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从“西盐”到“盐官”:陇蜀易盐史的演进与变迁 被引量:2
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作者 蒲向明 《盐业史研究》 CSSCI 2020年第3期11-19,共9页
陇蜀通道的军事经济往来,在周秦时期就有。秦封泥“西盐”的出土,标志着陇蜀营盐活动和易盐历史在秦早期就已发端。从“西盐”到“盐官”的演进,实际在秦汉时期的陇蜀交通领域已经基本完成。在整个陇蜀易盐史的演进与变迁中,西汉水流域... 陇蜀通道的军事经济往来,在周秦时期就有。秦封泥“西盐”的出土,标志着陇蜀营盐活动和易盐历史在秦早期就已发端。从“西盐”到“盐官”的演进,实际在秦汉时期的陇蜀交通领域已经基本完成。在整个陇蜀易盐史的演进与变迁中,西汉水流域的盐官设置及其机制的发挥贯穿着整个汉后历史进程,基本属于秦汉“盐官”体制的继承和发展。整个陇蜀营盐和易盐史的变迁,表现为周秦以来“盐官”制度源与流的演进,其脉络清晰地反映了中国西北—西南一线营盐易盐史的主要特征和内涵。由此表明,陇蜀易盐史早就成为了中华盐文化史不可或缺的组成部分。 展开更多
关键词 周秦 西 陇蜀 营盐 演进与变迁
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秦早期“西盐”与陇蜀易盐历程之消长 被引量:1
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作者 蒲向明 《文史杂志》 2020年第5期49-54,共6页
西汉水上游盐官营盐,从周秦以来至民国两千余年不乏"西盐"之称。秦汉时官营规模已大,私营情况不得而知,但肯定存在着公、私易盐并存的局面,只是私盐营运要卑弱得多。魏晋南北朝至隋唐,除战乱等的非正常情况外,营盐状况基本上... 西汉水上游盐官营盐,从周秦以来至民国两千余年不乏"西盐"之称。秦汉时官营规模已大,私营情况不得而知,但肯定存在着公、私易盐并存的局面,只是私盐营运要卑弱得多。魏晋南北朝至隋唐,除战乱等的非正常情况外,营盐状况基本上相差无几。宋时因为宋夏、宋金国势变化,陇蜀成为重要一线,盐官盐井为全国闻名。其产量和规模的剧增,一度出现了陇盐入蜀的情况。虽然历代都主政官营、打击民间私营,但西汉上游盐官的食盐生产、销售伴随着历代王朝的监管和调控,总有私营入蜀或至汉中的事实。考古证明民间陇蜀易盐还关涉南北丝绸之路。总体看,陇蜀易盐经历了朝廷征收过渡到间接专卖而后民间经营占主体的一个历程。西汉水上游的盐官镇成为陇蜀毗连地域重要的营盐和易盐中心,其历史地位和社会意义应予重估。 展开更多
关键词 秦早期 西 陇蜀道 营盐
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秦早期“西盐”与陇蜀易盐历程之消长
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作者 蒲向明 《咸阳师范学院学报》 2020年第3期6-11,共6页
西汉水上游盐官营盐,自周秦至民国存续两千余年,称为"西盐"。秦汉时官营规模已大,私营情况不得而知,但肯定存在着公、私易盐并存的局面。魏晋南北朝至隋唐,除战乱等非正常情况外,营盐状况基本上相差无几。宋时因为宋夏、宋金... 西汉水上游盐官营盐,自周秦至民国存续两千余年,称为"西盐"。秦汉时官营规模已大,私营情况不得而知,但肯定存在着公、私易盐并存的局面。魏晋南北朝至隋唐,除战乱等非正常情况外,营盐状况基本上相差无几。宋时因为宋夏、宋金国势变化,陇蜀成为重要一线,盐官盐井产量和规模剧增,一度出现陇盐入蜀的情况,考古证明民间陇蜀易盐还关涉南北丝绸之路。总体看,陇蜀易盐经历了朝廷征收到间接专卖到民间经营占主体的历程。西汉水上游的盐官镇作为陇蜀毗连地域重要的营盐和易盐中心,其历史地位和社会意义应予重估。 展开更多
关键词 秦早期 西 陇蜀道 营盐
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Effect of Fouling in Daya Bay Scallop chlamys nobilis (reeve) Cultivation:Food Competition and Nutrient Release 被引量:3
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作者 苏振霞 肖辉 +1 位作者 黄良民 严岩 《Marine Science Bulletin》 CAS 2009年第2期37-44,共8页
Biofouling is an important factor that affects bivalve farming industry. Fouling organisms may reduce growth and survival rate of the cultured species. Fouler are often filter feeders, so they are potential competitor... Biofouling is an important factor that affects bivalve farming industry. Fouling organisms may reduce growth and survival rate of the cultured species. Fouler are often filter feeders, so they are potential competitors for food resource with the cultured species. The present study was conducted to measure the impact of fouling on food uptake and nutrient release in April, 2006 in Daya Bay near Guangzhou, China. Results showed that fouling organisms had significant effect on food uptake and nutrient release. The chlorophyll a uptake rate of fouled scallops was 7.53 / Lh ±1.416 / Lh in April, significantly higher than those of cleaned scallops, Le., 4.23 / Lh±2.744 / Lh. The consumption of total particulate matter by fouled scallops in April was 5.52 / Lh± 0.818 / Lh; the corresponding results for cleaned scallops are 2.49 / Lh ±0.614 / Lh Fouling increased ammonia release significantly. The ammonia release rate of fouled scallops was 33.81/Lh ±7.699 / Lh in April, while cleaned scallops released 2.46 / Lh ±0.511 / Lh ammonia. Phosphate uptake of fouled scallops was 2.01± 0.699 / Lh and cleaned scallops released phosphate 6.01 / Lh + 0.876 / Lh in April. There was not significant difference in nitrate consumption between fouled and cleaned scallops. According to the phytoplankton classification of input and output water samples, fouled scallops filtered more phytoplankton species than cleaned scallops. Therefore, this study showed that fouling contributed much to phytoplankton depletion and concentration increase of ammonia in water. 展开更多
关键词 SCALLOP Chlamys nobilis FOULING food uptake nutrient release
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Preliminary Discussion on the Sea Water Quality Status in the 2008 Olympics Boat-sailing Field and Adjacent Area 被引量:1
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作者 石晓勇 陈莉莉 +1 位作者 祝陈坚 王修林 《Marine Science Bulletin》 CAS 2007年第2期90-96,共7页
A cruise of survey in the 2008 Olympics boat-sailing field and adjacent area was carried out on August 28^th, 2003. Preliminarily analysis on the eutrophication status was made on the basis of the content of dissolved... A cruise of survey in the 2008 Olympics boat-sailing field and adjacent area was carried out on August 28^th, 2003. Preliminarily analysis on the eutrophication status was made on the basis of the content of dissolved inorganic nitrogen (DIN), dissolved inorganic phosphate (PO4-P), dissolved oxygen(DO) and chemical oxygen demand (COD) as well. The results indicated that in most of the survey area, water quality was in accordance with the 1^st class National Seawater Standard except the average concentration of petroleum hydrocarbon which was beyond the 2^nd class National Seawater Standard. The concentrations of PO4-P as well as DIN were mainly influenced by the runoff or drainage from lands, with a comparatively higher concentration in the coastal areas from the Fushan Bay to the Shilaoren bathing beach. The distribution of eutrophication index (El) showed that part of the survey area was in a state of slight eutrophication The eutrophication was mostly influenced by the land runoff or drainage and related factors. The sea water quality of the Olympic boat-sailing field was fine and just slightly polluted on the whole. 展开更多
关键词 the 2008 Olympic boat-sailing field nutrients EUTROPHICATION pollution
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Indoor Simulation Study on Nutrient Release of Fishponds Sediment 被引量:2
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作者 杜旭彤 谢骏 +2 位作者 王广军 余德光 赵旭斌 《Agricultural Science & Technology》 CAS 2009年第3期127-130,138,共5页
[Objective] The study aimed to research the nutrients release of ponds sediment.[Method] The sediments which from a new pond(A) and an old one (B) these analyses used to carry out indoor experiment under the anaerobic... [Objective] The study aimed to research the nutrients release of ponds sediment.[Method] The sediments which from a new pond(A) and an old one (B) these analyses used to carry out indoor experiment under the anaerobic dark condition for researching on nutrient release. The N(nitrogenous) and P(phosphorous) release were analyzed every two days.[Result] At the prophase, the N release in B was bigger than that in A, while the decline sediment release in A was gentle.[Conclusion] There was no accumulation of organic compound during the breeding time. The NH4-N was the main form of N release; and the P release was correlated with N release, while PO4-P was the main form of P release. 展开更多
关键词 SEDIMENT Nutrient release Indoor simulation study Oxidation reduction potential (ORP)
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Responses of Picoplankton to Nutrient Perturbation in the South China Sea, with Special Reference to the Coast-wards Distribution of Prochlorococcus 被引量:3
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作者 焦念志 杨燕辉 +2 位作者 Hiroshi KOSHIKAWA Shigeki HARADA Masataka WATANABE 《Acta Botanica Sinica》 CSCD 2002年第6期731-739,共9页
Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosp... Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosphorus- (P), iron- (Fe), and cobalt- (Co) enriched incubations in the South China Sea in November 1997. Variations in abundance of the 4 groups of microorganism and cellular pigment content of the autotrophs during incubation were followed by flow-cytometric measurements for seven days. During the incubation, Syn and Euk showed a relatively higher demand on Fe and N, while Pro required higher levels of Co and P. The Fe was inadequate for all the organisms in the deep euphotic zone (75 m) of the study area. The experimental results also implied that biological interaction among the organisms played a role in the community structure shift during the incubation. It seemed that besides the effects of temperature, there are some other physical and chemical limitations as well as impacts from biological interactions on Pro distribution in coast waters. 展开更多
关键词 PROCHLOROCOCCUS PICOPLANKTON NUTRIENTS iron cobalt South China Sea
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The Effects of Nutrition Lick Brick and Salt Brick as Supplement Feed on the Production Performance of Tan Sheep 被引量:2
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作者 梅宁安 丁建宁 陈桂芬 《Agricultural Science & Technology》 CAS 2015年第6期1199-1200,1300,共3页
In the paper, the effects of nutrition lick brick and salt brick as supple-ment feed on the performance of Tan sheep were studied. 36 fattening Tan sheep with the average weight of about 23 kg were chosen, they were r... In the paper, the effects of nutrition lick brick and salt brick as supple-ment feed on the performance of Tan sheep were studied. 36 fattening Tan sheep with the average weight of about 23 kg were chosen, they were randomly divided into 3 groups according to the weight, and each group had 12 sheep. Control group was fed with normal daily ration, experimental group 1 was fed with normal daily ration+nutrition lick brick, experimental group 2 was fed with normal daily ration+salt brick, the experimental period was 60 d. The results showed that 1) compared with CK, daily gain of group 1 improved 17.09%(P〈0.01), feed conversion ratio reduced 11.69%(P〈0.05), and average gross profit per sheep improved 51.65 yuan; daily gain of group 2 improved 7.03%(P〈0.05), feed conversion ratio reduced 4.06%(P〉0.05), and average gross profit per sheep improved 19.78 yuan; 2) compared with group 2, daily gain of group 1 improved 9.40%(P〈0.05), feed conversion ratio re-duced 7.96%(P〈0.05), and average gross profit per sheep improved 31.87 yuan;these indicated that nutrition lick brick and salt brick as supplement feed for Tan sheep both can improve the production performance of Tan sheep, and the supple-mentary feeding effect of nutrition lick brick was better. 展开更多
关键词 Nutrition lick brick Salt brick Tan sheep Supplement feed
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Effect of Different K^+/Mg^(2+) Ration Nutrient Solutions on Soil Salinity
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作者 张敬敏 隋申利 魏珉 《Agricultural Science & Technology》 CAS 2017年第2期262-265,共4页
Using simulated soil column experiments, the effects of different dosages and ratios of KCI and MgCI2 mixture on salinization nutrient ions in the secondary salinization soil which had 3 years of planting were studied... Using simulated soil column experiments, the effects of different dosages and ratios of KCI and MgCI2 mixture on salinization nutrient ions in the secondary salinization soil which had 3 years of planting were studied, with the aim to provide the theory basis for the remediation of secondary salinization soil. Results showed that the content of soil K-, Mg2+, CI- and the total salinity were increased, with the increasing concentrations of nutrient solution, while Na+, Ca2+ and HCO3- contents were reduced. Compared with originals oil, soil K+, Na+, Ca2+, Mg2+, CI- and total soil salinity were decreased, and HCO3- and SO42 were increased. In terms of the variation of soil total charge, the change ranges in 1:1 treatment varied small, but the residual of soil cationic decreased with increasing application of K+ in the 2:1 treatment. It could be concluded that balanced and low application fertilizer could alleviate the soil saline, decrease the soil nutrition leaching and improve the balance among ions, while excess fertilization could accelerate the imbalance of zwitterions. 展开更多
关键词 Nutrient solution Soil in greenhouse Soil secondary salinization
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Effect of K^+ Nutrition on Growth and Activity of Leaf Tonoplast V-H^+-ATPase and V-H^+-PPase of Suaeda salsa Under NaCl Stress 被引量:12
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作者 李平华 陈敏 王宝山 《Acta Botanica Sinica》 CSCD 2002年第4期433-440,共8页
Suaeda salsa L. seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of K + (12 μmol/L and 6 mmol/L) to study the K + nutrition effect on plant g... Suaeda salsa L. seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of K + (12 μmol/L and 6 mmol/L) to study the K + nutrition effect on plant growth and leaf tonoplast V-H +-ATPase and V-H +-PPase activity. Increase of K + supply in the culture solution markedly increased the fresh weight, dry weight and K + content of S. salsa plants. Western blot analysis showed that the leaf V-H +-ATPase of S. salsa was at least composed of A,B,C,D,E and c subunits, and their expression decreased with the increase of NaCl concentration under K + starvation (12 μmol/L K +), but increased under normal K + application (6 mmol/L K +). Leaf V-H +-PPase molecular weight was about 72.6 kD and its expression increased as NaCl concentration increased under both high or low levels of K + concentration in nutrient solution. There was a positive correlation between of V-H +-ATPase or V-H +-PPase activity and the amounts of their expression. Results in this study suggest that K + nutrition plays an important role in the salt tolerance of S. salsa, and K + is involved in the regulation of V-H +-ATPase or V-H +-PPase activity under salt stress. 展开更多
关键词 Suaeda salsa GROWTH V-H +-ATPase V-H +-PPase K + nutrition
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Mechanisms of Enhanced Rice Growth and Nitrogen Uptake by Nitrate 被引量:6
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作者 DUAN Ying-Hua YIN Xiao-Ming ZHANG Ya-Li SHEN Qi-Rong 《Pedosphere》 SCIE CAS CSCD 2007年第6期697-705,共9页
Rice is being increasingly cultivated in intermittently irrigated regions and also in aerobic soil in which Nitrate (NO3^- ) plays important role in nutrition of plant. However, there is no information regarding the... Rice is being increasingly cultivated in intermittently irrigated regions and also in aerobic soil in which Nitrate (NO3^- ) plays important role in nutrition of plant. However, there is no information regarding the influence of nitrate on the overall growth and uptake of nitrogen (N) in rice plant. Solution culture experiments were carried out to study the effects of NO^3- on the plant growth, uptake of N, and uptake kinetics of NH4^+ in four typical rice (Oryza sativa L.) cultivars (conventional indica, conventional japonica, hybrid indica, and hybrid japonica), and on plasma membrane potential in roots of two conventional rice cultivars (indica and japonica) at the seedling stage. The results obtained indicated that a ratio of 50/50 NH4^+-N/NO3^--N increased the average biomass of rice shoots and roots by 20% when compared with that of 100/0 NH4^+-N/NO3^--N. In case of the 50/50 ratio, as compared with the 100/0 ratio, total N accumulated in shoots and roots of rice increased on an average by 42% and 57%, respectively. Conventional indica responds to NO3^- more than any other cultivars that were tested. The NO^3- supply increased the maximum uptake rate (Vmax) of NH4^+ by rice but did not show any effect on the apparent Michaelis-Menten constant (Km) value, with the average value of Vmax for NH4^+ among the four cultivars being increased by 31.5% in comparison with those in the absence of NO3^-. This suggested that NO3^- significantly increased the numbers of the ammonium transporters. However, the lack of effect on the Km value also suggested that the presence of NO3^- had no effect on the affinity of the transporters for NH4^+. The plasma membrane potential in the roots of conventional indica and japonica were greatly increased by the addition of NO3^- , suggesting that NO3^- could improve the uptake of N by roots of the rice plant. In conclusion, the mechanisms by which NO3^- enhances the growth and N uptake of rice plant was found by the increased value of Vmax of NH4^+ and increased plasma membrane potential. Thus promotion of nitrification in paddy soil is of great significance for improving the production of rice. 展开更多
关键词 ammonium uptake nitrate nutrition nitrogen uptake plasma membrane potential RICE
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Nutrient and chlorophyll a anomaly in red-tide periods of 2003-2008 in Sishili Bay, China 被引量:8
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作者 郝彦菊 唐丹玲 +1 位作者 喻龙 邢前国 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第3期664-673,共10页
Sishili Bay is the most important aquiculture and tourism area for the city of Yantai, China; however, red tides occurred frequently and have caused huge economic losses in this bay in recent years. To gain a better u... Sishili Bay is the most important aquiculture and tourism area for the city of Yantai, China; however, red tides occurred frequently and have caused huge economic losses in this bay in recent years. To gain a better understanding of the local ecological environments in the bay, we conducted this research between 2003 and 2008 to analyze variations in nutrients and chlorophyll (chl-a) during high frequency red tide period (May to September). The results show that the chl-a concentration increased from 2.70 in 2003 to 7.26 mg/m3 in 2008, while the concentration of total inorganic nitrogen (TIN) and silicate (SiO3-Si) increased lineally from 5.18 and 1.45 pmol/L in 2003 to 18.57 and 9.52 pmol/L in 2008, respectively, and the annual phosphate (PO4-P) varied between 0.15 and 0.46 μmol/L. Special attention was given to a red tide in August 2007 occurred when water temperature was high and nutrient concentrations increased sharply because of a heavy rainfall. Overall, the results show the P limitation in Sishili Bay, and reveal that red tides were caused by eutrophication from terrestrial inputs and local warm weather, particularly during rainy periods. Therefore, to control red tide, greater efforts should be made to reduce sewage discharges into Sishili Bay, particularly during rainfall seasons. 展开更多
关键词 CHL-A TIN PO4-P red tide frequency Sishili Bay
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Nutrient Structure of the Taiwan Warm Current and Estimation of Vertical Nutrient Fluxes in Upwelling Areas in the East China Sea in Summer 被引量:5
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作者 SHI Xiaoyong LI Hongmei WANG Hao 《Journal of Ocean University of China》 SCIE CAS 2014年第4期613-620,共8页
Based on field data for nutrients collected on the continental shelf of the East China Sea(ECS) during summer 2006, the structure and variations of nutrients in every water mass related to the Taiwan Warm Current(TWC)... Based on field data for nutrients collected on the continental shelf of the East China Sea(ECS) during summer 2006, the structure and variations of nutrients in every water mass related to the Taiwan Warm Current(TWC) were analyzed. The supplementary effect of nutrient of upwelling on harmful algal blooms(HABs) in the ECS was also estimated, based on upwelling data. Then the maintenance contribution of nutrient of upwelling to HABs was assessed. The results showed that N/P ratio is fairly low in both surface and deep layers of the TWC, which possibly controls nutrient structure of the HABs-frequently-occuring areas. In upwelling areas, the rate of phosphate(PO4-P) uptake exceeds that of nitrate(NO3-N) of the TWC. The TWC may relieve PO4-P limitation during the process of HABs. Furthermore, upwelling plays an important role in providing nutrients to HABs. After estimating nutrient fluxes(NO3-N, PO4-P, Si O3-Si) in the upwelling areas along a typical section(S07), the results showed that the nutrient uptake rate is the greatest at 10-20 m below euphotic zone, sustaining the ongoing presence of HABs. The uptake rate of PO4-P is the highest among dissolved inorganic nutrients. Therefore, upwelling is most likely the main source of PO4-P supply to HABs. 展开更多
关键词 nutrient structure FLUX Taiwan Warm Current UPWELLING East China Sea
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Characteristics of the δ15NNO3 distribution and its drivers in the Changjiang River estuary and adjacent waters 被引量:3
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作者 王文涛 俞志明 +4 位作者 宋秀贤 吴在兴 袁涌铨 周鹏 曹西华 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第2期367-382,共16页
In this study, we conducted investigations in the Changjiang (Yangtze) River estuary and adjacent waters (CREAW) in June and November of 2014. We collected water samples from different depths to analyze the nitrog... In this study, we conducted investigations in the Changjiang (Yangtze) River estuary and adjacent waters (CREAW) in June and November of 2014. We collected water samples from different depths to analyze the nitrogen isotopic compositions of nitrate, nutrient concentrations (including inorganic N, P, and Si), and other physical and biological parameters, along with the vertical distribution and seasonal variations of these parameters. The compositions of nitrogen isotope in nitrate were measured with the denitrifier method. Results show that the Changjiang River diluted water (CDW) was the main factor affecting the shallow waters (above 10 m) of the CREAW, and CDW tended to influence the northern areas in June and the southern areas in November. 615Nrqo~ values in CDW ranged from 3.21%o-3.55%o. In contrast, the deep waters (below 30 m) were affected by the subsurface water of the Kuroshio Current, which intruded into the waters near 3 I^N in June. The ~iI^NNo3 values of these waters were 6.03%0-7.6%0, slightly higher than the values of the Kuroshio Current. Nitrate assimilation by phytoplankton in the shallow waters of the study area varied seasonally. Because of the favorable temperature and nutrient conditions in June, abundant phytoplankton growth resulted in harmful algae blooms (HABs). Therefore, nitrate assimilation was strong in June and weak in November. The ~15NNo3 fractionations caused by assimilation of phytoplankton were 4.57%0 and 4.41%o in the shallow waters in June and November, respectively. These results are consistent with previous laboratory cultures and in situ investigations. Nitrification processes were observed in some deep waters of the study area, and they were more apparent in November than in June. The fractionation values of nitrification ranged from 24%0-25%o, which agrees with results for Nitrosospira tenuis reported by previous studies. 展开更多
关键词 Changjiang River estuary NITRATE nitrogen isotope ASSIMILATION NITRIFICATION
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Tempo-spatial Variation of Nutrient and Chlorophyll-a Concentrations From Summer to Winter in the Zhangzi Island Area (Northern Yellow Sea) 被引量:4
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作者 YIN Jiehui ZHAO Zengxia +2 位作者 ZHANG Guangtao WANG Shiwei WAN Aiyong 《Journal of Ocean University of China》 SCIE CAS 2013年第3期373-384,共12页
Nutrient and Chlorophyll-a (Chl-a) concentrations were investigated monthly along three transects extending from a mariculturc area to open waters around the Zhangzi Island area from July to December 2009. The objec... Nutrient and Chlorophyll-a (Chl-a) concentrations were investigated monthly along three transects extending from a mariculturc area to open waters around the Zhangzi Island area from July to December 2009. The objective of this study is to illus- trate food availability to the bottom-sowed scallop Patinopecten yessoensis under the influences of the Yellow Sea Cold Water Mass (YSCWM), freshwater input and feedbacks of cultivated scallops. Significant thermal stratification was present in open waters from July to October, and salinity decreased in July and August in surface layers in the mariculture area. Nutrient concentrations increased with depth in both areas in summer, but were similar through water column in November and December. On average, nutrient in- creased from summer to autumn in all components except ammonia. Nutrient concentrations lower than the minimum thresholds for phytoplankton growth were present only in upper layers in summer, but stoichiometric nitrogen limitation existed in the entire inves- tigation period. Column-averaged Chl-a concentration was lower in open waters than in mariculture area in all months. It increased significantly in mariculturc area in August and October, and was less variable in open waters. Our results show that nutrients limita- tion to phytoplankton growth is present mainly in upper layer in association with stratification caused by YSCWM in summer. Freshwater input and upwelling of nutrients accumulated in YSCWM can stimulate phytoplankton production in mariculture area. Farming activities may change stoichiometric nutrient ratios but have less influence on Chl-a concentration. 展开更多
关键词 Zhangzi Island CHLOROPHYLL-A nutrients scallop farming the Yellow Sea Cold Water Mass
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The influence of urbanization on karst rivers based on nutrient concentration and nitrate dual isotopes: an example from southwestern China 被引量:2
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作者 Zhong-Jun Wang Fu-Jun Yue +1 位作者 Jie Zeng Si-Liang Li 《Acta Geochimica》 EI CAS CSCD 2017年第3期446-451,共6页
China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore th... China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore the influence of urbanization on river ecosystems based on nutrient concentration and nitrate isotopes. The results show monthly variability of water chemistry and nutrient concentration. Nutrient concentration in two tributaries and the mainstem showed significant spatial variability, with heavy N and P pollution in one tributary near a suburban area,indicating a response to different levels of urbanization.Measurements of nitrate dual isotopes suggest thatvolatilization, assimilation, nitrification, and denitrification all occur in the polluted river. Water chemistry and nitrate isotopes show that major nitrogen sources included domestic waste and agricultural input, such as chemical fertilizer and manure. The results suggest that urbanization increases nutrient concentrations and accelerates the riverine nitrogen dynamic, and point to the need to manage point sources of sewage effluents to improve the water quality of urban rivers in southwestern China. 展开更多
关键词 URBANIZATION Urban river Nitrate isotopes Southwestern China Chengguan River
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Spatiotemporal Variation of Riverine Nutrients in a Typical Hilly Watershed in Southeast China Using Multivariate Statistics Tools 被引量:2
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作者 NIE Xiao-fei LI Heng-peng +2 位作者 JIANG Jia-hu DIAO Ya-qin LI Peng-cheng 《Journal of Mountain Science》 SCIE CSCD 2015年第4期983-998,共16页
The water quality of lakes can be degraded by excessive riverine nutrients.Riverine water quality generally varies depending on region and season because of the spatiotemporal variations in natural factors and anthrop... The water quality of lakes can be degraded by excessive riverine nutrients.Riverine water quality generally varies depending on region and season because of the spatiotemporal variations in natural factors and anthropogenic activities.Monthly water quality measurements of eight water quality variables were analyzed for two years at 16 sites of the Tianmuhu watershed.The variables were examined using hierarchical cluster analysis(HCA) and factor analysis/principal component analysis(FA/PCA) to reveal the spatiotemporal variations in riverine nutrients and to identify their potential sources.HCA revealed three geographical groups and three periods.Two drainages comprising towns and large villages were the most polluted, six drainages comprising widely distributed tea plantations and orchards were moderately polluted, and eight drainages without the factors were the least polluted.The river was most polluted in June when the first heavy rain(daily rainfall > 50 mm) occurs after fertilization and the number of rainy days is most(monthly number of rainy days > 20 days).Moderate pollution was observed from October to May, during which morethan 60% of the total nitrogen fertilizer and all of the phosphorus fertilizer are applied to the cropland, the total manure is applied to tea plantations and orchards, and a monthly rainfall ranging from 0 mm to 164 mm occurs.The remaining months were characterized by frequent raining(i.e., number of rainy days per month ranged from 5 to 24) and little use of fertilizers, and were thus least polluted.FA/PCA identified that the greatest pollution sources were the runoff from tea plantations and orchards,domestic pollution and the surface runoff from towns and villages, and rural sewage, which had extremely high contributions of riverine nitrogen, phosphorus,and chemical oxygen demand, respectively.The tea plantations and orchards promoted by the agricultural comprehensive development(ACD) were not environmentally friendly.Riverine nitrogen is a major water pollution parameter in hilly watersheds affected by ACD, and this parameter would not be reduced unless its loss load through the runoff from tea plantations and orchards is effectively controlled. 展开更多
关键词 Nitrogen Phosphorus Chemical oxygen demand Spatial variation Temporal variation Water quality FERTILIZATION Tianmuhu watershed
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Does salinity change determine zooplankton variability in the saline Qarun Lake(Egypt)? 被引量:1
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作者 Gamal M.EL-SHABRAWY Elena V.ANUFRIIEVA +2 位作者 Mousa O.GERMOUSH Mohamed E.GOHER Nickolai V.SHADRIN 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第6期1368-1377,共10页
Zooplankton and 14 abiotic variables were studied during August 2011 at 10 stations in Lake Qarun, Egypt. Stations with the lowest salinity and highest nutrient concentrations and turbidity were close to the discharge... Zooplankton and 14 abiotic variables were studied during August 2011 at 10 stations in Lake Qarun, Egypt. Stations with the lowest salinity and highest nutrient concentrations and turbidity were close to the discharge of waters from the El-Bats and E1-Wadi drainage systems. A total of 15 holozooplankton species were identified. The salinity in Lake Qarun increased and fluctuated since 1901:12 g/L in 1901; 8.5 g/L in 1905; 12.0 g/L in 1922; 30.0 g/L in 1985; 38.7 g/L in 1994; 35.3 g/L in 2006, and 33.4 g/L in 2011. The mean concentration of nutrients (nitrate, nitrite and orthophosphate) gradually increased from 35, 0.16 and 0.38 μg/L, respectively, in 1953-1955 to 113, 16.4, and 30.26 μg/L in 2011. From 1999-2003 some decrease of species diversity occurred. Average total zooplankton density was 30 000 ind./m^3 in 1974-1977; 356 125 ind./m^3 in 1989; 534 000 ind./m^3 in 1994-1995; from 965 000 to 1 452 000 ind./m^3 in 2006, and 595 000 ind./m^3 in 2011. A range of long-term summer salinity variability during the last decades was very similar to a range of salinity spatial variability in summer 2011. There is no significant correlation between zooplankton abundance and salinity in spatial and long-term changes. We conclude that salinity fluctuations since at least 1955 did not directly drive the changes of composition and abundance of zooplankton in the lake. A marine community had formed in the lake, and it continues to change. One of the main drivers of this change is a regular introduction and a pressure of alien species on the existent community. Eutrophication also plays an important role. The introduction ofMnemiopsis leidyi, first reported in 2014, may lead to a start of a new stage of the biotic changes in Lake Qarun, when eutrophication and the population dynamics of this ctenophore will be main drivers of the ecosystem change. 展开更多
关键词 saline lake Copepoda ROTIFERA Mnemiopsis leidyi alien species
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New Insights into the Nitrogen Form Effect on Photosynthesis and Photorespiration 被引量:8
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作者 GUO Shi-Wei ZHOU Yi GAO Ying-Xu LI Yong SHEN Qi-Rong 《Pedosphere》 SCIE CAS CSCD 2007年第5期601-610,共10页
Under high light conditions, ammonium nutrition has a negative effect on plant growth. This suggests that the adverse effects of ammonium nutrition on plant growth may be related to carbon gain, photosynthesis, and ph... Under high light conditions, ammonium nutrition has a negative effect on plant growth. This suggests that the adverse effects of ammonium nutrition on plant growth may be related to carbon gain, photosynthesis, and photorespiration. However, there is no consistent evidence of a specific mechanism that could explain the plant growth reduction under ammonium supply. It is generally accepted that during the light reaction, a surplus of nicotinamide adenine dinucleotide hydrogen phosphate (NADPH) is produced, which is not completely used during the assimilation of CO2, Nitrate reduc- tion in the leaf represents an additional sink for NADPH that is not available to ammonium-grown plants. Nitrate and ammonium nutrition may use different pathways for NADPH consumption, which leads to differences in photosynthesis and photorespiration. The morphological (i.e., cell size, mesophyll thickness, and chloroplast volume) and enzymic (i.e., ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPCase), and glutamine synthetase/glutamate synthetase (GS/GOGAT)) differences that develop when plants are treated with either nitrate or ammonium nitrogen forms are related to photosynthesis and photorespiration. The differences in photorespiration rate for plants treated with nitrate or ammonium are related to the conversion of citrate to 2-oxoglutarate (2-OG) and photorespiratory CO2 refixation. 展开更多
关键词 AMMONIUM NITRATE nitrogen form PHOTORESPIRATION PHOTOSYNTHESIS
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Glutamine-supplemented total parenteral nutrition attenuates plasma interleukin-6 in surgical patients with lower disease severity 被引量:5
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作者 Ming-Tsan Lin Sung-Pao Kung +5 位作者 Sung-Ling Yeh Koung-Yi Liaw Ming-Yang Wang Ming-Liang Kuo Po-Houng Lee Wei-Jao Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第39期6197-6201,共5页
AIM: To evaluate whether the effect of Gin dipeptideenriched total parenteral nutrition (TPN) on postoperative cytokine alteration depended on the disease severity of surgical patients. METHODS: Forty-eight patien... AIM: To evaluate whether the effect of Gin dipeptideenriched total parenteral nutrition (TPN) on postoperative cytokine alteration depended on the disease severity of surgical patients. METHODS: Forty-eight patients with major abdominal surgery were allocated to two groups to receive isonitrogenous (0.228 g nitrogen/kg per d) and isocaloric (30 kcal/kg per d) TPN for 6 d. Control group (Cony) using conventional TPN solution received 1.5 g amino acids/kg per day, whereas the test group received 0.972 g amino acids/kg per day and 0.417 g L-alanyI-L-glutamine (Ala-GIn)/kg per day. Blood samples were collected on d 1 and d 6 postoperatively for plasma interleukin (IL)-2, IL-6, IL-8, and interferon (IFN)-γ analysis. RESULTS: Plasma IL-2 and IFN-γ were not detectable. IL-6 concentrations were significantly lower on the 6^th postoperative day in the Ala-GIn group than those in the Cony group in patients with APACHE Ⅱ≤6, whereas no difference was noted in patients with APACHE Ⅱ〉6. There was no difference in IL-8 levels between the two groups. No difference in cumulative nitrogen balance was observed on d 2-5 after the operation between the two groups (Ala-GIn -3.2±1.6 g vs Cony -6.5±2.7 g). A significant inverse correlation was noted between plasma IL-6 levels and cumulative nitrogen balance postoperatively in the Ala-GIn group, whereas no such correlation was observed in the Conv group. CONCLUSION: TPN supplemented with Gin dipeptide had no effect on plasma IL-8 levels after surgery. However, Gin supplementation had a beneficial effect on decreasing systemic IL-6 production after surgery in patients with low admission illness severity, and lower plasma IL-6 may improve nitrogen balance in patients with abdominal surgery when Gin was administered. 展开更多
关键词 GLUTAMINE Total parenteral nutrition INTERLEUKIN-6 Abdominal surgery
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