP) level and 10.5 MJ metabolizable energy (ME) per kg DM, formulating different concentrate mixtures. German grass (Echinoclora grousgali) and paddy straw were offered at 2:1 ratio on DM basis as roughages. The results revealed that C:R ratio did not affect (P 〉 0.05) the intake of feed and nutrients, feed efficiency (7.04, 6.94 and 6.76) and average daily gain (981,958 and 976 g). Digestibility of nutrients was not affected (P 〉 0.05) by C:R. Animals fed diet with C:R = 55:45 had the lowest feed cost (Bangladeshi Taka 136.8 BDT/kg live weight gain), which was increased (147.5 B DT and 153.8 BDT) non-significantly (P 〉 0.05) with the increasing level of concentrate. The diet consisting of 55% concentrate mixture showed similar results with the diet consisting of 75% concentrate mixture, but was comparatively economic. Therefore, considering the growth performance and cost per kg gain of Brahman crossbred growing calves, it may be concluded that the diet consisting of 55:45 C:R may be used for economic beef production. 展开更多
关键词 Brahman crossbred concentrate to roughage ratio growth iso-nitrogenous.
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The Influence of Forage/Concentrate Ratio and Full Fat Soya By-Pass Supplementation on the Fatty Acids Profile from the Carcase of Fatting Lambs
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作者 D. Mierlita C. Pascal +2 位作者 St. Daraban F. G. Lup C. Maerescu 《Journal of Agricultural Science and Technology》 2011年第1期67-76,共10页
There was organized a 2×2 factorial type experience in which it has been aimed the influence of forage/concentrates ratio and the effect of supplementing the ratio with full fat soya by-pass (FFS) on the produc... There was organized a 2×2 factorial type experience in which it has been aimed the influence of forage/concentrates ratio and the effect of supplementing the ratio with full fat soya by-pass (FFS) on the production performance and carcass fatty acid profile of fattening lambs. 32 Tsigai lambs were divided into 4 groups and were fed with 2 different diets regarding the forage/concentrates ratio (35/65 and 65/35, on a DM basis), containing or not 5% FFS (full fat soya treated with formaldehyde 12.5%). Including FFS in diet and the ratios rich in concentrates determined a significant improvement in weight gain (P〈0.01), in the degree of food recovery and in fatty acid profile from the carcass. It has been significantly increased (P〈0.01) the weight of polyunsaturated fatty acids (PUFA) from intramuscular fat (longissimus dorsi-LD and femoral biceps-FB) and the deposit fat (subcutaneous-SC and perirenal-PR) and decreased the proportion of saturated (SFA) and monounsaturated fatty acids (MUFA). Most significant differences were recorded about PUFA from Omega-3 series (C18:3 n-3, EPA C22:3 n-3, DPA and DHA) and CLA isomers (conjugated linolenic acid: C 18:2 C9, tl I+C 18:2 t10, C 12). The best profile of fatty acids, considered in light of the influence on human health (high concentration of Omega 3 fatty acids and CLA and low in SFA) was established in LD, for lambs fed with diets high in concentrates and which contained FFS (HC/S). 展开更多
关键词 Forage/concentrate ratio full fat soya by-pass PUFA Omega 3 and CLA LAMBS
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Stability-mutation feature identification of Web search keywords based on keyword concentration change ratio
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作者 Hongtao LU Guanghui YE Gang LI 《Chinese Journal of Library and Information Science》 2014年第3期33-44,共12页
Purpose: The aim of this paper is to discuss how the keyword concentration change ratio(KCCR) is used while identifying the stability-mutation feature of Web search keywords during information analyses and predictions... Purpose: The aim of this paper is to discuss how the keyword concentration change ratio(KCCR) is used while identifying the stability-mutation feature of Web search keywords during information analyses and predictions.Design/methodology/approach: By introducing the stability-mutation feature of keywords and its significance, the paper describes the function of the KCCR in identifying keyword stability-mutation features. By using Ginsberg's influenza keywords, the paper shows how the KCCR can be used to identify the keyword stability-mutation feature effectively.Findings: Keyword concentration ratio has close positive correlation with the change rate of research objects retrieved by users, so from the characteristic of the 'stability-mutation' of keywords, we can understand the relationship between these keywords and certain information. In general, keywords representing for mutation fit for the objects changing in short-term, while those representing for stability are suitable for long-term changing objects. Research limitations: It is difficult to acquire the frequency of keywords, so indexes or parameters which are closely related to the true search volume are chosen for this study.Practical implications: The stability-mutation feature identification of Web search keywords can be applied to predict and analyze the information of unknown public events through observing trends of keyword concentration ratio.Originality/value: The stability-mutation feature of Web search could be quantitatively described by the keyword concentration change ratio(KCCR). Through KCCR, the authors took advantage of Ginsberg's influenza epidemic data accordingly and demonstrated how accurate and effective the method proposed in this paper was while it was used in information analyses and predictions. 展开更多
关键词 Web search Web search keyword Information analysis and prediction Concentration change ratio Feature identification Influenza epidemic
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Sedimentary record of climate change in a high latitude fjord—Kongsfjord
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作者 Hang Wu Binbin Deng +5 位作者 Jinlong Wang Sheng Zeng Juan Du Peng Yu Qianqian Bi Jinzhou Du 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第1期91-102,共12页
The sedimentary record of climate change in the Arctic region is useful for understanding global warming.Kongsfjord is located in the subpolar region of the Arctic and is a suitable site for studying climate change.Gl... The sedimentary record of climate change in the Arctic region is useful for understanding global warming.Kongsfjord is located in the subpolar region of the Arctic and is a suitable site for studying climate change.Glacier retreat is occurring in this region due to climate change,leading to an increase in meltwater outflow with a high debris content.In August 2017,we collected a sediment Core Z3 from the central fjord near the Yellow River Station.Then,we used the widely used chronology method of 210Pb,^(137)Cs,and other parameters to reflect the climate change record in the sedimentary environment of Kongsfjord.The results showed that after the mid-late 1990s,the mass accumulation rate of this core increased from 0.10 g/(cm^(2)·a)to 0.34 g/(cm^(2)·a),while the flux of^(210)Pb_(ex)increased from 125 Bq/(m^(2)·a)to 316 Bq/(m^(2)·a).The higher sedimentary inventory of^(210)Pb_(ex)in Kongsfjord compared to global fallout might have been caused by sediment focusing,boundary scavenging,and riverine input.Similarities between the inventory of^(137)Cs and global fallout indicated that terrestrial particulate matter was the main source of^(137)Cs in fjord sediments.The sedimentation rate increased after 1997,possibly due to the increased influx of glacial meltwater containing debris.In addition,the^(137)Cs activity,percentage of organic carbon(OC),and OC/total nitrogen concentration ratio showed increasing trends toward the top of the core since 1997,corresponding to a decrease in the mass balance of glaciers in the region.The results ofδ^(13)C,δ^(15)N and OC/TN concentration ratio showed both terrestrial and marine sources contributed to the organic matter in Core Z3.The relative contribution of terrestrial organic matter which was calculated by a two-endmember model showed an increased trend since mid-1990s.All these data indicate that global climate change has a significant impact on Arctic glaciers. 展开更多
关键词 Kongsfjord RADIONUCLIDE organic carbon/total nitrogen(OC/TN)concentration ratio δ^(13)C δ^(15)N sediment record climate change
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Broadband and wide-angle plane focal surface Luneburg lens
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作者 李珏 周杨阳 陈焕阳 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期16-20,共5页
The energy crisis has aroused widespread concern, and the reform of energy structure is imminent. In the future,the energy structure will be dominated by the solar energy and other renewable energy sources. The solar ... The energy crisis has aroused widespread concern, and the reform of energy structure is imminent. In the future,the energy structure will be dominated by the solar energy and other renewable energy sources. The solar concentrating technology as a promising method has been widely studied for collecting solar energy. However, the previous solar concentrating technologies suffer from some drawbacks, such as low focusing efficiency and large concentrating size. The Luneburg lens with highly efficient aberration-free focusing provides a new route for solar/energy concentrator. In this work, we designed a plane focal surface Luneburg lens(PFSLL) by transformation optics(TO). The PFSLL provides a relatively high focusing efficiency and concentration ratio of collection of energy. At the same time, it circumvents the disadvantage of curve surface of the classical Luneburg lens in device integration. Based on the reciprocity of electromagnetic waves, the PFSLL can also be applied to the antenna field to achieve broadband wide-angle scanning and highly directional radiation. 展开更多
关键词 plane focal surface Luneburg lens(PFSLL) focusing efficiency concentration ratio of collection of energy
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Reagent optimization for on-line simultaneous polarographic determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of anextremely large excess of Zn^(2+) 被引量:4
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作者 WANG Guo-wei YANG Chun-hua +2 位作者 ZHU Hong-qiu LI Yong-gang GUI Wei-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2199-2204,共6页
Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their d... Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their doses for the experiment are selected according to the characteristics of the zinc sulfate solution. Then, the reagent doses are optimized by analyzing the influence of reagent dose on the polarographic parameters(i.e. half-wave potential E_(1/2) and limiting diffusion current I_p). Finally, the optimization results are verified by simultaneously determining trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). The determination results indicate that the optimized reagents exhibit wide linearity, low detection limits, high accuracy and good precision for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). 展开更多
关键词 on-line simultaneous determination trace polymetallic ions reagent optimization high concentration ratio
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Characterizing the influence of tide on the physico-chemical parameters and nutrient variability in the coastal surface water of the northern Bay of Bengal during the winter season 被引量:1
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作者 SOURAV Das ABHRA Chanda +2 位作者 SANDIP Giri ANIRBAN Akhand SUGATA Hazra 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第12期102-111,共10页
The spatial distribution of physico-chemical parameters(sea surface temperature(SST), p H, sea surface salinity(SSS), dissolved oxygen(DO) and Secchi depth) along with filterable nutrients(dissolved inorganic... The spatial distribution of physico-chemical parameters(sea surface temperature(SST), p H, sea surface salinity(SSS), dissolved oxygen(DO) and Secchi depth) along with filterable nutrients(dissolved inorganic nitrate(DIN),dissolved inorganic phosphate(DIP) and reactive silicate(DSi)) are measured in the winter months of November,December, January and February for four consecutive years from 2009–2010 to 2012–2013 on the shallow continental shelf(〈20 m bathymetry) of the coastal waters(up to 18 km away from shoreline) of the northern Bay of Bengal(n Bo B) during the highest high tide(HHT) and lowest low tide(LLT) hours for the first time. The variability of the coastal biogeochemical environment is assessed during the HHT and LLT hours and for this purpose, seawater samples are collected from seven different locations of a transect in the coastal region. Physicochemical parameters(except SST) show significant difference in magnitude during the HHT and LLT hours respectively. p H, SSS and DO are found to increase in the HHT hours and vice-versa. The data reveal that during the LLT hours, a relative increase of freshwater input in the n Bo B can have elevated the nutrient concentration compared with that observed during the HHT hours. The ratio of nutrient concentration is found to deviate significantly from the Redfield ratio. The abundance of DIP is much higher compared with that of DIN and DSi.The anthropogenic sources of DIP from the upstream flow(especially the domestic effluent of several metropolises) can be mainly attributed behind such an observation. In order to characterize and establish the trend of such variation in such an important bio-climatic region, long-term and systematic ecosystem monitoring in the coastal water of the n Bo B northern Bay of Bengal should be carried out throughout the year. 展开更多
关键词 physico-chemical parameters nutrient concentration and ratio winter season highest high tide lowest low tide northern Bay of Bengal
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A compact and high-power silicon-wafer solar strip-cells-array module integrated with an array concentrator
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作者 林洁 陈梦霞 +4 位作者 柯永琦 任彩莹 徐泽升 张耀举 方朝龙 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期614-617,共4页
A compact, low-cost and high-output-power silicon-wafer solar strip-cells-array module (SCAM) wus experimentally demonstrated. The proposed SCAM consisted mainly of a silicon-wafer strip-cell sparse array and low-co... A compact, low-cost and high-output-power silicon-wafer solar strip-cells-array module (SCAM) wus experimentally demonstrated. The proposed SCAM consisted mainly of a silicon-wafer strip-cell sparse array and low-concentration- ratio array concentrator based on an epoxy resin polymer (ERP) cylindrical piano-convex lens. A polymer replication process based on a polydimethylsiloxane mold was used to fabricate the ERP lens array concentrator. The results show that 46.94% of the silicon-wafer cell was saved in the designed SCAM. Moreover, the output power of the SCAM with a low concentration ratio of 8 suns was improved by 8.6%, compared with a whole piece of a conventional silicon-wafer solar cell with the same area as the module. The proposed method encapsulating solar cells provides a means to reduce the usage of silicon cells in modules as well as improving the output power of modules. 展开更多
关键词 epoxy resin polymer lens strip-cell array low concentration ratio
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Microfinance Structure of Thailand
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作者 Ravipan Saleepon 《Chinese Business Review》 2013年第12期807-813,共7页
This paper was devoted to analyzing the structure of microfinance in Thailand. The theory of industrial organization (IO) was applied as a guideline to measure the degree of monopoly power in microfinance structure.... This paper was devoted to analyzing the structure of microfinance in Thailand. The theory of industrial organization (IO) was applied as a guideline to measure the degree of monopoly power in microfinance structure. The objective-of the study was investigation on Thai microfinance institution marketing structure by using Concentration Ratio (CR) and Herfindahl Hirschman Index (HHI). The data of the study focus on the outstanding loans market share of microfinance institutions (MFIs). The market share of the outstanding loans of MFIs from the largest to the smallest is as follows: Bank for Agriculture and Agricultural Cooperatives (BAAC), Village Fund Cooperatives, Government Saving Bank (GSB), Pawnshop, Self Help group: Saving Group, Commercial Bank, Self Help Group: Sudja Group and Isalamic Bank (IB), respectively. It stated that CR by outstanding loans is as follows: Cr 1, 59.35%; Cr 3, 81.11%; Cr 6, 92.14%; and Cr 9, 94.37%. At the same time HHI is 0.38. Additionally, BAAC remains the majority MFIs even though there are the other MFIs available in the microfinance system. The main role of providing the microfinance services mostly derived from BAAC. 展开更多
关键词 microfinance institutions (MFIs) market structure Concentration ratio (CR) Herfindahl HirschmanIndex (HHI)
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Flame Propagation Through Concentration Gradient
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作者 JunyaIINO MitsuakiTANABE 《Journal of Thermal Science》 SCIE EI CAS CSCD 2000年第4期371-375,共5页
The experiment was carried out in homogeneous propane-air mixture and in several concentration gradient of mixture. Igniter is put on the upper side of the combustion chamber In concentration gradient experiment, fixt... The experiment was carried out in homogeneous propane-air mixture and in several concentration gradient of mixture. Igniter is put on the upper side of the combustion chamber In concentration gradient experiment, fixture was ignited from lean side. An experimental study was conducted in a combustion chamber. The combustion chamber has glass windows for optical measurements at any side. For the measurement of distribution of fuel concentration, infrared absorption method using 3.39μm He-Ne laser was used, and for the observation of propagating flame, Schlieren method was employed. As a measurement result of flame propagation velocity and flammable limit, for a mixture of an identical local equivalence ratio, flame propagation velocity in concentration gradient is faster than that in homogeneous mixture, and rich flammable limit in concentration gradient shows a tendency to be higher than that in homogeneous mixture. 展开更多
关键词 COMBUSTION name propagation homogeneous mixture concentration gradient local equivalence ratio.
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The Income Redistribution Effect of Government Transfer Programs 被引量:1
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作者 Xu Jing Cai Meng +1 位作者 Yue Ximing Wang Wen’e 《Social Sciences in China》 2020年第1期79-99,共21页
The use of the trajectory of the Gini coefficient of total income formed by the increase in transfer income combined with the minimum Gini coefficient curve enables us to provide a comprehensive examination of the eff... The use of the trajectory of the Gini coefficient of total income formed by the increase in transfer income combined with the minimum Gini coefficient curve enables us to provide a comprehensive examination of the effect of government income redistribution policies,measure the efficiency of transfer income for income redistribution,and redress the methodological defects of research using the MT index and Gini coefficient decomposition.The findings of our new method of estimation show that China’s social security expenditure can reduce the income gap,but its efficiency in terms of redistribution is relatively low and has already passed the turning point of the Gini coefficient trajectory,resulting in some people being“over-allocated.”Readjusting the distribution of governmental transfers can help lower the Gini coefficient of residents’total income. 展开更多
关键词 redistribution policies dynamic concentration ratio trajectory of the Gini coefficient minimum Gini coefficient curve
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