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Thermal response of steel framing members in open car park fires

Xia YAN; Marion CHARLIER; Thomas GERNAY

《结构与土木工程前沿（英文）》 2022年第16卷第9期页码 1071-1088 doi: 10.1007/s11709-022-0879-0

摘要： For open car park structures, adopting a performance-based structural fire design is often justified and allowed because the fire does not reach flashover. However, this design approach requires an accurate assessment of temperatures in structural members exposed to car fires. This paper describes a numerical study on the thermal exposure on steel framing members in open car park fires. Steel temperatures are computed by the coupling of computational fluid dynamics and finite element modeling, and by analytical models from the Eurocodes. In addition, the influence of galvanization on the steel temperature evolution is assessed. Results show that temperatures in unprotected beams and columns are influenced by the section geometry, car fire scenario, modeling approach, and use of galvanization. Galvanization slightly delays and reduces peak temperature. Regarding the different models, CFD-FEM (CFD: computational fluid dynamics, FEM: finite-element method) coupled models predict lower temperatures than the Hasemi model, because the latter conservatively assumes that the fire flame continuously touches the ceiling. Further, the Hasemi model cannot account for the effect of reduced emissivity from galvanization on the absorbed heat flux. Detailed temperature distributions obtained in the steel members can be used to complete efficient structural fire designs based on the member sections, structure layout, and use of galvanization.

关键词： open car park localized fire steel frame numerical modeling computational fluid dynamics

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中国私用轿车发展的现状与问题

郭孔辉

《中国工程科学》 2000年第2卷第8期页码 25-30

摘要：

目前国内对中国应不应该发展私用轿车，中国应着重发展什么样的轿车，中国应不应该发展自己的轿车工业，中国轿车工业的出路在哪里，以及应如何发展中国的轿车工业，……等等，讨论颇多，已经成为社会上普遍关心的问题。文章试图分析目前提出的有代表性的各种观点，并对有关问题提出笔者自己的见解，以供参考。笔者认为解决"汽车灾难"问题的根本出路不在抑制私用轿车的发展，而在于发展汽车高新技术，加强城市规划与交通管理。文章在肯定引进合资对提高我国汽车制造技术和管理水平的重要作用的同时，指出它的负面影响是逐渐丧失产品开发的主动权；提出中国汽车工业的总战略应是："自强不息加国际合作"，其中包括：高新技术战略、自主双赢战略、内联自强战略、自主品牌战略和跨越赶超战略。

关键词：中国汽车工业私用轿车家用轿车现状与问题

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Design and analyses of open-ended pipe piles in cohesionless soils

Yuan GUO,Xiong (Bill) YU

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 22-29 doi: 10.1007/s11709-016-0314-5

摘要： Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method (DEM) was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.

关键词： open-ended pipe pile soil plug DEM base capacity

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Development of a cloud condensation nuclei (CCN) counter using a laser and charge-coupled device (CCD) camera

Mikyung PARK, Jinkwan OH, Kihong PARK

《环境科学与工程前沿（英文）》 2011年第5卷第3期页码 313-319 doi: 10.1007/s11783-011-0346-y

摘要： A continuous flow streamwise thermal gradient cloud condensation nuclei (CCN) counter with an aerosol focusing and a laser-charge-coupled device (CCD) camera detector system was developed here. The counting performance of the laser-CCD camera detector system was evaluated by comparing its measured number concentrations with those measured with a condensation particle counter (CPC) using polystyrene latex (PSL) and NaCl particles of varying sizes. The CCD camera parameters (e.g. brightness, gain, gamma, and exposure time) were optimized to detect moving particles in the sensing volume and to provide the best image to count them. The CCN counter worked well in the particle number concentration range of 0.6–8000 #·cm and the minimum detectable size was found to be 0.5 μm. The supersaturation in the CCN counter with varying temperature difference was determined by using size-selected sodium chloride particles based on K?hler equation. The developed CCN counter was applied to investigate CCN activity of atmospheric ultrafine particles at 0.5% supersaturation. Data showed that CCN activity increased with increasing particle size and that the higher CCN activation for ultrafine particles occurred in the afternoon, suggesting the significant existence of hygroscopic or soluble species in photochemically-produced ultrafine particles.

关键词： aerosol cloud condensation nuclei (CCN) counter ultrafine particle

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CRISPR-Cas9 mediated LAG-3 disruption in CAR-T cells

null

《医学前沿（英文）》 2017年第11卷第4期页码 554-562 doi: 10.1007/s11684-017-0543-6

摘要：

T cells engineered with chimeric antigen receptor (CAR) have been successfully applied to treat advanced refractory B cell malignancy. However, many challenges remain in extending its application toward the treatment of solid tumors. The immunosuppressive nature of tumor microenvironment is considered one of the key factors limiting CAR-T efficacy. One negative regulator of T cell activity is lymphocyte activation gene-3 (LAG-3). We successfully generated LAG-3 knockout T and CAR-T cells with high efficiency using CRISPR-Cas9 mediated gene editing and found that the viability and immune phenotype were not dramatically changed during in vitro culture. LAG-3 knockout CAR-T cells displayed robust antigen-specific antitumor activity in cell culture and in murine xenograft model, which is comparable to standard CAR-T cells. Our study demonstrates an efficient approach to silence immune checkpoint in CAR-T cells via gene editing.

关键词： CAR-T CRISPR-Cas9 LAG-3

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电动汽车市场加速发展

Chris Palmer

《工程（英文）》 2021年第7卷第2期页码 136-138 doi: 10.1016/j.eng.2020.12.009

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NC flame pipe cutting machine tool based on open architecture CNC system

Xiaogen NIE, Yanbing LIU

《机械工程前沿（英文）》 2009年第4卷第2期页码 147-152 doi: 10.1007/s11465-009-0025-x

摘要： Based on the analysis of the principle and flame movement of a pipe cutting machine tool, a retrofit NC flame pipe cutting machine tool (NFPCM) that can meet the demands of cutting various pipes is proposed. The paper deals with the design and implementation of an open architecture CNC system for the NFPCM, many of whose aspects are similar to milling machines; however, different from their machining processes and control strategies. The paper emphasizes on the NC system structure and the method for directly creating the NC file according to the cutting type and parameters. Further, the paper develops the program and sets up the open and module NC system.

关键词： flame pipe cutting flame incision tracks CNC open architecture CNC system

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CAR T-cell immunotherapy: a powerful weapon for fighting hematological B-cell malignancies

《医学前沿（英文）》 2021年第15卷第6期页码 783-804 doi: 10.1007/s11684-021-0904-z

摘要： The current standard of care in hematological malignancies has brought considerable clinical benefits to patients. However, important bottlenecks still limit optimal achievements following a current medical practice. The genetic complexity of the diseases and the heterogeneity of tumor clones cause difficulty in ensuring long-term efficacy of conventional treatments for most hematological disorders. Consequently, new treatment strategies are necessary to improve clinical outcomes. Chimeric antigen receptor T-cell (CAR T) immunotherapy opens a new path for targeted therapy of hematological malignancies. In this review, through a representative case study, we summarize the current experience of CAR T-cell therapy, the management of common side effects, the causative mechanisms of therapy resistance, and new strategies to improve the efficacy of CAR T-cell therapy.

关键词： CAR T cells hematological malignancies review

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Cavitation in semi-open centrifugal impellers for a miniature pump

LUO Xianwu, LIU Shuhong, ZHANG Yao, XU Hongyuan

《能源前沿（英文）》 2008年第2卷第1期页码 31-35 doi: 10.1007/s11708-008-0011-8

摘要： Cavitation in miniature pumps was investigated experimentally for two semi-open centrifugal impellers. Although both impellers had the same blade cross-section, one impeller had a two-dimensional blade, while the other had a leaned blade. The flows were also analyzed using a numerical model of the three-dimensional turbulent flow in the pumps near the peak efficiency point using the -? turbulence model and the VOF cavitation model. The average cavitation performance of each impeller was satisfactorily predicted by the numerical simulations. The results show that the miniature pumps have similar cavitation performances as an ordinary-size pump, with the cavitation performance of the semi-open impeller reduced by increased axial tip clearances. Also, both the hydraulic and cavitation performance of the semi-open impeller were improved by the leaned blade. The results also show that uniform flow upstream of the impeller inlet will improve the cavitation performance of a miniature pump.

关键词： cavitation performance semi-open impeller increased two-dimensional efficiency

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Characterization of hidden rules linking symptoms and selection of acupoint using an artificial neural network model

Won-Mo Jung, In-Soo Park, Ye-Seul Lee, Chang-Eop Kim, Hyangsook Lee, Dae-Hyun Hahm, Hi-Joon Park, Bo-Hyoung

《医学前沿（英文）》 2019年第13卷第1期页码 112-120 doi: 10.1007/s11684-017-0582-z

摘要： Comprehension of the medical diagnoses of doctors and treatment of diseases is important to understand the underlying principle in selecting appropriate acupoints. The pattern recognition process that pertains to symptoms and diseases and informs acupuncture treatment in a clinical setting was explored. A total of 232 clinical records were collected using a Charting Language program. The relationship between symptom information and selected acupoints was trained using an artificial neural network (ANN). A total of 11 hidden nodes with the highest average precision score were selected through a tenfold cross-validation. Our ANN model could predict the selected acupoints based on symptom and disease information with an average precision score of 0.865 (precision, 0.911; recall, 0.811). This model is a useful tool for diagnostic classification or pattern recognition and for the prediction and modeling of acupuncture treatment based on clinical data obtained in a real-world setting. The relationship between symptoms and selected acupoints could be systematically characterized through knowledge discovery processes, such as pattern identification.

关键词： acupuncture indication neural network pattern identification prediction

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虚实融合的协同工作环境CAR-CA工程技术研究进展

赵沁平

《中国工程科学》 2009年第11卷第10期页码 25-31

摘要：面向我国自行设计生产商用大飞机的需求，在863计划支持下，正在研制用于驾驶舱布局设计和飞机关键部件辅助拆装维护的虚实融合协同工作环境CAR-CA（collaborative augmented reality概要介绍CAR-CA的工程技术研究进展，包括体系结构、系统组成、关键技术研究和系统的应用前景等。

关键词：虚实融合协同工作驾驶舱设计维护

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Characteristics of pollutants behavior in a stormwater constructed wetland during dry days

Jianghua YU, Kisoo PARK, Youngchul KIM

《环境科学与工程前沿（英文）》 2012年第6卷第5期页码 649-657 doi: 10.1007/s11783-012-0426-7

摘要： A stormwater wetland treating non-point source pollution (NPS) from a 64 ha agricultural watershed was monitored over a period of five months. The results indicated that pH and dissolved oxygen (DO) were increased in the wetland due to the algal growth. The highest total suspended solids (TSS) concentration was observed in the aeration pond due to the resuspension of solids, decreased in the wetland. The respective decreases in total nitrogen (TN) and total kjeldahl nitrogen (TKN) were 15.9% and 28.7% on passing through the wetland. The nitrate and ammonia were increased by 45.4% and decreased by 79.9%, respectively. These variations provided strong evidence for the existence of nitrification. The total phosphorus (TP) and phosphate had respective reductions of 52.3% and 58.2% over the wetland. The total chemical oxygen demand (TCOD) and soluble chemical oxygen demand (SCOD) were also decreased. Generally, the TN, TP and phosphate removal efficiencies were positive. These positive removal efficiencies were mainly due to microbial activities, uptake by plants, and chemical precipitation at high pH. Negative removal efficiencies can be caused by continuous rainfall activities, with short antecedent dry days (ADDs) and unstable hydraulic conditions, some other biogeochemical transformations and algal growth also being important parameters.

关键词： constructed stormwater wetland dry days nitrification and denitrification pollutants characteristic

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Drivers and barriers to engage enterprises in environmental management initiatives in Suzhou Industrial Park

Bing ZHANG, Jun BI, Beibei LIU

《环境科学与工程前沿（英文）》 2009年第3卷第2期页码 210-220 doi: 10.1007/s11783-009-0014-7

摘要： Small- and medium-sized enterprises (SMEs) play an important role in sustainable development not only for their significant contribution to China’s economy, but also for their big share of total discharged pollutants. Therefore, this research takes the enterprises in Suzhou Industrial Park, China as the case study to investigate the environmental management practices of SMEs, and identify drivers and barriers to engaging businesses in environmental management initiatives. It is shown that, as in other countries, SMEs are less active in adopting environmental management initiatives than larger companies. Legislation remains the key driver to engage SMEs in environmental management initiatives. Based on the analysis, policy recommendations are also presented.

关键词： small- and medium-sized enterprises (SMEs) environmental management initiative Suzhou industrial park

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美国国家公园与门户城镇的建设经验与启示

刘辉亮

《中国工程科学》 2016年第18卷第5期页码 100-108 doi: 10.15302/J-SSCAE-2016.05.014

摘要：笔者以落基山国家公园和它的主要门户城镇——埃斯蒂斯公园小镇 (the Town of Estes Park) 作为案例，探讨其成功的经验与存在的具体问题，并就有关中国国家公园系统的设立

关键词：美国国家公园管理局门户城镇落基山国家公园埃斯蒂斯公园小镇

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Evaluation of the harmonic scalpel in open surgery for abdominal aortic aneurysm

null

《医学前沿（英文）》 2012年第6卷第1期页码 85-88 doi: 10.1007/s11684-012-0174-x

摘要：

The harmonic scalpel is a hemostatic device primarily designed for use in laparoscopic surgery. During the last few years, many surgeons have begun to use the harmonic scalpel in open surgery. Several papers have cited the benefits of the device compared with conventional knot-tying techniques; however, no evidence showing the advantages of using the harmonic scalpel in complicated abdominal aortic aneurysm (AAA) surgery has been presented. The aim of the present study is to determine the value of the harmonic scalpel in open operation for AAA. A total of 153 patients who underwent open surgery for AAA at the Department of Vascular Surgery of Guangdong General Hospital, China between January 2001 and December 2010, were retrospectively analyzed. Open surgery performed with the harmonic scalpel on 105 patients was compared with open operation using conventional knot-tying techniques on 48 patients. The operative time, intraoperative blood loss, total postoperative drainage fluid volumes, hospital stay, and postoperative complications between the two groups were compared. The harmonic scalpel group was associated with a shorter operation time (113.2±23.6 min vs. 232.1±39.2 min, P<0.01) and lower intraoperative blood loss (126.1±96.6 ml vs. 592.1±207.2 ml, P<0.01). Postoperative drainage fluid volumes were greater in the conventional surgery group than in the harmonic scalpel group (702.1±192.8 ml vs. 198.5±97.4 ml, P<0.01). The hospital stay was shorter for the harmonic scalpel group than for the conventional surgery group (10.7±3.3 d vs. 16.5±4.7 d, P<0.05). No differences between the postoperative complications or hospital mortality of the two groups were found. The harmonic scalpel is a safe and minimally invasive tool in open surgery for AAA and is associated with shorter operative time, shorter hospital stay, and lower intraoperative blood loss and postoperative drainage fluid volumes compared with conventional knot-tying techniques.

关键词： abdominal aortic aneurysm harmonic scalpel minimally invasive