Skewed Pressure Characteristics of Equivalent Load in Double-Arch Tunnel

It is of great importance to reasonably estimate the surrounding rock load of a double-arch tunnel for the design, construction and stability evaluation of the tunnel. Currently, the basic theory on surrounding rock pressure of double-arch tunnels is insufficient for properly making the design and calculations. Generally, simplified calculations based on experience are used, such as the calculation method of Protodyakonov\u27s theory, the building code method and others. Considering the fact that the surrounding rock pressure of double-arch tunnels has skewed distribution characteristics, a computational model of a double-arch tunnel was built using data from an actual excavation of a highway tunnel. Taking some factors into consideration, such as different stress states, different construction methods and different sizes of double-arch tunnels, the pressure evolution of the surrounding rock was analyzed during step-by-step excavation of the double-arch tunnel. The results showed that in each condition the surrounding rock pressure of the double-arch tunnel displayed skewed distribution characteristics. The skewed distribution of the surrounding rock pressure varied with changes in stress state, construction sequence and excavation size. The skewed pressure of the double-arch tunnel was converted to equivalent load. The conversion method and distribution characteristics of the equivalent load are specified. They have important theoretical significance and practical value for similar engineering practices

Pilot Investigation of Coal Chemical Wastewater Containing Phenol by Pervaporation Process

Coal chemical wastewater contains a large number of industrial raw materials, such as phenol, resulting in difficulty as target to be treated and the resource waste as industrial raw materials. A pilot pervaporation process is investigated to separate and recycle phenols from coal chemical wastewater to reduce the follow-up biochemical processing load. Operation parameters which affect removing and recovering efficiency are studied, such as temperature, flow rate and downstream pressure. Phenol removal efficiency could reach 50% under the conditions of 70o C, 210 L/h and 3000 Pa. The system could continuously run for 20 cycles. Furthermore, the pervaporation procedure could be enhanced when pumped with gas which made the removal efficiency up to 66%

A novel small-scale self-focusing suppression method for ultrahigh peak power lasers

We proposed a novel method, using an asymmetric four grating compressor (AFGC) to improve the spatial uniformity of laser beams, to suppress the small-scale self-focusing (SSSF) during the post-compression of ultrahigh peak power lasers. The spatial uniformity is an important factor in performing post-compression, due to the spatial intensity nonuniformity will be enhanced while going through a nonlinear process. And what's more, the strong intensity spikes induced during nonlinear process can seriously damage the subsequent optical components. Moreover, the three-dimensional numerical simulations of the post-compression are implemented based on a petawatt (PW) class laser with a standard compressor and an AFGC. The results show that the post-compression with AFGC can shorten the laser pulses from 30fs to sub-10fs and meanwhile efficiently suppress SSSF. This work provides a promising scheme for the post-compression scaling to PW and even 10PW lasers

Operating Conditions of Hollow Fiber Supported Liquid Membrane for Phenol Extraction from Coal Gasification Wastewater

The extraction and recycling of phenol from high concentration coal gasification wastewater has been studied using polypropylene (PP) hollow fiber membrane and polyvinylidene fluoride (PVDF) hollow fiber membrane as liquid membrane support, the mixture of tributyl phosphate (TBP) and kerosene as liquid membrane phase, and sodium hydroxide as stripping agent in the process of extraction. The experiments investigated the effect of the operating conditions of the hollow fiber supported liquid membrane, such as aqueous phase temperature and the connection forms of membrane modules, on the extraction efficiency of phenol from high concentration coal gasification wastewater. The conclusions obtained from lab scale experiments provided guidance for scale-up experiments. So, in the scale-up experiments, three membrane modules connected in parallel, then three membrane modules connected in series were used to increase the treatment capacity and improve the treatment effect, under the operating conditions of wastewater temperature 20 ˚C, PH 7.5~8.1, flow rate 100 L/h and the concentration of stripping phase 0.1 mol/L, stripping phase flow rate 50 L/h, the extraction efficiency of the PP-TBP supported liquid membrane system was 87.02% and the phenol concentration of effluent was 218.14mg/L. And the phenol concentration of effluent met the requirements of further biodegradation treatment

Shifts in Soil Microbial Community Composition, Function, and Co-occurrence Network of Phragmites australis in the Yellow River Delta

Soil microorganisms play vital roles in regulating biogeochemical processes. The composition and function of soil microbial community have been well studied, but little is known about the responses of bacterial and fungal communities to different habitats of the same plant, especially the inter-kingdom co-occurrence pattern including bacteria and fungi. Herein, we used high-throughput sequencing to investigate the bacterial and fungal communities of five Phragmites australis habitats in the Yellow River Delta and constructed their inter-kingdom interaction network by network analysis. The results showed that richness did not differ significantly among habitats for either the bacterial or fungal communities. The distribution of soil bacterial community was significantly affected by soil physicochemical properties, whereas that of the fungal community was not. The main functions of the bacterial and fungal communities were to participate in the degradation of organic matter and element cycling, both of which were significantly affected by soil physicochemical properties. Network analysis revealed that bacteria and fungi participated in the formation of networks through positive interactions; the role of intra-kingdom interactions were more important than inter-kingdom interactions. In addition, rare species acted as keystones played a critical role in maintaining the network structure, while NO3−−N likely played an important role in maintaining the network topological properties. Our findings provided insights into the inter-kingdom microbial co-occurrence network and response of the soil microbial community composition and function to different P. australis habitats in coastal wetlands, which will deepen our insights into microbial community assembly in coastal wetlands

Efficacy and safety of single-pill amlodipine/losartan versus losartan in patients with inadequately controlled hypertension after losartan treatment: a multicenter, double-blind, randomized phase III clinical trial

ObjectiveSingle-pill amlodipine besylate (AML) plus losartan (LOS) has been used to treat inadequately controlled hypertension after antihypertensive monotherapy; however, relevant data in China are limited. This study aimed to compare the efficacy and safety of single-pill AML/LOS and LOS alone in Chinese patients with inadequately controlled hypertension after LOS treatment.MethodsIn this multicenter, double-blind, randomized, controlled phase III clinical trial, patients with inadequately controlled hypertension after 4 weeks of LOS treatment were randomized to receive daily single-pill AML/LOS (5/100 mg, AML/LOS group, N = 154) or LOS (100 mg, LOS group, N = 153) tablets for 8 weeks. At weeks 4 and 8 of treatment, sitting diastolic and systolic blood pressure (sitDBP and sitSBP, respectively) and the BP target achievement rate were assessed.ResultsAt week 8, the sitDBP change from baseline was greater in the AML/LOS group than in the LOS group (−8.84 ± 6.86 vs. −2.65 ± 7.62 mmHg, P < 0.001). In addition, the AML/LOS group also showed greater sitDBP change from baseline to week 4 (−8.77 ± 6.60 vs. −2.99 ± 7.05 mmHg) and sitSBP change from baseline to week 4 (−12.54 ± 11.65 vs. −2.36 ± 10.33 mmHg) and 8 (−13.93 ± 10.90 vs. −2.38 ± 12.71 mmHg) (all P < 0.001). Moreover, the BP target achievement rates at weeks 4 (57.1% vs. 25.3%, P < 0.001) and 8 (58.4% vs. 28.1%, P < 0.001) were higher in the AML/LOS group than those in the LOS group. Both treatments were safe and tolerable.ConclusionSingle-pill AML/LOS is superior to LOS monotherapy for controlling BP and is safe and well tolerated in Chinese patients with inadequately controlled hypertension after LOS treatment

第868回千葉医学会例会・第8回磯野外科例会

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Numerical Simulation of Residual Oil Flooded by Polymer Solution in Microchannels

This paper establishes a flow equation using non-Newtonian fluid mechanics and defines the deformation of residual oil using numerical computation in order to conduct a study on the flow law of residual oil in microchannels of rock during polymer flooding, the influence of flooding fluid elasticity on the deformation of residual oil, and flooding mechanism of viscoelastic displacing fluid. Computation shows that advancing contact angle increases and receding contact angle decreases as the viscosity ratio decreases. The higher elasticity of polymer solution with higher concentration or molecular weight leads to significantly more obvious deformation of residual oil and benefits migration and stripping of residual oil. The impact of the initial wetting angle of residual oil film on deformation is analyzed. A smaller initial wetting angle corresponds to a bigger change of advancing contact angle and smaller change of receding contact angle. A better understanding of the flooding process is gained via a study on residual oil deformation in polymer flooding. Consequently, oil flooding efficiency and oil recovery can be enhanced. This is the hydrodynamic mechanism of enhanced oil recovery (EOR) by polymer flooding