Efficient extraction of phenol from wastewater by ionic micro-emulsion method:Anionic and cationic

Phenolic wastewater is one of the priorities in the field of wastewater treatment,which poses a serious threat to the human health and nature environment.In this paper,cationic cetyltrimethylammonium bromide(CTAB)and anionic sodium oleate(Na OL)microemulsions were utilized to extract phenol from the wastewater.The optimal extraction factors were investigated by exploring the effects of microemulsion composition ratio and extraction conditions on the phenol extraction performance.Furthermore,the enhanced extraction mechanism of phenol by cations microemulsions is illustrated by studying the extraction process of cationic and anionic microemulsions in the extraction of phenol.The optimum components were obtained:surfactant concentration of 0.2 mol·L^(-1),isoamyl alcohol volume of 30%,internal aqueous phase concentration of CTAB microemulsion of 0.05 mol·L^(-1),and internal aqueous phase concentration of Na OL microemulsion of 0.09 mol·L^(-1).The extraction efficiencies were 96.44%and 82.0%when using CTAB and Na OL microemulsions under optimal conditions(water-emulsion ratio of 5,contact time of 9 min,extraction temperature of 298.15 K,and p H of 9),confirming the enhanced extraction of phenol by CTAB cationic microemulsion.It was analyzed that the enhanced extraction of CTAB microemulsion was due to the electrostatic adsorption of cations with phenol root ions.

Centralized-local PV voltage control considering opportunity constraint of short-term fluctuation

This study proposes a two-stage photovoltaic(PV)voltage control strategy for centralized control that ignores short-term load fluctuations.In the first stage,a deterministic power flow model optimizes the 15-minute active cycle of the inverter and reactive outputs to reduce network loss and light rejection.In the second stage,the local control stabilizes the fluctuations and tracks the system state of the first stage.The uncertain interval model establishes a chance constraint model for the inverter voltage-reactive power local control.Second-order cone optimization and sensitivity theories were employed to solve the models.The effectiveness of the model was confirmed using a modified IEEE 33 bus example.The intraday control outcome for distributed power generation considering the effects of fluctuation uncertainty,PV penetration rate,and inverter capacity is analyzed.

Differentiation degree combination weighting method for investment decision-making risk assessment in power grid construction projects

Power grid construction projects are distinguished by their wide variety,high investment,long payback period,and close relation to national development and human welfare.To improve the investment accuracy in such projects and effectively prevent investment risks,this paper proposes an investment optimization decision-making method for multiple power grid construction projects under a certain investment scale.Firstly,an in-depth analysis of the characteristics and development requirements of China’s power grid projects was performed.Thereafter,the time sequence and holographic method was adopted to conduct multi-dimensional,multi-perspective risk assessment of different parts of power grid projects,and a holographic risk assessment index system was developed.Moreover,an investment decision model considering the comprehensive risk based on combination weighting was developed according to the output and input of power grid construction projects.A new combination weighting optimization method that takes into account the investment willingness of enterprises was designed to improve the current weighting evaluation methods.Finally,the validity and applicability of the proposed evaluation method were verified by case examples.

Coordinated Cyber-Physical equipment planning for distributed generation based on chance constrained

With development of distributed generation(DG),configuration of optimization equipment is crucial for absorbing excess electricity and stabilizing fluctuations.This study proposes a two-layer configuration strategy coordinates active cyber control and the physical energy storage(ES)system.First,an upper economic model is developed.Based on chance-constrained programming,an operation model accounts for inherent uncertainty are then developed.Under constraint of voltage risk level,a lower operation model is developed.Finally,a solution based on differential evolution is provided.An IEEE 33 bus system simulation was used to validate efficacy of model.The effects of risk level,equipment price,and chance-constrained probability were analyzed,providing a foundation for power consumption and expansion of cyber-physical systems.

核-壳-冠结构两亲性环状刷形共聚物的合成及自组装

采用原子转移自由基聚合、开环聚合和酯化反应合成了一系列核-壳-冠结构两亲性环状刷形共聚物--聚(2-羟乙基甲基丙烯酸酯-graft-(聚己内酯-block-聚寡聚(乙二醇甲基丙烯酸酯)))(P(HEMA-g-PCL_(18)-POEGMA)_(50))。通过核磁和凝胶渗透色谱对聚合物的组成进行了分析。通过动态光散射得出共聚物自组装胶束的粒径为33~43 nm,说明聚合物为纳米结构;通过荧光光谱测试了共聚物自组装胶束的临界聚集浓度,得出POEGMA的聚合度为30时,其在水中稳定性最好;通过透射电镜观察得出共聚物自组装胶束为分散性较好的球形结构纳米粒子;通过共聚物对体外抗癌药物阿霉素(DOX)的负载与释药实验,得出其载药率为4.60%,在还原剂二硫苏糖醇(DTT)条件下培养72 h后的DOX累积释放量与无DTT相当,说明共聚物结构不受DTT影响而保持稳定。

Optimization modeling method for coal-to-electricity heating load considering differential decisions

Heating by electricity rather than coal is considered one effective way to reduce environmental problems. Thus, the electric heating load is growing rapidly, which may cause undesired problems in distribution grids because of the randomness and dispersed integration of the load. However, the electric heating load may also function as an energy storage system with optimal operational control. Therefore, the optimal modeling of electric heating load characteristics, considering its randomness, is important for grid planning and construction. In this study, the heating loads of distributed residential users in a certain area are modeled based on the Fanger thermal comfort equation and the predicted mean vote thermal comfort index calculation method. Different temperatures are considered while modeling the users' heating loads. The heat load demand curve is estimated according to the time-varying equation of interior temperature. A multi-objective optimization model for the electric heating load with heat energy storage is then studied considering the demand response(DR), which optimizes economy and the comfort index. A fuzzy decision method is proposed, considering the factors influencing DR behavior. Finally, the validity of the proposed model is verified by simulations. The results show that the proposed model performs better than the traditional method.

Nanoparticle-stabilized Alkenyl Succinic Anhydride(ASA)Emulsions:A Review

Alkenyl succinic anhydride(ASA) is a popular paper-sizing agent that is generally added to papermaking systems as an aqueous emulsion. Herein, we reviewed the recent work focusing on ASA emulsions stabilized by solid particles. Solid particle-stabilized ASA emulsions generally possess high ASA content and exhibit good sizing performance. The particles that have been used to stabilize ASA emulsions typically include montmorillonite, laponite, alumina, TiO_2, Fe_3O_4, polyaluminum sulfate(PAS), and cellulose nanocrystals(CNCs). Montmorillonite is the first extensively studied particle stabilizer for ASA emulsions. Laponite is undoubtedly the most competent particle stabilizer for preparing ASA emulsions with high sizing efficiency. Montmorillonite and laponite can be used individually as stabilizers after modification or as co-stabilizers with other particles or polymers. TiO_2, alumina, PAS, and CNCs are commonly used as stabilizers either individually or with other particles.

中国仿制药替代影响因素分析--基于“4+7”带量采购精神科用药患者角度

中国仿制药替代受到多种因素的影响,然而现有的研究主要集中在政策分析和临床使用上。本文旨在从“4+7”带量采购精神科用药患者角度,研究中国仿制药替代的影响因素。以问卷调研四个试点城市精神科患者的人口特征、使用中选仿制药意愿及影响因素等,并对其进行统计分析。研究发现,单因素影响分析中,使用中选仿制药意愿与患者教育水平、年龄、平均月收入、患病时间、患病程度显著相关;影响因素回归分析中,使用中选仿制药意愿与患者年龄显著相关。因此,政府应当重视中青年群体在仿制药替代中的作用,进行差异化管理,加强对各方人士的教育宣传,调整中选仿制药的医保支付标准,要求医生对目标患者提出使用中选仿制药建议。

基于问卷调查的我国家庭储备药现况分析

本研究采用随机抽样的方法,对6278份家庭储存药品的现状进行了调查。调查中发现,超半数家庭存在储备药,中成药、非处方药、药店购药占比分别为64.2%、53.8%和79.1%。加强合理处方、合理备药、合理用药的宣传教育可能是十分必要的。

利用黄原胶和PEDOT:PSS共同稳定Ga液滴以协同改善聚丙烯酰胺水凝胶的韧性和传感性能

导电性水凝胶作为一种具有高度延展性和生物相容性的应变传感材料,在柔性应变传感器的制备中受到了广泛的关注.然而,制备同时具有高韧性和优异传感性能的多功能导电水凝胶用于检测细微应变仍然是一项巨大的挑战.本文以聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS)和黄原胶(XG)共稳定的液态金属Ga液滴为导电材料,以原位合成和化学交联的聚丙烯酰胺(PAM)为水凝胶基体,研制了一种新型导电水凝胶. PEDOT:PSS与Ga液滴同时构成刚性导电网络, XG构成刚性牺牲网络. Ga液滴在室温下同时促进PAM的原位合成和交联.制备的XG-PEDOT-Ga-PAM水凝胶具有较高的韧性、良好的可塑性和粘附性.作为应变传感材料时,基于该水凝胶的应变传感器具有非常高的灵敏度(175%–300%应变范围内的GF=12.6)、较短的响应/恢复时间(250 ms)、超低的检测极限(0.1%应变)和优异的耐久性(>500次循环).基于水凝胶的应变传感器具有优异的传感性能,能够准确监测从细微的腕部脉搏到大规模的人体关节弯曲等各种人体活动.

Optimal planning of battery energy storage considering reliability benefit and operation strategy in active distribution system

In this paper, a cost-benefit analysis based optimal planning model of battery energy storage system(BESS) in active distribution system(ADS) is established considering a new BESS operation strategy. Reliability improvement benefit of BESS is considered and a numerical calculation method based on expectation is proposed for simple and convenient calculation of system reliability improvement with BESS in planning phase. Decision variables include both configuration variables and operation strategy control variables. In order to prevent the interaction between two types of variables and enhance global search ability, intelligent single particle optimizer(ISPO) is adopted to optimize this model. Case studies on a modified IEEE benchmark system verified the performance of the proposed operation strategy and optimal planning model of BESS.

Reliability Assessment of a Cyber Physical Microgrid System in Island Mode

As cyber physical systems,microgrids(MGs),with distributed generations and energy management systems,can improve the reliability of power supply for customers in MGs.To quantify the reliability of isolated MGs,a cyber-physical assessment model is proposed.In this model,the circuit breakers and distributed energy resources are treated as the coupling elements between the cyber system and physical system,where the circuit breakers are uniquely modelled by using the Markov process theory based on the indirect interdependencies between cyber physical elements.For the cyber system,the reliability model of communication networks is formulated based on the link connectivity evaluation method.For the physical system,a system state generating method is presented to account for the optimal operation strategy,which considers the influence of the optimization strategy on the failure consequence analysis.With the proposed cyber and physical reliability models,the sequential Monte Carlo(SMC)simulation method is adopted to assess the reliability of islanded MGs.Simulations are carried out on a test system,and results verify the feasibility and effectiveness of proposed assessment method.Furthermore,one application of the proposed method is on the parameter setting of the cyber system,in terms of enhancing MGs reliability.

Wind farm polymerization influences on security and economic operation in power system based on Copula function

Wind speed dependences on different areas in a wind farm have influences on security and economic operation in power system.In order to simulate the correlation of wind speed series between different positions,this paper applies Copula function and rank correlation matrix methods to measure the coherence of wind speed in a wind farm.The correlated wind sample space is established.According to active power output characteristics of wind turbines,the polymerization model in a wind farm can be achieved.Monte Carlo optimal power flow is applied to IEEE-30 and IEEE-300 bus systems based on the principle of energy saving dispatching.The study shows that the accuracy of outputs is improved,thus reducing the fluctuation ranges in unit generating costs and power flow in branches while considering wind speed polymerization.This approach provides a new method to improve the effectiveness of energy saving dispatching and system operation arrangement.Results have been tested to be effective.

Preparation of hydrophobic transparent paper via using polydimethylsiloxane as transparent agent

Transparent paper with good hydrophobicity and flexibility was expected to act as an alternative substrate in fabrication of flexible electronics.However,conventional paper made of cellulose fibers was opaque and hydrophilic without undergoing special processing.Herein,cellulose fiber paper was treated by impregnating with hydrolyzed tetraethyl orthosilicate(TEOS)followed by coating with hydrophobic polydimethylsiloxane(PDMS)to prepare hydrophobic transparent pa-per.The results showed that silica nanoparticles produced by the TEOS hydrolysis improved the paper transparency to some extent,increased the paper thermal stability,but still remained the hydrophilicity of paper.After the paper was further coated with the PDMS and the PDMS was consolidated,the paper became clearly transparent and hydrophobic.The processed paper had a transmittance of more than 90%at 550 nm.The water contact angle of the paper reached about 110°.This work provided a new approach for the fabrication of hydrophobic transparent paper with conventional cellulose fiber paper.

A Reliability Assessment of an Integrated Energy System Based on Coupling Energy Flow and Thermal Inertia

With the wide application of integrated energy systems(IES),the degree of coupling between different types of energy sources is further strengthened,and the mechanism of fault development tends to be complicated.Therefore,in order to improve the accuracy and practicability of the reliability assessment of IESs,a sequential simulation reliability assessment method considering multi-energy flow and thermal inertia is proposed in this paper.In this method,the IES structure model is constructed with the combined cooling,heating and power(CCHP)unit as the core equipment,combining with the new energy source to realize the comprehensive energy power flow calculation considering any loss.Then,a load reduction optimization model is established,considering the importance of load and operational economy,in the system status analysis.Furthermore,the heat supply reliability index is corrected taking into account the transmission delay characteristics and terminal thermal inertia.A case study based on the 20-node and the analysis of the influence factors demonstrates the validity of the proposed method.

Evaluation Method for Voltage Fluctuation Performance Considering Cyber Soft Failure

Voltage regulation based upon cyber systems has been extensively used with the development of cyber-physical systems.Still,cyber failure may result in controlling failure,which inevitably has an effect on the overall voltage performance of distribution networks.In order to access the influence of a cyber fault on voltage regulation,a cyber system validity model considering cyber soft failure is proposed.The analytical approach of voltage fluctuation and measurement indices of voltage fluctuation are also developed.Based on a simulation of a IEEE 33-bus system,the proposed model is proved to simulate the voltage regulation process taking cyber soft failure into consideration.Each influence of different fault factors is analyzed,which provides practical technical support for the planning and operation of the distribution system.This paper provides strategies for the research into cyber fault of distribution networks,which has critical significance along with follow-up value.

Cellulose-based photocatalytic paper with Ag_(2)O nanoparticles loaded on graphite fibers

TiO_(2) nanoparticle is the most extensively used photocatalyst for photocatalytic paper.However,TiO_(2) nanoparticle is active only under UV light that accounted for less than 5%of the solar light energy.There is a need to develop a photocatalytic paper with full spectrum photoactivity.Herein,a full spectrum photocatalytic paper was fabricated by incorporating cellulose fibers with graphite fibers which were pre-loaded with Ag_(2)O nanoparticles.X-ray diffraction(XRD)testing and scanning electron microscopy(SEM)examination confirmed the loading of the Ag_(2)O nanoparticles onto the graphite fibers.The photocatalytic activity of the paper was evaluated with the degradation of methyl orange(MO)under ultraviolet,visible or near-infrared light irradiation.It was found that the degradation rate of MO could reach 32%,19%and 19%under UV,visible and NIR light,respectively after 3 h of irradiation.Meanwhile,the photocatalytic paper was very stable and can be reused repeatedly.Antibacterial tests showed that the photocatalytic paper could inhibit Escherichia coli(E.coli)growth under office lighting condition.