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saccharification and fermentation of sweet potato powder for the production of ethanol under conditions of veryhigh gravity

Yinxiu CAO, Hongchi TIAN, Kun YAO, Yingjin YUAN

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 318-324 doi: 10.1007/s11705-010-1026-3

摘要: Due to its merits of drought tolerance and high yield, sweet potatoes are widely considered as a potential alterative feedstock for bioethanol production. Very high gravity (VHG) technology is an effective strategy for improving the efficiency of ethanol fermentation from starch materials. However, this technology has rarely been applied to sweet potatoes because of the high viscosity of their liquid mash. To overcome this problem, cellulase was added to reduce the high viscosity, and the optimal dosage and treatment time were 8 U/g (sweet potato powder) and 1 h, respectively. After pretreatment by cellulase, the viscosity of the VHG sweet potato mash (containing 284.2 g/L of carbohydrates) was reduced by 81%. After liquefaction and simultaneous saccharification and fermentation (SSF), the final ethanol concentration reached 15.5% (v/v), and the total sugar conversion and ethanol yields were 96.5% and 87.8%, respectively.

关键词: bioethanol     sweet potato     very high gravity     viscosity reduction     simultaneous saccharification and fermentation    

Linear viscoelastic behavior of asphalt binders and mixtures containing very high percentages of reclaimed

《结构与土木工程前沿(英文)》   页码 1211-1227 doi: 10.1007/s11709-023-0983-9

摘要: The primary aim of this study is to correlate the impact of aggregates, if any, on the viscoelastic behavior of rejuvenated asphalt mixtures containing very high amounts of reclaimed asphalt pavement (RAP) (> 50%). First, gradation of 100% RAP was rectified, using a modified Bailey method by adding virgin aggregates to achieve two coarse dense-graded and one fine dense-graded blends. Complex modulus test was then performed from −35 to +35 °C and 0.01–10 Hz. In addition to performance grade (PG) testing, extracted and recovered binders from different asphalt mixtures underwent shear complex modulus test within −8 °C to high temperature PG and frequencies from 0.001 to 30 Hz. Cole−Cole, Black space, complex modulus and phase angle master curves were constructed and Shift-Homothety-Shift in time-Shift (SHStS) transformation was used to compare the linear viscoelastic behavior of asphalt binders and mixtures. The influence of aggregates on the viscoelastic behavior of asphalt mixtures depends on temperature and/or frequency. The role of asphalt binders in the behavior of asphalt mixtures is more pronounced at high temperatures and the effect of the aggregate structure increases as the temperature falls. The maximum difference (60% to 70%) in the viscoelastic behavior of the binder and mixture based on SHStS transformed Cole−Cole curves is within the phase angle of 15°–20°.

关键词: RAP     complex modulus     SHStS transformation     rejuvenation     behavior of asphalt binder and mixture    

High-gravity intensified iron-carbon micro-electrolysis for degradation of dinitrotoluene

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1595-1605 doi: 10.1007/s11705-022-2204-9

摘要: The application of iron–carbon (Fe–C) micro-electrolysis to wastewater treatment is limited by the passivation potential of the Fe–C packing. In order to address this problem, high-gravity intensified Fe–C micro-electrolysis was proposed in this study for degradation of dinitrotoluene wastewater in a rotating packed bed (RPB) using commercial Fe–C particles as the packing. The effects of reaction time, high-gravity factor, liquid flow rate and initial solution pH were investigated. The degradation intermediates were determined by gas chromatography-mass spectrometry, and the possible degradation pathways of nitro compounds by Fe–C micro-electrolysis in RPB were also proposed. It is found that under optimal conditions, the removal rate of nitro compounds reaches 68.4% at 100 min. The removal rate is maintained at approximately 68% after 4 cycles in RPB, but it is decreased substantially from 57.9% to 36.8% in a stirred tank reactor. This is because RPB can increase the specific surface area and the renewal of the liquid–solid interface, and as a result the degradation efficiency of Fe–C micro-electrolysis is improved and the active sites on the Fe–C surface can be regenerated for continuous use. In conclusion, high-gravity intensified Fe–C micro-electrolysis can weaken the passivation of Fe–C particles and extend their service life.

关键词: high-gravity technology     rotating packed bed     Fe–C micro-electrolysis     dinitrotoluene wastewater     active sites    

and mechanism of nitrobenzene degradation by hydroxyl radicals-based ozonation process enhanced by highgravity technology

Weizhou Jiao, Shengjuan Shao, Peizhen Yang, Kechang Gao, Youzhi Liu

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1197-1205 doi: 10.1007/s11705-020-1998-6

摘要: This study investigated the indirect oxidation of nitrobenzene (NB) by hydroxyl radicals (·OH) in a rotating packed bed (RPB) using competitive kinetics method with -nitrochlorobenzene as a reference compound. The rate constants of NB with ·OH are calculated to be between (1.465±0.113) × 10 L/(mol·s) and (2.497±0.192) × 10 L/(mol·s). The experimental data are fitted by the modified Arrhenius equation, where the activation energy is 4877.74 J/mol, the order of NB concentration, rotation speed, and initial pH is 0.2425, 0.1400 and 0.0167, respectively. The ozonation process of NB could be enhanced by RPB, which is especially effective for highly concentrated NB-containing wastewater under alkaline conditions. The high gravity technology can accelerate ozone mass transfer and self-decomposition of ozone to produce more ·OH, resulting in an increase in the indirect oxidation rate of NB by ·OH and consequently effective degradation of NB in wastewater.

关键词: high gravity technology     hydroxyl radicals     nitrobenzene     reaction kinetics    

High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersionwith high solids content

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 1087-1099 doi: 10.1007/s11705-019-1895-z

甚高频雷达复杂场景中目标高度和多径衰减联合估计 Research Articles

陈胜,赵永波,胡毅立,曹成虎,庞晓娇

《信息与电子工程前沿(英文)》 2022年 第23卷 第6期   页码 937-949 doi: 10.1631/FITEE.2100003

摘要:

由于多径效应的影响,甚高频雷达低角估计是雷达领域难题之一,尤其是在反射条件未知的复杂情况下,低角估计更难解决。针对这一问题,提出一种目标高度和多径衰减联合估计算法。该算法首先利用数据本身的特性估算反射系数幅度,当该幅度估计值很小时,认为没有反射信号,然后将反射系数的相位和直达信号与反射信号之间的相位差当作同一部分,即多径相位衰减,并对其进行搜索。推导了该算法的克拉美罗界。最后,计算机仿真和实测数据处理结果表明,该算法在复杂场景下具有良好估计性能,并且在仅有单次快拍的条件下仍能较好地工作。

关键词: 低角估计;甚高频雷达;复杂场景;多径效应;高度估计    

超重力环境下非金属氮掺杂石墨烯泡沫催化还原反应性能研究 Article

王志勇, 赵志建, Jesse Baucom, 王丹, Liming Dai, 陈建峰

《工程(英文)》 2020年 第6卷 第6期   页码 680-687 doi: 10.1016/j.eng.2019.12.018

摘要:

本文以硝基苯还原和亚甲基蓝降解为模型反应体系,以非金属氮掺杂石墨烯泡沫(NGF)作为三维结构式催化材料,研究了超重力环境对催化反应性能的影响。在超重力旋转圆管反应器内6484 g (g = 9.81 m·s–2)的超重力环境下,非金属催化硝基苯还原的表观速率常数是传统搅拌反应器内的6 倍。通过计算流体力学理论模拟,揭示了超重力旋转管式反应器内超重力水平较高,湍流动能比传统反应器内有显著提高,液固相表面更新速度快,提高了催化反应效率。X射线光电子能谱和拉曼光谱测试表明该催化材料组成和结构在超重力环境下的反应过程中保持稳定。在另一个模型反应体系中,非金属氮掺杂石墨烯泡沫催化亚甲基蓝降解的速率也随着超重力水平的增加而增大。这些结果表明了超重力强化非金属碳基催化材料催化还原反应的潜力。

关键词: 超重力技术     过程强化     非金属催化     碳基纳米材料     催化还原    

我国高温气冷堆发展战略研究

张作义,吴宗鑫,王大中,童节娟

《中国工程科学》 2019年 第21卷 第1期   页码 12-19 doi: 10.15302/J-SSCAE-2019.01.003

摘要:

高温气冷堆和在此基础上发展起来的超高温气冷堆是第四代核能系统研发重点的6种堆型之一。本文介绍了高温气冷堆的特点,对高温气冷堆技术在国内外的最新研发进展进行了简要综述,对高温气冷堆的发展定位等问题进行了讨论。在此基础上对我国高温气冷堆发展路线进行了展望。我国高温气冷堆技术历经跟踪、跨越和自主创新,目前在商业规模模块式高温气冷堆核电站技术上处于世界领先地位。在此基础上,我国正在启动部署后续60万千瓦级模块式高温气冷堆核电机组的研发和配套关键技术的攻关工作,以进一步推动高温气冷堆技术的产业化,保持我国在该领域的国际领先优势。

关键词: 高温气冷堆     高温     技术路线    

我国高坝建设和科技攻关

陈宗梁

《中国工程科学》 2000年 第2卷 第12期   页码 84-89

摘要:

介绍了我国大坝建设的发展和特点,概括了高坝建设中的地质勘探、坝工技术、泄洪消能、坝基处理和髙边坡处理等方面的科技成果和应用水平,展望了我国高坝发展前景并指出今后高坝科技攻关重点。

关键词: 水力发电     高坝     重力坝     拱坝     碾压混凝土坝     面板堆石坝    

高分辨率地球重力场模型DQM99

石磐,夏哲仁,孙中苗,李迎春

《中国工程科学》 1999年 第1卷 第3期   页码 51-55

摘要:

地球扰动位的球谐展开式表示是地球重力场模型应用最广泛的一种表示方法。目前通用的位系数模型的分辨率是0.5°,最高完全阶次为360。由于全球重力数据覆盖的密度和数据精度差别较大,所以已知的重力场模型的实际分辨率及其精度也因地区而异,故重力场模型的精化是一个漫长的过程,局部积分谱权综合法是改善已知重力场模型的有效而简便的方法。基于重力场模型OSU91A及EGM96,利用我国15′×15′及5′×5′重力异常,我们解算了更高阶次的地球重力场模型DQM99A、B、C、D四个模型,给出了精度比较分析结果。

关键词: 地球重力场模型DQM99     地球形状     地球位系数模型    

Structure improvement and strength finite element analysis of VHP welded rotor of 700°C USC steam turbine

Jinyuan SHI,Zhicheng DENG,Yong WANG,Yu YANG

《能源前沿(英文)》 2016年 第10卷 第1期   页码 88-104 doi: 10.1007/s11708-015-0387-1

摘要: The optimized structure strength design and finite element analysis method for very high pressure (VHP) rotors of the 700°C ultra-super-critical (USC) steam turbine are presented. The main parameters of steam and the steam thermal parameters of blade stages of VHP welded rotors as well as the start and shutdown curves of the steam turbine are determined. The structure design feature, the mechanical models and the typical position of stress analysis of the VHP welded rotors are introduced. The steady and transient finite element analysis are implemented for steady condition, start and shutdown process, including steady rated condition, 110% rated speed, 120% rated speed, cold start, warm start, hot start, very hot start, sliding-pressure shutdown, normal shutdown and emergency shutdown, to obtain the temperature and stress distribution as well as the stress ratio of the welded rotor. The strength design criteria and strength analysis results of the welded rotor are given. The results show that the strength design of improved structure of the VHP welded rotor of the 700°C USC steam turbine is safe at the steady condition and during the transient start or shutdown process.

关键词: 700°C ultra-super-critical unit     steam turbine     very high pressure rotor     structure strength design     strength design criteria     finite element analysis    

卫星重力梯度数据用于精化地球重力场的研究

宁津生,罗志才,陈永奇

《中国工程科学》 2002年 第4卷 第7期   页码 23-28

摘要:

确定厘米级大地水准面和发展超高阶地球重力场模型是现代物理大地测量的主要科学目标之一。卫星重力梯度测量的实现将为这一目标做出重大贡献。文章着重评述这一领域的研究进展,并讨论利用卫星重力梯度数据精化地球重力场的若干理论和方法问题。

关键词: 卫星重力梯度测量     卫星重力梯度边值问题     地球重力场模型     大地水准面    

Stability analysis on Tingzikou gravity dam along deep-seated weak planes during earthquake

Weiping HE, Yunlong HE

《结构与土木工程前沿(英文)》 2012年 第6卷 第1期   页码 69-75 doi: 10.1007/s11709-012-0146-x

摘要: The stability of a gravity dam against sliding along deep-seated weak planes is a universal and important problem encountered in the construction of dams. There is no recommended method for stability analysis of the dam on deep-seated weak planes under earthquake condition in Chinese design codes. Taking Tingzikou dam as an example, the research in this paper is focused on searching a proper way to evaluate the seismic safety of the dam against sliding along deep-seated weak planes and the probable failure modes of dam on deep-seated weak planes during earthquake. It is concluded that there are two probable failure modes of the dam along the main weak geological planes in the foundation. In the first mode, the concrete tooth under the dam will be cut and then the dam together with part foundation will slide along the muddy layer; in the second mode, the dam together with part foundation will slide along the path consist of the weak rock layer under the tooth and the muddy layer downstream the tooth. While there is no geological structure planes to form the second slip surface, the intersection of the main and the second slip surface is 40 to 80 m downstream from dam toe, and the angle between the second slip surface and the horizontal plane probably be 25 to 45 degrees.

关键词: gravity dam     deep-seated weak planes     stability against sliding     earthquake    

A comprehensive simulation approach for pollutant bio-transformation in the gravity sewer

Nan Zhao, Huu Hao Ngo, Yuyou Li, Xiaochang Wang, Lei Yang, Pengkang Jin, Guangxi Sun

《环境科学与工程前沿(英文)》 2019年 第13卷 第4期 doi: 10.1007/s11783-019-1144-1

摘要:

A comprehensive pollutant transformation model for sewer systems is established.

The model comprises fermentation, sulfate reduction and ammonification processes.

Biochemical reactions related to distinct carbon sources are depicted in the model.

Pollutant transformation is attributed to different biochemical reaction processes.

关键词: Gravity sewer     Modeling     Pollutant transformation     Biochemical reaction process    

Evaluation of seismic reliability of gravity dam-reservoir-inhomogeneous foundation coupled system

Hamid Taghavi GANJI, Mohammad ALEMBAGHERI, Mohammad Houshmand KHANEGHAHI

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 701-715 doi: 10.1007/s11709-018-0507-1

摘要: The seismic performance of gravity dam-reservoir-foundation coupled system is investigated utilizing probabilistic approach. In this research, the uncertainties associated with modeling parameters are incorporated in nonlinear response history simulations to realistically quantify their effects on the seismic performance of the system. The methodology is applied to Pine Flat gravity dam and the foundation is considered to be inhomogeneous assuming a constant spatial geometry but with various rock material properties. The sources of uncertainty are taken into account in the reliability analysis using Latin Hypercube Sampling procedure. The effects of the deconvolution process, number of samples, and foundation inhomogeneity are investigated.

关键词: gravity dams     dam-reservoir-foundation interaction     seismic reliability     inhomogeneous foundation     earthquake deconvolution    

标题 作者 时间 类型 操作

saccharification and fermentation of sweet potato powder for the production of ethanol under conditions of veryhigh gravity

Yinxiu CAO, Hongchi TIAN, Kun YAO, Yingjin YUAN

期刊论文

Linear viscoelastic behavior of asphalt binders and mixtures containing very high percentages of reclaimed

期刊论文

High-gravity intensified iron-carbon micro-electrolysis for degradation of dinitrotoluene

期刊论文

and mechanism of nitrobenzene degradation by hydroxyl radicals-based ozonation process enhanced by highgravity technology

Weizhou Jiao, Shengjuan Shao, Peizhen Yang, Kechang Gao, Youzhi Liu

期刊论文

High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersionwith high solids content

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

期刊论文

甚高频雷达复杂场景中目标高度和多径衰减联合估计

陈胜,赵永波,胡毅立,曹成虎,庞晓娇

期刊论文

超重力环境下非金属氮掺杂石墨烯泡沫催化还原反应性能研究

王志勇, 赵志建, Jesse Baucom, 王丹, Liming Dai, 陈建峰

期刊论文

我国高温气冷堆发展战略研究

张作义,吴宗鑫,王大中,童节娟

期刊论文

我国高坝建设和科技攻关

陈宗梁

期刊论文

高分辨率地球重力场模型DQM99

石磐,夏哲仁,孙中苗,李迎春

期刊论文

Structure improvement and strength finite element analysis of VHP welded rotor of 700°C USC steam turbine

Jinyuan SHI,Zhicheng DENG,Yong WANG,Yu YANG

期刊论文

卫星重力梯度数据用于精化地球重力场的研究

宁津生,罗志才,陈永奇

期刊论文

Stability analysis on Tingzikou gravity dam along deep-seated weak planes during earthquake

Weiping HE, Yunlong HE

期刊论文

A comprehensive simulation approach for pollutant bio-transformation in the gravity sewer

Nan Zhao, Huu Hao Ngo, Yuyou Li, Xiaochang Wang, Lei Yang, Pengkang Jin, Guangxi Sun

期刊论文

Evaluation of seismic reliability of gravity dam-reservoir-inhomogeneous foundation coupled system

Hamid Taghavi GANJI, Mohammad ALEMBAGHERI, Mohammad Houshmand KHANEGHAHI

期刊论文