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基于物种敏感度分布及相平衡理论的汾河流域磺胺类抗生素生态风险阈值研究
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作者 刘瑞民 赵静 +3 位作者 韩文辉 王林芳 马双绕 夏星辉 《生态毒理学报》 CAS CSCD 北大核心 2024年第1期115-126,共12页
磺胺素类抗生素(SAs)广泛应用于医疗、畜禽养殖等领域。但过量的SAs通过多种方式最终进入流域水体和沉积物中,对流域生态系统带来潜在的风险。预测无效应浓度(PNEC)可以作为评估污染物潜在生态风险的阈值,因此确定水体和沉积物中SAs的P... 磺胺素类抗生素(SAs)广泛应用于医疗、畜禽养殖等领域。但过量的SAs通过多种方式最终进入流域水体和沉积物中,对流域生态系统带来潜在的风险。预测无效应浓度(PNEC)可以作为评估污染物潜在生态风险的阈值,因此确定水体和沉积物中SAs的PNEC是风险评估的关键。本研究以黄河支流——汾河流域为研究区,通过采集水体和沉积物的样品,发现水体中SAs的磺胺甲恶唑(SMX)含量最高,均值为73.6 ng·L^(-1),而磺胺醋酰(SAAM)检出率最高,高达100%。沉积物中仅检出了2种SAs类抗生素,为磺胺醋酰(SAAM)和磺胺喹恶啉(SQX),但检出频率却高达100%。基于物种敏感度分布(SSD)得到水体中SAs的生态风险阈值为3.40~440μg·L^(-1)。在此基础上,基于水-沉积物密度、体积比等参数,采用相平衡理论(EqP)进一步得到了沉积物中SAs的生态风险阈值为0.065~75.5 mg·kg^(-1)。基于确定的生态风险阈值,对汾河流域SAs现状进行风险评估,结果表明仅水体中的甲氧苄啶(TMP)的风险商(RQ)均值为0.014,存在一定的低风险,但超标概率仅为8%,而其他类别在水体和沉积物中RQ均低于0.01,均无显著风险。 展开更多
关键词 磺胺类抗生素(SAs) 预测无效应浓度(PNEC) 物种敏感度分布(SSD) 相平衡理论(EqP) 生态风险阈值
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盐渍土中固相相态变化规律的研究 被引量:6
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作者 虞卫国 房建宏 《公路工程》 北大核心 2013年第4期94-98,共5页
根据相平衡理论,分析了盐渍土中冰固相、冰盐固相、氯化钠固相、硫酸钠固相、芒硝固相等各固相随盐渍土温度与含水量、温度与氯化钠含量、温度与硫酸钠含量、含水量与氯化钠含量、含水量与硫酸钠含量、氯化钠与硫酸钠含量的变化规律,为... 根据相平衡理论,分析了盐渍土中冰固相、冰盐固相、氯化钠固相、硫酸钠固相、芒硝固相等各固相随盐渍土温度与含水量、温度与氯化钠含量、温度与硫酸钠含量、含水量与氯化钠含量、含水量与硫酸钠含量、氯化钠与硫酸钠含量的变化规律,为定量分析和掌握盐渍土的工程特性变化规律及盐渍土病害的产生机理提供了理论基础。 展开更多
关键词 盐渍土 相平衡理论 水盐体系
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某油田原油气提塔脱硫工艺模拟与改进方案研究
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作者 熊一凡 侯磊 +4 位作者 刘珈铨 张鑫儒 陈军毅 王文君 胡占州 《石油和化工设备》 CAS 2024年第1期19-22,共4页
针对某油田气提塔存在油路出口含硫量偏高的问题,根据气提相平衡理论,构建气提塔仿真模型,模拟气提塔运行工况,分析油气出口的压力、温度及流量参数,发现气提气超负荷造成气提气的流量特性与调节阀流量特性不匹配,无法将出口压力调至设... 针对某油田气提塔存在油路出口含硫量偏高的问题,根据气提相平衡理论,构建气提塔仿真模型,模拟气提塔运行工况,分析油气出口的压力、温度及流量参数,发现气提气超负荷造成气提气的流量特性与调节阀流量特性不匹配,无法将出口压力调至设计压力,塔内原料油的硫化氢组分无法被充分解吸,导致油路出口油品含硫量偏高。提出气提塔的气动调节阀改进方案,确定新阀的额定流量系数为650,公称直径为200mm。更换调节阀后,油路出口处的H2S流量从12.56×103mg/h降为1.91×103mg/h,脱硫效果得到显著提高。 展开更多
关键词 气提塔 气提相平衡理论 脱硫 工艺模拟 气动调节阀
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Some Special Types of Solitary Wave Solutions for (3+1)-Dimensional Jimbo-MiwaEquation 被引量:3
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作者 BAICheng-Lin ZHAOHong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第6期875-877,共3页
Using the extended homogeneous balance method, we find some special types of single solitary wave solution and new types of the multisoliton solutions of the (3+1)-dimensional Jimbo-Miwa equation.
关键词 (3+1)-dimensional Jimbo-Miwa equation extended homogeneous balance method soliton solutions
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Solitary Waves for Cubic-Quintic Nonlinear Schroedinger Equation with Variable Coefficients 被引量:6
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作者 ZHANG Jin-Liang WANG Ming-Liang LI Xiang-Zheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第2期343-346,共4页
The cubic-quintic nonlinear Schroedinger equation (CQNLS) plays important parts in the optical fiber and the nuclear hydrodynamics. By using the homogeneous balance principle, the bell type, kink type, algebraic sol... The cubic-quintic nonlinear Schroedinger equation (CQNLS) plays important parts in the optical fiber and the nuclear hydrodynamics. By using the homogeneous balance principle, the bell type, kink type, algebraic solitary waves, and trigonometric traveling waves for the cubic-quintic nonlinear Schroedinger equation with variable coefficients (vCQNLS) are derived with the aid of a set of subsidiary high-order ordinary differential equations (sub-equations for short). The method used in this paper might help one to derive the exact solutions for the other high-order nonlinear evolution equations, and shows the new application of the homogeneous balance principle. 展开更多
关键词 cubic-quintic nonlinear Schroedinger equation with variable coefficients homogeneous balance principle solitary wave
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(Anti-)de Sitter Black Hole Entropy and Generalized Uncertainty Principle
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作者 ZHAO Ren ZHANG Li-Chun HU Shuang-Qi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4X期635-638,共4页
We generalize the method that is used to study corrections to Cardy-Verlinde formula due to generalized uncertainty principle and discuss corrections to Cardy-Verlinde formula due to generalized uncertainty principle ... We generalize the method that is used to study corrections to Cardy-Verlinde formula due to generalized uncertainty principle and discuss corrections to Cardy-Verlinde formula due to generalized uncertainty principle in (anti)- de Sitter space. Because in de Sitter black hole spacetime the radiation temperature of the black hole horizon is different from the one of the cosmological horizon, this spacetime is a thermodynamical non-equilibrium spacetime. 展开更多
关键词 entropy correction generalized uncertainty principle non-equilibrium spacetime
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Total energy equation leading to exchange-correlation functional
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作者 LIU Feng WANG TzuChiang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第5期93-98,共6页
By solving the total energy equation, we obtain the formula of exchange-correlation functional for the first time. This functional is usually determined by fitting experimental data or the numerical results of models.... By solving the total energy equation, we obtain the formula of exchange-correlation functional for the first time. This functional is usually determined by fitting experimental data or the numerical results of models. In the uniform electron gas limit, our exchangecorrelation functional can exactly reproduce the results of Perdew-Zunger parameterization from the jellium model. By making use of a particular solution, our exchange-correlation functional could take into accotmt the case of non-uniform electron density, and its validity can be confirmed through comparisons of the band structure, equilibrium lattice constant, and bulk modulus of aluminum and silicon. The absence of mechanical prescriptions for the systematic improvement of exchange-correlation functional hinders further development of density-functional theory (DFT), and the formula of exchange-correlation functional given in this study might provide a new perspective to help DFT out of this awkward situation. 展开更多
关键词 Density-functional theory exchange-correlation functional bulk modulus band structure ALUMINUM silicon
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