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51.
52.
Janja Vidmar Tea Zuliani Petra Novak Ana Drinčić Janez Ščančar Radmila Milačič 《Journal of Soils and Sediments》2017,17(7):1917-1927
Purpose
River ecosystems are under pressure from several different stressors. Among these, inorganic pollutants contribute to multiple stressor situations and the overall degradation of the ecological status of the aquatic environments. The main sources of pollution include different industrial activities, untreated effluents from municipal waste waters and intensive agriculture. In the present study, water, suspended particulate matter (SPM) and sediments of the Sava River were studied in order to assess the pollution status of this river system.Materials and methods
Sampling was performed during the first sampling campaign of the EU 7th FW funded GLOBAQUA project in September 2014, at 18 selected sampling sites along the Sava River. In 2014, floods predominated from spring to fall. Water samples were collected to determine the total element concentrations, the dissolved (0.45 μm) fraction and element concentrations in SPM. In order to assure comparative results with other river basins, the fraction below 63 μm was analysed in sediments. The extent of pollution was estimated by determination of the total element concentrations and by the identification of the most hazardous highly mobile element fractions (extraction 0.11 mol L?1 acetic acid) and anthropogenic inputs of elements to sediments (normalization to aluminium (Al) concentration). Concentrations of selected elements were determined by inductively coupled plasma mass spectrometry (ICP-MS).Results and discussion
Since during sampling campaign the water level was extremely high, water samples contained high amounts of SPM (in general between 80 and 100 mg L?1). The data of chemical analysis revealed that concentrations of elements in water, SPM and sediments in general increase along the Sava River from its origin to the confluence with the Danube River. Elevated concentrations of chromium (Cr) and nickel (Ni) in SPM and sediments were observed at industrially exposed sites. Concentrations of Cr and Ni in sediments were up to 320 and 250 mg kg?1, respectively. Nevertheless, these elements were present in sparingly soluble forms and hence did not represent an environmental threat. Phosphorus (P) was found in elevated concentrations (up to 1500 mg kg?1) at regions with intensive agricultural activities and cities with dense population.Conclusions
With respect to element concentrations, the pollution of the Sava River is similar to other moderately polluted European rivers. The data from the present study are beneficial for the water management authorities and can contribute to sustainable utilization, management and protection of the Sava River water resources.53.
茶鲜叶匀浆悬浮发酵体系优化模型 总被引：2，自引：1，他引：2
采用旋转回归正交组合设计,研究了温度,ｐＨ、供氧及发酵时间等因子对悬浮发酵红茶色素形成的综合效应,建立了以茶黄素（ＴＦｓ）、茶红素（ＴＲｓ）和ＴＲｓ／ＴＦｓ为目标函数的数学模型。借助模型研究了各因子及其交互作用对ＴＦｓ含量的影响,结果表明：发酵过程中采取先高温后逐步降低温度、降低ｐＨ值和早期充分供氧,有利于ＴＦｓ的积累。对数学模型进行计算机选优,筛选出ＴＲｓ和ＴＲｓ／ＴＦｓ取值限分别在１０％～１２％和１０～１２的悬浮发酵体系的最佳因子组合为：温度２８５～２９０℃,ｐＨ４６～４８,供氧１３０～１５０ｍｌ／ｍｉｎ,发酵时间（ＦＴ）５５５～５８９ｍｉｎ。 相似文献
54.
中国茶树的起源与分布——根据茶叶香气组分中萜烯指数化学分类所作的推论(英文) 总被引：1，自引：1，他引：0
茶挥发性成分中的萜烯醇类具有生物合成的遗传特性。根据萜烯指数(即:芳樟醇及其氧化物/(芳樟醇及其氧化物十香叶醇)比值,TI〕所作的化学分类表明,云南省茶的 TI 值接近于1.0,而分布于其他产茶省区的茶树 TI 值均低于上述值,并伴随有由西南向东和东南逐渐下降的趋势。由云南引入的日本山茶,具有与云南相近的 TI 值,而日本当地茶树品种的 TI 值与中国浙江相近似,因而推测中国茶树的原产地为云南,然后沿长江和沿海逐渐向东和南方传播。 相似文献
55.
采用大田和盆栽试验相结合的方法,研究了氮素对茶树不同品种在产量、品质及生长、生理上的效应。结果表明,适量的施氮对各品种的产量和品质均有较好的促进作用,而过量施氮则对品质不利,肥料增产率也下降。过量的氮肥还会使茶树产生肥害,其中苹云、碧峰等大叶品种尤为敏感,而肥害又只能经过茶树自身的生长稀释才能解除。施氮后,新梢叶片中的硝酸还原酶活性、叶绿素含量和含氮化合物含量在小叶品种中增加的幅度较大,而淀粉和蛋白质含量的增加在品种间并未表现出明显的规律,可溶性糖的含量反而下降。此外,还对茶树氮素营养品种间差异的原因以及 相似文献
56.
57.
Roles of discharge and temperature in recruitment of a cold‐water fish,the European grayling Thymallus thymallus,near its southern range limit 
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下载免费PDF全文 Tea Bašić J. Robert Britton Richard J. Cove Anton T. Ibbotson Stephen D. Gregory 《Ecology of Freshwater Fish》2018,27(4):940-951
Recruitment of salmonids is a result of density‐dependent factors, specifically egg production in the previous year, and density‐independent environmental processes driven by discharge and temperature. With the plethora of knowledge on major drivers of Atlantic salmon Salmo salar and brown trout Salmo trutta recruitment, there is a requirement to explore less known species, such as European grayling Thymallus thymallus, whose postemergence time coincides with period of increasing temperature and low discharge. This study assessed drivers of grayling recruitment in a southern English chalk stream, a system vulnerable to discharge and temperature alterations under future climate change predictions. The analyses explored age 0+ grayling survival in relation to conspecific and heterospecific densities and discharge‐ and temperature‐derived factors. The final mixed‐effects model revealed a positive relationship between age 0+ grayling survival and incubation temperature anomaly and age 0+ trout abundance. Similarly, postincubation temperature anomaly had a positive effect on 0+ grayling survival, but only up to a threshold temperature of 13.5°C, beyond which it had a negative effect. In contrast, increasing number of days with low discharge postincubation negatively influenced age 0+ grayling survival, with no evidence of an effect of elevated discharges following spawning. Our results emphasise the importance of maintaining natural discharge regimes in salmonid rivers by tackling multiple stressors operating at the catchment scale, including land and water use to mitigate for predicted climate driven changes. In addition, further research on recruitment drivers in less stable, rain‐fed systems, is required. 相似文献
58.
Using high resolution molecular technique of atomic force microscopy, we address the extracellular polymer production of Adriatic diatom Cylindrotheca closterium analyzed at the single cell level and the supramolecular organization of gel phase isolated from the Northern Adriatic macroaggregates. Our results revealed that extracellular polysaccharides freshly produced by marine diatoms can self-assemble directly to form gel network characteristics of the macroscopic gel phase in the natural aquatorium. Based on the experiments performed with isolated polysaccharide fractions of C. closterium and of macroaggregates gel phase, we demonstrated that the polysaccharide self-assembly into gel network can proceed independent of any bacterial mediation or interaction with inorganic particles. 相似文献
59.
茶树喷施1.5、1.0、0.5μL·L-1TA BR制备液后,叶色浓绿,叶片肥厚,发芽密度明显增大,平均增幅分别为23.01%、15.90%、7.11%,百芽重明显提高,平均增幅分别为13.70%、21.50%、16.20%.TA BR对茶叶内含物也有影响,喷施TA BR制备液后,游离氨基酸和水溶性糖的总量有所升高,而茶多酚和水浸出物含量均有所下降. 相似文献
60.