超声引导下腘窝入路坐骨神经和隐神经阻滞在足部负压封闭引流手术中的应用效果研究

目的分析超声引导下腘窝入路坐骨神经和隐神经阻滞在足部负压封闭引流手术中的麻醉效果,为该麻醉方案的推广应用积累临床经验。方法选取2022年3月至2023年12月中山市港口医院收治的140例足踝部清创患者,采用随机数字表法分为对照组(73例,采用腰硬联合麻醉)和研究组(67例,采用超声引导下腘窝入路坐骨神经和隐神经阻滞麻醉)。观察对比两组患者的运动神经与感觉神经麻醉效果、不良反应发生情况,以及麻醉前和麻醉后10 min的生命体征指标情况。结果研究组患者运动神经与感觉神经的麻醉起效时间均短于对照组,麻醉持续时间均长于对照组;与麻醉前比,麻醉后10 min两组患者收缩压、舒张压、心率水平均降低,但研究组均高于对照组;研究组患者不良反应总发生率低于对照组(均P<0.05)。结论对于接受足部负压封闭引流术的患者而言,采用超声引导下腘窝入路坐骨神经和隐神经阻滞能够展现出良好的麻醉效果,且患者围术期生命体征更为平稳,不良反应发生风险较低。

文丘里施肥器喉部负压的影响因素分析

为了了解文丘里施肥器的工况特性,通过理论分析与试验测定,研究了进、出口压力,喉部水流流速和局部水头损失系数对喉部负压的影响及变化规律。喉部负压的变化随进口压力的增大呈负相关线性函数递减,当喉部负压降到最低值-0.09 MPa后,进口压力的增大将不再影响喉部负压变化;出口压力对水流通过喉部有阻滞作用,从而影响喉部负压的产生。出口压力越大,喉部负压的产生以及达到最小负压所需的进口压力越大;喉部水流流速对喉部负压的产生及变化与进口压力对其影响相似;对于不同的局部水头损失系数ξ1和ξ2,ξ值越大,喉部负压随进口压力的增大而降低的速度越缓慢,达到最小值-0.09 MPa时所需的进口压力越高。

全程负压浅部吸痰联合气管内滴药在喉癌术后护理中的应用及探讨

目的分析全程负压浅部吸痰联合气管内滴药在喉癌术后护理中的应用效果。方法方便选取2016年3月—2017年12月于该院实施喉癌术的54例患者作为研究对象,回顾性分析所有患者的病历资料,按照护理方式的不同将患者分成两组,一组采用常规护理措施,为对照组,一组实施全程负压浅部吸痰联合气管内滴药护理,为研究组,每组27例,对比分析两组患者的护理效果。结果研究组患者一次性导管洁净度达2分的患者占比77.78%(21例),高于对照组的51.85%(14例),两组数据比较差异有统计学意义(χ2=3.978 9,P<0.05);研究组患者肺部感染等不良事件的发生率为7.41%(1例),明显低于对照组的29.63%(8例),组间数据比较差异有统计学意义(χ2=4.418 3,P<0.05);研究组患者的治疗依从性为92.59%(25例),护理满意度为96.30%(26例),对照组患者的治疗依从性为70.37%(19例),护理满意度为74.07%(20例),两组数据比较差异有统计学意义(χ2=4.418 2、5.282 6,P<0.05)。结论喉癌术后患者实施全程负压浅部吸痰联合气管内滴药可有效减少术后并发症,并保持导管清洁度,患者的护理依从性和满意度也更高,该联合护理方式在喉癌术后患者的护理中具有较高的应用价值。

一类超越方程根皆具负实部的条件

一、引言与引理以λ为未知数的超越方程det(a_(ij)+b_(ij)e^((-λ)_τ_(ij))+λC_(ij)e^(λrij)-δ_(ij)λ)=0 (1)

关于带参数六次代数方程有一对纯虚根且剩根均具有负实部的一个充要条件

本文绷带出了带参数六次代数方程：ｆ（ｘ）＝ｘ＾６＋ａ１ｘ＾５＋ａ３ｘ＾４＋ａ３ｘ＾３＋ａ５ｘ＋ａ６＝０有一对纯虚根且剩余根均具有负实部的一个充要条件。

全程负压浅部吸痰联合气管内滴药在喉癌术后护理中的应用效果

目的探讨全程负压浅部吸痰联合气管内滴药在喉癌术后护理中的应用效果。方法选择2017年1月~2019年6月我院收治的采用全程负压浅部吸痰联合气管内滴药术后护理的喉癌30例患者作为观察组,以同期我院收治的术后行常规人工排痰30例喉癌患者作为对照组。比较两组护理不良事件总发生率、一次性气管导管清洁度评分、吸痰依从率、满意度评分。结果观察组护理不良事件总发生率为6.67%,低于对照组的30.00%,差异有统计学意义(χ2=4.007,P<0.05)。观察组一次性气管导管清洁度评分高于对照组,差异有统计学意义(t=17.146,P<0.05)。观察组吸痰总依从性为93.33%,高于对照组的66.67%,差异有统计学意义(χ2=5.104,P<0.05)。观察组满意度评分高于对照组,差异有统计学意义(t=25.781,P<0.05)。结论在喉癌术后护理中应用全程负压浅部吸痰联合气管内滴药有利于保持导管清洁度,降低护理不良事件发生率,提升患者依从性与满意度,具有推广使用的临床价值。

文丘里施肥器能量转化关系

为了深入了解文丘里施肥器喉部负压的产生条件和变化过程,通过对进出口和喉部分别有测压设计的文丘里施肥器进行有压过流试验,研究了水流在不同特征断面处的能量转化关系.对于试验用文丘里施肥器,试验结果表明:当压力水流通过时,进口处的压能将转化成喉部处的动能,随着进口压能和流量的不断增大,喉部动能增大,喉部的压能完全消失,局部开始产生负压,负压达到最小值后,继续增大进口压力水头将不再引起喉部负压值的变化,但流速的增幅明显增大,喉部动能随流量的增加呈抛物线形趋势增大,产生的水头损失急剧增大;对于同一流量,喉部实际流速与理论流速的差异反映了喉部对应断面处的真空空间的大小;相对于自由出流,非自由出流条件下,喉部开始产生负压时对应的进口起点压力提高,流量相对较大,产生相同负压时的进口压力和流量明显高于自由出流条件.

关于解析函数的一些注记

设h(r,s,t)为定义在D(?)C^3上的复函数,通过限定h(r,s,t)的条件定义了函数类H_n(a),并利用其得到判断具有负实部函数的定理,给出其在微分方程方面的应用.

方程 λ(1+ ce^(-τλ)+a+ be^(-τλ)= 0所有根具有负实部的充要条件

考虑方程λ（１＋ｃｅ^（－τλ）＋ａ＋ｂｅ^（－τλ）＝０，（２）其中ａ，ｂ和ｃ为任意常数，τ为正常数，ｃ≠０．方程（１）为中立型方程 ｘ（ｔ）＋ｃｘ（ｔ－τ）＋ａｘ（ｔ）＋ｂｘ（ｔ－τ）＝０ （２）的特征方程．方程（１）为一常见的拟多项式方程．关于拟多项式函数， Ｐｏｎｔｒｙａｇｉｎ在 １９４２年给出了判断这类函数所有零点位于左半复平面的充要条件．但对中立型方程来说，由于这些条件往往难以验证，使得人们长期以来无法用Ｐｏｎｔｒｙａｐｉｎ定理找出方程（１）所有根具有负实部的充要条件．本文在克服了上述困难后，用Ｐｏｎｔｒｇｉｎ定理找出方程（１）所有根具有负实部的充要条件．

Study on Electromagnetic Force and Vibration of Turbogenerator End Windings under Impact Load(Ⅰ): Analysis of Electromagnetic Force of End Windings under Impact Load

In this paper, the boundary value problem (BVP) of 3 D transient eddy current field in the end region in the case that the generator is affected by impact load is specified. Besides, ways to implement discrete methods in both time domain and space domain during the solution of the problem are investigated. The Crank Nicolson scheme is utilized to attain the iterative format of time differential, after taking factors that can ensure both computation precision and stability into consideration. In this paper, the magnetic distribution in the end region of a turbogenerator in the case that the generator is affected by impact load is specified. As a result, it provides foundation for further study of electromagnetic force and electromagnetic vibration in the end region of the turbogenerator.

Study on Electromagnetic Force and Vibration of Turbogenerator End Windings under Impact Load(Ⅱ): Analysis of Vibration of End Windings under Impact Load

On the basis of the study of transient eddy current field in the end region of turbogenerator and electromagnetic force of end region winding, this paper analyzes the electromagnetic vibration of the turbogenerator roundly. A 320 MW turbogenerator is taken as an example to specify the electromagnetic force of end region winding and therefore the vibration in the case that the generator is affected by impact load. Some conclusions are drawn on the basis of the specification. Vibration of windings under imaginary faults is simulated, so that the vibration law of the end winding of turbogenerator can be studied further. On the basis of this, the countermeasure against winding vibration can be advanced.

Rural Carbon Emissions Based on Community Management

Rural community is an effective way to simultaneously achieve manage- ment of ecological resources and protection of natural resources, depending on its management mode based on cooperation, motivation, local experiences and extensi- ble boundary. In the research, carbon emission in community is a kind of ecological resources and negative externality is the cause of increase of rural carbon emission. Compared with governmental ruling and marketing approach, community manage- ment mode proves more effective to solve the problem of negative externality of carbon emission in community. Furthermore, rural carbon, emission was analyzed in detail on basis of community management mode and extending mode of carbon emis- sion in rural areas. In addition, some policies and suggestions were proposed to im- prove community management of carbon emission in rural areas, providing an ef- fective way for low-carbon economy in rural areas.

Effect of exhaust gas recirculation and intake pre-heating on performance and emission characteristics of dual fuel engines at part loads

Achieving simultaneous reduction of NOx,CO and unburned hydrocarbon(UHC) emissions without compromising engine performance at part loads is the current focus of dual fuel engine research.The present work focuses on an experimental investigation conducted on a dual fuel(diesel-natural gas) engine to examine the simultaneous effect of inlet air pre-heating and exhaust gas recirculation(EGR) ratio on performance and emission characteristics at part loads.The use of EGR at high levels seems to be unable to improve the engine performance at part loads.However,it is shown that EGR combined with pre-heating of inlet air can slightly increase thermal efficiency,resulting in reduced levels of both unburned hydrocarbon and NOx emissions.CO and UHC emissions are reduced by 24% and 31%,respectively,The NOx emissions decrease by 21% because of the lower combustion temperature due to the much inert gas brought by EGR and decreased oxygen concentration in the cylinder.

甲醇电氧化过程中恒电流模式下电位振荡分析

研究了甲醇电氧化体系的交流阻抗与循环伏安响应特征,分析了恒电流电位振荡的特点。循环伏安曲线中,在正扫描方向有三个氧化峰和一个肩峰,反扫时出现一个不对称氧化峰,认为在该氧化峰低电位一侧存在一个隐藏的氧化峰。交流阻抗图谱对施加电位十分敏感,随着频率降低,施加电位为0.1V时Nyquist图上阻抗点以顺时针方式出现,在0.12V时则以逆时针方式出现,即,阻抗实部在非零有限频率下可以变成负值。在0.13V下阻抗的特征更加复杂。恒流模式下发现电极电位振荡现象,先后出现单周期、双周期、四周期、五周期和六周期振荡行为。恒电流早期出现的振荡周期在1～10s数量级,而恒电流测试后期的振荡行为周期达到26s,振幅可达到0.15V以上。

Parallel Operation Characteristics Analysis of Sewage Source Heat Pump Units in Winter

Sewage source heat pump unit operates under partial load most of the time, and study on the law of coefficient of performance (COP) of the unit varying with load ratio can provide basis for the heat pump units running in high efficiency. A mathematical model determining COP, evaporation temperature and condensation temperature of a single unit was proposed. Under the condition of uniform load distribution, the model was established according to different ways of bearing partial load with the same type multi...

端弯矩和横向力作用下工字钢梁的整体稳定性

现行钢结构设计规范有关钢梁整体稳定计算的条文基于简支梁的分析,对梁端为刚性以及半刚性的情况未作考虑。本文基于上述事实对端部负弯矩和横向荷载共同作用下的钢梁弯扭屈曲进行研究,得到形式简单的回归公式,供设计人员参考。

某类高阶、高维非线性非自治系统的零解的全局稳定性

本文对某类高阶、高维非线性非自治系统的零解全局渐近稳定性进行讨论,得到了零解全局稳定的某些判别公式。本文的结论推广了文[2]的结果。

Response of Box-Type Structures Under Internal-Blast Loading

The tests of box-type structures under internal-blast loading are carried out. Then a numerical analysis of the test structures is done using a fully coupled numerical finite element model. The break-up process of the structure is simulated. The failure modes of the simulated structure agree well with the experimental results. The effects of the size of the reinforcing bars and the detailing of connections among the rebars in the concrete on the throw velocity of the fragments are discussed.