A structural equation modeling approach to factors that influence farmers' behaviour and behavioural intentions towards water policy changes

The objective of this study is to develop a better understanding of farmers’ behavioural intentions to possible water policy changes in Alberta. A survey of irrigators in southern Alberta was conducted in 2012 and the data were analyzed with Structural Equation Models. Findings indicate that farm business characteristics, values, attitudes, and past behaviour influenced farmers’ behavioural intentions towards water policy changes. Farmers’ intention to agree to volumetric water pricing was influenced negatively by business cycle and positively by values of Universalism related to nature and farming business attitudes; farmers’ intention to transfer water was influenced negatively by business cycle, values of Universalism related to human and land attachment attitudes, and positively by values of Universalism related to nature. Farms’ position in the business cycle was positively related to intentions to improve irrigation equipment; past behaviour was negatively related to intention to reduce irrigation water if the price of water increased.Alberta Innovates: Energy and Environment Solution, Nexen Corporatio

Generation of rotational ground state HD+^+ ions in an ion trap using a resonance-enhanced threshold photoionization process

We report a method for producing ultracold HD+ molecular ions populated in a rotational ground state in an ion trap based on [2+1'] resonance-enhanced threshold photoionization (RETPI) and sympathetic cooling with the laser-cooled Be$^+$ ions. The effect of electric field of the ion trap on the RETPI process of neutral HD molecules and the blackbody radiation (BBR) on the population evolution of rotational states of the generated polar HD+ ions have been studied. The initial rotational ground state population of HD$^+$ ions is 0.93(12). After the cumulation time of 5 s, the rotational ground state population is reduced to 0.77(8) due to the BBR coupling. This method of generating ultracold state-selected HD$^+$ ions is beneficial for the studies in precision rovibrational spectroscopy, state-controlled cold chemical reaction, and quantum logic spectroscopy.Comment: accepted by PRA, 7 pages, 7 figure

Construction applicability of mechanical methods for connecting aisle in the bohai mudstone stratum with high water pressure

China’s traditional connecting aisle construction technology is mainly to combine soil reinforcement with mining excavation. The technology is relatively mature, but it has shortcomings such as long construction period and long-term construction settlement. In order to overcome the above shortcomings, mechanical methods for connecting aisle technology has become increasingly mature after years of research and development, and has been successfully applied in many areas. For the cross-sea tunnel project, this technology was first tried and applied in the interval tunnel of Qingdao Metro Line 8. It is challenging to construct the connecting aisle by mechanical method in Bohai mudstone stratum with high water pressure, which has the construction difficulties such as high excavation requirements, high requirements for post-support function and limited space of main tunnel. In this study, a cutter, propulsion system, and back supporting system were designed to handle the key and difficult points and risks of the aforementioned construction. Furthermore, targeted construction schemes were adopted for sleeve sealing, sleeve removal, and improvement of sleeve sealing. The applicability of the improved mechanical construction method to the geological conditions of the Qingdao area was verified through a numerical simulation. The research results can provide a reference for the mechanical construction of connecting aisle under similar formation conditions

Superior cervical ganglionectomy alters gut microbiota in rats

The diversity and complexity of sympathetic function highlight the importance of fundamental research. Little is known about the interaction of superior cervical sympathetic ganglion (SCG) and gut microbiota. In this study, the engagement of the sympathetic ganglia with gut microbiota was investigated. Bilateral superior cervical ganglionectomy (SCGx) significantly altered the microbiota composition in rats 14 days post-surgery, and these microbiotas may participate in several biological pathways in the host, suggesting the vital role of the cervical sympathetic ganglion in regulating the microbiome-brain axis, and further confirming that the sympathetic nervous system (SNS) regulates the microbiome-brain axis

MODIFICATION OF DYNAMIC CONSTITUTIVE RELATION OF440C STAINLESS STEEL BASED ON J-C MODEL (MT)

In order to construct a constitutive model that reasonably describes the changing relationship of flow stress of 440C stainless steel, quasi-static and dynamic compression experiments were carried out with the help of a universal testing machine and a Hopkinson compression bar device. Based on the obtained experimental data, the parameters of the original J-C constitutive model were calibrated, and its applicability and prediction accuracy for describing the stress-flow behavior of the studied materials were discussed. Based on the analysis results, a modified J-C constitutive model considering the coupling among strain, strain rate and temperature was proposed, and the model parameters were calibrated. The experimental data and the model predicted value were compared and analyzed, and the validity of the proposed model was evaluated by three statistical parameters: correlation coefficient R, average relative error AARE and root mean square deviation RMSE. The results show that the dynamic mechanical behavior of 440C stainless steel is jointly dominated by the coupling between strain, strain rate and temperature. The correlation coefficient R of the proposed modified J-C constitutive model is 0.995 9, the average relative error AARE is 0.073, and the root mean square deviation RMSE is 0.761 8, which can reasonably describe its stress flow behavior

EXPERIMENTAL STUDY ON RHEOLOGICAL BEHAVIOR OF022Cr18Ni14Mo2 STAINLESS STEEL AT HIGH TEMPERATURE AND HIGH STRAIN RATE

To explore the influence of external temperature and loading rate on itsrheological behavior and mechanism, the dynamic impact compression test was conducted on 022 Cr18 Ni14 Mo2 stainless steel by using the split Hopkinson compression bar test platformat at 2 000 s-1～5 000 s-1 and 25℃～400℃.The results show that the flow stress, strain rate sensitivity, strain hardening and temperature sensitivity of the sample are closely related to strain, temperature and strain rate. At a constant temperature, the flow stress, strain hardening effect, and strain rate sensitivity increase with the increase of strain rate.At a constant strain rate, the temperature sensitivity increases with the increase of temperature, and the sample exhibits a significant thermal softening effect. The strain rate sensitivity and strain hardening effect appear to weaken with increasing temperature. In addition, the microstructure observation by scanning electron microscope（SEM） shows that deformation twins are mainly present in the grains, and a deformation zone with positioning or stacking faults is present in the grains. Under high strain rate or low temperature conditions, the number of deformation zone in the grain is more. The deformation twins within the grains help to adjust the degree of deformation between the grains and improve the uniformity of sample deformation at high strain rate

Risk Assessment Study on Mechanical Connecting Aisle Construction in the Bohai Mudstone Stratum with High Water Pressure

With the in-depth advancement of underground transportation in China, the connecting aisle is used as a link between different underground spaces to provide sufficient security and connection. The basic structural units of underground and aboveground spaces play an extremely important role. The use of the mechanical connecting aisle construction of over mucky strata is difficult, and it is easy to have an impact on the main tunnel. To ensure the safety of connecting aisle construction, studies should be performed on the construction technology, equipment, scheme, and related risk analysis of mechanical connecting aisle construction. In this study the work breakdown structure-risk breakdown structure combined with the expert investigation method is used to comprehensively identify the construction process, construct the risk index system of mechanical connecting aisle construction, determine the initial risk value, and comprehensively use the fuzzy-analytic hierarchical process to establish a fuzzy complementary judgment matrix, obtain the risk-weighted correction value, and quantitatively evaluate the risk source level of the mechanical connecting aisle construction. Based on the assessment method, the risk assessment of the mechanical connecting aisle construction project in Daqing section of Qingdao Metro Line 8 was performed, 113 potential risk sources were identified, and the comprehensive assessment obtained 7 major risk sources such as “improperly designed construction organization,” “instability of excavation surface,” and “easy leakage of lower river crossing” that were greater than the total risk average of 2.053. Corresponding risk response measures were proposed, which provided a reference for the risk assessment of similar projects in the construction of similar projects on mechanical connecting aisle construction in the Bohai mudstone stratum with high water pressure