北部湾潮汐数值计算参数的试验

选不同的海底摩擦系数以及水平湍流摩擦系数，对北部湾的ｋｉ分潮进行了数值模拟试验。结果表明，当底摩擦系数取０．００２～０．００３，而水平湍流摩擦系数取１×１０２～５×１０３ｍ２／ｓ时其模拟结果与实测潮波系统比较吻合。潮波动力学方程中的底摩擦项对数值结果影响较大，而水平湍摩擦项对数值结果的影响不甚明显。     

错列布置下游圆柱尾流驰振特性的数值模拟与荷载分析

尾流驰振气动荷载在实验中测量较为复杂,利用Fluent数值模拟可以较快得到尾流驰振全过程的气动荷载并加以分析。采用基于2DRANS的SST k-ω非平稳湍流模型,利用ICEM对流域进行结构化网格划分,结合动网格技术以及用户自定义接口编程,将计算结构响应的Newmark-β代码嵌入Fluent软件进行流固耦合数值模拟。假定上游圆柱固定,下游圆柱简化为两自由度的弹簧振子,在流向间距和横向间距为L/D=2、T/D=1,折减风速V_r=6-50,雷诺数Re=2.4×10³~2.82×10⁴的范围内,研究了下游圆柱的尾流驰振特性,并将模拟得到的尾流驰振结果与准定常数值计算结果进行对比分析。结果表明,尾流驰振振幅会随着折减风速增加而接近线性增加,Fluent数值模拟结果与已有实验结果吻合较好,验证了SST k-ω湍流模型模拟尾流驰振的可行性;在涡激共振区尾流抑制了下游圆柱表面的随机涡脱;下游圆柱尾流驰振运动轨迹为具有明确方向性和自限性的椭圆环;准定常数值计算方法对涡脱频率和自然频率的高倍频考虑不足,但是2种方法得到的位移时程结果吻合度非常高,自振频率的前四阶倍频的自激力对振动位移响应起主要控制作用,在一定程度上说明尾流驰振是一种自激振动。     

重金属污染底泥固化体负载铁去除水中磷的研究

采用免烧结技术将重金属污染的底泥固化稳定化,在满足安全性的基础上,利用FeCl₃对固化体改性,研究改性固化体吸附去除水中磷的性能及机制。研究结果表明：经过免烧结固化之后,当水泥掺量质量分数为40%,养护龄期28 d,Cd,Cu与Pb稳定化率达到92.5%,91.8%,99.5%;Cd,Cu和Pb的浸出浓度分别为1.00×10^-4 ,1.18×10^-2和1.40×10^-4 g·L^-1;改性后底泥固化体的磷去除率由41.2%提升至98.7%,铁改性固化体较佳的铁含量配比为112.0 g·kg^-1（Fe/固化体）;在水体除磷应用中,当磷浓度为5.00×10^-3 g·L^-1,改性固化体投加比为10 g·L^-1、pH为6、在90 min时达到吸附平衡,吸附过程符合Freundlich模型,且与准二级动力学方程的拟合程度高。     

CdS/Ru（bpy）32+电致化学发光传感器的构建及邻苯二酚的检测

基于硫化镉量子点（CdS QDs）对三联吡啶钌（Ru（bpy）₃²⁺）电致化学发光（ECL）信号的增敏作用,在电极表面滴涂CdS QDs,然后引入含有多壁碳纳米管（MWCNTs）和金纳米粒子（Au NPs）的（Ru（bpy）₃²⁺）复合物（MWCNTs-Au NPs-Ru（bpy）₃²⁺）,得到了自增强CdS/Ru（bpy）₃²⁺ECL传感器.该传感器同时包含了ECL物质Ru（bpy）₃²⁺和共反应剂CdS QDs,具有自增强特点,MWCNTs和Au NPs的存在可进一步放大传感器的信号.邻苯二酚的电极氧化产物与Ru（bpy）₃²⁺之间存在能量转移,导致ECL信号淬灭,从而实现了邻苯二酚的灵敏检测,线性响应范围为5.0×10^-9~1.0×10^-5 mol·L^-1,检出限为1.5×10^-9 mol·L^-1.该传感器用于河水中邻苯二酚的检测,结果令人满意.同时,传感器也表现出良好的重现性和稳定性.     

循环伏安法对邻苯二酚的测定

将氧化石墨烯分散液及谷氨酸的混合液用循环伏安法修饰在玻碳电极上,制备出聚L-谷氨酸/石墨烯修饰电极。通过循环伏安法,对邻苯二酚在此修饰电极上的电化学行为进行研究。结果表明,在最佳优化的实验条件下,邻苯二酚在0.507 V处出现一对氧化还原峰,且浓度在2.00×10^-6mol/L~4.00×10^-4mol/L范围内表现出良好的线性关系,检出限为6.7×10^-7mol/L。利用该方法测定样品中的邻苯二酚,结果令人满意。     

广西近岸强额孔雀水蚤对球形棕囊藻的下行控制

为认识广西近岸强额孔雀水蚤Parvocalanus crassirostris对球形棕囊藻（Phaeocystis globosa,下文简称棕囊藻）的下行控制作用,首先通过垂直拖网的方式对广西近岸强额孔雀水蚤丰度的月变化进行调查;然后,通过室内实验获得强额孔雀水蚤对单细胞棕囊藻的摄食率;最后,在棕囊藻赤潮易发季节,选择固定站位对棕囊藻囊体数量与强额孔雀水蚤丰度之间的关系进行连续观测。结果发现,强额孔雀水蚤在广西近岸终年存在;在调查海域,其丰度变化为（1 005±886）ind.·m^-3到（10 723±5 168）ind.·m^-3,平均值为（5 878±3 373）ind.·m^-3。棕囊藻囊体密度高值期出现在强额孔雀水蚤丰度低值期。强额孔雀水蚤可高效摄食单细胞棕囊藻,水温从16℃到28℃时,其对单细胞棕囊藻的摄食率从（61.55±44.65）×10³ cells·ind.·h^-1到（73.92±4.66）×10³ cells·ind.·h^-1,但统计分析结果表明,水温对摄食率影响并不显著（P>0.05）。较之小孔径浮游生物网（孔径160 μm）,以往使用大孔径浮游生物网（孔径505 μm）对广西近岸强额孔雀水蚤进行采样,所得强额孔雀水蚤丰度降低2个数量级。鉴于强额孔雀水蚤可高效摄食单细胞棕囊藻,而自然海区中又存在高密度的强额孔雀水蚤,推测强额孔雀水蚤是广西近岸单细胞棕囊藻的重要捕食者,其摄食调控在控制棕囊藻赤潮的形成中可能发挥重要作用。在研究广西近岸棕囊藻赤潮发生机理时,建议考虑以强额孔雀水蚤为代表的小型桡足类动物的下行控制作用。     

底摩擦系数对渤海潮波系统数值模拟的影响

采用非结构有限体积近岸海洋模型（finite volume coastal ocean model,FVCOM）,对渤海潮波系统进行1年的数值模拟．分析了不同底摩擦系数对渤海潮波系统数值模拟的影响,并选取潮波系统误差较小的结果,进行15天、1月和1年的调和分析,以比较不同调和分析时间对结果准确性的影响．结果表明：模拟结果与实测调和常数分布有较好的一致性;开边界条件一定,当底摩擦增大时整体海域振幅值相对减小,无潮点也向潮波传入方向左偏;底摩擦系数为0．002时潮波系统整体模拟结果较好;调和分析的时间不宜少于1月．     

固体酸催化混合胺的CO2解吸性能分析

碳捕获与封存技术（CCS）是针对能源危机的一种综合性解决方案,胺基溶液CO₂吸收与解吸是其关键技术步骤。试验以胺基溶液乙醇胺（MEA）为主体吸收剂,分别选取N-甲基二乙醇胺（MDEA）和4-（二乙胺）-2-丁醇（DEAB）为添加剂,然后分别选取γ-Al₂O₃和沸石分子筛（HZSM-5）为催化剂,探究不同配比条件对MEA的CO₂解吸性能的影响。试验结果表明,添加DEAB比添加MDEA所消耗的热负荷更少,最高可减少61.8%,最低可达0.15~0.20 MW·h·t^-1 CO₂。相对于γ-Al₂O₃,HZSM-5能更显著地提高反应速率,反应速率最高可达17.2×10^-3 mol·L^-1·h^-1。5 M（mol/L）MEA/1.25 M DEAB+HZSM-5的组合效果最佳,是胺基溶液CO₂解吸的优选方案。     

3种观赏性石斛的光合特性比较研究

为探明3种观赏性石斛属Dendrobium Sw.植物在光合生理方面的差异,为其栽培及规模化种植提供理论依据。本研究以3种观赏性石斛(叠鞘石斛D.denneanum Kerr.、流苏石斛D.fimbriatum Hook.和束花石斛D.chrysanthum Wall.ex Lindl.)为材料,测定其叶片的光响应曲线、CO₂响应曲线及叶绿素相对含量(SPAD值),探究其光合特性。结果表明,叠鞘石斛、流苏石斛和束花石斛3种石斛属植物的光补偿点(LCP)分别为2.15 μmol·m^-2·s^-1、3.74 μmol·m^-2·s^-1、1.79 μmol·m^-2·s^-1,光饱和点(LSP)分别为995.09 μmol·m^-2·s^-1、679.44 μmol·m^-2·s^-1、712.28 μmol·m^-2·s^-1,LCP均低于5 μmol·m^-2·s^-1,LSP均低于1 000 μmol·m^-2·s^-1,属于典型的阴生植物,具有较强的耐阴性;3种石斛的最大净光合速率(P_max)分别为3.54 μmol·m^-2·s^-1、3.86 μmol·m^-2·s^-1、4.03 μmol·m^-2·s^-1,表观量子效率(AQY)分别为0.042,0.044和0.051,束花石斛的P_max和AQY最大,光合作用能力较强。3种石斛的CO₂响应曲线中,最大净光合速率(A_max)大小依次为叠鞘石斛(11.99 μmol·m^-2·s^-1)、流苏石斛(10.87 μmol·m^-2·s^-1)、束花石斛(4.75 μmol·m^-2·s^-1),叠鞘石斛利用CO₂进行光合作用的能力最强;3种石斛的CO₂饱和点(CSP)无显著性差异,在CO₂浓度不大于2 000 μmol·mol^-1时均未到达饱和点;CO₂补偿点(CCP)具有显著性差异,CCP分别为100.12 μmol·m^-2·s^-1、158.02 μmol·m^-2·s^-1、134.44 μmol·m^-2·s^-1,其中叠鞘石斛的CCP最低,对低浓度CO₂的利用能力最强。3种石斛叶片的SPAD值分别为51.09,56.93和58.06,其高低与其净光合速率的大小有一定程度的相关性。在3种石斛中,束花石斛的光合作用能力最强,对弱光的利用能力较强;流苏石斛对弱光的利用能力较弱,光照适应范围狭窄;叠鞘石斛对强光的利用能力较强,光合作用适应范围较广。此外,3种石斛均具有较强的耐阴性,对CO₂的耐受性也较强,在种植时应提供适当的遮阴和增加CO₂浓度来提高石斛的光合作用能力。     

燃煤电厂锅炉PM2.5现场实测与排放特征研究

采用自设固定源PM_2.5稀释采集系统对陕西省关中地区多个燃煤电厂烟气中的颗粒物开展了现场实测与样品化学源组分分析。结果表明：4个燃煤电厂PM_2.5、PM₁₀占颗粒物比重差异较大（PM_2.5占比范围为6.92%~54.34%,PM₁₀占比范围为36.36%~73.02%）;4个燃煤电厂数浓度水平最高值（2.0×10⁴~4.0×10⁵个/cm³）差异较大,相差约1个数量级;燃煤电厂PM_2.5小粒径段颗粒物质量浓度占比大多较低,但其对PM_2.5数浓度贡献却很大（最小值>95%）,大粒径段颗粒物则相反;煤粉炉PM₁/PM_2.5较大,占比范围为35.29%~51.35%,循环流化床锅炉PM₁/PM_2.5较小,占比范围为16.62%~21.47%;SO₄^2-是燃煤电厂PM_2.5中最丰富的离子成分,各电厂SO₄^2-占总离子浓度比重范围为50.02~65.52%,Na⁺和Ca²⁺位于第2或第3位;各燃煤电厂主要检出无机元素是Si、Al、Ca、Na、Fe、Na等地壳元素;燃煤电厂PM_2.5、PM₁₀和颗粒物的排放因子范围分别为0.001~0.028 kg/t、0.002~0.086 kg/t、0.003~0.236 kg/t;除尘设施组合越复杂先进,排放因子就可能越小。     

Analysis of the characteristics of the harmonics coefficient <Emphasis Type="Italic">J</Emphasis><Subscript>2</Subscript> of the Earth’s gravity field in different periods

The characteristics of the geopotential coefficient J2 in different periods are analyzed using satellite laser ranging data spanning the last 27 years.The satellites used in the analysis are Lageos1 and Lageos2.The variations in J2 are obtained by determining the dynamic orbit.The results show that there are strong seasonal and long-term variations.For different data spans,the seasonal variations agree well in terms of both amplitude and phase.Using all the data,the amplitude and phase of the annual term are 2.5 10-10 and 127°,respectively,while the amplitude and phase of the semiannual term are 0.94 10-10 and 213°,respectively.In the case of long-term variation,the secular variation in J2(J2) is-2.2 10-11 a-1 from 1984 to 2010.J2 differs for the different periods because of interannual variations,such as the "1998 anomaly".Another anomaly may have taken place during 2007-2010.Although the cause of the anomaly is unknown,it is an important observational constraint on the shape of the Earth.     

Observation of small-scale processes over shelf break in the East China Sea

The turbulent dissipation along with temperature and salinity was measured on board R/V Dong Fang Hong 2 over the shelf break of the East China Sea from March 7 to 9, 2004. Applying the Turner angle, it is found that the ＇diffusive＇ double diffusion, salt-fingering, and stable stratification coexist in the upper water column of about 50 m. Below that depth, there exists weak salt-fingering. The turbulent dissipation rates are enhanced along the ray paths of M2 internal tides emanating from the shelf break with values ranging from 1.0×10^-9 W·kg^-1 to 1.2×10^-6 W·kg^-1. The corresponding diapycnal mixing rates are from 1×10^-6 m^2· s^-1 to 1×10^-2 m^2· s^-1. The spatially averaged mixing rate over the whole observation section is 2.3×10^-3 m^2· s^-1, which is much larger than 1×10^-5 m^2·s^-1 of the background diapycnal mixing rate in the open ocean.     

Variable diffusion boundary layer and diffusion flux at sediment-water interface in response to dynamic forcing over an intertidal mudflat

The diffusion boundary layer (DBL) significantly limits the exchange between sediment and overlying water and therefore becomes a bottleneck of diffusive vertical flux at the sediment-water interface (SWI). Variable DBL thickness and diffusion flux in response to dynamic forcing may influence replenishment of nutrients and secondary pollution in coastal waters. In situ measurements of velocity in the bottom boundary layer (BBL) and oxygen concentration in the DBL were made over an intertidal mudflat, using an acoustic Doppler current and mini profiler. A linear distributed zone in the oxygen profile, the profile slope discontinuity and variance of concentration can be used to derive accurate DBL thickness. Diffusion fluxes calculated from the water column and sediment are identical, and their bias is less than 6%. A numerical model PROFILE is used to simulate the in situ dissolved oxygen profile, and layered dissolved oxygen consumption rates in the sediment are calculated. The DBL thickness (0.10-0.35 mm) and diffusion flux (15.4-53.6 mmol m 2 d 1) vary with a factor of 3.5 during a tidal period. Over an intertidal mudflat, DBL thickness is controlled by flow speed U in the BBL, according to δDBL=1686.1DU 1+0.1 (D is the molecular diffusion coefficient). That is, the DBL thickness δDBL increases with decreasing flow speed U. Changes of diffusion flux at the SWI are caused by variations in the water above the sediment and the turbulent mixing intensity. The diffusion flux is positively related to the turbulent dissipation rate, friction velocity and turbulent energy. Under the influence of dynamics in the BBL, DBL thickness and flux vary significantly.     

基于植酸锆/普鲁士蓝复合膜的电催化行为研究

通过层层自组装技术,构建植酸锆/普鲁士蓝(Zr-IP_6/PB)多层结构膜.基于普鲁士蓝(PB)对双氧水(H_2O_2)有很高的电催化性能,加之5层植酸锆/普鲁士蓝膜多孔结构有利于传质过程,该H_2O_2传感器具有高灵敏度和高选择性.实验结果显示:修饰电极对H_2O_2响应的物质的量浓度范围为2.00×10~(-5)～1.76×10~(-3) mol·L~(-1),线性相关系数R=0.998 9.     

Y_CΩ_(2n)are easy terms

For any natural number n≥1, Y CΩ 2n is an easy term; that is, for any λ term M, λβ+Y\-CΩ 2n =M is consistent, where Y C is Curry fixed point combinator, Ω 2n ≡ω 2n ω 2n and ω 2n ≡λx.xx...x (there are 2n occurrences of x after λx ). This result is a partial solution to Jacopini's conjecture: Y CΩ n is an easy term for any natural number n≥2.     

Doping effect on thermoelectric properties of nonstoichiometric AgSbTe<Subscript>2</Subscript> compounds

Nonstoichiometric ternary thermoelectric materials Ag_0.84Sb_1.15M_0.01Te_2.16 (M=Ce, Yb, Cu) were prepared by a direct melt-quench and hot press process. The carrier concentration of all the samples increased after doping. Thermoelectric properties, namely electrical conductivity, Seebeck coefficient, and thermal conductivity, were measured from 300 to 673 K. The phase transition occurring at about 418 K representing the phase transition from β-Ag₂Te to α-Ag₂Te influenced the electrical transport properties. The electrical conductivities of Ce and Yb doped samples increased after doping from 1.9×10⁴ to 2.5×10⁴ and 2.3×10⁴ S·m⁻¹, respectively, at 673 K. Also, at room temperature, the Seebeck coefficient of the Ce doped sample relatively increased corresponding to the high carrier concentration due to the changes in the band structure. However, all the thermal conductivities increased after doping at low temperature. Because of the higher thermal conductivity, the dimensionless figure of merit ZT of these doped samples has not been improved.     

Myoglobin as Mimetic Enzyme and Its Analytical Application in Determination of H2O2

0 IntroductionSltougdiiceasl csoynstceermnsin gharveeac btieveen o txhyeg ei nm psopretcaienst ( oRbjOecSt) iinn bbiioo--medicine and analytical chemistry in recent years[1-4]. Manyi mportant life phenomena and diseases are relatedtotheinter-mediates of ROS[5-7].ROS have beeni mplicated as ani mpor-tant causative factor in cell damage,including apoptosis andnecrosis . Their proposed actions comprise lipid peroxidation,DNAdamage,the mitochondrial respiratory chain destructionand protein mo…     

三聚磷酸二氢铝二水物的合成和表征

用磷酸和氢氧化铝为原料制备三聚磷酸二氢铝二水物。用X-衍射、红外光谱、化学分析、DTA-TG结合X-ray分析,证明产品的化学结构式为AlH2P3O10*2H2O。其晶体结构属正交晶系,空间群为PZ1/bZ1/aZ/m,D92h,晶胞参数a=15.919×10-8 cm,b=8.884×10-8cm,c=9.936×10-8 cm,单位晶胞体积V=1 405×10-8 cm3,Z=6。防绣性能测试表明其防锈能力与红丹颜料相当。毒理学试验表明该颜料半致死量LD50=18.0 g/kg(小白鼠),属实际无毒级,符合食品容器及儿童玩具涂装的要求。     

恭城沙田柚果实品质与土壤环境化学的研究

在恭城县城选择三不同情况的沙田柚环境（挂果好，当年产３００多个，挂果一般，当年产５０个，从不挂果，树龄已有８年，结果无望）采样，分析土壤，果实，树枝叶的常量元素和微量元素，结果表明，恭城沙田柚全糖含量平均值达１０％以上，可溶性固形物含量达１７％，柠檬酸０．３１％，糖酸比和固酸比多在３０以上。品质优的沙田柚生长的土壤Ｋ２Ｏ，Ｐ２Ｏ５含量分别为１．８００３％～２．２１２５％和０．１５２４％～０．１８１     

Organic media enhanced spectrofluorimetric determination of L-ascorbic acid

A novel spectrofluorimetric method for the determination of L-ascorbic acid is proposed. It is based on the inhibition of L-ascorbic acid on the formation of 2,3-diaminophenazine, which is an oxidation product ofo-phenylenediamine catalyzed by laccase. The fluorescence (at λ_cx/λ_cm=464 nm /530 nnm) was enhanced strongly in the presence of organic media. The mechanism ofo-phenylenediamine oxidation reaction catalyzed by laccase in the presence of L-ascorbic acid is discussed. L-ascorbic acid is determined in the ethanol, 1,4-dioxane and acetone over the linear range of 4.0×10⁻⁷≈1.2×10⁻⁴ mol/L, 4.0×10⁻⁷≈8.0×10⁻⁵ mol/L and 4.0×10⁻⁷≈1.0×10⁻⁴ mol/L with a detection limit of 1.20×10⁻⁵ mol/L, 1.19×10⁻⁵ mol/L and 1.24×10⁻⁸ mol/L, respectively. The method has been successfully applied to the simple and rapid determination of L-ascorbic acid in pharmaceuticals and milk powder. Supported by National Natural Science Foundation of China and the Special Funds of State Education Committe for Doctorate Research Huang Zuyun: born in Aug. 1963. Ph.D