Trichoderma spp. is a kind of multi-functional probiotics fungus that can stimulate crop growth and increase its capability against abiotic and biotic stresses. However,advanced and systematic global research is very limited in the areas of its plant salt tolerance increase and function mechanism. This paper addresses the impacts of Trichoderma harzianum LTR-2 on NaCl tolerant physiological characteristics of peppermint( Mentha piperita L.). Results show that LTR-2 can effectively alleviate growth inhibition and photosynthetic damage of peppermint under 200 mmol /L NaCl stress.The paper also investigates the physiological and biochemical basis of NaCl stress tolerance of LTR-2 inoculated peppermint. Results indicate that LTR-2 can increase antioxidant activity of peppermint and reduce ROS accumulation. It can also increase the activities of plasma membrane( PM) and tonoplast H+-ATPase and Na+/H+antiporter and then regulate salt absorption and distribution. These results provide experimental basis for the development and application of peppermint and LTR-2 in saline soil.
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.
Abstract The article proposes a new implication for three-valued logical systems. The tautologies of this implication are exactly the same as for the classical implication in the two-valued Boolean logic. In the setting of this new implication, the conjunction and disjunction can be viewed as binary modalities. The article studies the definability and complete axiomatisation of the three versions of these modalities capturing Kleene’s, weak Kleene’s, and short-circuit versions of the connectives.
A new type of lightweight shear walls made with a laminated bamboo (glubam) stud frame and ply-bamboo sheathing panels is introduced in this paper. The lateral loading experiments of such shear walls and corresponding similar lightweight wood shear walls with three different panel-frame nailing connections and two thicknesses of sheathing panels were performed, in accordance with international standards. Test results demonstrate that the lightweight glubam shear walls have similar performance as conventional lightweight wood-frame shear walls, with higher initial stiffness and peak load, but less ductility. An increase in nail diameter can improve the load-bearing capacity of the shear walls until the failure mode of panel-frame connection changes from yielding of the nails to pull-through of nails from the ply-bamboo panels. Increased panel thickness can increase the bearing capacity and deformability of the shear walls when the failure pattern of panel-frame connection changes from panel failure to nail yielding. A new uplift hold-down device and improved design of edge studs were used to increase the ductile performance of glubam shear walls.
One of the problems with current practice in software development is that customer requirements are often not well captured, understood and analysed, and there is no clear traceable path from customer requirements to software specifications. This often leads to a mismatch between what the customer needs and what the software developer understands the customer needs.
As an important branch of waterway transportation of China, the inland river transportation is playing a more and more important role in the social development and the growth of the national economy. Based on the analysis on the overall development level of inland port of China, a two-level indicator evaluation system for inland port competitiveness is established, and the weight of the indicators of different levels is determined through analytic hierarchy process (AHP). Moreover, based on Delphi technique method, six typical inland ports such as Chongqing Port and Wuhan Port are selected to conduct an analysis on the indicators of the port through F-AHP so as to obtain the overall sequence for the comprehensive competitiveness evaluation on the port, furthermore the evaluation results are analyzed. The results show that, the conclusion of competitiveness evaluation is essentially consistent with the actual situations, the evaluation indicator system is reasonably constructed and the evaluation method is correct.
In order to promote the application of bamboo materials in construction industry,this paper reports lateral loading test results of lightweight woodframe shear walls with ply-bamboo sheathing panels.ASTM E2126-09 was selected as the experimental guideline for the monotonic and cyclic tests of eight shear walls.Two types of shear walls were made using two different nails,51 mm long nail-gun driven nails and 51 mm long nail staples.The bearing capacity is 5.2 kN / m and 6.2 kN / m respectively.Shear walls keep its integrity and most of its bearing capacity when the lateral displacement is below 100 mm.Test results show that the application of ply-bamboo sheathing panel can satisfy the bearing capacity requirements of shear walls designed as structural elements,according to current codes for timber structures.
The elastic finite element analysis (FEA) and the experimental method of testing the cleavage strength of the joint were used to investigate the effect of the recessing as well as its length on the stress distribution in both the mid-bondline and the adherend near the interface along the bondline of adhesively bonded steel cleavage joint. The results from the FEA simulation showed that the peak values of the stresses distributed in the mid-bondline were nearly the same when the length of the arranged recessing was not greater than 10 mm except that the shear stress Sxy was increased a little when the length of the recessing was increased. For the normal stress Sy near the interface of the joint with a 16 mm length recessing, the peak stress in the adherend is about 49% higher than the one in the adhesive at the left edge of the joint. And it is supported with the results from the experiments that the ultimate load of the steel-to-steel cleavage joint decreased a little when the gap length was less than 10 mm.
ABSTRACT The selection of roller types and feeding parameters is critical for the automated fiber placement. However, it has not been extensively explored. In this study, based on contact mechanics and incorporating Fourier series theory, a theoretical model was developed to describe the contact behavior between different striped rollers and the tow in the feeding mechanism. The validity of the model was verified using Laser‐Doppler Anemometry. In addition, a numerical algorithm was proposed to calculate the contact behavior between different striped rollers and the tow. Using this algorithm, the contact behavior under various process parameters was obtained, and the influence of stripe geometric features on the contact behavior was analyzed. The proposed model and algorithm provide theoretical support for the selection of roller types and the optimization of parameters in the feeding mechanism.
