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.
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.
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.
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.
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.
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.
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.
