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Heterogeneous reactions of sulfur dioxide on dust

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Science China Chemistry 2006年第3期49卷 273-280页

作者： gao Yunchuan CHEN dan Department of Environmental Engineering Shanghai Normal University Shanghai 200234 China Department of Environmental Engineering Shanghai Normal University Shanghai 200234 China

The source of urban atmospheric particles is broad, and the major source is the building dust from urban construction. Calcium is the tagged element and Portland cement is the major com- ponent of building dust. In this study, CaO was regarded as the representative oxide of building dust, and mixtures were synthesized in terms of the major element ingredients of building dust. The het- erogeneous uptake of SO2 on CaO, mixtures, Portland cement and building dust samples was inves- tigated. In situ FTIR and X-ray photoelectron spectroscopy (XPS) were used to identify the products of the reactions. In addition, the crystal phases and the surface properties of the samples were charac- terized by XRD patterns and BET specific surface area. The results show that in the presence of oxygen, sulfur dioxide can be adsorbed to sulfite and further catalytically oxidized to sulfate on the surface of CaO, the mixtures, Portland cement and building dust. The reactivity of SO2 on the surface of dust and oxides is basically a first order. The main ingredient of building dust sample is SiO2, and the one of Portland cement is Ca3SiO5.

关键词： sulfur dioxide, heterogeneous reaction, oxides, building dust, atmospheric aerosol, in situ FTIR.

Theoretical Analysis and Numerical Simulation of the Static and Dynamic Characteristics of Hydrostatic Guides Based on Progressive Mengen Flow Controller

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Chinese Journal of Mechanical Engineering 2010年第6期23卷 709-716页

作者： gao Dianrong ZHENG dan ZHANG Zuochao Key Laboratory of Heavy Machinery Fluid Power Transmission and Control of Hebei Province Yanshan University Qinhuangdao 066004 China

The oil film thickness of oil hydrostatic guide with constant pressure supply based on capillary restrictor is greatly affected by load, and this kind of hydrostatic guide is usually applied to the machine tools with moderate load. The static and dynamic characteristics of the guide have been studied by using some theoretical, numerical and experimental approaches, and some methods and measures have been proposed to improve its performances. The hydrostatic guide based on progressive mengen（PM） flow controller is especially suitable for the heavy numerical control（NC） machine tools. However, few literatures about the research on the static and dynamic characteristics of the hydrostatic guides based on PM flow controller are reported. In this paper, the formulae are derived for analyzing the static and dynamic characteristics of hydrostatic guides with rectangle pockets and PM flow controller according to the theory of hydrostatic bearing. On the basis of the analysis of hydrostatic bearing with circular pocket, some equations are derived for solving the static pressure, volume pressure and squeezing pressure which influence the dynamic characteristics of hydrostatic guides with rectangle pocket. The function and the influencing factors of three pressures are clarified. The formulae of amplitude-frequency characteristics and dynamic stiffness of the hydrostatic guide system are derived. With the help of software MATLAB, programs are coded with C＋＋ language to simulate numerically the static and dynamic characteristics of the hydrostatic guide based on PM flow controller. The simulation results indicate that the sensitive oil volume between the outlet of the PM flow controller and the guide pocket has the greatest influence on the characteristics of the guide, and it should be reduced as small as possible when the field working condition is met. Choosing the oil with a greater viscosity is also helpful in improving the dynamic performance of hydrostatic guides. The re

关键词： PM flow controller rectangle pocket static characteristics dynamic characteristics hydrostatic guides

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城市污水淤泥生物质对水稻幼苗生长的影响

北方水稻 2017年第1期47卷 32-34页

作者：孟凌霄易军刘宇金丹丹高继平张文忠沈阳市第二十七中学高一十班沈阳110011 沈阳农业大学水稻研究所沈阳110866 辽宁省生物炭工程技术研究中心沈阳110866

针对北方育苗取土难、基质保水和保肥性较差等问题,本试验采用了城市生活污水淤泥加工制成的淤泥生物质作为育苗基质进行育苗。研究结果发现,过10目筛后的淤泥生物质保水性较营养土好,容重适宜。以过10目筛的淤泥生物质为基质培育的幼... 详细信息

针对北方育苗取土难、基质保水和保肥性较差等问题,本试验采用了城市生活污水淤泥加工制成的淤泥生物质作为育苗基质进行育苗。研究结果发现,过10目筛后的淤泥生物质保水性较营养土好,容重适宜。以过10目筛的淤泥生物质为基质培育的幼苗成苗率高,物质积累速率快;在茎粗、百株重、重高比、壮苗指数和生长函数G值等幼苗素质方面,均显著优于营养土,利于秧苗移栽。

关键词：淤泥生物质水稻育秧基质幼苗素质

A survey of hybrid energy devices based on supercapacitors

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Green Energy & Environment 2023年第4期8卷 972-988页

作者： dan gao Zhiling Luo Changhong Liu Shoushan Fan Tsinghua-Foxconn Nanotechnology Research Center and Department of Physics Tsinghua University1Qinghua GardenBeijing100084China Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials College of Physics and EnergyFujian Normal UniversityFuzhou350117China

Developing multifunctional energy storage systems with high specific energy, high specific power and long cycling life has been the one of the most important research directions. Compared to batteries and traditional capacitors, supercapacitors possess more balanced performance with both high specific power and long cycle-life. Nevertheless, regular supercapacitors can only achieve energy storage without harvesting energy and the energy density is still not very high compared to batteries. Therefore, combining high specific energy and high specific power,long cycle-life and even fast self-charging into one cell has been a promising direction for future energy storage devices. The multifunctional hybrid supercapacitors like asymmetric supercapacitors, batteries/supercapacitors hybrid devices and self-charging hybrid supercapacitors have been widely studied recently. Carbon based electrodes are common materials used in all kinds of energy storage devices due to their fabulous electrical and mechanical properties. In this survey, the research progress of all kinds of hybrid supercapacitors using multiple effects and their working mechanisms are briefly reviewed. And their advantages and disadvantages are discussed. The hybrid supercapacitors have great application potential for portable electronics, wearable devices and implantable devices in the future.

关键词： Hybrid supercapacitors Pseudocapacitors Electric double layer capacitor Self-charging Carbon materials

Efficacy of Qizi Yusi Pill on Pregnancy Outcomes in Women of Advanced Reproductive Age:A Multicenter,Randomized,Double-Blind,Placebo-Controlled Trial

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Chinese Journal of Integrative Medicine 2022年第8期28卷 675-682页

作者： ZHANG Yi QIAO Yan LI Li gao dan-dan SONG Jing-yan SUN Zhen-gao College of Traditional Chinese Medicine Shandong University of Traditional Chinese MedicineJinan250355China The First Clinical College Shandong University of Traditional Chinese MedicineJinan250014China Reproductive and Genetic Center of Integrated Medicine The Affiliated Hospital of Shandong University of Traditional Chinese MedicineJinan250011China

Objective:To evalvate efficacy of Qizi Yusi Pills(QYP),a Chinese medicine compound preparation,on in vitro fertilization-embryo transfer(IVF-ET)in women of advanced reproductive ***:This multicenter,randomized,double-blind,placebo-controlled trial was conducted from June 2018 to October2019.A total of 124 patients were randomly allocated to either the QYP group or the placebo group using a stratified block randomization design,with 62 patients in each *** patients completed controlled ovarian stimulation using a standard gonadotropin-releasing hormone agonist(GnRH-a)long *** the QYP group,QYP was administered while the control group received *** and placebo were administered for a total of 24 to 30 days from the day of GnRH-a pituitary downregulation to transvaginal oocyte *** medications were taken orally at doses of 10 g three times each *** primary outcome was cumulative pregnancy rate,and the secondary outcomes were periodic medication,follicular status,serum hormone and endometrial ***-up continued until 4 weeks after *** and neonatal complications,such as gestational diabetes,were also ***:Overall,119 patients completed the study,60 in the QYP group and 59 in the placebo *** protocol(PP)analysis revealed that 6-month cumulative pregnancy rate in the QYP group was significantly higher than that in the placebo group[43.33%(26/60)vs.25.42%(15/59),P=0.040].Additionally,more oocytes were retrieved from the QYP group than those from the placebo group(8.95±3.12 vs.7.85±1.91,P=0.022).Moreover,the endometrial thickness of HCG day in the QYP group was significantly higher than that in the placebo group(11.78±2.27 mm vs.10.68±2.07 mm,P=0.012).Maternal and neonatal complications between the two groups were not significantly different(P>0.05).Intention-to-treat analysis was in line with PP ***:QYP can enhance ovarian reserve capacity and ovarian response,and possibl

关键词： advanced age Qizi Yusi Pills in vitro fertilization-embryo transfer randomized controlled trial

The structural,electronic and magnetic properties of the 3d TM(V,Cr,Mn,Fe,Co,Ni and Cu) doped ZnO nanotubes:A first-principles study

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Science China(Physics,Mechanics & Astronomy) 2012年第3期55卷 428-435页

作者： ZHANG JianMin gao dan XU KeWei College of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062China Department of Physics Xi’an University of Arts and ScienceXi’an 710065China

We have performed the first-principles calculations onto the structural,electronic and magnetic properties of seven 3d transition-metal(TM=V,Cr,Mn,Fe,Co,Ni and Cu) atom substituting cation Zn in both zigzag(10,0) and armchair(6,6) zinc oxide nanotubes(ZnONTs).The results show that there exists a structural distortion around 3d TM impurities with respect to the pristine *** magnetic moment increases for V-,Cr-doped ZnONTs and reaches maximum for Mn-doped ZnONTs,and then decreases for Fe-,Co-,Ni-and Cu-doped ZnONTs successively,which is consistent with the predicted trend of Hund's rule for maximizing the magnetic moments of the doped TM ***,the values of the magnetic moments are smaller than the predicted values of Hund's rule due to strong hybridization between p orbitals of the nearest neighbor O atoms of ZnONTs and d orbitals of the TM ***,the Mn-,Fe-,Co-,Cu-doped(10,0) and(6,6) ZnONTs with half-metal and thus 100% spin polarization characters seem to be good candidates for spintronic applications.

关键词： ZnO nanotubes transition-metal atoms dilute magnetic semiconductors first-principles

Long-Term Effects of Recommendation on the Evolution of Online Systems

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Chinese Physics Letters 2013年第11期30卷 211-214页

作者： ZHAO dan-dan ZENG An SHANG Ming-Sheng gao Jian School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054 Department of Physics University of FribourgChemin du Musée 3CH-1700 FribourgSwitzerland

We employ a bipartite network to describe an online commercial *** of investigating accuracy and diversity in each recommendation,we focus on studying the influence of recommendation on the evolution of the online bipartite *** analysis is based on two benchmark datasets and several well-known recommendation *** structure properties investigated include item degree heterogeneity,clustering coefficient and degree *** work highlights the importance of studying the effects and performance of recommendation in long-term evolution.

关键词： bipartite correlation evolution

Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 125-132页

作者： Sheng-gao LU Shi-qiang BAI Hong-dan SHAN College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 China

We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants of k 6.372 and 1/n 1.739 for BFS, and of k 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively. These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify the formation of phosphate salts (CaHPO4·2H2O) after adsorption process. We conclude that the removal of phosphate by BFS and SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

关键词： Phosphate removal Blast furnace slag (BFS) Steel furnace slag (SFS) Adsorption Precipitation

Performance Analysis and Structural Optimization of Torsional Flow Heat Exchangers with Sinusoidal Corrugated Baffle

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Journal of Thermal Science 2023年第2期32卷 680-691页

作者： GU Xin SHI Qiming gao Wei LI Menghong WANG dan School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450001China

The thermal performance of the heat exchanger is strongly influenced by the supporting *** baffle enhances flow field disturbance and heat transfer through its complex and changeable flow *** order to enhance the thermal performance of the torsional flow heat exchanger(TFHX),the sinusoidal corrugated baffle(SCB)is used to replace the flat baffle(FB)and the full-section cycle model of the torsional flow heat exchanger with sinusoidal corrugated baffle(TFHX-SCB)is *** fluid dynamics(CFD)method was used to discuss the flow resistance characteristics of the shell-side of heat *** results show that the SCB can improve the turbulence intensity and the uniformity of the flow field between the adjacent *** combination of structural configurations on the shell-side of TFHX-SCB is analyzed by the central composite design(CCD)-response surface method(RSM).When the amplitude of the SCB is 1.37 mm,the cycles of the SCB are 4.42;the initial phase of the SCB is 112.73°,and the combination of heat transfer coefficient and comprehensive performance is *** with the original structure,the heat transfer coefficient is increased by 11.58%,and the comprehensive performance is increased by 5.48%.The laser doppler velocimetry(LDV)experimental device irradiated the specified measurement point,and the dependability and accuracy of numerical simulation methods were *** research conclusion provides a basic theory for the structural development of the TFHX.

关键词： sinusoidal corrugated baffle torsional flow heat exchanger response surface method heat transfer enhancement