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The spectrum of a weighted composition operator $$C_{\psi , \varphi }$$ that is induced by an automorphism has been investigated for over 50 years. However, many results are got only under the condition that the weight function $$\psi $$ is continuous up to the boundary. In this paper we study the spectra and essential spectra of $$C_{\psi ,\varphi }$$ on weighted Bergman spaces when $$\varphi $$ is an elliptic automorphism, without the assumption that $$\psi $$ is continuous up to the boundary.

The effective elimination of sound energy traveling in open ducts is critical in acoustics, with considerable potential in diverse applications ranging from duct noise control to exhaust system design. However, previous absorber mechanisms are bulky or have limited ventilation or unsatisfactory absorption capability. We propose and experimentally demonstrate the concept of meta-mufflers capable of quasi-perfectly absorbing airborne sound propagating in an open duct while minimizing the influence on airflow because of its vanishing thickness. The mechanism uses coupling among asymmetric metasurfaces to achieve impedance match and subsequent high absorption in a subwavelength scale, which is explained analytically and validated experimentally. The proposed meta-muffler features an uncomplicated design, high attenuation efficiency, and a thickness of nearly two orders of magnitude of wavelength, ensuring the free pass of other entities. Furthermore, our design offers the flexibility of tuning and extending working bandwidth by hybridization of weak resonances. The performance of the proposed muffler is verified via experiments, which correlate excellently with theoretical predictions. The realization of meta-mufflers opens a route to novel acoustic absorbers and could have far-reaching implications in a plethora of important scenarios calling for both perfect sound absorption and open acoustic paths.

Broadband acoustic absorbers with thin thickness are highly desired in practical situations such as architectural acoustics, yet it is still challenging to achieve high absorption by using structure with limited thickness. Here we report the theoretical optimal design, numerical simulation and experimental demonstration of a planar acoustic absorber capable of producing broadband sound absorption with deep-subwavelength thickness. The mechanism is that, we use a hybrid design of individual unit cell comprising multiple resonators with a coiled configuration for expanding the working bandwidth and downscaling the resulting device, and, on the other hand, the geometries of the constituent resonance elements are optimally designed by using genetic algorithm. Based on an analytical formula we derive for an efficient prediction of the absorption efficiency, the optimization process is accelerated and gives rise to an optimally maximized amount of absorbed energy with limited device thickness. As a result, the proposed absorber features planar profile, broad bandwidth, wide absorbing angle (the absorber works well when the incident angle of sound wave reaches 60°) and thin thickness (

After classifying the Beijing subway transfer stations into different types, a comprehensive investigation on entire transfer stations of Beijing subway is conducted. According to the transfer station characteristics with respect to interchange form, transfer time and passenger flow volume during rush hours, some problems of Beijing subway transfer stations are analyzed. Then, some suggestions are offered to provide theoretical reference for the planning and operation of subway transfer stations.

Constellations of small satellites have a promising use in satellite remote sensing or satellite communication. Launching several small satellites at the same time with one vehicle is a good way to keep the budget of the whole project under control. Multi-payload adapter is an important equipment on the launch vehicle to carry those small satellites during the rising phase and shoot them into their own trajectories during the orbiting phase. The paper studies the relations between the demands of small satellites launching and the multi-payload adapter designing. Also the paper illustrates the necessity of putting the multi-payload adapter into a project and the necessity of researching on the multi-payload concurrent experiment.

The enantioselective bioaccumulation of diniconazole in Tenebrio molitor Linne larva was investigated with liquid chromatography tandem mass spectrometry based on the ChiralcelOD-3R[cellulose tri-(3,5-dimethylphenyl carbamate)] column. In this study we documented the effects of dietary supplementation with wheat bran contaminated by racemic diniconazole at two dose levels of 20 mg kg(-1) and 2 mg kg(-1) (dry weight) in Tenebrio molitor. The results showed that both doses of diniconazole were taken up by Tenebrio molitor rapidly in the first few days, the concentrations of R-enantiomer and S-enantiomer at high doses reached the highest level of 0.55 mg kg(-1) and 0.48 mg kg(-1) , respectively, on the 1(st) d, and the concentrations of them obtained a maxima of 0.129 mg kg(-1) and 0.128 mg kg(-1) at low dose, respectively, on the 3(rd) d, which means that the concentration of diniconazole was proportional to the time of achieving the highest accumulated level. It afterwards attained equilibrium after a sharp decline at both 20 mg kg(-1) and 2 mg kg(-1) of diniconazole. The determination results from the feces of Tenebrio molitor demonstrated that the extraction recovery (ER) values of the high dose group were higher than that of the low dose group and the values were all above 1; therefore, it could be inferred that enantiomerization existed in Tenebrio molitor. Additionally, the biota accumulation factor was used to evaluate the bioaccumulation of diniconazole enantiomers, showing that the bioaccumulation of diniconazole in Tenebrio molitor was enantioselective with preferential accumulation of S-enantiomer.

Is a huge coal mine in China, is also a State of psychological crisis intervention started later, mine will affect their mental and physical health in multiple ways, the impact could be short-lived, too, there may be long, and leads to severe mental suffering or mental disorder or post-traumatic stress disorder (PTSD) and adjustment disorders. This analysis of coal mine emergency psychological assistance, submit cooperative, universality, such as scientific principles for emergency psychological assistance. At the same time the study of coal mine emergency psychological continuity, make secondary disaster measures taken do not appear.

Is Automation technique in substation integrated automation for substation applied a concentrated expression, was unattended substations necessary technical conditions, on integrated automation principle of analysis in the article, simultaneous analysis of control into the centralized control of unattended substation and grade control, focusing on analysis of unattended substation communication networks, and make recommendations on the communication engineering mode for unattended substation.

Electronic transformer Manager nature is a will simulation volume transformation for digital volume of device, they will simulation of current and the voltage signal in as possible near signal source of local used most has price of reliable way will its transformation for digital volume, electronic type transformer Manager and merged unit as digital substation of component, and traditional transformer Manager compared to has insulated simple, and dynamic range wide, and anti-saturated performance strong, and Advantages of data output. combined digital substation with IEC61850 in the text, examined issues such as data synchronization of electronic instrument transformers, made recommendations on engineering practice.

Micro-grid to facilitate a large number of distributed energy resources (DER) interconnection and access in the low voltage distribution system, provides a mechanism to take advantage of DER generating units, micro-grid profiles are described in the text and its development, micro-Islanding detection of grid management systems, micro-grid issues and micro-grids, market competitive issues. That urgency of micro-grid and Islanding detection methods, along with bidding in power market, the only generation involved in unilateral bidding mechanism and power side and the user side and participate in bilateral bidding mechanism.

Places of importance of coal mine ground transformer substation in mine electric power supply, according to this article the IEC61850 standard, through the analysis of the function of substation secondary equipment, from the structure of integrated substation automation system-oriented, hierarchical and logical interfaces and interoperability focus analysis of IED, making coal mine ground transformer substation integrated automation communication systems tend to be reasonable. This article is intended to point out that the IEC61850 standard application supports peer to peer traffic patterns, GOOSE information transmission mechanisms will be hard to be effective in reducing IED device wiring, greatly simplifies design and experiment of secondary system for engineering application interoperability between different manufacturers when IED provides effective support.

A Control Moment Gyroscopes (CMG) is a torque generator for attitude control of a high resolution and high agility satellite without any increase in power, mass or volume. In this paper, a new support structure of the CMG is proposed. According to the configuration idea of the CMGs, the original design model of the support structure is established. Furthermore, the topology optimization is performed by the FEM software ANSYS and after that came up with a suitable layout of the support structure of the CMG. Based on the optimized design results, the 3D models of the CMG and its support structure are established by the 3D design software Pro/E. Frequency of the assembly is analyzed and calculated. Finally, took the launch dynamics environments into consideration, the vibration testing are carried out to verify the rationality of the new design structure.

The enantioselective bioaccumulation of diniconazole in Tenebrio molitor Linne larva was investigated with liquid chromatography tandem mass spectrometry based on the ChiralcelOD-3R[cellulose tri-(3,5-dimethylphenyl carbamate)] column. In this study we documented the effects of dietary supplementation with wheat bran contaminated by racemic diniconazole at two dose levels of 20 mg kg(-1) and 2 mg kg(-1) (dry weight) in Tenebrio molitor. The results showed that both doses of diniconazole were taken up by Tenebrio molitor rapidly in the first few days, the concentrations of R-enantiomer and S-enantiomer at high doses reached the highest level of 0.55 mg kg(-1) and 0.48 mg kg(-1) , respectively, on the 1(st) d, and the concentrations of them obtained a maxima of 0.129 mg kg(-1) and 0.128 mg kg(-1) at low dose, respectively, on the 3(rd) d, which means that the concentration of diniconazole was proportional to the time of achieving the highest accumulated level. It afterwards attained equilibrium after a sharp decline at both 20 mg kg(-1) and 2 mg kg(-1) of diniconazole. The determination results from the feces of Tenebrio molitor demonstrated that the extraction recovery (ER) values of the high dose group were higher than that of the low dose group and the values were all above 1; therefore, it could be inferred that enantiomerization existed in Tenebrio molitor. Additionally, the biota accumulation factor was used to evaluate the bioaccumulation of diniconazole enantiomers, showing that the bioaccumulation of diniconazole in Tenebrio molitor was enantioselective with preferential accumulation of S-enantiomer.

To investigate the relationship between serum miRNA-21 (miR-21) expression in esophageal squamous cell carcinomas (ESCCs) and their clinicopathologic features, a 1:1 matched case-control study including 21 patients with ESCC and 21 age- and gender-matched healthy controls was carried out. Serum specimens were taken from all subjects. Total RNA was extracted and the stem-loop real time polymerase chain reaction was used to measure serum miR-21 in both groups. Clinical parameters were assessed to determine associations with serum miR-21 concentrations. Serum miR-21 expression in ESCC samples was significantly higher than in paired cancer-free samples (P0.05). Metastasis was associated with mir-21 expression in serum (P0.05), ESCC patients with metastasis having 8.4-fold higher serum miR-21 concentrations than healthy controls. There were no statistically significant associations between miR-21 expression and clinicopathologic parameters, such as gender (P0.05), age (P0.05), tumor location (P0.05), cell differentiation (P0.05), TNM staging (P0.05), whether chemo/radiotherapy had been administered (P0.05), or whether surgery had been performed (P0.05). These findings suggest that the detection of microRNA-21 in serum might serve as a new tumor biomarker in diagnosis and assessment of prognosis of ESCCs.

A construction of authentication codes with arbitration from symplectic geometry is given. The parameters are computed. Assuming the encoding rules are chosen according to a uniform probability distribution, the probabilities of success for different types of deception are also computed.

To investigate alterations of the pancreatic endocrine component in the early stage of acute necrotic pancreatitis (ANP) in rats.Thirty-six Sprague-Dawley rats were randomly allocated to two groups: ANP group (n = 18) and sham-operated (control) group (n = 18). ANP was induced by retrograde injection of 4% sodium deoxycholate (40 mg/kg, 0.1 mL/min) into the biliopancreatic duct and the severity of pancreatitis induced was assessed by histopathological examination and level of plasma amylase. The pancreatic endocrine function was assessed by measuring the levels of plasma glucose and insulin and by measuring the insulin content in pancreatic beta cells by immunofluorescence and immunocytochemistry.Five hours after operation, the pancreas of rats in the ANP group showed pathological changes with edema, hemorrhage, fatty necrosis, acinar destruction and leukocyte infiltration in the exocrine portion of the pancreas. Plasma amylase activity increased significantly (P0.01) and bloody ascites appeared in the abdominal cavity. Nevertheless the endocrine islets appeared normal and the beta cells contained intensive labeling of insulin. Levels of glucose and insulin in plasma increased significantly. In the ANP group, 5 h after operation the plasma level of glucose was 8.18 +/- 2.26 mmol/L vs 6.39 +/- 1.26 mmol/L, and of insulin was 23.27 +/- 3.50 MIU/L vs 18.40 +/- 3.98 MIU/L. In the control group, 5 h after operation the plasma level of glucose was 9.39 +/- 0.62 mmol/L vs 5.89 +/- 0.62 mmol/L, and of insulin was 26.28 +/- 4.77 MIU/L vs 12.89 +/- 2.05 MIU/L; there was no significant difference between these two groups (P0.05). After a bolus injection of glucose, however, a much higher level of insulin was found in the control group (35.30 +/- 5.05 MIU/L) than that in the ANP group (23.91 +/- 4.62 MIU/L, P0.05).There may be an impaired ability of insulin release in response to glucose stimulation in the early stage of ANP, although the morphology of the pancreatic endocrine component remains intact.