斑纹鲟凝集素(CFL)的初步研究 Ⅱ.CFL的分子组成及性质鉴定   总被引：3，自引：0，他引：3  

戴聪杰  王桂忠  李少菁  艾春香 《海洋学报》2006,28(3):98-102

采用生化方法对斑纹鲟(Charybdis feriatus)凝集素进行了初步研究.结果表明,斑纹鲟的血清中有动物红细胞和微生物细胞凝集活性的凝集素(Charybdis feriatuslectin,CFL),其活力表现依赖于Ca2+,并为多种糖所抑制;CFL对40℃以上的温度敏感,其活力在pH6.0~8.0内稳定.经巯基乙醇处理和未经巯基乙醇处理的CFL在SDS-PAGE上均为一条蛋白带,说明斑纹鲟凝集素不含二硫键,且只有一种亚基,分子量为40.8 kDa,CFL氨基酸组成分析表明其富含酸性氨基酸.  相似文献   

Economic assessment of production of flour from Prosopis alba and P. pallida pods for human food applications.     

Peter Felker  Nora Grados  Gaston Cruz  Dante Prokopiuk 《Journal of Arid Environments》2003,53(4):517-528

This paper presents a detailed cost accounting of the processes involved in the production of flours from the mesocarps of the fruits of Prosopis alba and P. pallida to be used in human foods. The flours from both species are similar and contain 7–8% protein, 0·8–2% fat, 26–32% total dietary fiber and 48–59% sucrose. The data were based on actual production rates in use at the Universidad de Piura pilot plant using simple machinery. Machinery hourly charges were based on equivalent rental costs in order to avoid interest charge calculations. As opposed to other analyses which only included processing costs delivered to the plant, our analysis ascribed value to the owner of the trees in order to provide incentives to plant and care for the trees. The sensitivity analyses showed that the most economically important factor was the conversion efficiency of pods into flour. When a 40% conversion efficiency, such as that which has been obtained in both Peru and Argentina was obtained, and by-product credits for high fiber containing fraction were assumed, the wholesale selling price with a 5% marketing cost and a 40% profit direct costs was estimated to be $0·66 kg⁻¹ for Peru (using a $0·40 h⁻¹ labor rate ) and $1·76 kg⁻¹ for Argentina (using a $1·5 h⁻¹ labor rate).  相似文献   

宝顶山石窟造象岩壁风化产物化学特征及形成分析     

汪东云  谢本立 《工程地质学报》1995,3(3):18-30

为研究宝顶山石窟区造象岩壁风化破坏及渗水危害的作用机理,选择不同类型风化产物进行定期采样监测。本文重点论述了外围岩石和造象岩壁风化产物的化学成分及矿物成分、风化产物可溶盐的化学特征及可溶盐类型,以及这些特征的多年变化规律,分析论证了可溶盐不同水化学成因类型的形成特征,为防风化防渗水危害治理措施提供可靠依据。  相似文献   

Renewable, controlled and environmentally safe phosphorus release in soils from mixtures of NH4 +-phillipsite tuff and phosphate rocks     

I. M. Dwairi 《Environmental Geology》1998,34(4):293-296

 The renewable and controlled-release fertilization system investigated here uses NH₄ ⁺-exchanged phillipsite tuff, from Jordan, to help in the dissolution of phosphate rock. Accordingly, controlled and renewable soluble nitrogen, phosphate and Ca are released as nutrients for plants. NH₄ ⁺ phillipsite can sequester Ca ions released by the dissolution of phosphate rock, therefore, leading to further phosphate rock dissolution. In this study the results show that the amount of phosphate released is more than that released by phosphate rock alone. This method offers an alternative to the use of highly soluble fertilizers and may avoid environmental problems associated with their extensive use in agriculture. Received: 22 May 1997 · Accepted: 12 August 1997  相似文献   

苍梧县砂糖桔低温冷害风险区划     

李敬源  钟晓云  叶瑜  潘绍勇  赵伟明 《气象研究与应用》2014,(1):63-66,I0001

通过对苍梧县各个镇低温冷害的分析,找出影响苍梧县砂糖桔生产的4个气候关键因子,通过归一化方法和加权综合评价法分析,利用地理信息系统（GIS）绘制出苍梧县砂糖桔低温冷害风险区划专题图.区划图明确分出苍梧县低温冷害的低风险区、次低风险区、中等风险区、次高风险区和高风险区.在此基础上,针对各风险区域进行了分析与评述,特别指出了防御低温冷害的措施,为苍梧县砂糖桔生产趋利避害和优化布局提供科学决策依据.  相似文献   

Moisture sorption behaviour of salt mixtures in porous stone     

Christoph Franzen  Peter W. Mirwald 《Chemie der Erde / Geochemistry》2009,69(1):91-98

Moisture in stone material is the key factor for all stone deterioration processes and also in weathering of cultural heritage. With additional presence of salts in the material the situation gets even more critical. While the properties of pure salts with moisture are well known, knowledge about the interaction of salt mixtures with moisture is still poor. In different approaches the reactions of salt-contaminated stone material on changing moisture were tested in the laboratory. Experiments with different solutions in the Na-Mg-SO₄-NO₃-H₂O system revealed interesting new results on the moisture behaviour of salt-contaminated samples. Theoretical considerations and computer simulations are helpful to interpret the data obtained, but are not yet sufficient to explain the real processes acting on site at the monuments. More encouraging to this fact are complementary studies on visible efflorescences in the same salt system. It is shown how by experimental approaches the understanding on salt-induced stone deterioration is strongly complemented.  相似文献   

Physiological acclimation strategies of riparian plants to environment change in the delta of the Tarim River,China     

Xiao Ruan  Qiang Wang  Cun-De Pan  Ya-Ning Chen  Hao Jiang 《Environmental Geology》2009,57(8):1761-1773

The occurrence and development of riparian forests, which were mainly dominated by mesophytes species related closely with surface water. Since there was no water discharged to the lower reaches of Tarim River in the past three decade years, the riparian forests degrade severely. The groundwater table, the saline content of the groundwater, as well as the content of free proline, soluble sugars, plant endogenous hormones (abscisic acid (ABA), and cytokinins (CTK)) of the leaves and relative rates of sap flow of the Populus euphratica Oliv. (arbor species), Tamarix ramosissima Ldb. (bush species), and Apocynum venetum L. (herb species) were monitored and analyzed at the lower reaches of the Tarim River in the study area where five positions on a transect were fixed at 100 m intervals along a sampling direction from riverbank to the sand dunes before and after water release. The physiological responses and acclimation strategies of three species to variations in water and salinity stress were discussed. It was found that A. venetum population recovered to groundwater table ranging from −1.73 to −3.56 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L; P. euphratica appeared to be more sensitive to the elevation of groundwater table than the A. venetum and T. ramosissima at groundwater table ranging from −5.08 to −5.80 m, and when exposed to saline content of the groundwater ranging from 42.17 to 49.55 m mol/L. T. ramosissima tended to be the best candidate species for reclamation in this hyper-arid area because it responded to groundwater table ranging from −1.73 to −7.05 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L. These results explained the distribution patterns of desert vegetation in the lower reaches of the Tarim River. Understanding the relationships among ecological factors variables, physiological response and acclimation strategies of plant individuals could provide guidance to sustainable management, reclamation and development of this and similar regions.  相似文献   

Effects of Buoyancy and Season on Turion Dispersal of Submerged Macrophyte Potamogeton crispus L          下载免费PDF全文

Dong Xie  Hengjie Zhou  Haiting Ji  Yushun Chen  Shuqing An 《洁净——土壤、空气、水》2015,43(3):324-329

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Measurement of soluble reactive phosphorus concentration profiles and fluxes in river-bed sediments using DET gel probes   总被引：3，自引：0，他引：3  

Helen P. Jarvie  Robert J.G. Mortimer  Elizabeth J. Palmer-Felgate  Katherine St. Quinton  Sarah A. Harman  Patricia Carbo 《Journal of Hydrology》2008,350(3-4):261-273

DET (diffusive equilibrium in thin films) gel probes were used for sampling river-bed sediment porewaters, to characterise in situ soluble reactive phosphorus (SRP) concentration profiles and fluxes. DET probes were deployed in three contrasting rural streams: (1) a headwater ‘pristine’ stream, with minimal P inputs from low intensity grassland and no point sources, (2) an intensively cultivated arable catchment, and (3) a stream subject to high P loadings from sewage effluent and intensive arable farming. The DET results showed highly enriched porewater SRP concentrations of between ca. 400 and 5000 μg-P l⁻¹ in the sewage-impacted stream. In contrast, the arable and pristine streams had porewater SRP concentrations <70 μg-P l⁻¹ and <20 μg-P l⁻¹, respectively. Porewater SRP concentration profiles in both the sewage-impacted and arable-impacted streams showed well-defined vertical structure, indicating internal sources and sinks of SRP within the sediment. However, there was little variability in porewater SRP concentrations in the pristine stream. The DET porewater profiles indicated net diffusion of SRP (a) from the overlying river water into the surface sediment and (b) from subsurface sediment upwards towards the sediment–water interface. A mass balance for the sewage-impacted site showed that the influx of SRP into the surface sediments from the overlying river water was small (ca. 1% of the daily river SRP load). The DET results indicated that, in the arable and sewage-impacted streams, the surface ‘cap’ of fine sediment may play an important role in inhibiting upward movement of SRP from subsurface porewaters into the overlying river water, under steady-state, low-flow conditions.  相似文献   

An empirical regression model of soluble phosphorus retention for small pristine streams evaluating tracer experiments     

Marcus Schulz  Maik Bischoff  Jörg Klasmeier  Jürgen Berlekamp  Michael Matthies 《Aquatic Sciences - Research Across Boundaries》2008,70(2):115-122

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