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Three types of methods, including Laser flash, Hot-Disk, and Wiedemann-Franz law, have been applied for thermal conductivity measurements of Al-Si casting alloys. The first two methods can obtain the thermal parameter directly for specific samples, while the third one calculates the target value by formula containing the electrical conductivity. Thus, the latter is widely used in the foundries because of its convenient and rapid characteristics. The purpose of this paper was to make a polite comparison among them and optimize the key constant C in the Wiedemann-Franz law to improve the calculation accuracy for Al-Si alloys. Measurements were conducted on the same set of specimens of Al-Si-xCu alloys (x ranges from 0.1 wt.% to 2.0 wt.%) at room temperature. The results showed that the measured value of Laser Flash method was well consistent with Hot Disk. While that of the Wiedemann-Franz law was different with them, the average deviation percentages were 2.17% and 2.36% when using empirical constant C (12.6 W/m·K) in the formula. Then, the constant C was modified to 8.4 W/ m·K and the average deviation percentage were decreased to 0.4% and 0.2% respectively. The reason for the differences was analyzed and a thermal conductivity evaluation model was proposed.

A practical sodium tert-butoxide (NaOtBu)-mediated protocol is disclosed for the transamidation of various N,N-dimethyl amides with primary amines to afford the corresponding amides in moderate to good yields at room temperature under solvent-free conditions. This protocol features a facile work-up procedure and good functional group compatibility, especially for N,N-dimethyl amides with long-chain alkyl groups and heteroatom-containing amines. Notably, a few representative gram-scale reactions proceed smoothly to furnish the desired amides in high yields, which demonstrates the potential of this process for further practical applications. Several control experiments are carried out and a plausible mechanism is provided.

Herein, a wide range of mono- and di-arylated products were efficiently prepared from C–N coupling of 2-halobenzothiazoles and primary aromatic amines, and representative compounds 3b and 4b were further confirmed by X-ray crystallography. It was noteworthy that the di-arylated products, denoted as di(benzothiazolyl)amines, are new chemical entities which have not yet been reported. Moreover, the ligand-controlled protocol was extended to the synthesis of target molecules bearing a diphenyl ether or diphenyl amine scaffold. To our delight, several compounds exhibited good inhibitory activity against succinate-cytochrome c reductase (SCR), which revealed the practical application of this protocol. Notably, selective mono- and di-arylation could be switched simply by varying the ligand from Xantphos to a pyridine-functionalized N-heterocyclic carbene (NHC) ligand, and further investigations were carried out to elucidate the possible reason for this new finding.

BACKGROUND: High breast density is significantly associated with an increased risk of breast diseases. Presently, suspected breast masses assessed as Breast Imaging-Reporting and Data System (BI-RADS) grade 4 provide a wide range of positive predictive values. Moreover, subcategories (4a, 4b, and 4c) are still under consideration as the diagnostic criteria are neither comprehensive nor objective. However, whether mammography breast density (MBD) has any impact on the accurate grading of BI-RADS 4 assessed by ultrasound (US) remains unknown. METHODS: A total of 1,086 women with 1,293 breast masses were included and assessed as BI-RADS 3–5 by US. The subcategories of MBD (from the ACR-a to the ACR-d group) were assessed by mammography according to the criteria of the American College of Radiology (ACR). The clinicopathological characteristics of these patients were reviewed retrospectively. The malignancy rates of breast masses among different subgroups assessed by BI-RADS were re-estimated with MBD. RESULTS: Almost all BI-RADS 3 masses were classified as benign and nearly all BI-RADS 5 masses were identified as malignant. Significant inverse associations between MBD and malignancy rates were detected between the BI-RADS 4a and BI-RADS 4b groups. Moreover, malignancy rates decreased significantly from ACR-a to ACR-d for BI-RADS 4a and 4b breast lesions (P

C26H27ClN8NiO7, triclinic, P1̄ (no. 2), a = 9.893(2) Å, b = 11.503(2) Å, c = 13.295(3) Å, α = 78.77(3)°, β = 70.52(3)°, γ = 83.40(3)°, V = 1397.0(6) Å3, Z = 2, R gt(F) = 0.0423, wR ref(F 2) = 0.1032, T = 153.15 K.

C33H39Cl2N9NiO12, monoclinic, P21/c (no. 14), a = 9.7478(4) Å, b = 20.6247(7) Å, c = 19.0897(11) Å, β = 92.767(5)°, V = 3833.4(3) Å3, Z = 4, R gt(F) = 0.0527, wR ref(F 2) = 0.1143, T = 108.4(2) K.

Objective: To compare pre- and post-therapy symptom scores reported on the National Institute of Health Chronic Prostatitis Symptom Index (NIHCPSI) after trans-rectal antibiotic injections therapy for men suffering from chronic prostatitis. Materials and methods: Retrospective analysis of NIHCPSI symptom scores obtained from chart reviews of 77 treated males suffering from chronic prostatitis before and after trans rectal injections for the treatment of chronic prostatitis. Results: Most patients reported a 40% to 60% improvement in symptom scores. In subgroups comparing scores in patients with less than 5 injections, the improvement was less than in patients who received 10 or more injections. Patients’ responses after a shorter (3 months) follow up showed better pain scores than patient’s scores after longer, over one-year or more, follow- up periods. Conclusion: Our findings show that direct antibiotic injection for chronic prostatitis is a viable addition to standard therapies. Improvements in symptom scores are long lasting. Discomfort is minimal and side effects are rare and avoidable

The regeneration process is simulated under the condition of different expansion tubes by the established model on CFD technology. It turns out that, increasing expansion angle of the expansion tube does good to lower the maximum wall temperature and the axial temperature gradient during the DPF regeneration, while it makes the uniformity of the wall regeneration temperature worse. At the same time, the regeneration rate becomes slower and the radial maximum temperature gradient increases. This study makes great significance to the design and optimization of DPF device structure and prolonging the service life of DPF.

Nowadays, the operation of orchard vehicle which is used in China has the disadvantages such as single function poor automation level etc. Therefore, it can hardly adapt to the complex environment in orchard. The electric vehicle that powered by electrical drive motor can not only save energy, but also achieve the goal of controlling more conveniently and efficiently. Some electrical vehicles in China can take a variety of steering modes. However, most orchard vehicles lack of targeted terrain design. Electric four-wheel independent drive and steering vehicles have strongly strengthened this weakness. This paper uses four-wheel independent drive & four-wheel independent steering structure and completes the design of the control system. The aim is to achieve five different orchard vehicle driving modes which based on microcontroller system, real-time feedback and achieve differential speed calculating model through the multi-channel sensor in the steering modes. Thus, it can ensure the slip angle within the allowable range and driving stability. It also proposes the design & manufacturing of wireless remote control device and operation panel in order to simplify drivers operation and increase the efficiency.

Based on study of space vector modulation, cca novel over-modulation strategy of matrix converter is proposed for the problem of low voltage transfer ratio of matrix converter. According to the relation of the voltage space vector trace and hexagon trace vector, the control level is divided into linear modulation level and over-modulation level. The over modulation strategy is achieved by transforming the voltage modulation coefficient. The simulation results demonstrate that the voltage transfer ratio can be up to 0.955.

The introduction of the AQC boiler has complex effects on the temperature of Tertiary air, traditional PID is difficult to achieve the effective control. Combined the method of the conventional PID with the fuzzy control theory, a fuzzy self-tuning PID controller is designed. Compared with traditional PID, results of simulation show that the fuzzy PID controller improves not only the adaptability and robustness of the system, but also the system's static and dynamic performance.

The RCS of the patch antenna which works at 9.15 GHz is reduced by loading a metamaterial absorber. The period and thickness of the metamaterial absorber are 5.5mm and 0.3 mm, respectively. Simulated results show that the metamaterial absorber can achieve absorptivity over 99% at frequency 9.15 GHz. The patch antenna patterns and reflection coefficient (S 11 ) for loading and unloading the metamaterial absorber are compared, which shows that the radiation performance of the patch antenna is not affected by loading on the metamaterial absorber. RCS Simulation of the patch antenna loading the metamaterial also shows that the RCS is reduced more than 15 dB.

The copolymers of polysulfone-graft-acrylic (PSF-g-PAAc) acid were synthesized by homogeneous photo-initiated graft copolymerization method. Variable affecting the degree of grafting (DG), such as the ultraviolet irradiation time, and the concentrations of the acrylic acid monomer and photoinitiator, were investigated. The graft copolymers were characterized by chemical titration, attenuated total reflection-Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy analysis. It is verified that acrylic acid groups were present on the polysulfone polymer. Then, membranes were prepared from the PSF-g-PAAc powder with different DG using phase inversion method. It is found that the flux properties of the membranes were dependent on the pH value of the aqueous solution.

Detecting population (group) differences is useful in many applications, such as medical research. In this paper, we explore the probabilistic theory for identifying the quantile differences between two populations. Suppose that there are two populations x and y with missing data on both of them, where x is nonparametric and y is parametric. We are interested in constructing confidence intervals on the quantile differences of x and y. Random hot deck imputation is used to fill in missing data. Semi-empirical likelihood confidence intervals on the differences are constructed.

In this paper, we consider the q-difference analogue of the Clunie theorem. We obtain there is no zero-order entire solution of f n ( z ) + ( ∇ q f ( z ) ) n = 1 when n ≥ 2 ; there is no zero-order transcendental entire solution of f n ( z ) + P ( z ) ( ∇ q f ( z ) ) m = Q ( z ) when n > m ≥ 0 ; and the equation f n + P ( z ) ∇ q f ( z ) = h ( z ) has at most one zero-order transcendental entire solution f if f is not the solution of ∇ q f ( z ) = 0 , when n ≥ 4 . MSC:30D35, 30D30, 39A13, 39B12.

Tag collision is an obstacle in the population process of Internet of Things (IoT). Based on Dynamic Frame-Slotted Aloha (DFSA) algorithm, an improved algorithm was presented and designed, namely Reserved Frame-Slotted Aloha (RFSA) algorithm. The improved reserve mechanism enables reader access to data reading status on each slot in advance, so that subsequent communication can directly performed on normal slots. Then, key parameters of RFSA were determined. Process model, node model and network model of RFSA were also presented with OPNET 14.5 tool. Simulation experiment results based on OPNET show that the improved algorithm is superior to DFSA in overall performance.

Hierarchical multicast can effectively achieve multicast communication of heterogeneous network. RED algorithm and HTH algorithm were analyzed and discussed. RED can keep low delay while pursuit larger throughput, but it has shortcoming of sensitive to parameters. HTH algorithm can rapidly respond to congestion and effectively improve throughput as well as utilization of link, but it occupies too much router resources in case of many streams. On the basis, a kind of hop-to-hop controlled hierarchical multicast congestion control mechanism combining RED and HTH was presented. With this mechanism, each router determines its congestion status based on current network state. If congestion occurs, it discards with certain probability and report congestion status to upstream router. After router received congestion state from other routers, it will take appropriate measures to increase or decrease transmission rate to some downstream router. At the same time, packet discard number of each link was considered in congestion control to ensure fairness. Simulation result based on NS-2 shows that the proposed algorithm is superior to RED in aspects of throughput and packet loss rate.

Objective A lot of instruments and devices were reported in standardized realignment of intraoral film. However, these instruments either are too cumbersome and time consuming to be used or require extensive fabrication. In this study we described a prototype of a instrument for realignment of intraoral film and evalated its reproducibility. Study design A technique that uses this instrument was compared with a validated method serving as control. An adult human dry skull with full dentition was exposed for measuring the angular errors. Two types of angular errors were calculated. Results Results of the analysis of the alignment error caused by projection of the x-ray beam showed the mean horizontal angulation error (±SD) was 1.70 ± 0.75 degrees and the vertical one was 1.32 ± 0.44 degrees in the new instrument group, and 1.65 ± 0.70 degrees and 1.40 ± 0.61 degrees, respectively, in the control group. Bite block seating error was 2.12 ± 0.55 degrees in the newly developed instrument and 2.01 ± 0.49 degrees in the instrument with registration material. Statistical analysis showed no significant difference in the 2 instruments ( P > .05). Conclusion The prototype of the new instrument reported by the authors can produce almost identical radiographs in vitro with only slight angular errors. Clinical use of the advanced type of the instrument can be expected to show similar results.

OBJECTIVE: To investigate the prevalence rate, malocclusion type and treatment rate as well as awareness of malocclusion among children and adolescents living in the Hangzhou municipality. METHODS: 1818 children and adolescents ages 7 approximate, equals 16 living in Hangzhou municipality were evaluated. RESULTS: The overall malocclusion rate was 35.75%. In Angle's classification: Angle I 593 cases (32.62%), Angle II 48 cases(2.64%),Angle III 9 cases (0.49%). Among the malocclusion type of crowding was mixed dentition 70.66%,permanent dentition 85.89%. In the overjet malocclusion mixed dentition was noted in 60.57% and permanent dentition in 51.05%.The type of overbite was mixed dentition 67.82%,permanent dentition 31.23%. In the crossbite of anterior teeth mixed dention was noted in 12.30% and permanent dention in 9.91%. Overall treatment rate for malocclusion was 10.15%.CONCLUSION: Among Hangzhou municipality juveniles there is both inadequate prevention and treatment of dental malocclusion.