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Case study of data-oriented approach for building energy performance investigation

Jianjun XIA, He XIAO, Yi JIANG,

《能源前沿（英文）》 2010年第4卷第1期页码 22-34 doi: 10.1007/s11708-010-0024-y

摘要： The key parameters that may influence building energy performance is studied by comparing the building energy data of college buildings in two different regions (the USA and China). By introducing data-orientated approach, a study of a set of on-campus building energy demand and consumption is conducted for cooling, heating and electricity. In addition, the heating, ventilation and air conditioning (HVAC) and lighting systems are studied in great detail. The breakdown analyses of the current energy consumption data are used to focus the investigation on critical issues. The analysis shows that the energy consumption of college buildings in the USA can be 3–5 times more than that of college buildings in China. The over-high energy consumption in campus buildings in the USA is mainly caused by operation schedule, system style, cooling and heating counteraction and sensor/actuator faults in the control systems, which also leads to the discussion of energy difference on the concept of “full control” or “local improvement” in building environment control. The study also indicates that the building energy efficiency can only be achieved by adjusting the demand according to natural conditions, encouraging green life behaviors, and developing relative technical solutions coordinated with the thrift culture and human behavior.

关键词： USA counteraction on-campus building over-high sensor/actuator

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NO hydrogenation to NH over FeCu/TiO catalyst with improved activity

《化学科学与工程前沿（英文）》 2023年第17卷第12期页码 1973-1985 doi: 10.1007/s11705-023-2364-2

摘要： Ammonia is crucial in industry and agriculture, but its production is hindered by environmental concerns and energy-intensive processes. Hence, developing an efficient and environmentally friendly catalyst is imperative. In this study, we employed a straightforward and efficient impregnation technique to create various Cu-doped catalysts. Notably, the optimized 10Fe-8Cu/TiO₂ catalyst exhibited exceptional catalytic performance in converting NO to NH₃, achieving an NO conversion rate exceeding 80% and an NH₃ selectivity exceeding 98% at atmospheric pressure and 350 °C. We employed in situ diffuse reflectance Fourier transform infrared spectroscopy and conducted density functional theory calculations to investigate the intermediates and subsequent adsorption. Our findings unequivocally demonstrate that Cu doping enhances the rate-limiting hydrogenation step and lowers the energy barrier for NH₃ desorption, thereby resulting in improved NO conversion and enhanced selectivity toward ammonia. This study presents a pioneering approach toward energy-efficient ammonia synthesis and recycling of nitrogen sources.

关键词： NO hydrogenation synthetic ammonia 10Fe-xCu/TiO₂ high selectivity

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Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 89-95 doi: 10.1007/s11705-010-0558-x

摘要： Although an important industrial catalyst for producing high density polyethylene, the SiO -supported organosilyl chromate UCC S-2 catalyst has not been fully investigated compared with the SiO -supported oxo chromium Phillips catalyst. In this work, gas phase ethylene polymerization by S-2 catalysts (Cat-1, Cat-2, and Cat-3) was carried out in a high-speed stirred-autoclave reactor. The effects of temperature, time, and pressure on kinetics, activity, and product properties were studied. All kinetics were typical built-up types with slow decay. Compared to the simple physical mixtures of Cat-1 and Cat-2, Cat-3 showed higher activity and its product had a broader molecular weight distribution, indicating new active species induced during blending of Cat-1 and Cat-2 in -hexane. The innovation by a simple catalyst technology created a new application to meet market demands.

关键词： UCC S-2 catalyst Al-alkyl co-catalyst gas-phase ethylene polymerization high density polyethylene

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Combined static mixers for high viscous fluids mixing

Zhenhao XI, Weizhen SUN, Ling ZHAO, Zhaoyan LIU

《化学科学与工程前沿（英文）》 2009年第3卷第1期页码 93-96 doi: 10.1007/s11705-009-0112-x

摘要： A new static mixer Cross-over-Disc has been invented to strip off the boundary layer and to make strong radial mixing. The pressure drop of Cross-over-Disc is 12—26 times as large as that of empty pipe with equivalent diameter and length. The mixing performance of Cross-over-Disc with 14 elements has been investigated in the viscosity range of 190—250 Pa?s by decoloration method, and the gray analysis of images shows that mixing inhomogeneity is about 7.5% and 9.4% for the mixing ratio of 5∶1 and 10∶1, respectively. Furthermore, mixing inhomogeneity for a combination of static mixing elements (four from Cross-over-Disc and three pairs from Sulzer-type) can be decreased to 2.1%—3.1% within a reasonable range of pressure drop.

关键词： static mixer Cross-over-Disc pressure drop mixing performance high viscous fluid

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High-precision diffusion measurement of ethane and propane over SAPO-34 zeolites for methanol-to-olefin

Dali Cai, Yu Cui, Zhao Jia, Yao Wang, Fei Wei

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 77-82 doi: 10.1007/s11705-017-1684-5

摘要： The methanol-to-olefin (MTO) process has attracted much attention and many problems including lifetime and selectivity of light olefins have all been connected to the diffusion problems in zeolite crystals. However, a quantitative study of diffusion problems in SAPO-34 zeolites is lacking. In this paper, we performed a high-precision diffusion measurement of the diffusion behavior of ethane and propane, which represent ethylene and propylene respectively, over SAPO-34. The diffusions of ethane and propane over fresh and coked SAPO-34 zeolites with different crystal sizes were carefully studied. Ethane and propane show different diffusion behavior in SAPO-34. The diffusion of ethane is almost not influenced by the crystal size and coke percentage, whereas that of propane is strongly affected. A slower diffusion velocity was observed in bigger crystals, and the diffusion velocity decline significantly with the coke percentage increasing. The diffusion coefficient was calculated with both the internal and surface diffusion models, and the results show that the surface diffusion plays a key role in the diffusion process of both ethane and propane. We believe that this work would be helpful for understanding the diffusion of different molecules in SAPO-34 zeolites, and may lay the foundation of MTO research.

关键词： diffusion measurement methanol-to-olefin process

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NO oxidation over Co-La catalysts and NO

Tiejun Zhang,Jian Li,Hong He,Qianqian Song,Quanming Liang

《环境科学与工程前沿（英文）》 2017年第11卷第2期 doi: 10.1007/s11783-017-0906-x

摘要： The Co-La catalyst (pH= 1) exhibited maximum NO conversion of 43% at 180°C. Acid modified catalyst enhanced the resistance to SO . The formed sulfates may block the pore structure of the catalyst. The NO conversion of compact SCR was 91% at 180°C at the highest space velocity. A series of Co-La catalysts were prepared using the wet impregnation method and the synthesis of catalysts were modified by controlling pH with the addition of ammonium hydroxide or oxalic solution. All the catalysts were systematically investigated for NO oxidation and SO resistance in a fixed bed reactor and were characterized by Brunanuer–Emmett–Teller (BET) method, Fourier Transform infrared spectroscopy (FTIR), X–ray diffraction (XRD), Thermogravimetric (TG) and Ion Chromatography (IC). Among the catalysts, the one synthesized at pH= 1 exhibited the maximum NO conversion of 43% at 180°C. The activity of the catalyst was significantly suppressed by the existence of SO (300 ppm) at 220°C. Deactivation may have been associated with the generation of cobalt sulfate, and the SO adsorption quantity of the catalyst might also have effected sulfur resistance. In the case of the compact selective catalytic reduction (SCR), the activity increased from 74% to 91% at the highest gas hourly space velocity (GHSV) of 300000 h when the NO catalyst maintained the highest activity, in excess of 50% more than that of the standard SCR.

关键词： NO catalytic oxidation pH effect Low temperature Sulfur dioxide High space velocity SCR

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High-quality industrial n-type silicon wafers with an efficiency of over 23% for Si heterojunction solar

Fanying MENG,Jinning LIU,Leilei SHEN,Jianhua SHI,Anjun HAN,Liping ZHANG,Yucheng LIU,Jian YU,Junkai ZHANG,Rui ZHOU,Zhengxin LIU

《能源前沿（英文）》 2017年第11卷第1期页码 78-84 doi: 10.1007/s11708-016-0435-5

摘要： n-type CZ-Si wafers featuring longer minority carrier lifetime and higher tolerance of certain metal contamination can offer one of the best Si-based solar cells. In this study, Si heterojuction (SHJ) solar cells which was fabricated with different wafers in the top, middle and tail positions of the ingot, exhibited a stable high efficiency of>22% in spite of the various profiles of the resistivity and lifetime, which demonstrated the high material utilization of n-type ingot. In addition, for effectively converting the sunlight into electrical power, the pyramid size, pyramid density and roughness of surface of the Cz-Si wafer were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). Furthermore, the dependence of SHJ solar cell open-circuit voltage on the surface topography was discussed, which indicated that the uniformity of surface pyramid helps to improve the open-circuit voltage and conversion efficiency. Moreover, the simulation revealed that the highest efficiency of the SHJ solar cell could be achieved by the wafer with a thickness of 100 µm. Fortunately, over 23% of the conversion efficiency of the SHJ solar cell with a wafer thickness of 100 µm was obtained based on the systematic optimization of cell fabrication process in the pilot production line. Evidently, the large availability of both n-type ingot and thinner wafer strongly supported the lower cost fabrication of high efficiency SHJ solar cell.

关键词： n-type Cz-Si thinner wafer surface texture high efficiency SHJ solar cell

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万吨级组块浮托技术研究及典型专项设备设施

荀海龙,朱晓环

《中国工程科学》 2011年第13卷第5期页码 93-97

摘要：

通过对海洋平台万吨级组块浮托技术的研究，结合多项技术在渤海湾大型油田开发工程中的成功应用，简要阐述了万吨级组块浮托技术在平台设计、建造、安装及专项设备设施研究中的关键技术、关键做法，用于指导渤海湾万吨级组块的浮托技术应用，同时为下一步浮托技术应用于南海油田开发工程提出参考和指导。

关键词：浮托技术桩腿耦合装置高承载力滑靴组块支撑单元护悬

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Reductive amination of -hexanol to -hexylamine over Ni–Ce/-AlO catalysts

《化学科学与工程前沿（英文）》 2023年第17卷第1期页码 82-92 doi: 10.1007/s11705-022-2181-z

摘要： The amination of alkyl alcohols is one of the most promising paths in synthesis of aliphatic amines. Herein, cerium doped nickel-based catalysts were synthesized and tested in a gas-phase amination of n-hexanol to n-hexylamine. It was found that the activity of the Ni/γ-Al₂O₃ catalyst is significantly improved by doping an appropriate amount of cerium. The presence of cerium effectively inhibits the agglomeration of nickel particle, resulting in better Ni dispersion. As Ni particle size plays critical role on the catalytic activity, higher turnover frequency of n-hexanol amination was achieved. Cerium doping also improves the reduction ability of nickel and enhances the interactions between Ni and the catalyst support. More weak acid sites were also found in those cerium doped catalysts, which promote another key step—ammonia dissociative adsorption in this reaction system. The overall synergy of Ni nanoparticles and acid sites of this Ni–Ce/γ-Al₂O₃ catalyst boosts its superior catalytic performance in the amination of n-hexanol.

关键词： amination alcohol cerium nickel acidity interaction

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Supersonic flows over cavities

FANG Tianwen, DING Meng, ZHOU Jin

《能源前沿（英文）》 2008年第2卷第4期页码 528-533 doi: 10.1007/s11708-008-0055-9

摘要： The characteristics of supersonic cold flows over cavities were investigated experimentally and numerically, and the effects of cavities of different sizes on supersonic flow field were analyzed. The results indicate that the ratio

关键词： supersonic different ratio

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Efficient conversion of lignin to alkylphenols over highly stable inverse spinel MnFeO catalysts

《化学科学与工程前沿（英文）》 2023年第17卷第8期页码 1085-1095 doi: 10.1007/s11705-022-2236-1

摘要： The aromatic properties of lignin make it a promising source of valuable chemicals and fuels. Developing efficient and stable catalysts to effectively convert lignin into high-value chemicals is challenging. In this work, MnFe₂O₄ spinel catalysts with oxygen-rich vacancies and porous distribution were synthesized by a simple solvothermal process and used to catalyze the depolymerization of lignin in an isopropanol solvent system. The specific surface area was 110.5 m²∙g^–1, which substantially increased the active sites for lignin depolymerization compared to Fe₃O₄. The conversion of lignin reached 94%, and the selectivity of alkylphenols exceeded 90% after 5 h at 250 °C. Underpinned by characterizations, products, and density functional theory analysis, the results showed that the catalytic performance of MnFe₂O₄ was attributed to the composition of Mn and Fe with strong Mn–O–Fe synergy. In addition, the cycling experiments and characterization showed that the depolymerized lignin on MnFe₂O₄ has excellent cycling stability. Thus, our work provides valuable insights into the mechanism of lignin catalytic depolymerization and paves the way for the industrial-scale application of this process.

关键词： lignin depolymerization spinel catalysts hydrogenation

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基于5 μm厚向列相液晶的高效圆极化相控阵系统的设计、校准和实验验证 Article

Xin Yu Wu,Fengshuo Wan,Hongyuan Feng,Shichao Jin,Chong Guo,Yu Wei,Dunge Liu,Yuqian Yang,Longzhu Cai,Zhi Hao Jiang,Wei Hong

《工程（英文）》 2024年第32卷第1期页码 70-82 doi: 10.1016/j.eng.2023.08.013

摘要：

This paper presents a systematic investigation and demonstration of a K-band circularly polarized liquid-crystal-based phased array (LCPA), including the design, over-the-air (OTA) in-array calibration, and experimental validation. The LCPA contains 16 phase-shifting radiating channels, each consisting of a circularly polarized stacked patch antenna and a liquid-crystal-based phase shifter (LCPS) based on a loaded differential line structure. Thanks to its slow-wave properties, the LCPS exhibits a maximum phase-shifting range of more than 360° with a figure of merit of 78.3°·dB⁻¹ based on a liquid crystal layer with a thickness of only 5 μm. Furthermore, an automatic OTA calibration based on a state ergodic method is proposed, which enables the extraction of the phase–voltage curve of every individual LCPA channel. The proposed LCPA is manufactured and characterized with a total profile of only 1.76 mm, experimentally demonstrating a scanned circularly polarized beam from −40° to +40° with a measured peak gain of 12.5 dBic and a scanning loss of less than 2.5 dB. The bandwidth of the LCPA, which satisfies the requirements of port reflection (|S₁₁|) < −15 dB, an axial ratio (AR) < 3 dB, beam squinting < 3°, and a gain variation < 2.2 dB, spans from 25.5 to 26.0 GHz. The total efficiency is about 34%, which represents a new state of the art. The use of the demonstrated low-profile LCPA to support circularly polarized scanning beams, along with the systematic design and calibration methodology, holds potential promise for a variety of millimeter-wave applications.

关键词： Circularly polarized Liquid crystal Liquid-crystal-based phased array (LCPA) Phase shifter Over-the-air (OTA) calibration

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REVEALS METABOLITE VARIATION AND FLAVONOID REGULATORY NETWORKS IN FRESH SHOOTS OF TEA (CAMELLIA SINENSIS) OVER

《农业科学与工程前沿（英文）》 2021年第8卷第2期

摘要：

Metabolites, especially secondary metabolites, are very important in the adaption of tea plants and the quality of tea products. Here, we focus on the seasonal variation in metabolites of fresh tea shoots and their regulatory mechanism at the transcriptional level. The metabolic profiles of fresh tea shoots of 10 tea accessions collected in spring, summer, and autumn were analyzed using ultra-performance liquid chromatography coupled with quadrupole-obitrap mass spectrometry. We focused on the metabolites and key genes in the phenylpropanoid/flavonoid pathway integrated with transcriptome analysis. Multivariate statistical analysis indicates that metabolites were distinctly different with seasonal alternation. Flavonoids, amino acids, organic acids and alkaloids were the predominant metabolites. Levels of most key genes and downstream compounds in the flavonoid pathway were lowest in spring but the catechin quality index was highest in spring. The regulatory pathway was explored by constructing a metabolite correlation network and a weighted gene co-expression network.

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Plastic materials and water sources actively select and shape wastewater plastispheres over time

《环境科学与工程前沿（英文）》 2022年第16卷第11期 doi: 10.1007/s11783-022-1580-1

摘要：

● Wastewater MPs exhibited resistomes and therefore health threats.

关键词： Microplastics Whole-genome metagenomic sequencing Plastisphere Plastic degradation MHETase

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Stability and agility: biped running over varied and unknown terrain

Yang YI,Zhi-yun LIN

《信息与电子工程前沿（英文）》 2015年第16卷第4期页码 283-292 doi: 10.1631/FITEE.1400284

摘要： We tackle the problem of a biped running over varied and unknown terrain. Running is a necessary skill for a biped moving fast, but it increases the challenge of dynamic balance, especially when a biped is running on varied terrain without terrain information (due to the difficulty and cost of obtaining the terrain information in a timely manner). To address this issue, a new dynamic indicator called the sustainable running criterion is developed. The main idea is to sustain a running motion without falling by maintaining the system states within a running-feasible set, instead of running on a periodic limit cycle gait in the traditional way. To meet the precondition of the criterion, the angular moment about the center of gravity (COG) is restrained close to zero at the end of the stance phase. Then to ensure a small state jump at touchdown on the unknown terrain, the velocity of the swing foot is restrained within a specific range at the end of the flight phase. Finally, the position and velocity of the COG are driven into the running-feasible set. A five-link biped with underactuated point foot is considered in simulations. It is able to run over upward and downward terrain with a height difference of 0.15 m, which shows the effectiveness of our control scheme.

关键词： Underactuated running biped Dynamic balance Varied and unknown terrain