SUS^2和Jasper Jumper矫治安氏Ⅱ类1分类患者的疗效对比

目的探讨SUS2和Jasper Jumper 2种口腔正畸矫治器治疗安氏Ⅱ类1分类患者的疗效异同点。方法筛选安氏Ⅱ类1分类青少年患者共46例,随机分为2组,分别使用SUS2和Jasper Jumper,拍摄头颅侧位片,观测18项测量指标治疗前后的变化值。结果 2组矫治前后ANB、Y-axis、L1-MP、U6-OLP等指标存在显著性差异。结论 SUS2和Jasper Jumper 2种矫治器的疗效不完全一致,治疗中应合理选择。

Jasper-Jumper矫治器治疗Ⅱ类骨性下颌后缩口腔功能间隙变化的研究

目的:量化评估经Jasper-Jumper矫治器治疗的骨性下颌后缩患者治疗前后口腔功能间隙变化。方法:采用国产Jasper-Jumper矫治器临床矫治30例骨性下颌后缩患者,拍摄治疗前后头颅定位侧位片和手腕片。结果:Jasper-Jumper矫治器治疗5～7个月(平均6个月)后,口腔功能间隙面积平均增加了5.67mm2,前下面高平均增加了3.46mm,后面高平均增加了1.90mm。结论:Jasper-Jumper矫治器矫治骨性下颌后缩使口腔功能间隙有明显增大,有利于上下颌骨关系以及口系统功能的完善。

Jasper Jumper矫治器治疗恒牙期骨性Ⅱ类错的疗效观察

目的探讨Jasper Jumper矫治器治疗恒牙期骨性Ⅱ类错的临床疗效。方法对13例恒牙期骨性Ⅱ类错病人应用Jasper Jumper矫治器治疗。通过治疗前后的头影测量对比,分析其疗效。结果 13例病人戴用Jasper Jumper矫治器5～7个月后,下颌均明显前移,下颌后缩面型显著改善。SNB角增大了1.9°;前牙覆盖减小了4.6 mm,其中骨性变化占43.5%;牙性变化占56.5%;磨牙关系改善了4.4 mm,其中骨性占45.5%,牙性变化占54.5%。治疗后Olp-Pg、Ii-OLp、Mi-OLp、覆盖、磨牙关系及SNB角、ANB角与治疗前比较差异均有统计学意义(均P<0.05)。结论 Jasper Jumper矫治器能有效的治疗骨性Ⅱ类错。

Jasper Jumper矫治器治疗儿童安氏Ⅱ^1下颌后缩对颞颌关节的影响

目的:研究JasperJumper矫治器对儿童安氏Ⅱ1下颌后缩患者颞颌关节的影响。方法:随机选择22例处于生长发育期的安氏Ⅱ1下颌后缩儿童应用JasperJumper矫治器治疗,6～8个月后,通过颞下颌关节中位断层片测量、Helkimo指数研究,观察并比较治疗前后儿童颞颌关节改建情况。结果:JasperJumper矫治器治疗期间引起TMD的机率为17.6%。治疗7个月后,关节前间隙平均增加0.85mm,中间隙平均减少0.74mm,后间隙平均减少1.01mm,关节前间隙面积平均增加10.96mm2,关节后间隙面积平均减少9.72mm2,说明关节窝发生了适应性改建。结论:JasperJumper矫治器治疗安氏Ⅱ1下颌后缩儿童过程中对TMJ产生了一定的影响,使之产生了适应性改建。

Jasper Jumper矫治器治疗恒牙早期安氏Ⅱ类远中错的临床体会

目的:探讨Jasper Jumper矫治器治疗安氏Ⅱ类远中错的临床效果。方法:应用Jasper Jumper矫治器治疗9例安氏Ⅱ类错患者,治疗前治疗后进行头影测量分析。结果:9例患者经平均5.36个月治疗后SNA平均减小0.30,°SNB平均增加2.70°,获得Ⅰ类磨牙关系,侧貌明显改善。结论:Jasper Jumper矫治器可与固定矫治器结合使用,装配简便,既可刺激下颌骨的生长同时又可抑制上颌骨的生长,对于恒牙早期Ⅱ类Ⅰ分类错的患者矫治效果明显。

Jasper Jumper矫治器的结构与作用

Jasper Jumper作为对Herbst的改良,具有结构简单,易于取戴、施力和清洁,以及相对增加患者舒适度的优势。本文从Jasper Jumper矫治器的结构和安装使用、矫治产生的力和支抗预备、对于硬组织的改建和软组织侧貌的影响、其它应用及优缺点等几方面作一综述。

操作系统中SPOOLING系统的分析与实现

如何实现低速字符设备与CPU或内存进行合理高效的信息交换是操作系统面临的一个常见问题。本文分析了SPOOLING系统在解决假脱机问题上相对于批处理和脱机方式的优点,并提出了如何在现有操作系统下对假脱机实现的初步构想。

一个MS—DOS的SPOOLing系统

为MS-DOS操作系统设计一个专门的SPOOLing系统,以实现数据处理和I/O处理的并发进行,这是十分必要的。由于中文信息处理系统在I/O 方面的特点,所以这种系统更有必要配置 SPOOLing系统。本文介绍一个基于 MS-DOS的SPOOLing系统的设计和实现,包括它的总体结构、用户界面、数据结构和有关模块的算法。另外还对该系统的进一步升级作了讨论。事实证明,SPOOLing系统可大大提高整个系统的效率。

SPOOL图在管道设计中的应用

回顾配管图的发展历程,结合SPOOL图在国外工程的具体应用,介绍SPOOL图的绘制步骤,阐述SPOOL图的意义及具体应用。

Finite Element Numerical Simulation and PIV Measurement of Flow Field inside Metering-in Spool Valve

The finite element method （FEM） and particle image velocimetry （PIV） technique are utilized to get the flow field along the inlet passage, the chamber, the metering port and the outlet passage of spool valve at three different valve openings. For FEM numerical simulation, the stream function ψ-vorticity ω forms of continuity and Navier-Stokes equations are employed and FEM is applied to discrete the equations. Homemade simulation codes are executed to compute the values of stream function and vorticity at each node in the flow domain, then according to the correlation between stream function and velocity components, the velocity vectors of the whole field are calculated. For PIV experiment, pulse Nd： YAG laser is exploited to generate laser beam, cylindrical and spherical lenses are combined each other to produce 1.0 mm thickness laser sheet to illuminate the object plane, Polystyrene spherical particle with diameter of 30-50 μm is seeded in the fluid as a tracing particles, Kodak ES 1.0 CCD camera is employed to capture the images of interested, the images are processed with fast Fourier transform （FFT） cross-correlation algorithm and the processing results is displayed. Both results of numerical simulation and PIV experimental show that there are three main areas in the spool valve where vortex is formed. Numerical results also indicate that the valve opening have some effects on the flow structure of the valve. The investigation is helpful for qualitatively analyzing the energy loss, noise generating, steady state flow forces and even designing the geometry structure and flow passage.

Optimum Design and Global Analysis of Flexible Jumper for An Innovative Subsurface Production System in Ultra-Deep Water

The study focuses on the flexible jumper issue of Subsurface Tension Leg Production （STLP） system concept, which is considered as a competing alternative system to support well completion devices and rigid risers in ultra-deep water for offshore petroleum production. The paper presents analytical and numerical approaches for the optimum design and global analysis of the flexible jumper. Criteria using catenary concept are developed to define the critical length for optimum design. Based on the criteria, detailed hydrodynamic analyses including quasi-static analysis, modal analysis, and dynamic analysis are performed. Modal analysis with respect to the quasi-static analysis shows that the existence of resonant modes requires special consideration. The results of dynamic analysis confirm the effectiveness of the de-coupled effect from the jumper on STLP system. The approaches developed in the study also have wide application prospect in reference to the optimum design and analysis of any Hybrid Riser （HR） concept.

Optical coherence transfer over 50-km spooled fiber with frequency instability of 2×10^(-17) at 1s

We demonstrate coherent transfer of an ultra-stable optical frequency at 192.8 THz over 50-km spooled fiber. Random phase noise induced by environmental disturbance through fiber is detected and suppressed by feeding a correctional signal into an acousto-optic modulator. After being compensated, the fiber-induced frequency instability is 2×10-17 at 1-s averaging time and reaches 8×10-20 after 16 h. The noise floor of the compensation system could be as low as 2×10-18 at 1-s averaging time.

Thermal-hydraulic modeling and analysis of spool valve with sloping U-shape notch by bond graph

To increase the efficiency and reliability of the thermodynamics analysis of the spool valve, the precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke and thermal-hydraulic bond graph based on the conservation of mass and energy were introduced. Subsequently, the connection rule for the bond graph elements and the method to construct the complete thermal-hydraulic system model were proposed. On the basis of heat transfer analysis of a typical hydraulic circuit containing the spool valve, the lumped parameter for mathematical model of the system was given. At last, the reliability of the mathematical model of the flow area and the thermal-hydraulic system for the sloping U-shape notch orifice on the spool were demonstrated by the test. The good agreement between the simulation results and experimental data demonstrates the validity of the modeling method.

Flow field simulation and establishment for mathematical models of flow area of spool valve with sloping U-shape notch machined by different methods

Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape notch on the spool, such as mass flow rates, flow coefficients, effiux angles and steady state flow forces under different operating conditions. At last, the reliability of the mathematical model of the flow area for the sloping U-shape notch orifice on the spool was demonstrated by the comparison between the orifice area curve derived and the corresponding experimental data provided by the test. It is presented that the bottom arc of sloping U-shape notch （ABU） should not be omitted when it is required to accurately calculate the orifice area of ABU. Although the theoretical flow area of plain bottom sloping U-shape notch （PBU） is larger than that of ABU at the same opening, the simulated mass flow and experimental flow area of ABU are both larger than these of PBU at the same opening, while the simulated flow force of PBU is larger than that of ABU at the same opening. Therefore, it should be prior to adapt the ABU when designing the spool with proportional character.

Investigation into the Independent Metering Control Performance of a Twin Spools Valve with Switching Technology-controlled Pilot Stage

In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.

Subsea rigid jumper design and VIV fatigue evaluation

The purpose of this paper is to present a design procedure for subsea rigid jumper system including strength and fatigue analysis. Special attention gives to a methodology based on DNV-RP-F105 to evaluate jumper fatigue damage caused by vortex induced vibration (VIV). Jumper strength analysis is to determine the jumper con-figuration which can accommodate various load conditions and all possible span lengths driven by installation tole-rances of connected subsea structures. Fatigue analysis includes two parts:thermal fatigue and VIV fatigue. This paper presents the procedure of VIV fatigue damage calculation. An example is given to illustrate above methodologies.

Spooling打印系统的汉化改造

在多用户操作系统的汉化过程中,Spooling打印系统(SPS)的汉化是一项重要工作。本文分析SPS原理,说明其汉化的目标、技术和环境要求。通过介绍一个实例,给出了汉化工作要点和实现技巧。

An optical fiber spool for laser stabilization with reduced acceleration sensitivity to 10^(-12)/g

Environmental vibration causes mechanical deformation in optical fibers, which induces excess frequency noise in fiber-stabilized lasers. In order to solve such a problem, we propose an ultralow acceleration sensitivity fiber spool with symmetrically mounted structure. By numerical analysis with the finite element method, we obtain the optimal geometry parameters of the spool with which the horizontal and vertical acceleration sensitivity can be reduced to 3.25 × 10^-12/g and 5.38 × 10^-12/g respectively. Moreover, the structure features the insensitivity to the variation of geometry parameters,which will minimize the influence from numerical simulation error and manufacture tolerance.

Development of a Novel Parallel-spool Pilot Operated High-pressure Solenoid Valve with High Flow Rate and High Speed

High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system.However,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design.Mathematical models of the opening process and flow rate of the valve are established.Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response.Corresponding formulas to solve 4 parts of the response time are derived.Key factors that influence the opening response time are analyzed.According to the mathematical model of the valve,a simulation of the opening process is carried out by MATLAB.Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve.Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool.The experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is verified.Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa.The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s.According to the result of the load driving test,the valve can meet the demands of the driving system.The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.

Electromagnetic-Wave Mechanism of Formation and Propagation of Astrophysical Vortex Jets Generated in the Jumper of a Spiral Galaxy

An explanation of the mechanism of generation and acceleration of jets in outer space is given on the basis of experiments in the physics of electrical discharge. The presence of two arms in the spiral Galaxy gives grounds to assume that they have excess charges of the opposite sign. At the moment when the electric field strength between the tips of the arms becomes sufficient, an electrical breakdown occurs, which is accompanied by the movement of the current-plasma leader in the jumper between the tips of the arms. In the head part of the leader there is a flat electric domain of a strong field, which, during its inception, emits intense transverse electromagnetic waves in a direction perpendicular to the direction of the leader’s motion and to the plane of the accretion disk. The electric domain periodically appears and collapses due to the entry of neutral particles. Transverse electromagnetic waves capture charged particles from the discharge region and accelerate them in the direction of wave propagation. The crossed fields of an electromagnetic wave perform the functions of a multistage accelerator. The acceleration of the particles of the plasma produced in the discharge to relativistic energy values in the region of narrow vortex jets occurs under the action of forces caused by the components of the electromagnetic wave fields and the pressure gradient. The charged particles of a vortex jet acquire a significant rotational moment under the action of the Lorentz force. Explanations of the generation of microwave, bremsstrahlung and optical radiation from the region of the jumper between the arms of the Galaxy in the absence of electrical breakdown are also given.