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Biomineralization of soil with crude soybean urease using different calcium salts

Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1788-1798页

作者： Yajie Weng Junjie Zheng Hanjiang Lai Mingjuan Cui xingzhi ding School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan430074China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350108China College of Civil Engineering Fuzhou UniversityFuzhou350116China

Calcium salt is an important contributing factor for calcium-based *** study the effect of calcium salt on soil biomineralization using crude soybean urease,the calcium salts,including the calcium chloride (CaCl_(2)),calcium acetate ((CH_(3)COO)_(2)Ca) and calcium nitrate (Ca(NO_(3))_(2)),were used to prepare the biotreatment solution to carry out the biomineralization tests in this *** series of biomineralization tests in solution and sand column,respectively,were *** electron microscopy (SEM) and X-ray diffraction (XRD) were performed to determine the microscopic characteristics of the precipitated calcium carbonate (CaCO_(3)) *** experimental results indicate that the biomineralization effect is the best for the CaCl2 case,followed by (CH_(3)COO)_(2)Ca,and worst for Ca(NO_(3))_(2) under the test conditions of this study (i.e.1 mol/L of calcium salt-urea).The mechanism for the effect of the calcium salt on the biomineralization of crude soybean urease mainly involves: (1) inhibition of urease activity,and (2) influence on the crystal size and morphology of CaCO_(3).Besides Ca^(2+) ,the anions in solution can inhibit the activity of crude soybean urease,and NO_(3)− has a stronger inhibitory effect on the urease activity compared with both CH_(3)COO^(−) and Cl^(−) .The co-inhibition of Ca^(2+) and NO_(3)− on the activity of urease is the key reason for the worst biomineralization of the Ca(NO_(3))_(2) case in this *** difference in biomineralization between the CaCl_(2) and (CH_(3)COO)_(2) Ca cases is strongly correlated with the crystal morphology of the precipitated CaCO_(3).

关键词： Biomineralization Crude soybean urease Calcium salt Influence mechanism

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A new bacterial concentration method for large-scale applications of biomineralization

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JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING 2024年第12期16卷 5109-5120页

作者： Lai, Hanjiang ding, xingzhi Cui, Mingjuan Zheng, Junjie Chu, Jian Chen, Zhibo Zhang, Jianwei Fuzhou Univ Zijin Sch Geol & Min Fuzhou 350108 Peoples R China Fujian Taiwan Sci & Technol Cooperat Base Fujian P Fuzhou 350116 Fujian Peoples R China Fuzhou Univ Coll Civil Engn Fuzhou 350108 Peoples R China Wuhan Univ Sch Civil Engn Wuhan 430072 Peoples R China Nanyang Technol Univ Sch Civil & Environm Engn Singapore Singapore Henan Univ Sch Civil Engn & Architecture Kaifeng 475004 Peoples R China

Bacterial suspension is an essential component of microbially induced carbonate precipitation (MICP)based biocement and a large-scale production is required for field applications. In this study, a new bacterial concentration method is proposed to enable high concentration bacterial suspension to be produced to facilitate field work. By adding low concentration calcium to bacterial suspension, flocs are formed and bacterial cells are adsorbed on the flocs to achieve bacterial concentration. Compared to the traditional bacterial concentration method using centrifugation and freezing-drying method, the proposed method can concentrate a large volume of bacterial suspension without using special equipment. The feasibility of this method is verified by bacterial concentration tests, solution tests and sand column treatment tests. The results of both the solution test and the sand column treatment test show that the bacterial suspension concentrated by the proposed method can be effectively used for soil biocementation. There is a threshold calcium concentration that allows a complete bacterial concentration for the proposed method, and this threshold calcium concentration tends to increase linearly with the optical density of the cell suspension at a wavelength of 600 nm (OD600). (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/ 4.0/).

关键词： Biocement Biocementation Bacterial concentration Microbially induced carbonate precipitation (MICP)

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Variety Selection and Green Cultivation Technology of Courtyard Ornamental and Edible Peppers

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Plant Diseases and Pests 2024年第3期15卷 26-30页

作者： Xilu ZHANG Shengying JI Yinglin YE xingzhi ding Juan CHEN Hunan Vegetable Research Institute Changsha 410125China

In order to comply with the development trend of the multifunctional use of peppers,we conducted an investigation into the characteristics and features of varieties,potting management techniques,and the methods of extending the fruit ornamental period and other aspects of courtyard ornamental and edible peppers.A set of cultivation techniques suitable for courtyard ornamental and edible peppers has been developed,including timely sowing and seedling,nutrient soil preparation,water and fertilizer management,trimming and pruning,preservation of flowers and fruits,green prevention and control of diseases and pests,harvesting,and so on.

关键词： Ornamental and edible pepper Courtyard gardening Variety characteristics Cultivation technique

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基于动态重叠网格方法的尾翼对螺旋桨滑流的影响

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航空学报 2019年第4期40卷 87-98页

作者：缪涛陈波马率杨小川丁兴志中国空气动力研究与发展中心计算空气动力研究所绵阳621000 航空工业第一飞机设计研究院西安710089

螺旋桨飞机产生的滑流会对其扫掠过的部件产生显著干扰,研究尾翼部件对滑流的影响有助于将滑流与尾翼的干扰进行解耦分解。采用动态重叠网格方法模拟螺旋桨定轴转动,通过求解三维非定常雷诺平均Navier-Stokes(URANS)方程,数值模拟了某... 详细信息

螺旋桨飞机产生的滑流会对其扫掠过的部件产生显著干扰,研究尾翼部件对滑流的影响有助于将滑流与尾翼的干扰进行解耦分解。采用动态重叠网格方法模拟螺旋桨定轴转动,通过求解三维非定常雷诺平均Navier-Stokes(URANS)方程,数值模拟了某螺旋桨飞机带尾翼构型的有/无滑流状态,通过试验结果对计算方法的正确性进行了验证。在此基础上,分别开展了有/无尾翼构型的滑流计算,结果表明:扣除尾翼气动力后,有/无尾翼的升阻力变化规律基本一致,俯仰力矩由于机身后体修形不同呈线性平移关系;对比有/无尾翼空间切面的速度分布云图、不同空间位置和拉力系数下的下洗角和侧洗角变化曲线,发现尾翼对滑流的影响仅局限在其周围,不同拉力系数下尾翼的干扰规律也基本类似。通过研究认为,在飞机初期设计和选型阶段,螺旋桨滑流与尾翼的相互干扰,可简化为滑流单向对尾翼产生影响,尾翼对滑流的影响可以忽略。

关键词：螺旋桨滑流尾翼动态重叠网格下洗角侧洗角

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Bio-grouting technologies for enhancing uniformity of biocementation:A review

Biogeotechnics

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Biogeotechnics 2023年第3期1卷 1-7页

作者： Junjie Zheng Hanjiang Lai Mingjuan Cui xingzhi ding Yajie Weng Jianwei Zhang School of Civil Engineering Wuhan UniversityWuhan 430072China Institute of Geotechnical and Underground Engineering Huazhong University of Science and TechnologyWuhan 430074China Zijin School of Geology and Mining Fuzhou UniversityFuzhou 350108China College of Civil Engineering Fuzhou UniversityFuzhou 350108China School of Civil Engineering and Architecture Henan UniversityKaifeng 475004China

Biocementation-based soil improvement is an emerging ground treatment method in geotechnical engineering that has garnered extensive attention over the past two *** of the challenges associated with this method revolves around the uniformity of biocementation,a crucial factor closely tied to bio-grouting *** traditional biotreatment methods,the two-phase method and the one-phase method,suffer from the issue of non-uniform ***,in recent years,various improved grouting technologies have been proposed to address this concern by aiding bacterial adsorption and controlling carbonate *** paper reviews the mechanisms and grouting processes employed in these enhanced bio-grouting ***,the challenges of implementing these grouting technologies in real-world applications are also thoroughly discussed.

关键词： Biocementation Soil improvement Grouting technology Uniformity

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面向飞行试验的混合层流机翼优化设计

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航空学报 2022年第11期43卷 149-162页

作者：赵彦段卓毅丁兴志杨体浩王猛航空工业西安飞机设计研究所西安710089 西北工业大学航空学院西安710072 航空工业空气动力研究院沈阳110034

层流减阻技术可大幅减小飞机摩阻,具有重要的应用前景。层流验证机是专为验证层流机翼设计技术研制的一型飞行试验平台,其中混合层流试验段主要用来验证前缘抽吸气对转捩位置的推迟效果。针对混合层流飞行试验首先开展了混合层流试验段... 详细信息

层流减阻技术可大幅减小飞机摩阻,具有重要的应用前景。层流验证机是专为验证层流机翼设计技术研制的一型飞行试验平台,其中混合层流试验段主要用来验证前缘抽吸气对转捩位置的推迟效果。针对混合层流飞行试验首先开展了混合层流试验段设计约束分析和初步方案设计,随后开展了机翼和吊舱、挂架外形的高速气动优化设计。然后在此基础上,研究了不同吸气分布对吸气功率、流量和转捩推迟效果的影响,确定了最佳分布。最后通过风洞试验研究了最终优化构型的转捩特性。研究结果表明:优化后的混合层流试验段具有良好的高速气动特性,同时在设计点能验证前缘抽吸气对横流不稳定性的转捩抑制效果;折中吸气分布能保证吸气区大部分区域的吸气效果,并能降低吸气功率和流量。所得研究结果对混合层流机翼外形、吸气策略优化设计具有借鉴意义。

关键词：混合层流机翼优化吸气分布转捩风洞试验

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Factors affecting the effectiveness of biocementation of soil

Biogeotechnics

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Biogeotechnics 2024年第3期2卷 19-27页

作者： Hanjiang Lai xingzhi ding Mingjuan Cui Junjie Zheng Jian Chu Zhibo Chen Zijin School of Geology and Mining Fuzhou UniversityFuzhou 350108China College of Civil Engineering Fuzhou UniversityFuzhou 350108China School of Civil Engineering Wuhan UniversityWuhan 430072China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore Fujian-Taiwan Science and Technology Cooperation Base of Fujian Province on Intelligent Geoenvironmental Engineering Fuzhou 350116China

Microbially or enzyme induced carbonate precipitation has emerged to be a new type of soil improvement ***,it appears that the biocementation process is affected by many factors and a common understanding on the control factors on the biocement effect has not been *** paper attempts to identify the main factors that controlling the MICP or EICP effect through an in-depth discussion on the fundamentals of biocementation *** to other cemented granular materials,biocemented soil is a structural soil composite consisting of soil skeleton and biocement force chain or biocement *** strength and stiffness of the biocemented soil is controlled by the reinforcement effect of the biocement network on the soil skeleton or the interplay of the soil skeleton and *** contribution of the strength by soil skeleton is affected by the soil types and soil properties,while the contribution of the precipitates is through the distribution of the biocement network and the properties of the precipitates.

关键词： Biocementation Strength enhancement Mechanism Influencing factor

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Mechanisms and influencing factors of biomineralization based heavy metal remediation:A review

Biogeotechnics

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Biogeotechnics 2023年第3期1卷 77-86页

作者： Hanjiang Lai xingzhi ding Mingjuan Cui Junjie Zheng Zhibo Chen Jialong Pei Jianwei Zhang Zijin School of Geology and Mining Fuzhou UniversityFuzhou 350108China College of Civil Engineering Fuzhou UniversityFuzhou 350108China Fujian-Taiwan Science and Technology Cooperation Base of Fujian Province on Intelligent Geoenvironmental Engineering Fuzhou 350116China School of Civil Engineering Wuhan UniversityWuhan 430072China School of Civil Engineering and Architecture Henan UniversityKaifeng 475004China

Heavy metal contamination of soil and water is one of the most prominent environmental issues *** bioaccumulation and biomagnification of the food chain,heavy metals can be enriched hundreds of times and eventually enter the human body,posing a major threat to human *** has the greatest potential to become an efficient and environmentally friendly heavy metal remediation technology and has received much attention in recent *** review summarizes the latest progress of biomineralization technology on carbonate precipitation and phosphate precipitation in heavy metal *** microorganisms(including bacteria and fungi)and enzymes can induce carbonate and phosphate precipitation,converting the free heavy metal ions into insoluble ***,the mechanisms of the heavy metal remediation are significantly *** example,urea hydrolysis,which occurs intracellularly when urease-producing bacteria(UPB)are used,is the most commonly used mechanism for carbonate precipitation based *** contrast,phosphate solubilization by either enzymes or organic acids secreted by phosphate solubilizing bacteria(PSB)is extracellular,and both soluble and insoluble phosphorus can be decomposed by ***,some influencing factors such as the different species of microorganism,heavy metals and some environmental conditions that may affect the bioremediation of heavy metals were also summarized in this *** challenges of biomineralization based heavy metal remediation are also *** on the reviews of previous studies,a comprehensive understanding of heavy metal removal through microorganism can be increased,and thus promotes the applications of biomineralization technology in the treatment of large-scale heavy metal contaminated sites.

关键词： Heavy metal contamination Bioremediation Biomineralization Mechanisms Influencing factor

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飞机大迎角非对称涡组合扰动主动控制研究

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力学学报 2007年第4期39卷 433-441页

作者：王延奎魏占峰邓学蓥黄涛丁兴志北京航空航天大学流体力学教育部重点实验室北京100083

采用测压、测力以及流动显示方法研究了头部微三角扰动块对飞机大迎角非对称背涡的主控作用和背风侧单孔位微吹气对背涡空间位置及相应侧向力的控制作用,以此为基础提出了基于微三角块扰动和单孔位微吹气扰动的组合扰动主动控制新技术,... 详细信息

采用测压、测力以及流动显示方法研究了头部微三角扰动块对飞机大迎角非对称背涡的主控作用和背风侧单孔位微吹气对背涡空间位置及相应侧向力的控制作用,以此为基础提出了基于微三角块扰动和单孔位微吹气扰动的组合扰动主动控制新技术,并在某飞机模型上进行了验证．实验是在北京航空航天大学D4风洞中进行的．研究结果表明:该组合扰动控制技术能够实现对飞机大迎角非对称侧向力的有效主动控制．

关键词：组合扰动主动控制技术大迎角非对称涡微吹气扰动微三角块扰动

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舰载机着舰纵向甲板运动补偿系统设计

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航空科学技术 2016年第12期27卷 13-17页

作者：曲浩郭润兆丁兴志中航工业第一飞机设计研究院陕西西安710089

为减小着舰误差,提高安全性,通过纵向自动着舰系统频域响应特性分析,确定出不满足自动着舰要求的参数项目,有针对性地进行纵向补偿设计,给出纵向补偿系统详细的参数设计方法。设计中考虑了航母俯仰运动对理想着舰点垂直位移影响。通过... 详细信息

为减小着舰误差,提高安全性,通过纵向自动着舰系统频域响应特性分析,确定出不满足自动着舰要求的参数项目,有针对性地进行纵向补偿设计,给出纵向补偿系统详细的参数设计方法。设计中考虑了航母俯仰运动对理想着舰点垂直位移影响。通过算例验证了纵向甲板运动补偿系统设计的有效性。该纵向甲板运动补偿系统设计方法可应用于舰载飞机设计。

关键词：舰载飞机自动着舰甲板运动补偿

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