新型防压疮病号服48例临床应用观察

目的:介绍一种卧床病人防压疮病号服(简称防压疮病号服),并观察临床应用效果。方法:自行设计并制作防压疮病号服。选择在我科住院卧床患者96例,分观察组和对照组(各48例),观察组着防压疮病号服,对照组着普通病号服,两组均不使用气垫床,给予相同的其它预防压疮措施,观察两组患者压疮发生率、患者满意度及护士满意度。结果:观察组压疮发生率为0%,对照组465例发生压疮,其中I期压疮3例,Ⅱ期压疮1例,压疮发生率为8.3%。观察组压疮发生率明显低于对照组,组间比较,差异有统计学意义(P<0.05)。两组意识清晰伴偏瘫患者对防压疮病号服和普通病号服的总满意度分别94.3%和17.6%。防压疮病号服在神经疾病科卧床患者使用后护士满意度为100%。结论:防压疮病号服可降低患者压疮发生率,穿着方便、节力、省时、便于操作,可提高病人及护士的满意度,利于医护人员各项治疗护理操作和病情观察,值得推广应用。

抗压防护服设计构想及应用展望

针对灭火和抢险救援过程中因建筑坍塌引发消防官兵伤亡的事故频频发生的现况,结合高压气体的受力、传力特点,提出了多级气囊缓冲式抗压防护服的设计构想;探讨了抗压防护服的材料选择和各主要部分的设计,分析了多级气囊缓冲式抗压防护服在实际灭火和抢险救援工作中得到运用的可能性,为灭火和抢险救援过程中消防人员的安全提供一定的保障。

河南省城市社区卫生服务利用现状

目的了解河南省城市社区慢性病监测网络中高血压、糖尿病患者对社区卫生服务的利用情况。方法对河南省城市社区慢性病监测试点的高血压、糖尿病患者进行面对面问卷调查。结果1/3以上的高血压、糖尿病管理患者将社区作为知识获取的第一途径;对社区卫生服务基本满意率为92.9%;6个月内到社区就诊率平均为64.6%;86.0%的高血压患者和54.1%糖尿病患者能做到1月内定期测量血压和检测血糖;60%的管理患者选择社区就诊;80.03%以上的管理患者接受了药物性治疗,有56.7%～82.3%的管理患者接受了非药物性治疗服务。结论要积极推广社区高血压、糖尿病综合防控适宜技术,加强患者规范管理,提升社区卫生服务能力,促进居民对社区卫生服务的利用。

High strength magnesium alloy with α-Mg and W-phase processed by hot extrusion

Fine-grained Mg-6Zn-4Y alloy was prepared by an ingot metallurgy process with hot extrusion at 300 ℃.The microstructure was studied by XRD,OM,SEM and TEM,and the tensile properties were tested at room temperature.The results show that the alloy is composed of α-Mg and W-phase.The microstructure of the as-extruded alloy has a bimodal grain size distribution.The fine grains with the mean size of 1.2 μm are formed by dynamic recrystallization.The coarse grains（about 23% in area fraction） are unrecrystallized regions which are elongated along extrusion direction.The engineering stress—strain curve shows a pronounced yield point.The ultimate tensile strength,yield strength,and elongation are（371±10） MPa,（350±5） MPa and（7±2）%,respectively.The high strengths are attributed to the fine-grained matrix structure enhanced by W-phase particles,nano-scaled precipitates,and strong basal plane texture.

Mathematical Model Analysis of Quasi Preconsolidation Soft Clay

Soft clay may cause quasi preconsolidation effect under the constant hydrostatic pressure after some time. The result of drained triaxial test represents the effective stress yield surface, which can be described by simple binary linear fabric model. Therefore the pore pressure and deformation of clay can be decided. It also can be used to resolve the real boundary problems with finite element method.

Mechanical properties of strengthened surface layer in Ti-6Al-4V alloy induced by wet peening treatment

A modified surface layer was formed on Ti-6Al-4V alloy by wet peening treatment. The variations of the residual stress,nano-hardness and microstructure of the modified layer with depth from surface were studied using X-ray diffraction analysis,nano-indentation analysis, scanning electron microscopy and transmission electron microscopy observations. The results show thatboth the compressive residual stress and hardness decrease with increasing depth, and the termination depths are 160 and 80 μm,respectively. The microstructure observation indicates that within 80 μm, the compressive residual stress and the hardness areenhanced by the co-action of the grain refinement strengthening and dislocation strengthening. Within 80–160 μm, the compressiveresidual stress mainly derives from the dislocation strengthening. The strengthened layer in Ti-6Al-4V alloy after wet peeningtreatment was quantitatively analyzed by a revised equation with respect to a relation between hardness and yield strength.

Use of piezocone tests to predict consolidation yield stress and overconsolidation ratio of lagoonal deposit soil

Existing empirical methods for interpreting the consolidation yield stress and the overconsolidation ratio （OCR） in clays from piezocone tests are briefly reviewed. It can be seen that no universal correlation exists for all worldwide sites. However, for a given clay deposit, there does exist a most appropriate method to reflect the consolidation yield stress and the OCR based on piezocone test data. Three empirical methods are compared based on the piezocone test data collected on Lixia River lagoonal deposit soil sites in the north of Jiangsu province. The objective of this study is to evaluate the validity of the existing relationships linking the consolidation yield stress to piezocone test data and identify the appropriate method for Lixia River lagoonal deposit soil. It is shown that the correlation based on the net tip resistance has much higher accuracy for estimating the consolidation yield stress of lagoonal deposit soil than other methods.

Measurement and control system for servo pressure pulse testing equipment

Servo pressure pulse testing equipment uses servo-hydraulic technology to build the model of hydraulic system. By improving measurement and control system, the equipment accomplishes signal acquisition, data processing and process con- trol. LabVIEW and programmable logic controller （PLC） are used to carry out the hardware configuration and software de- velopment. The system can communicate between LabVIEW and PLC by virtual instrumentation software architecture （VI- SA） and run automatically in accordance with setting commands. Therefore, accuracy and performance of the equipment are improved.

Evaluation of Relationship Between Clothing Pressure of Men's Suit and Comfort

An investigation on relationship between clothing pressure of men's suit and wearing comfort is conducted. With the pressure measurements at different parts of men's suit under normal standing posture and in motion, the objective assessment of the total comfort are related to the subjective ratings of clothing pressure. There is a common strong sensation of pressure on shoulder with normal standing posture, and a strong relationship between total comfort and clothing pressure in back armhole and the front of upper arm with posture in motion.

Effect of Garment Pressure on Peripheral Skin Blood Flow(SBF)

To well understand the effect of garment pressure on skin blood flow(SBF) at lower limb,external pressures of various magnitudes were exerted on lower limb in supine or sitting postures respectively using sphygmomanometer.Five male subjects volunteered to participate in this study.An alternating pressure loading protocol between non-pressure and pressure was employed.The SBF was observed by laser flowmeter.No matter the subjects being sitting or supine,SBF obviously increased under low pressure;as the pressure increasing,it turned to decrease.Moreover,while lying supine,SBF turned to decrease under lower pressure than sitting;SBF at calf turned to decrease under lower pressure than at ankle.It was also confirmed that the increment of SBF was obviously higher when the pressure of the same magnitudes was exerted at ankle than at calf.The pressure around 5.32 kPa was confirmed to be a crucial value to SBF.The findings will be helpful in design and application of tight-fit garments.

Active disturbance rejection control for hydraulic width control system for rough mill

The highly nonlinear behavior of the system limits the performance of classical linear proportional and integral （PI） controllers used for hot rolling. An active disturbance rejection controller is proposed in this paper to deal with the nonlinear problem of hydraulic servo system in order to preserve last response and small overshoot of control system. The active disturbance rejection （ADR） controller is composed of nonlinear tracking differentiator （TD）, extended state observer （ESO） and nonlinear feedback （NF） law. An example of the hydraulic edger system case study is investigated to show the effectiveness and robustness of the proposed nonlinear controller, especially, in the circumstance of foreign disturbance and working condition variation, compared with classic PI controller.

High precise control method for a new type of Piezoelectric electro-hydraulic servo valve

A new type of piezoelectric electro-hydraulic servo valve system was proposed. And then multilayer piezoelectric actuator based on new piezoelectric ceramic material was used as the electricity-machine converter of the proposed piezoelectric electro-hydraulic servo valve. The proposed piezoelectric electro-hydraulic servo valve has ascendant performance compared with conventional ones. But the system is of high nonlinearity and uncertainty, it cannot achieve favorable control performance by conventional control method. To develop an efficient way to control piezoelectric electro-hydraulic servo valve system, a high-precise fuzzy control method with hysteresis nonlinear model in feedforward loop was proposed. The control method is separated into two parts: a feedforward loop with Preisach hysteresis nonlinear model and a feedback loop with high-precise fuzzy control. Experimental results show that the hysteresis loop and the maximum output hysteresis by the PID control method are 4.22% and 2.11 μm, respectively; the hysteresis loop and the maximum output hysteresis by the proposed control method respectively are 0.74% and 0.37 μm, respectively; the maximum tracking error by the PID control method for sine wave reference signal is about 5.02%, the maximum tracking error by the proposed control method for sine wave reference signal is about 0.85%.

Mechanical characteristics of intact Middle Pleistocene Epoch loess in northwestern China

In order to research the mechanical characteristics of intact Middle Pleistocene Epoch loess, triaxial shear tests and isotonic compression test of intact Middle Pleistocene Epoch loess were conducted by improved SJ-IA triaxial shear equipment. According to test results, it can be found that the intact Middle Pleistocene Epoch loess has the properties of shear dilatancy and shear shrinkage. With the increase of confining pressure, stress-strain curve develops from softening to hardening. The failure mode of intact Middle Pleistocene Epoch loess is shear failure with the rupture angle between 55° and 61°. And it is better to determine the yield stress （py, qy） of the intact loess under different confining pressures by using the εv-q/p curve. Along with the increase of confining pressure, yield deviatoric stress qy and yield spherical stress py present logarithmic relationship. Besides, the strength parameters, elastic modulus K and G of intact loess, are obtained, which are benefit for loess projects design.

Numerical and experimental investigation of leakage behavior at null position of high-pressure electro-pneumatic servo valve

The high-pressure electro-pneumatic servo valve(HESV)is a core element of the high-pressure pneumatic servo system.The annular clearance and the rounded corner of the spool-sleeve can cause the leakage at null position,thereby affecting high-precision control and stability of the servo system.This paper investigates the effects of the clearance structure on leakage behavior at null position of the HESV.A numerical approach was employed to evaluate the effects,and then a mathematical model was established to obtain the variation law of leakage flow rate at null position.The results indicate that the leakage flow rate at null position varies linearly with supply pressure and rounded corner radius,and is nonlinear as a quadratic concave function with annular clearance.The leakage flow rate of the annular clearance and the rounded corner varies with the valve opening in an invariable−nonlinear−linear trend.A test rig system of leakage behavior at null position of the HESV was built to confirm the validity of the numerical model,which agrees well with the conducted experimental study.

Analysis of nonlinearities and effects in direct drive electro-hydraulic position servo system

The direct drive electro-hydraulic servo system is a new approach hydraulic system. It is much smaller and easier controlled than traditional systems and is a perfect energy saver. This paper will briefly introduce the popular nonlinearities in the electro-hydraulic system and analyse the effect of nonlinearities in direct drive electro-hydraulic position servo system by means of simulation research. Some valuable conclusions are given.

Customer participation in the service encounter

This paper considers the role of service customers in those service encounters where the customer participates in the service production and delivery process, and the customer factors, motivations and incentive mechanism to participate in service delivery are analyzed. This study explores the relationship between service quality and service customer participation in the service encounter and the effect of customer participation on service providers＇ job stress. Finally, the management implications about customer participation in the service encounter from the findings are discussed.

Work characteristic analysis of single-rod symmetric cylinders

Hydraulic cylinders are divided into single-rod asymmetric cylinders and double-rod symmetric cylinders. The single-rod asymmetric cylinder has the advantages of small size and simple structure,but its speed characteristic is not symmetric. The double rod symmetric cylinder has the characteristic of symmetric speed,but it cannot be used in some special occasions. In this paper,one special hydraulic cylinder,a single-rod symmetric cylinder,is developed. Firstly,characters of this type of cylinder are introduced. Then,the system model is constructed by using one software which is Simulation X. Moreover,one single rod asymmetric cylinder is designed and the test rig using the symmetric valve to control single-rod symmetric or asymmetric cylinder is constructed. Both of the simulation and experimental results show that the symmetric valve control single-rod symmetric cylinder servo system is of symmetric speed characteristic,which can be used in practical occasion.

Pressure impact characteristic of vane type continuous rotary motor under different buffer structures

In order to solve the problem of pressure shock on the continuous rotary electro-hydraulic servo motor,the mathematical models of pressure gradient under the structure of pre-compressed chamber and U-shaped groove were established.The optimal structure dimensions of the pre-compressed chamber and the U-shaped groove were determined.The fluid models were established by Solidworks under the four structures of triangular groove,triangular groove with pre-compression chamber,U-shaped groove and U-shaped groove with pre-compression chamber.Simulation analysis of depressurization process of fluid models was performed based on FLUENT.The pressure nephograms of different buffer structures were compared and analyzed,and the pressure change curves and pressure gradient change curves in the process of depressurization were obtained.The results show that the optimal edge length of the pre-compressed chamber of continuous rotary electro-hydraulic servo motor is 20 mm in the process of decompression.The pressure reduction effect is the best when the width of the U-shaped groove is 1.5 mm and the depth is 1.65 mm.The U-shaped groove structure with pre-compression chamber is more conducive to alleviate the pressure shock phenomenon of the motor compared with different combine buffer structures.

Annealing hardening and deformation behavior of layered gradient Zr–Ti composite

To investigate potential strengthening approaches,multi-layered zirconium–titanium(Zr-Ti)composites were fabricated by hot-rolling bonding and annealing.The microstructures of these composites were characterized using scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS)and electron backscatter diffractometry(EBSD).Their mechanical properties were evaluated by uniaxial tension and compression measurements.It was found that the fabricated Zr–Ti composites are composed of alternating Zr/diffusion/Ti layers,and chemical compositions of Zr and Ti showed a gradient distribution in the diffusion layer.Compared with as-rolled samples,annealing can strengthen the layered gradient Zr–Ti composite,and this is mainly caused by solid-solution strengthening and microstructure refinement-induced strengthening.Compared with the raw materials,a synergistic improvement of strength and ductility is achieved in the Zr–Ti composite as a result of the layered gradient microstructure.Tension–compression asymmetry is observed in the Zr–Ti composites,which may be attributed to twinning and microvoids induced by unbalanced diffusion.