Publications

Mechanical Properties of Engineered Bamboo Boards for Glubam Structures

Glued laminated bamboo (glubam) is a type of engineered bamboo that resembles timber-based glued laminated lumber (glulam). The glubam components are made by laminating 20- to 40-mm-thick engineered bamboo boards; thus, the performance is determined by the quality and properties of the laminated boards. A comprehensive testing program was conducted on typical engineered bamboo boards. The experiments were performed according to the general requirements given by international standards; however, the size of specimens and loading jigs were redesigned according to the modular thickness of typical bamboo boards. Mechanical behaviors and failure modes of the specimens under 15 stress conditions are reported, along with the surface strain distribution recorded through digital image correlation (DIC). A simple design-oriented axial stress–strain model is proposed, and strength values, including the corresponding coefficient of variance (COV), are calculated and provided. A comparison of characteristic strength values between engineered bamboo and typical wood products is also given in this research.

Evaluation on compatibility of interspecific cross among several species of Rosa

The interspecific cross was carried out using modern roses as female parents,while some wild species of Rosa from China,including R. primula,R. xanthina f. spontanea,R. brunonii,R. laxa and so on,as male parents. 20 compatible cross combinations were selected. The stigma receptivity and pollen vitalities of some parents were tested. Combined with precious hybridization studies,the influences of parent's sterility,genetic relationship,ploidy level and environment on inter-specific cross compability were analyzed. The results showed that parents' fertility was not the decisive factor in seed harvest;R. laxa was more compatible than other wild roses when crossed with modern roses. It was probably compatible when one parent of compatible cross was replaced by genetically close species or cultivars. Triploid and tetraploid were generated when hybridization was taken between tetraploid and diploid. Most hybrid seeds of Rosa canina inermis × R. primula and R. canina inermis × R. xanthina f. spontanea were tetraploid. According to the results,a new method of using diploid wild roses was proposed. This study further improved the system of cross-breeding.

Study on the Evaluation Method of Coordinated Development of the Regional Ecological Civilization Construction

From the different angles of the stock indicators,quality indicators,structural indicators and changes in the degree of indicators,the paper proposed the evaluation index system of the construction of regional ecological civilization and discussed the index weight,comprehensive evaluation model and the index synthesis method.Then,the paper discussed the degree of the regional comprehensive ecological civilization,according to the three indicators of degree of development,coordination and duration.The degree of development described the quantitative dimension,the degree of duration described the time dimension and the degree of coordination described the quality dimension.

Failure Analysis of Adhesively Bonded Single Lap Joints Embedded with Metal Component as Part of Fillet

In order to understand the effects of the metal components embedded in adhesive fillets on the strength of adhesively bonded single lap joint, the failed surfaces were studied with diagrams of scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectrometer. The stress distribution along the length of the bondline of single lap steel joints was also studied with an elasto-plastic finite element analysis (FEA) model to understand its effect in the view of mechanics. The SEM images and the FT-IR spectra diagrams revealed that the failure in the interface was primarily mixture mode with fillets and they also presented the interface strength being higher and there were more polar links formed in the adhesive fillets with metal components. The result obtained from the numerical modeling is in compliance with it from experiment that the stress distributed in lap zone of the joint is gentler when a couple of steel wires embedded in fillet.

Accounting for Eco-compensation based on a PES model——a case study of Jiangsu Province.

Regional ecological compensation plays an important role in balancing and coordinating the development of different regions.Determining the account and scope is the key of regional eco-compensation.Considering the change relation between ecosystem service value(ESV) and gross domestic product(GDP),we construct a new integrated estimate model(PES) for ecological compensation,using county as study unit,and present the best evidence for defining the amount and scope of eco-compensation.Further,we determined standard value and performed a case study for evaluating eco-compensation from 2010 to 2012 in Jiangsu province,China.The evaluation results of Jiangsu province showed as follows:(1)There was obvious district difference in the economy and ecosystem in areas,particularly in the south,the central,and the north region of Jiangsu province.And it showed a significant inverse correlation between economy and ecosystem.(2)The range of eco-compensation account varied greatly and this compensation scheme was grouped into five phases:Stage one,-416 ×108RMB;Stage two,-252 ×108~-101 ×108RMB;Stage three,-101 ×108~-5×108RMB;Stage four,2×108~44×108RMB;Stage five,48×108~91 ×108RMB.(3)The eco-compensation account showed the obvious district difference in areas,the regions that need to pay for eco-compensation mainly lied in the south and middle regions of Jiangsu province,and most of north regions could be compensated for the loss of economy.

The Sanitary Condition of The Water in Swimming Pools in Xingning City in 2007

A numerical study of parallel slot in adherend on the stress distribution in adhesively bonded aluminum single lap joint

Holographic Simulation of the Electric Field of a 6KA Rare Earth Molten Salt Electrolytic Cell

Molten salt electrolysis stands as an indispensable technique for the production of rare earth metals, where the judicious distribution of the electric field within the electrolytic cell is paramount for ensuring the seamless operation of the electrolysis process. This study introduces a pioneering approach by integrating the Nernst-Planck equation with the Butler-Volmer equation, thereby devising a holographic electric field model tailored for the electrolysis of the NdF3-LiF molten salt system. The paper presents pioneering experimental measurements concerning the potential distribution and voltage drop characteristics within a 6kA rare earth electrolytic cell, elucidating the interplay between decomposition voltage and current density, which substantiates the model's precision. Our findings unveil that, under operational conditions of 4010 amperes, the 6kA electrolytic cell incurs a total voltage drop of 6.3 volts, delineating a melt voltage drop of 4.43 volts, an ohmic voltage drop of 0.248 volts, and an interfacial voltage drop of 1.622 volts at the electrode-electrolyte junction. The discrepancy in error is confined to within 0.3% of the actual measured voltage of 6.28 volts.The simulation outcomes from the holographic electric field model have been confirmed to precisely and comprehensively reflect the characteristics of the electric field distribution during the rare earth molten salt electrolysis process, offering valuable theoretical insights for practical manufacturing applications.

Axial load–deformation behavior and fracture characteristics of bolted steel to laminated timber and glubam connections

Determination and influential factors of fracture toughness in unidirectional laminated bamboo-composite using double cantilever beams and single-edge notched bend tests

Literature Classification Model of Deep Learning Based on BERT-BiLSTM——Taking COVID-19 as an Example

Research on civil aircraft cabin noncontinuous occupancy area smoke detection flight test

Before obtaining airworthiness certification for modern civil aircraft, it is necessary to carry out flight test verification for the fire detection system in the non-continuous occupancy area of the cabin. This paper discusses a method for conducting flight tests based on airworthiness regulations, firstly the aircraft status during the flight test implementation such as altitude and ventilation configuration, and then a strategy of selecting smoke generator and smoke generation materials which are used to generate simulated fire smoke for different scenarios is provided, finally flight test risks of using burn box smoke generator and theatrical smoke generator is evaluated respectively. In addition, further research on smoke generation materials was discussed and recommendations were made, taking into account the experience of the test implementation. This paper can be used as a reference for other aircraft models to conduct smoke detection flight test in non-continuous occupancy area of cabin.

Experiment and simulation of high current temperature rise of valve hall fittings

Value hall fittings play an important role in electrical connection and mechanical fixing. Fittings usually work under large current, so it is necessary to pay attention to its temperature rise. Fittings' shape, material and the environment will affect its temperature rise. In order to study the temperature rise characteristics of fittings, high-current temperature rise experiment were carried out on fittings of different types and materials at different altitudes. In addition, convective heat transfer coefficients between fittings and surrounding environment at different altitudes are derived. The finite element calculation model of fittings is established, and the temperature rise of fittings is simulated by COMSOL Multiphysics. The steady temperature field distribution of fittings at different altitudes is obtained, and the results are compared with the experimental results, which verified the correctness of the theoretical analysis and simulation settings. Finally, the temperature rise of fittings at different altitudes is predicted. This paper can provide reference for material selection and numerical simulation of valve hall fittings in converter stations at different altitudes.

Fire resistance of light wood frame walls sheathed with innovative gypsum-particle composite: Experimental investigations

PARAMETRIC STUDIES ON THE MOMENT RESISTANT BEAMCOLUMN CONNECTION BEHAVIOR OF CONCRETE FILLED DOUBLE STEEL TUBULAR COLUMNS AND I STEEL BEAMS

The configuration of Concrete filled double steel tubular cross-section (CFDST) has the potential to overcome the beam-column connection difficulties found in steel tubular cross-sections. Since experimental parametric studies are expensive, numerical methods are adopted in this study to understand the behavior of beam-CFDST column connection under monotonic and cyclic loading conditions. The connection type is observed to be as semi-rigid as per EN1993-1-8. Parametric study includes design parameters like, concrete infill strength, yield strength of inner steel tube and outer steel tube, hollowness ratio, width to thickness ratio of inner steel tube and outer steel tube, end plate thickness and provision of stiffeners for end plate. Thickening the inner steel tube locally at the bolt location and providing stiffener plate or bracket at the compression zone of the extended end plate improves the rotational capacity of the connection as high as 0.06 rad for full plastic moment capacity of the beam. Recommendations are given for proportioning the connection components like end plates, bolts, inner steel tube and stiffeners for an optimal semi-rigid connection design.

Lightweight Woodframe Shear Walls with Ply-Bamboo Sheathings

A new type of hybrid wood-bamboo shear wall was studied. Ply-bamboo is used as the sheathing panel for conventional two-by-four lightweight woodframe shear walls herein. Two different nails were adopted for the ease constructability and used for constructing the shear walls, as follows: gun-driven T shape nail and 6d common nail. Monotonic and cyclic test results of sheathing-frame connectors and corresponding full scare shear walls were also reported. The results obtained from the research reported in this paper indicated that ply-bamboo panels can be used as sheathings for light-weight timber shear walls.

Design for structural adaptation with demountable cross-laminated timber connections

An emerging strategy to prolong the service lives of buildings is to design them to be adaptable. For timber structures, life extension strategies have the added benefit of prolonged carbon storage. Yet, there are unsolved technical barriers to realizing adaptability for timber structures, in particular for panel-type construction with cross-laminated timber (CLT). While there are several demountable CLT connections on the market, they are typically aimed at facilitating the reuse of individual panels. There is an added level of complexity regarding the removal or replacement of a CLT panel where the surrounding structure is kept intact. This paper defines the relevant characteristics of a structurally adaptable CLT connection. The paper further proposes an indicator system to assess the adaptability potential of connections in CLT structures. This system can be used in the continued development of CLT connections for structural adaptability, to further advance the development towards resource-efficient timber structures.

EXPERIMENTAL STUDY ON BEHAVIOR OF THE GUSSET-PLATE JOINT OF ALUMINUM ALLOY PORTAL FRAME

"The aluminum alloy portal frames are increasingly being used for lightweight building construction. This paper investigated the flexural behavior of the bolted gusset-plate joint applied in the beam-beam connection of aluminum alloy portal frames. Bending tests were conducted on 3 aluminum alloy bolted gusset-plate joints. The failure phenomenon indicated that the thin plate joint failed by the buckling of gusset plates, while the thick plate joint failed by the buckling of sleeves. The momentrotation curves showed that thickening the gusset plate can effectively prevent the buckling of gusset plates and increase the flexural capacity and bending stiffness of joints. In addition, the longitudinal spacing of bolts has a significant influence on the joint stiffness but has no obvious influence on the bearing capacity of the joint. The stress on the two gusset plates of the joint was uneven, which led to the decline of bearing performance of thin plate joints."