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Experiment study of a quartz tube falling particle receiver

Tianjian WANG, Fengwu BAI, Shunzhou CHU, Xiliang ZHANG, Zhifeng WANG

《能源前沿（英文）》 2017年 第11卷 第4期   页码 472-479 doi: 10.1007/s11708-017-0502-6

摘要： This paper presents an experimental evaluation of a specially designed falling particle receiver. A quartz tube was used in the design, with which the particles would not be blown away by wind. Concentrated solar radiation was absorbed and converted into thermal energy by the solid particles flowed inside the quartz tube. Several experiments were conducted to test the dynamic thermal performance of the receiver on solar furnace system. During the experiments, the maximum particle temperature rise is 212°C, with an efficiency of 61.2%, which shows a good thermal performance with a falling distance of 0.2 m in a small scale particle receiver. The average outlet particle temperature is affected by direct normal irradiance (DNI) and other factors such as wind speed. The solid particles obtain a larger viscosity with a higher temperature while smaller solid particles are easier to get stuck in the helix quartz tube. The heat capacity of the silicon carbide gets larger with the rise of particle temperature, because as the temperature of solid particles increases, the temperature rise of the silicon carbide decreases.

关键词： solar thermal electricity     central receiver     particle receiver     experimental research    

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Geometric optimization model for the solar cavity receiver with helical pipe at different solar radiation

Chongzhe ZOU, Huayi FENG, Yanping ZHANG, Quentin FALCOZ, Cheng ZHANG, Wei GAO

《能源前沿（英文）》 2019年 第13卷 第2期   页码 284-295 doi: 10.1007/s11708-019-0613-3

摘要： In consideration of geometric parameters, several researches have already optimized the thermal efficiency of the cylindrical cavity receiver. However, most of the optimal results have been achieved at a fixed solar radiation. At different direct normal irradiance (DNI), any single optimal result may not be suitable enough for different regions over the world. This study constructed a 3-D numerical model of cylindrical cavity receiver with DNI variation. In the model of a cylindrical cavity receiver containing a helical pipe, the heat losses of the cavity and heat transfer of working medium were also taken into account. The simulation results show that for a particular DNI in the range of 400 W/m to 800 W/m , there exists a best design for achieving a highest thermal efficiency of the cavity receiver. Besides, for a receiver in constant geometric parameters, the total heat losses increases dramatically with the DNI increasing in that range, as well as the temperature of the working medium. The thermal efficiency presented a different variation tendency with the heat losses, which is 2.45% as a minimum decline. In summary, this paper proposed an optimization method in the form of a bunch of fitting curves which could be applied to receiver design in different DNI regions, with comparatively appropriate thermal performances.

关键词： cylindrical cavity receiver     3-D numerical simulation     geometric optimization     direct normal irradiation    

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Liquid-based high-temperature receiver technologies for next-generation concentrating solar power: A

《能源前沿（英文）》 2023年 第17卷 第1期   页码 16-42 doi: 10.1007/s11708-023-0866-8

摘要： To reduce the levelized cost of energy for concentrating solar power (CSP), the outlet temperature of the solar receiver needs to be higher than 700 °C in the next-generation CSP. Because of extensive engineering application experience, the liquid-based receiver is an attractive receiver technology for the next-generation CSP. This review is focused on four of the most promising liquid-based receivers, including chloride salts, sodium, lead-bismuth, and tin receivers. The challenges of these receivers and corresponding solutions are comprehensively reviewed and classified. It is concluded that combining salt purification and anti-corrosion receiver materials is promising to tackle the corrosion problems of chloride salts at high temperatures. In addition, reducing energy losses of the receiver from sources and during propagation is the most effective way to improve the receiver efficiency. Moreover, resolving the sodium fire risk and material compatibility issues could promote the potential application of liquid-metal receivers. Furthermore, using multiple heat transfer fluids in one system is also a promising way for the next-generation CSP. For example, the liquid sodium is used as the heat transfer fluid while the molten chloride salt is used as the storage medium. In the end, suggestions for future studies are proposed to bridge the research gaps for > 700 °C liquid-based receivers.

关键词： next-generation concentrating solar power     liquid-based solar receiver     molten salt     liquid metals    

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A new approach for fuel injection into a solar receiver/reactor: Numerical and experimental investigation

M Helal Uddin, Nesrin Ozalp, Jens Heylen, Cedric Ophoff

《化学科学与工程前沿（英文）》 2018年 第12卷 第4期   页码 683-696 doi: 10.1007/s11705-018-1782-z

摘要：

An innovative and efficient design of solar receivers/reactors can enhance the production of clean fuels via concentrated solar energy. This study presents a new jet-type burner nozzle for gaseous feedstock injection into a cavity solar receiver inspired from the combustion technology. The nozzle design was adapted from a combustion burner and successfully implemented into a solar receiver and studied the influence of the nozzle design on the fluid mixing and temperature distribution inside the solar receiver using a 7 kW solar simulator and nitrogen as working fluid. Finally, a thorough computational fluid dynamics (CFD) analysis was performed and validated against the experimental results. The CFD results showed a variation of the gas flow pattern and gas mixing after the burner nozzle adaptation, which resulted an intense effect on the heat transfer inside the solar receiver.

关键词： solar reactor     nozzle     CFD     heat transfer     mixing and recirculation    

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Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 429-455 doi: 10.1007/s11709-018-0483-5

摘要： In this study, average-interpolating radial basis functions (RBFs) are successfully integrated with central high-resolution schemes to achieve a higher-order central method. This proposed method is used for simulation of generalized coupled thermoelasticity problems including shock (singular) waves in their solutions. The thermoelasticity problems include the LS (systems with one relaxation parameter) and GN (systems without energy dissipation) theories with constant and variable coefficients. In the central high resolution formulation, RBFs lead to a reconstruction with the optimum recovery with minimized roughness on each cell: this is essential for oscillation-free reconstructions. To guarantee monotonic reconstructions at cell-edges, the nonlinear scaling limiters are used. Such reconstructions, finally, lead to the total variation bounded (TVB) feature. As RBFs work satisfactory on non-uniform cells/grids, the proposed central scheme can handle adapted cells/grids. To have cost effective and accurate simulations, the multiresolution–based grid adaptation approach is then integrated with the RBF-based central scheme. Effects of condition numbers of RBFs, computational complexity and cost of the proposed scheme are studied. Finally, different 1-D coupled thermoelasticity benchmarks are presented. There, performance of the adaptive RBF-based formulation is compared with that of the adaptive Kurganov-Tadmor (KT) second-order central high-resolution scheme with the total variation diminishing (TVD) property.

关键词： central high resolution schemes     RBFs     higher order accuracy     generalized thermoelasticity     multiresolution-based adaptation    

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Degradation of refractory organics in concentrated leachate by the Fenton process: Central composite

Senem Yazici Guvenc, Gamze Varank

《环境科学与工程前沿（英文）》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1294-1

摘要： Abstract • 90% total COD, 95.3% inert COD and 97.2% UV254 were removed. • High R2 values (over 95%) for all responses were obtained with CCD. • Operational cost was calculated to be 0.238 €/g CODremoved for total COD removal. • Fenton oxidation was highly-efficient method for inert COD removal. • BOD5/COD ratio of leachate concentrate raised from 0.04 to 0.4. The primary aim of this study is inert COD removal from leachate nanofiltration concentrate because of its high concentration of resistant organic pollutants. Within this framework, this study focuses on the treatability of leachate nanofiltration concentrate through Fenton oxidation and optimization of process parameters to reach the maximum pollutant removal by using response surface methodology (RSM). Initial pH, Fe2+ concentration, H2O2/Fe2+ molar ratio and oxidation time are selected as the independent variables, whereas total COD, color, inert COD and UV254 removal are selected as the responses. According to the ANOVA results, the R2 values of all responses are found to be over 95%. Under the optimum conditions determined by the model (pH: 3.99, Fe2+: 150 mmol/L, H2O2/Fe2+: 3.27 and oxidation time: 84.8 min), the maximum COD removal efficiency is determined as 91.4% by the model. The color, inert COD and UV254 removal efficiencies are determined to be 99.9%, 97.2% and 99.5%, respectively, by the model, whereas the total COD, color, inert COD and UV254 removal efficiencies are found respectively to be 90%, 96.5%, 95.3% and 97.2%, experimentally under the optimum operating conditions. The Fenton process improves the biodegradability of the leachate NF concentrate, increasing the BOD5/COD ratio from the value of 0.04 to the value of 0.4. The operational cost of the process is calculated to be 0.238 €/g CODremoved. The results indicate that the Fenton oxidation process is an efficient and economical technology in improvement of the biological degradability of leachate nanofiltration concentrate and in removal of resistant organic pollutants.

关键词： Concentrated leachate     Fenton oxidation     Central composite design     Biodegradability     Inert COD    

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Development of a multi-component drug from turmeric using central composite design

Xiaohang ZHANG,Shengnan HAN,Yan LI,Jianlan JIANG

《化学科学与工程前沿（英文）》 2014年 第8卷 第3期   页码 362-368 doi: 10.1007/s11705-014-1439-5

摘要： A methodology to develop multi-component drugs based on traditional Chinese medicines has been developed using central composite design. Several active components from the traditional Chinese medicine turmeric were chosen for use in a multi-component antitumor drug. Response surface methodology based on a central composite design was applied to determine the quantitative composition-activity relationships in order to optimize the amount of each component in the drug. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to measure the pharmacological activity as the response value. The experimental antitumor activity of the optimum combination was 92.85% in the MTT assay and superior to the activities of each single component. These results demonstrate that response surface methodology based on a central composite design is suitable for the design of multi-component drugs.

关键词： multi-component drug development     central composite design     turmeric     curcuminoids    

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Prevalence of vitamin D deficiency in girls with idiopathic central precocious puberty

null

《医学前沿（英文）》 2018年 第12卷 第2期   页码 174-181 doi: 10.1007/s11684-017-0544-5

摘要：

The relationship between vitamin D deficiency and idiopathic central precocious puberty (ICPP) has been recently documented. In this study, 280 girls diagnosed with ICPP and 188 normal puberty control girls of similar ages were enrolled and retrospectively studied. The ICPP group had significantly lower serum 25-hydroxyvitamin D (25[OH]D) levels than the control group. Furthermore, a nonlinear relationship was found between serum 25[OH]D and ICPP, and a cut-off point for serum 25[OH]D was found at 31.8 ng/ml for ICPP with and without adjusting the different confounding factors. Girls with serum 25[OH]D≥31.8 ng/ml had a lower odds ratio (unadjusted: OR 0.36, 95% CI 0.15 to 0.83, <0.05; height and weight adjusted: OR 0.44, 95% CI 0.18 to 1.08, = 0.072; BMI adjusted: OR 0.36, 95% CI 0.16 to 0.84, <0.05). The ICPP subjects with 25[OH]D deficiency had a higher body mass index (BMI) than the subjects from the two other subgroups. Correlation analysis showed that vitamin D level is correlated with BMI and some metabolic parameters in the ICPP group. Our study suggested that vitamin D status may be associated with ICPP risk and may have a threshold effect on ICPP.

关键词： idiopathic central precocious puberty     threshold effects     vitamin D status    

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Anterior cervical surgery methods for central cord syndrome without radiographic spinal fracture-dislocation

Chengwei JING, Qin FU, Xiaojun XU

《医学前沿（英文）》 2009年 第3卷 第1期   页码 45-48 doi: 10.1007/s11684-009-0019-4

摘要： This study was aimed to explore the anterior cervical surgery methods to treat central cord syndrome without radiographic spinal fracture-dislocation (CCSWORFD), retrospectively analyze the cases of CCSWORFD, and evaluate the curative effect of anterior cervical surgery methods for CCSWORFD. Twenty four cases of CCSWORFD (19 males and 5 females), all suffering from cervical hyperextension injury, between 45-68 (average 59) years old, were operated on by anterior cervical surgery methods. Among these, 18 cases had been followed up for 6-24 (average 15) months; 18 cases, who had anterior decompression and plate fixation with titanium mesh bone grafting or iliac bone grafting achieved reliable effects based on the Japanese Orthopedics Association (JOA) evaluation (improved scores of cases with titanium mesh bone grafting, = 2.800, <0.05; improved scores of cases with iliac bone grafting, = 3.270, <0.05), and reliable reconstruction of cervical spine. The two groups obtained the same curative effect ( = 0.470, >0.05) Most of these cases had degeneration of cervical vertebra. The decompression which relieves the oppression to the spinal cord can help lessen edema of the spinal cord, and early fixation for stability of cervical vertebra is better for the recovery of spinal cord injury. Anterior operation with titanium mesh bone grafting or iliac bone grafting are both reliable curative methods for CCSWORFD, and titanium mesh bone grafting can avoid the trauma of the supplying graft. Mesh bone grafting can also shorten hospital stay.

关键词： central cord syndrome     decompression     surgical     titanium mesh    

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Erratum to: Folded down-conversion mixer for a 60 GHz receiver architecture in 65-nm CMOS technology

Najam Muhammad AMIN,Zhi-gong WANG,Zhi-qun LI

《信息与电子工程前沿（英文）》 2015年 第16卷 第5期 doi: 10.1631/FITEE.14e0087

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Environment and economic feasibility of municipal solid waste central sorting strategy: a case study

Hua ZHANG, Zongguo WEN, Yixi CHEN

《环境科学与工程前沿（英文）》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0852-z

摘要： The Green House program reduced the amount of waste by 34%. The Green House is now running with a monthly loss of 1982 CNY. Involve government, expand scale, use professional technology are main suggestions. Improved program can reduce the amount of waste by 37% (33.8 tons monthly). Improved program can flip the loss into a profit worth 35034 CNY monthly. Although Beijing has carried out municipal solid waste (MSW) source separation since 1996, it has largely been ineffective. In 2012, a “Green House” program was established as a new attempt for central sorting. In this study, the authors used material flow analysis (MFA) and cost benefit analysis (CBA) methods to investigate Green House’s environment and economic feasibility. Results showed that the program did have significant environmental benefits on waste reduction, which reduced the amount of waste by 34%. If the Green House program is implemented in a residential community with wet waste ratio of 66%, the proportion of waste reduction can reach 37%. However, the Green House is now running with a monthly loss of 1982 CNY. This is mainly because most of its benefits come from waste reduction (i.e., 5878 CNY per month), which does not turn a monetary benefit, but is instead distributed to the whole of society as positive environmental externalities. Lack of government involvement, small program scale, and technical/managerial deficiency are three main barriers of the Green House. We, thus, make three recommendations: involve government authority and financial support, expand the program scale to separate 91.4 tons of waste every month, and use more professional equipment/technologies. If the Green House program can successfully adopt these suggestions, 33.8 tons of waste can be reduced monthly, and it would be able to flip the loss into a profit worth 35034 CNY.

关键词： Environment and economic feasibility     Municipal solid waste (MSW)     Waste central sorting     Green House    

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Analysis of the genomic landscape of primary central nervous system lymphoma using whole-genome sequencing

《医学前沿（英文）》   页码 889-906 doi: 10.1007/s11684-023-0994-x

摘要： Primary central nervous system lymphoma (PCNSL) is an uncommon non-Hodgkin’s lymphoma with poor prognosis. This study aimed to depict the genetic landscape of Chinese PCNSLs. Whole-genome sequencing was performed on 68 newly diagnosed Chinese PCNSL samples, whose genomic characteristics and clinicopathologic features were also analyzed. Structural variations were identified in all patients with a mean of 349, which did not significantly influence prognosis. Copy loss occurred in all samples, while gains were detected in 77.9% of the samples. The high level of copy number variations was significantly associated with poor progression-free survival (PFS) and overall survival (OS). A total of 263 genes mutated in coding regions were identified, including 6 newly discovered genes (ROBO2, KMT2C, CXCR4, MYOM2, BCLAF1, and NRXN3) detected in ≥ 10% of the cases. CD79B mutation was significantly associated with lower PFS, TMSB4X mutation and high expression of TMSB4X protein was associated with lower OS. A prognostic risk scoring system was also established for PCNSL, which included Karnofsky performance status and six mutated genes (BRD4, EBF1, BTG1, CCND3, STAG2, and TMSB4X). Collectively, this study comprehensively reveals the genomic landscape of newly diagnosed Chinese PCNSLs, thereby enriching the present understanding of the genetic mechanisms of PCNSL.

关键词： primary central nervous system lymphoma     whole-genome sequencing     TMSB4X     copy number variation     gene mutation    

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Making central-local relations work: Comparing America and China environmental governance systems

Dan GUTTMAN, SONG Yaqin

《环境科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 418-433 doi: 10.1007/s11783-007-0068-3

摘要： The challenge of making central requirements work at local levels is a common problem for environmental governance throughout the world. Countries can learn from one another s approaches, but must understand the local context in w
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模糊中心聚类的模式识别学习方法

曾黄麟,袁慧,刘小芳

《中国工程科学》 2004年 第6卷 第11期   页码 33-37

摘要：

基于一个约束条件下的非线性规划问题的优化计算思想，把模糊中心聚类中计算输入矢量与中心的距离来实现聚类作为一种优化计算问题，证明了模糊中心聚类方法，取一个适当的属函数，其聚类中心vi为模糊聚类中心价值函数的极小值，推导出了基于模糊中心聚类的模式识别的无导师递推学习方法，提出了模糊中心聚类模式分类神经网络结构，该网络可以实现并行数据处理和模式分类的软划分和硬划分。

关键词： 模糊     中心聚类     模式识别     神经网络    

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Distributed fiber optic monitoring of a CFA pile with a central reinforcement bar bundle

Yi RUI, Nicholas de BATTISTA, Cedric KECHAVARZI, Xiaomin XU, Mei YIN

《结构与土木工程前沿（英文）》 2021年 第15卷 第1期   页码 167-176 doi: 10.1007/s11709-020-0581-z

摘要： In this paper, we present an application of distributed fiber optic sensor (DFOS) technology to measure the strain of a continuous flight auger (CFA) test pile with a central reinforcement bar bundle, during a static load test carried out in London. Being distributed in nature, DFOS gives much more information about the pile performance as compared to traditional point sensors, such as identifying cross-sectional irregularities or other anomalies. The strain profiles recorded along the depth of the piles from the DFOS were used to calculate pile deformation (contraction), shaft friction, and tip resistance under various loads. Based on this pile load test, a finite element (FE) analysis was performed using a one-dimensional nonlinear load-transfer model. Calibrated by the shaft friction and tip resistance derived from the monitored data, the FE model was able to simulate the pile and soil performance during the load testing with good accuracy. The effect of the reinforcement cage and central reinforcement bar bundle were investigated, and it was found that the addition of a reinforcement cage would reduce the pile settlement by up to 20%.

关键词： continuous flight auger pile     static load test     central reinforcement bar bundle     distributed fiber optic sensor     finite element     load transfer    

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标题 作者 时间 类型 操作

Experiment study of a quartz tube falling particle receiver

Tianjian WANG, Fengwu BAI, Shunzhou CHU, Xiliang ZHANG, Zhifeng WANG

期刊论文

Geometric optimization model for the solar cavity receiver with helical pipe at different solar radiation

Chongzhe ZOU, Huayi FENG, Yanping ZHANG, Quentin FALCOZ, Cheng ZHANG, Wei GAO

期刊论文

Liquid-based high-temperature receiver technologies for next-generation concentrating solar power: A

期刊论文

A new approach for fuel injection into a solar receiver/reactor: Numerical and experimental investigation

M Helal Uddin, Nesrin Ozalp, Jens Heylen, Cedric Ophoff

期刊论文

Multiscale RBF-based central high resolution schemes for simulation of generalized thermoelasticity problems

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI

期刊论文

Degradation of refractory organics in concentrated leachate by the Fenton process: Central composite

Senem Yazici Guvenc, Gamze Varank

期刊论文

Development of a multi-component drug from turmeric using central composite design

Xiaohang ZHANG,Shengnan HAN,Yan LI,Jianlan JIANG

期刊论文

Prevalence of vitamin D deficiency in girls with idiopathic central precocious puberty

null

期刊论文

Anterior cervical surgery methods for central cord syndrome without radiographic spinal fracture-dislocation

Chengwei JING, Qin FU, Xiaojun XU

期刊论文

Erratum to: Folded down-conversion mixer for a 60 GHz receiver architecture in 65-nm CMOS technology

Najam Muhammad AMIN,Zhi-gong WANG,Zhi-qun LI

期刊论文

Environment and economic feasibility of municipal solid waste central sorting strategy: a case study

Hua ZHANG, Zongguo WEN, Yixi CHEN

期刊论文

Analysis of the genomic landscape of primary central nervous system lymphoma using whole-genome sequencing

期刊论文

Making central-local relations work: Comparing America and China environmental governance systems

Dan GUTTMAN, SONG Yaqin

期刊论文

模糊中心聚类的模式识别学习方法

曾黄麟,袁慧,刘小芳

期刊论文

Distributed fiber optic monitoring of a CFA pile with a central reinforcement bar bundle

Yi RUI, Nicholas de BATTISTA, Cedric KECHAVARZI, Xiaomin XU, Mei YIN

期刊论文