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Low-k integration: Gas screening for cryogenic etching and plasma damage mitigation

Romain Chanson, Remi Dussart, Thomas Tillocher, P. Lefaucheux, Christian Dussarrat, Jean François de Marneffe

《化学科学与工程前沿（英文）》 2019年第13卷第3期页码 511-516 doi: 10.1007/s11705-019-1820-5

摘要： The integration of porous organo-silicate low- materials has met a lot of technical challenges. One of the main issues is plasma-induced damage, occurring for all plasma steps involved during interconnects processing. In the present paper, we focus on porous SiOCH low- damage mitigation using cryogenic temperature so as to enable micro-capillary condensation. The aim is to protect the porous low- from plasma-induced damage and keep the -value of the material unchanged, in order to limit the RC delay of interconnexion levels while shrinking the microchip dimension. The cryogenic temperature is used to condense a gas inside the porous low- material. Then, the etching process is performed at the temperature of condensation in order to keep the condensate trapped inside the material during the etching. In the first part of this work, the condensation properties of several gases are screened, leading to a down selection of five gases. Then, their stability into the porous structure is evaluated at different temperature. Four of them are used for plasma damage mitigation comparison. Damage mitigation is effective and shows negligible damage for one of the gases at –50°C.

关键词： low-k nanotechnology micro-electronics cryo-etching plasma processing

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Promotional effect of ion-exchanged K on the low-temperature hydrothermal stability of Cu/SAPO-34 and

Chen Wang, Jun Wang, Jianqiang Wang, Meiqing Shen

《环境科学与工程前沿（英文）》 2021年第15卷第2期 doi: 10.1007/s11783-020-1322-1

摘要： Abstract • K+ hinder the structural degradation of Cu/SAPO-34 under humid condition<100°C. • K+ on Cu/SAPO-34 brings lower acidity and inferior SCR activity at high temperature. • Fe/Beta was used to compensate the low activity of Cu/SAPO-34 at high temperature. • The hybrid catalysts with KCu/SAPO-34 and Fe/Beta show a great potential for using. K ions were introduced onto Cu/SAPO-34 catalysts via the ion-exchange process in order to improve their stability under low-temperature hydrothermal aging. The changes in structure and copper-species contents of these catalysts upon hydrothermal aging were probed in order to investigate their effects on selective catalytic reduction (SCR) activity. For the fresh Cu/SAPO-34 catalysts, K ions had little influence on the chabazite framework but effected their acidities by exchanging with acid sites. After hydrothermal aging, the structural integrity and amount of active sites decreased on pure Cu/SAPO-34. While the K-loaded catalysts showed improved chabazite structure, acidity, and active site conservation with increasing K loading. However, although the 0.7 wt% K catalyst maintained the same crystallinity, active site abundance, and low-temperature SCR activity as the fresh catalyst upon aging, an apparent decrease in SCR activity at high temperature was observed because of the inevitable decrease in the number of Brönsted acid sites. To compensate for the activity disadvantage of K-loaded Cu/SAPO-34 at high temperature, Fe/Beta catalysts were co-employed with K-loaded Cu/SAPO-34, and a wide active temperature window of SCR activity was obtained. Thus, our study reveals that a combined system comprising Fe/Beta and K-loaded Cu/SAPO-34 catalysts shows promise for the elimination of NOx in real-world applications.

关键词： Selective catalytic reduction Cu/SAPO-34 catalyst Ion-exchanged K Low-temperature hydrothermal stability Fe/Beta catalyst

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Effect of K and Ca on catalytic activity of Mn-CeO

Boxiong SHEN, Lidan DENG, Jianhong CHEN

《环境科学与工程前沿（英文）》 2013年第7卷第4期页码 512-517 doi: 10.1007/s11783-013-0519-y

摘要： Mn-CeO /Ti-pillared clay (PILC) is an attractive catalyst for selective catalytic reduction of NO at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeO /Ti-PILC is an important problem because K and Ca are always in presence in flue gas. To investigate the effect of K and Ca on the physicochemical characters of the catalysts, the techniques of NH -temperature programmed desorption (TPD), H -temperature programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) were used to analyze the fresh and deactivated catalysts of Mn-CeO /Ti-PILC. (Ca)Mn-CeO /Ti-PILC and (K)Mn-CeO /Ti-PILC are denoted for the dopes of the catalyst of Mn-CeO /Ti-PILC with Ca and K, respectively. The activities of Mn-CeO /Ti-PILC, (Ca)Mn-CeO /Ti-PILC and (K)Mn-CeO /Ti-PILC for NH -selective catalytic reduction (SCR) reaction at low temperature were investigated. The results showed that with the dopes of K and Ca on the catalysts, the SCR activities of the catalysts decreased greatly, and K exhibited more poisoning effect than Ca. With the dopes of K and Ca, the acidity, the redox property and chemisorbed oxygen on the surfaces of the catalysts were decreased, which resulted in a decreasing in SCR activity.

关键词： Mn-CeO_x/Ti-pillared clay (PILC) low-temperature selective catalytic reduction (SCR) K and Ca poisoning effect

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Bioleaching of copper from pre and post thermally activated low grade chalcopyrite contained ball mill

Sandeep PANDA, Nilotpala PRADHAN, Umaballav MOHAPATRA, Sandeep K. PANDA, Swagat S. RATH, Danda S.SUKLA, Barada K. MISHRA

《环境科学与工程前沿（英文）》 2013年第7卷第2期页码 281-293 doi: 10.1007/s11783-013-0484-5

摘要： Bioleaching of a low grade chalcopyrite (ball mill spillage material) was tested for copper recovery in shake flasks. The original samples (as received) were thermally activated (600°C, 30 min) to notice the change in physico-chemical and mineralogical characteristics of the host rock and subsequently its effect on copper recovery. A mixed culture of acidophilic chemolithotrophic bacterial consortium predominantly entailing strain was used for bioleaching studies and optimization of process parameters of both original and thermally activated samples. Mineralogical characterization studies indicated the presence of chalcopyrite, pyrite in the silicate matrix of the granitic rock. Field emission scanning electron microscopy coupled with Energy dispersive spectroscopy (FESEM-EDS) and X-ray Fluorescence (XRF) analysis indicated mostly SiO . With pH 2, pulp density 10% w/v, inoculum 10% v/v, temperature 30°C, 150 r·min , 49% copper could be recovered in 30 days from the finest particle size (-1+ 0.75 mm) of the original spillage sample. Under similar conditions 95% copper could be recovered from the thermally activated sample with the same size fraction in 10 days. The study revealed that thermal activation leads to volume expansion in the rock with the development of cracks, micro and macro pores on its surface, thereby enabling bacterial solution to penetrate more easily into the body, facilitating enhanced copper dissolution.

关键词： ball mill spillage thermal activation bioleaching copper

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Update on Mayer–Rokitansky–Küster–Hauser syndrome

《医学前沿（英文）》 2022年第16卷第6期页码 859-872 doi: 10.1007/s11684-022-0969-3

摘要： This review presents an update of Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome on its etiologic, clinical, diagnostic, psychological, therapeutic, and reproductive aspects. The etiology of MRKH syndrome remains unclear due to its intrinsic heterogeneity. Nongenetic and genetic causes that may interact during the embryonic development have been proposed with no definitive etiopathogenesis identified. The proportion of concomitant extragenital malformations varies in different studies, and the discrepancies may be explained by ethnic differences. In addition to physical examination and pelvic ultrasound, the performance of pelvic magnetic resonance imaging is crucial in detecting the presence of rudimentary uterine endometrium. MRKH syndrome has long-lasting psychological effects on patients, resulting in low esteem, poor coping strategies, depression, and anxiety symptoms. Providing psychological counseling and peer support to diagnosed patients is recommended. Proper and timely psychological intervention could significantly improve a patient’s outcome. Various nonsurgical and surgical methods have been suggested for treatment of MRKH syndrome. Due to the high success rate and minimal risk of complications, vaginal dilation has been proven to be the first-line therapy. Vaginoplasty is the second-line option for patients experiencing dilation failure. Uterine transplantation and gestational surrogacy are options for women with MRKH syndrome to achieve biological motherhood.

关键词： MRKH (Mayer–Rokitansky–Küster–Hauser) syndrome etiology clinical characteristic diagnosis treatment psychological effect

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用智能药丸提供胰岛素？

Elizabeth K. Wilson

《工程（英文）》 2019年第5卷第4期页码 603-604 doi: 10.1016/j.eng.2019.07.008

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Stochastic analysis of laminated composite plate considering stochastic homogenization problem

SAKATA,K. OKUDA,K. IKEDA

《结构与土木工程前沿（英文）》 2015年第9卷第2期页码 141-153 doi: 10.1007/s11709-014-0286-2

摘要： This paper discusses a multiscale stochastic analysis of a laminated composite plate consisting of unidirectional fiber reinforced composite laminae. In particular, influence of a microscopic random variation of the elastic properties of component materials on mechanical properties of the laminated plate is investigated. Laminated composites are widely used in civil engineering, and therefore multiscale stochastic analysis of laminated composites should be performed for reliability evaluation of a composite civil structure. This study deals with the stochastic response of a laminated composite plate against the microscopic random variation in addition to a random variation of fiber orientation in each lamina, and stochastic properties of the mechanical responses of the laminated plate is investigated. Halpin-Tsai formula and the homogenization theory-based finite element analysis are employed for estimation of effective elastic properties of lamina, and the classical laminate theory is employed for analysis of a laminated plate. The Monte-Carlo simulation and the first-order second moment method with sensitivity analysis are employed for the stochastic analysis. From the numerical results, importance of the multiscale stochastic analysis for reliability evaluation of a laminated composite structure and applicability of the sensitivity-based approach are discussed.

关键词： stochastic homogenization multiscale stochastic analysis microscopic random variation laminated composite plate

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Shape control of multi-cellular inflatable panels

KATAYAMA, K. ISHIMURA, K. MINESUGI, DANIEL J. INMAN

《机械工程前沿（英文）》 2013年第8卷第3期页码 276-282 doi: 10.1007/s11465-013-0267-5

摘要：

Multi-cellular inflatable structures are ultra-light and robust against membrane damage such as pinholes caused by space debris. Due to their robustness, inflatable structures supported by inner gases can be applied as space structures. In the present study, shape control for a simple multi-cellular inflatable panel was achieved via a novel diaphragm mechanism. When the bending actuator in a center membrane bends, the inner pressures of sub-cells become different, and the diaphragm mechanism bends as a whole. Because a sliding component is not included, this deformable system is a reliable mechanism. In addition, the proposed mechanism has higher rigidity than that of a bending actuator used alone. In the present paper, we investigate the feasibility of a novel diaphragm mechanism and its characteristics using experimental and numerical results.

关键词： Membrane structures inflatable structure shape control smart structures structural mechanics space engineering

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A multi-attribute decision making approach of mix design based on experimental soil characterization

Amit K. BERA, Tanmoy MUKHOPADHYAY, Ponnada J. MOHAN, Tushar K. DEY

《结构与土木工程前沿（英文）》 2018年第12卷第3期页码 361-371 doi: 10.1007/s11709-017-0425-7

摘要：

The clay mineral composition is one of the major factors that governs the physical properties of silty sand subgrade. Therefore, a thorough knowledge of mineral composition is essential to predict the optimum engineering properties of the soil, which is generally characterized by different indices like maximum dry density (MDD), California bearing ratio (CBR), unconfined compressive strength (UCS) and free swelling index (FSI). In this article, a novel multi-attribute decision making (MADM) based approach of mix design has been proposed for silty sand – artificial clay mix to improve the characteristic strength of a soil subgrade. Experimental investigation has been carried out in this study to illustrate the proposed approach of selecting appropriate proportion for the soil mix to optimize all the above mentioned engineering properties simultaneously. The results show that a mix proportion containing approximately 90% silty sand plus 10% bentonite soil is the optimal combination in context to the present study. The proposed methodology for optimal decision making to choose appropriate combination of bentonite and silty sand is general in nature and therefore, it can be extended to other problems of selecting mineral compositions.

关键词： silty sand bentonite soil soil mix design multi-attribute decision making

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K型钢管混凝土节点疲劳性能试验研究

钟新谷,杨胜,石卫华

《中国工程科学》 2011年第13卷第9期页码 97-100

摘要：

以湘潭四大桥桁架拱为工程背景，进行了三种规格的K型钢管混凝土节点的疲劳试验，基于热点应力计算了K型钢管混凝土节点的疲劳荷载幅值，表明热点应力法能够较好地评估钢管混凝土节点的疲劳寿命；试验表明K型钢管混凝土节点的疲劳性能明显优于K型钢管节点。在此基础上初步提出了K型钢管混凝土节点的S—N曲线，对建立K型钢管混凝土节点疲劳寿命设计准则具有一定的参考意义。

关键词： K型钢管混凝土节点疲劳性能 S—N曲线

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Evaluation of the k-nearest neighbor method for forecasting the influent characteristics of wastewater

Minsoo KIM,Yejin KIM,Hyosoo KIM,Wenhua PIAO,Changwon KIM

《环境科学与工程前沿（英文）》 2016年第10卷第2期页码 299-310 doi: 10.1007/s11783-015-0825-7

摘要： The k-nearest neighbor (k-NN) method was evaluated to predict the influent flow rate and four water qualities, namely chemical oxygen demand (COD), suspended solid (SS), total nitrogen (T-N) and total phosphorus (T-P) at a wastewater treatment plant (WWTP). The search range and approach for determining the number of nearest neighbors (NNs) under dry and wet weather conditions were initially optimized based on the root mean square error (RMSE). The optimum search range for considering data size was one year. The square root-based (SR) approach was superior to the distance factor-based (DF) approach in determining the appropriate number of NNs. However, the results for both approaches varied slightly depending on the water quality and the weather conditions. The influent flow rate was accurately predicted within one standard deviation of measured values. Influent water qualities were well predicted with the mean absolute percentage error (MAPE) under both wet and dry weather conditions. For the seven-day prediction, the difference in predictive accuracy was less than 5% in dry weather conditions and slightly worse in wet weather conditions. Overall, the k-NN method was verified to be useful for predicting WWTP influent characteristics.

关键词： influent wastewater prediction data-driven model k-nearest neighbor method (k-NN)

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5G将带来哪些改变？

Erika K. Carlson

《工程（英文）》 2020年第6卷第7期页码 725-727 doi: 10.1016/j.eng.2020.05.012

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太空旅游离我们越来越近

Elizabeth K. Wilson

《工程（英文）》 2019年第5卷第5期页码 819-821 doi: 10.1016/j.eng.2019.08.006

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基于层次的K-means初始化算法

汤九斌,陆建峰,唐振民,杨静宇

《中国工程科学》 2007年第9卷第11期页码 74-79

摘要：

K-means算法是一种常用的聚类算法，但是聚类中心的初始化是其中的一个难点。笔者提出了一个基于层次思想的初始化方法。模拟数据和真实数据的实验结果均显示基于层次抽样初始化的K-means算法不仅收敛速度快、聚类质量高，而且对噪声不敏感，其性能明显优于现有的相关算法。

关键词：层次技术初始聚类中心加权数据 K平均聚类

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Hydrotreating of light gas oil using a NiMo catalyst supported on activated carbon produced from fluid petroleum coke

Rambabu,Sandeep Badoga,Kapil K. Soni,A.K. Dalai,J. Adjaye

《化学科学与工程前沿（英文）》 2014年第8卷第2期页码 161-170 doi: 10.1007/s11705-014-1430-1

摘要： Nitric acid functionalized steam activated carbon (NAFSAC) was prepared from waste fluid petroleum coke (FPC) and used as a support material for the synthesis of a NiMo catalyst (2.5 wt-% Ni and 13 wt-% Mo). The catalyst was then used for the hydrotreatment of light gas oil. The support and catalysts were characterized by Brunauer-Emmett-Teller (BET) gas adsorption method, X-ray diffraction, H -temperature programmed reduction, NH -temperature programmed desorption, CO-chemisorption, mass spetrography, scanning electron microscopy (SEM), Boehm titration, and Fourier transform infrared spectroscopy (FTIR). The SEM results showed that the carbon material retained a needle like structure after functionalization with HNO . The Boehm titration, FTIR, and BET results confirmed that the HNO functionalized material had moderate acidity, surface functional groups, and mesoporosity respectively. The produced NAFSAC had an inert nature, exhibited the sink effect and few metal support interactions, and contained functional groups. All of which make it a suitable support material for the preparation of a NiMo hydrotreating catalyst. Hydrotreating activity studies of the NiMo/NAFSAC catalyst were carried out under industrial operating conditions in a laboratory trickle bed reactor using coker light gas oil as the feedstock. A parallel study was performed on the hydrotreating activity of NiMo/ -Al O as a reference catalyst. The hydrodesulfurization and hydrodenitrogenation activities of the NiMo/NAFSAC catalyst were 62% and 30%, respectively.

关键词： activated carbon fluid petroleum coke NiMo catalyst hydrotreating light gas oil