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Effect of mineral additives and permeability reducing admixtures having different action mechanisms on

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1277-1291 doi: 10.1007/s11709-021-1752-2

摘要: In this paper, the effect of usage of the permeability reducing admixture (PRA) having different action mechanisms on hardened state properties of cementitious systems containing mineral additives is examined. For this aim, three commercial PRAs were used during investigation. The effective parameters in the first and third PRAs were air-entraining and high-rate air-entraining, respectively. The second one contained the insoluble calcium carbonate residue and had a small amount of the air-entraining property. Mortar mixes with binary and ternary cementitious systems were prepared by partially replacing cement with fly ash and metakaolin. The hardened state properties of mortar mixtures such as compressive strength, ultrasonic pulse velocity, water absorption, drying shrinkage and freeze–thaw resistance were investigated. The ternary cement-based mixture having both fly ash and metakaolin was selected as the most successful mineral-additive bearing mix in regard to hardened state properties. In this sense, PRA-B, with both insoluble residues and a small amount of air-entraining properties, showed the best performance among the mixtures containing PRA. The combined use of mineral additive and PRA had a more positive effect on the properties of the mixes.

关键词: cementitious system     mineral additive     permeability reducing admixture     mechanical properties     durability performance    

Odour reducing microbial-mineral additive for poultry manure treatment

Kajetan Kalus, Sebastian Opaliński, Devin Maurer, Somchai Rice, Jacek A. Koziel, Mariusz Korczyński, Zbigniew Dobrzański, Roman Kołacz, Beata Gutarowska

《环境科学与工程前沿(英文)》 2017年 第11卷 第3期 doi: 10.1007/s11783-017-0928-4

摘要: Poultry production systems are associated with emissions of odorous volatile organic compounds (VOCs), ammonia (NH ), hydrogen sulfide (H S), greenhouse gases, and particulate matter. Development of mitigation technologies for these emissions is important. Previous laboratory-scale research on microbial-mineral treatment has shown to be effective for mitigation of NH , H S and amines emissions from poultry manure. The aim of this research was to assess the effectiveness of surface application of a microbial-mineral treatment for other important odorants, i.e., phenolics and sulfur-containing VOCs. Microbial-mineral litter additive consisting of 20% (w/w) of bacteria powder (six strains of heterotrophic bacteria) and 80% of mineral carrier (perlite-bentonite) was used at a dose of 500 g?m (per ~31 kg of manure). Samples of air were collected in two series, 4 and 7 days after application of additives. An odor profile of the poultry manure was determined using simultaneous chemical and sensory analysis. Reduction levels of VOCs determined on Day 4 was between 31% and 83% for mineral adsorbent treatment and in the range of 9% and 96% for microbial-mineral additive, depending on the analyzed compound. Reduction levels on Day 7 were considerably lower than on Day 4, suggesting that the odorous VOCs treatment efficacy is relatively short. There was no significant difference between treatments consisting of microbial-mineral additive and mineral carrier alone.

关键词: Odour mitigation     Poultry manure additive     GC-MS-Olfactometry     Volatile organic compounds    

Effects of exercise therapy on bone mineral density in early postmenopausal women: a controlled trial

Shilin DENG MD ,

《医学前沿(英文)》 2009年 第3卷 第3期   页码 323-329 doi: 10.1007/s11684-009-0061-2

摘要: The purpose of this article is to determine the effect of a well-designed combined aerobic, resistance, and extension exercise program on bone mineral density (BMD) in postmenopausal women. The population comprised 45 postmenopausal women, who exercised over 12months (exercise group), and 36 women who served as a non-training control group. BMD of the hip, and lumbar spine was measured at the baseline and 12th month. Repeated measurement analysis of variance and nonparametric test were utilized to compare differences between the exercise group and controls. Thirty-six out of 45 persons in the exercise group and 36 controls completed the study. Average compliance was 82.2% for the whole exercise group at the 12th month. All the subjects had decreased BMD, but the rate of bone loss was lower in the exercise group than in the control group at the L4 and hip. Although the exercise program in this study may probably reduce the rate of bone loss in weight-bearing skeletal sites, we do not suggest the exercise by itself be viewed as prevention or treatment for osteoporosis. Further, the exact dose-response relationship of exercise and bone mass in early postmenopause is not clear.

关键词: early postmenopausal women     bone mineral density     exercise     effects    

矿物浮选吸附平衡模型构建与应用:精准解析矿物 表面离子 / 药剂特征吸附

高雅,付心壮,韩海生,王丽,岳彤,孙伟

《中国工程科学》 2023年 第25卷 第6期   页码 248-258 doi: 10.15302/J-SSCAE-2023.07.020

摘要:

矿物浮选吸附平衡模型是准确描述矿物浮选过程中所涉及的矿物表面离子 / 药剂吸附平衡的数学模型,首次实现了矿物表面位点与浮选药剂吸附作用亲和性的量化解析。传统浮选理论对矿物表面作用位点缺乏科学描述,难以阐明浮选药剂的吸附作用能力及平衡状态,新浮选药剂体系开发多以“试错法”“复配法”等经验性方法为主。药剂选择性吸附作为浮选作业的核心机制,若不能准确预测其在各矿物表面的吸附行为,将严重限制浮选工艺智能化控制的发展。本文详细论述了矿物浮选吸附平衡模型的构建原理,以赤铁矿 ‒ 石英和一水硬铝石 ‒ 高岭石两个浮选体系为例,通过对少量实验数据的拟合计算,解析出矿物表面活性位点密度Ns、加 / 去质子反应常数Kt1/Kt2、药剂吸附常数Kf等矿物浮选特征常数。将解析的矿物浮选特征常数代入到平衡模型中,预测出各条件下矿物表面电性、离子及浮选药剂的吸附量,通过零电点、实验及测试等方法验证了可靠性,形成了矿物浮选过程预测系统的内核算法。该算法对各条件下每种矿物药剂吸附的初步准确预测,可在一定程度上反映其可浮性趋势,有助于缩短浮选工艺开发周期,对矿物表面药剂吸附机理研究、浮选药剂分子设计、浮选工艺流程优化及智能控制等具有重要意义。

关键词: 矿物加工;浮选机理;矿物浮选吸附平衡模型;可浮性预测;矿物浮选特征常数    

Relationship between the development of energy and mineral resources and ecological conservation redline

Dawei ZHANG

《工程管理前沿(英文)》 2019年 第6卷 第4期   页码 557-563 doi: 10.1007/s42524-019-0077-5

摘要: From a philosophical point of view, this study discusses the dialectical relationship between the development of energy and mineral resources and the ecological conservation redline. We propose that the ecological conservation redline and the development of energy and mineral resources should be guided by ecological civilization construction, that is, the energy and mineral resources should be rationally developed under the condition that the ecological environment is protected. This study analyzes the influence of the development of energy and mineral resources on the ecological environment. The handling of mining rights within the ecological conservation redline based on the law and the reduction of the influence of the development of energy mineral resources on the ecological environment by science and technology are presented. The environmental assessment system and technical standards for energy and mineral development are suggested to implement policies and measures for the disposal of mining rights within the redline and facilitate technological innovations of ecological conservation for energy and mineral development. Hence, a coordinated development between the ecological conservation redline and the development of energy and mineral resources can be promoted.

关键词: ecological conservation redline     development of energy and mineral resources     coordinated development    

A state-of-the-art review on interfacial behavior between asphalt binder and mineral aggregate

Meng GUO, Yiqiu TAN, Linbing WANG, Yue HOU

《结构与土木工程前沿(英文)》 2018年 第12卷 第2期   页码 248-259 doi: 10.1007/s11709-017-0422-x

摘要: The interface between asphalt binder and mineral aggregate directly affects the service life of pavement because the defects and stress concentration occur more easily there. The interaction between asphalt binder and mineral aggregate is the main cause of forming the interface. This paper presents an extensive review on the test technologies and analysis methods of interfacial interaction, including molecular dynamics simulation, phase field approach, absorption tests, rheological methods and macro mechanical tests. All of the studies conducted on this topic clearly indicated that the interfacial interaction between asphalt binder and mineral aggregate is a physical-chemical process, and can be qualitatively characterized by microscopical technique (such as SEM and AFM), and also can be quantitatively evaluated by rheological methods and interfacial mechanical tests. Molecular dynamics simulation and phase field approach were also demonstrated to be effective methods to study the interfacial behavior and its mechanism.

关键词: Asphalt binder     Mineral aggregate     Interfacial behavior     Multiscale    

喷气发动机部件的增材设计与制造

韩品连

《工程(英文)》 2017年 第3卷 第5期   页码 648-652 doi: 10.1016/J.ENG.2017.05.017

摘要:

喷气发动机部件的增材设计(AD)和增材制造(AM)将彻底改变传统的航空航天工业。增材设计的独特性开创了喷气发动机设计和制造的新方向,比如梯度材料和微观结构。工程师已经从传统方法和技术的诸多限制中解放出来。增材制造过程最重要的特征之一是其可以确保零件的一致性,因为它始于点,继而到线和层面,直至整个部件完成。设计和制造之间的协调是空气动力学、热力学、结构整合、传热、材料开发和加工等方面取得成功的关键。工程师必须改变设计零件的方式,因为他们要从传统的“减材”方法转移到“增材”的新方法来制造零件。增材设计与增材制造设计不一样。我们需要一种新方法和新工具来协助这种新的设计和制方式。本文详细讨论了增材设计与增材制造中的需求,以及如何解决当前的问题。

关键词: 增材制造     增材设计     喷气发动机     多孔结构    

Atmospheric heterogeneous reaction of chlorobenzene on mineral -FeO particulates: a chamber experiment

《环境科学与工程前沿(英文)》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1734-9

摘要:

● Photochemical conversion of chlorobenzene (CB) on α-Fe2O3 was evaluated.

关键词: Photochemical conversion     Chlorobenzene     α-Fe2O3     PCDD/Fs     Mineral particulate    

Data sharing mechanism of various mineral resources based on blockchain

Yili REN, Jia LIANG, Jian SU, Gang CAO, He LIU

《工程管理前沿(英文)》 2020年 第7卷 第4期   页码 592-604 doi: 10.1007/s42524-020-0132-2

摘要: Basins with various mineral resources coexisting and enriching often occupy an important strategic position. The exploration of various mineral resources is repetitive at present due to unshared data and imperfect management mechanism. This situation greatly increases the cost of energy exploitation in the country. Traditional data-sharing mode has several disadvantages, such as high cost, difficulty in confirming the right of data, and lack of incentive mechanism, which make achieving real data sharing difficult. In this paper, we propose a data-sharing mechanism based on blockchain and provide implementation suggestions and technical key points. Compared with traditional data-sharing methods, the proposed data-sharing mechanism can realize data sharing, ensure data quality, and protect intellectual property. Moreover, key points in the construction are stated in the case study section to verify the feasibility of the data-sharing system based on blockchain proposed in this paper.

关键词: data sharing     blockchain     various mineral resources     collaborative exploration     big data    

Identification of differentially expressed miRNAs associated with chronic kidney disease–mineral bone

null

《医学前沿(英文)》 2017年 第11卷 第3期   页码 378-385 doi: 10.1007/s11684-017-0541-8

摘要:

The purpose of this study is to characterize a meta-signature of differentially expressed mRNA in chronic kidney disease (CKD) to predict putative microRNA (miRNA) in CKD–mineral bone disorder (CKD–MBD) and confirm the changes in these genes and miRNA expression under uremic conditions by using a cell culture system. PubMed searches using MeSH terms and keywords related to CKD, uremia, and mRNA arrays were conducted. Through a computational analysis, a meta-signature that characterizes the significant intersection of differentially expressed mRNA and expected miRNAs associated with CKD–MBD was determined. Additionally, changes in gene and miRNA expressions under uremic conditions were confirmed with human Saos-2 osteoblast-like cells. A statistically significant mRNA meta-signature of upregulated and downregulated mRNA levels was identified. Furthermore, miRNA expression profiles were inferred, and computational analyses were performed with the imputed microRNA regulation based on weighted ranked expression and putative microRNA targets (IMRE) method to identify miRNAs associated with CKD occurrence. TLR4 and miR-146b levels were significantly associated with CKD–MBD. TLR4 levels were significantly downregulated, whereas pri-miR-146b and miR-146b were upregulated in the presence of uremic toxins in human Saos-2 osteoblast-like cells. Differentially expressed miRNAs associated with CKD-MBD were identified through a computational analysis, and changes in gene and miRNA expressions were confirmed with an in vitro cell culture system.

关键词: chronic kidney disease     microRNA     mineral bone disorder     uremia    

Compressive behavior and energy absorption of polymeric lattice structures made by additive manufacturing

Sheng WANG, Jun WANG, Yingjie XU, Weihong ZHANG, Jihong ZHU

《机械工程前沿(英文)》 2020年 第15卷 第2期   页码 319-327 doi: 10.1007/s11465-019-0549-7

摘要: Lattice structures have numerous outstanding characteristics, such as light weight, high strength, excellent shock resistance, and highly efficient heat dissipation. In this work, by combining experimental and numerical methods, we investigate the compressive behavior and energy absorption of lattices made through the stereolithography apparatus process. Four types of lattice structures are considered: (i) Uniform body-centered-cubic (U-BCC); (ii) graded body-centered-cubic (G-BCC); (iii) uniform body-centered-cubic with -axis reinforcement (U-BCCz); and (iv) graded body-centered-cubic with -axis reinforcement (G-BCCz). We conduct compressive tests on these four lattices and numerically simulate the compression process through the finite element method. Analysis results show that BCCz has higher modulus and strength than BCC. In addition, uniform lattices show better energy absorption capabilities at small compression distances, while graded lattices absorb more energy at large compression distances. The good correlation between the simulation results and the experimental phenomena demonstrates the validity and accuracy of the present investigation method.

关键词: lattice structure     polymer     compressive behavior     additive manufacturing     simulation    

Topology optimization based on reduction methods with applications to multiscale design and additive

Emmanuel TROMME, Atsushi KAWAMOTO, James K. GUEST

《机械工程前沿(英文)》 2020年 第15卷 第1期   页码 151-165 doi: 10.1007/s11465-019-0564-8

摘要: Advanced manufacturing processes such as additive manufacturing offer now the capability to control material placement at unprecedented length scales and thereby dramatically open up the design space. This includes the considerations of new component topologies as well as the architecture of material within a topology offering new paths to creating lighter and more efficient structures. Topology optimization is an ideal tool for navigating this multiscale design problem and leveraging the capabilities of advanced manufacturing technologies. However, the resulting design problem is computationally challenging as very fine discretizations are needed to capture all micro-structural details. In this paper, a method based on reduction techniques is proposed to perform efficiently topology optimization at multiple scales. This method solves the design problem without length scale separation, i.e., without iterating between the two scales. Ergo, connectivity between space-varying micro-structures is naturally ensured. Several design problems for various types of micro-structural periodicity are performed to illustrate the method, including applications to infill patterns in additive manufacturing.

关键词: multiscale topology optimization     micro-structure     additive manufacturing     reduction techniques     substructuring     static condensation     super-element    

Surface accuracy optimization of mechanical parts with multiple circular holes for additive manufacturing

Jinghua XU, Hongsheng SHENG, Shuyou ZHANG, Jianrong TAN, Jinlian DENG

《机械工程前沿(英文)》 2021年 第16卷 第1期   页码 133-150 doi: 10.1007/s11465-020-0610-6

摘要: Surface accuracy directly affects the surface quality and performance of mechanical parts. Circular hole, especially spatial non-planar hole set is the typical feature and working surface of mechanical parts. Compared with traditional machining methods, additive manufacturing (AM) technology can decrease the surface accuracy errors of circular holes during fabrication. However, an accuracy error may still exist on the surface of circular holes fabricated by AM due to the influence of staircase effect. This study proposes a surface accuracy optimization approach for mechanical parts with multiple circular holes for AM based on triangular fuzzy number (TFN). First, the feature lines on the manifold mesh are extracted using the dihedral angle method and normal tensor voting to detect the circular holes. Second, the optimal AM part build orientation is determined using the genetic algorithm to optimize the surface accuracy of the circular holes by minimizing the weighted volumetric error of the part. Third, the corresponding weights of the circular holes are calculated with the TFN analytic hierarchy process in accordance with the surface accuracy requirements. Lastly, an improved adaptive slicing algorithm is utilized to reduce the entire build time while maintaining the forming surface accuracy of the circular holes using digital twins via virtual printing. The effectiveness of the proposed approach is experimentally validated using two mechanical models.

关键词: surface accuracy optimization     multiple circular holes     additive manufacturing (AM)     part build orientation     triangular fuzzy number (TFN)     digital twins    

Manufacturing cost constrained topology optimization for additive manufacturing

Jikai LIU, Qian CHEN, Xuan LIANG, Albert C. TO

《机械工程前沿(英文)》 2019年 第14卷 第2期   页码 213-221 doi: 10.1007/s11465-019-0536-z

摘要: This paper presents a manufacturing cost constrained topology optimization algorithm considering the laser powder bed additive manufacturing process. Topology optimization for additive manufacturing was recently extensively studied, and many related topics have been addressed. However, metal additive manufacturing is an expensive process, and the high manufacturing cost severely hinders the widespread use of this technology. Therefore, the proposed algorithm in this research would provide an opportunity to balance the manufacturing cost while pursuing the superior structural performance through topology optimization. Technically, the additive manufacturing cost model for laser powder bed-based process is established in this paper and real data is collected to support this model. Then, this cost model is transformed into a level set function-based expression, which is integrated into the level set topology optimization problem as a constraint. Therefore, by properly developing the sensitivity result, the metallic additive manufacturing part can be optimized with strictly constrained manufacturing cost. Effectiveness of the proposed algorithm is proved by numerical design examples.

关键词: topology optimization     manufacturing cost     additive manufacturing     powder bed    

Enhancing thermostability of -mannanase by protective additives

LIU Zhaohui, QI Wei, WU Weina, LIU Yue, HE Zhimin

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 439-442 doi: 10.1007/s11705-008-0062-8

摘要: The effects of some sugars (glucose, mannose, fructose, sucrose and chitosan) and polyols (glycol, glycerol and sorbitol) as protective additive on the thermostability of -mannanase were studied. The optimal reaction temperatures of -mannanase and the thermodynamics and the deactivation kinetics with or without additives were also investigated. The experimental results show that sucrose, chitosan and sorbitol could apparently improve the thermal stability of -mannanase when their concentration was kept at 2 g/L. The optimal combination additive proportion was sucrose: chitosan : sorbitol = 1 : 2 : 2 (molar ratio) using the orthogonal experimental design. The sucrose, chitosan, glycerol, sorbitol and the combination additive might increase the optimal reaction temperature from 50°C to about 60°C due to their good protection effect. The thermal deactivation curves of -mannanase accorded with the kinetic rules of first order reaction, and the corresponding kinetic and thermodynamic parameters were calculated. Meanwhile, the protective mechanism of the additives against deactivation of enzyme was also discussed.

关键词: protective additive     g/L     orthogonal experimental     combination additive     corresponding    

标题 作者 时间 类型 操作

Effect of mineral additives and permeability reducing admixtures having different action mechanisms on

期刊论文

Odour reducing microbial-mineral additive for poultry manure treatment

Kajetan Kalus, Sebastian Opaliński, Devin Maurer, Somchai Rice, Jacek A. Koziel, Mariusz Korczyński, Zbigniew Dobrzański, Roman Kołacz, Beata Gutarowska

期刊论文

Effects of exercise therapy on bone mineral density in early postmenopausal women: a controlled trial

Shilin DENG MD ,

期刊论文

矿物浮选吸附平衡模型构建与应用:精准解析矿物 表面离子 / 药剂特征吸附

高雅,付心壮,韩海生,王丽,岳彤,孙伟

期刊论文

Relationship between the development of energy and mineral resources and ecological conservation redline

Dawei ZHANG

期刊论文

A state-of-the-art review on interfacial behavior between asphalt binder and mineral aggregate

Meng GUO, Yiqiu TAN, Linbing WANG, Yue HOU

期刊论文

喷气发动机部件的增材设计与制造

韩品连

期刊论文

Atmospheric heterogeneous reaction of chlorobenzene on mineral -FeO particulates: a chamber experiment

期刊论文

Data sharing mechanism of various mineral resources based on blockchain

Yili REN, Jia LIANG, Jian SU, Gang CAO, He LIU

期刊论文

Identification of differentially expressed miRNAs associated with chronic kidney disease–mineral bone

null

期刊论文

Compressive behavior and energy absorption of polymeric lattice structures made by additive manufacturing

Sheng WANG, Jun WANG, Yingjie XU, Weihong ZHANG, Jihong ZHU

期刊论文

Topology optimization based on reduction methods with applications to multiscale design and additive

Emmanuel TROMME, Atsushi KAWAMOTO, James K. GUEST

期刊论文

Surface accuracy optimization of mechanical parts with multiple circular holes for additive manufacturing

Jinghua XU, Hongsheng SHENG, Shuyou ZHANG, Jianrong TAN, Jinlian DENG

期刊论文

Manufacturing cost constrained topology optimization for additive manufacturing

Jikai LIU, Qian CHEN, Xuan LIANG, Albert C. TO

期刊论文

Enhancing thermostability of -mannanase by protective additives

LIU Zhaohui, QI Wei, WU Weina, LIU Yue, HE Zhimin

期刊论文