Tap试验阴性老年iNPH患者行腰大池置管脑脊液压力持续检测的可行性和必要性

目的:研究腰椎穿刺脑脊液放液试验(Tap试验)阴性老年特发性正常压力脑积水(iNPH)患者行腰大池置管脑脊液压力持续检测的可行性和必要性。方法:回顾性分析2017年1月—2022年7月北京市昌平区医院收治的86例Tap试验阴性老年i NPH患者的资料,所有患者均在Tap试验后行腰大池置管引流术+脑脊液压力测试,然后行脑室-腹腔(VP)分流术治疗,根据不同预后将86例患者分为预后良好组(n=37)和预后不良组(n=49),根据脑脊液压力(CSFP)与颅内压相关系数(RAP)两者联合诊断最佳截断值分为A组(n=35)与B组(n=51)。比较Tap试验阴性老年iNPH患者VP分流术前后简易精神状态评价量表(MMSE)评分、计时-起立-行走测试(TUGT)时间和排尿评分,比较不同预后患者相关指标,绘制ROC曲线分析CSFP、RAP及两者联合预测Tap试验阴性老年iNPH患者VP分流术预后的价值,比较A组和B组步态不稳、认知障碍、排尿障碍改善率。结果:Tap试验阴性老年iNPH患者VP分流术后1个月MMSE评分高于术前,TUGT时间短于术前,排尿评分低于术前,差异有统计学意义(P<0.05)。预后良好组CSFP、RAP均高于预后不良组,差异有统计学意义(P<0.05);两组性别、平均年龄、Hakim三联征症状构成比较,差异无统计学意义(P>0.05)。两者联合诊断曲线下面积(AUC)大于CSFP、RAP单独诊断,差异有统计学意义(P<0.05)。A组术后1个月步态不稳、认知障碍及排尿障碍改善率均高于B组,差异有统计学意义(P<0.05)。结论:Tap试验阴性老年iNPH患者行腰大池置管脑脊液压力持续检测,通过CSFP、RAP可反映脑室内与周围组织对压力梯度的代偿能力和耐受能力,CSFP、RAP越大,VP分流术的效果越好。

圆锥形件充液拉深过程中的上限液池压力

圆锥形零件充液拉深过程中存在两种破裂失效形式──侧壁破裂和凸模肩部破裂，理论分析与数值模拟给出了不产生上述破裂的上限液池压力—行程曲线，该曲线表明拉深初期工件在凸模肩部破裂，此后则在侧壁破裂。试验验证了文中提出的数学模型与模拟方法的有效性。

腰椎穿刺放液试验和腰大池置管脑脊液压力持续测定在特发性正常压力脑积水诊疗中的应用

目的探讨腰大池置管脑脊液压力持续测定与腰椎穿刺放液试验在特发性正常压力脑积水患者中的诊疗价值。方法将50例iNPH患者作研究样本,腰椎穿刺放液试验提示阳性的患者采取脑室腹腔分流术(分流术);对腰椎穿刺放液试验提示阴性的患者,部分采取腰大池置管脑脊液压力持续测定(12 h),试验后接受分流术治疗,分析颅内压波幅与颅内压相关系数值(RAP)在iNPH患者手术筛查中的应用价值。结果50例患者中执行手术者37例,所有患者术后未出现并发症;术后症状改善者31例,未改善者6例。腰椎穿刺放液试验阳性30例,阴性20例;所有阳性患者接受分流术治疗,术后症状改善者28例,未改善者2例。7例腰椎穿刺放液试验阴性者接受腰大池置管脑脊液压力持续测定并行分流术治疗,RAP>0.6者3例,术后症状改善率66.67%;RAP≤0.6者4例,术后症状改善率25.00%;RAP>0.6时患者术后症状改善率高于RAP≤0.6时(P<0.05)。结论针对腰椎穿刺放液试验阴性者予以腰大池置管脑脊液压力持续测定,结果若提示RAP>0.6,则评估此类患者接受分流术治疗同样可取得较确切疗效。

排水泵站泵机组及基础设施大修经验点滴

介绍了大中型立式泵检修中传动轴找正方法，水泵室密封板防渗漏方法和排水泵站压力出水池井盖（人孔）结构改进。

高含藻水净水厂水处理工程研究

针对净水厂重度含藻水污染问题,提出了机械絮凝池与压力溶气气浮池联合工艺,以达到高效处理含藻水的效果,并在对主体构筑物进行设计及设备选型后,对药剂投加量进行了试验研究,结果表明,高锰酸钾投加量为2.5 mg/L,氧化5 min后投加PAC 30 mg/L对藻类、CODMn和浊度的去除效果良好,去除率分别达到62.9%,69.5%和94.5%,减轻了后续处理构筑物负担,研究结果为重度含藻水厂建设和改造提供了参考依据。

轧制差厚板盒形件充液拉深成形工艺参数研究

针对轧制差厚板成形过程中的破裂、起皱以及厚度过渡区移动缺陷,将充液拉深技术引入差厚板盒形件的成形过程,建立了差厚板盒形件有限元模型,进行了差厚板盒形件充液拉深成形仿真,推导了临界液池压力的解析公式。对比分析了压边力、液池压力以及液池压力加载路径对差厚板最大厚度减薄率以及厚度过渡区中心位移量的影响。结果表明,压边力和液池压力对差厚板零件的成形过程均有较大的影响,采用薄-厚侧压边力比为2,最高液池压力为3 MPa的递增型液池压力加载路径1对于提高差厚板的成形性能非常有利。

Development of hydraulic power unit and accumulator charging circuit for electricity generation,storage and distribution

It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to induction motor to drive cylinder loads. During upstroke operation, the variable pump/motor （P/M） driven by both electric motor and the second （P/M） works as hydraulic pump and output flow to the cylinders which drive the load. During load deceleration, the cylinders work as pump while the operation of the two secondary units are reversed, the variable （P/M） works as a motor generating a torque with the electric motor to drive the other （P/M） which transforms mechanical energy to hydraulic energy that is saved in the accumulator. When the energy storage capacity of the accumulator is attained as the operation continues, energy storage to the accumulator is thermostatically stopped while the induction motor begins to work as a generator and generates electricity that is stored in the power distribution unit. Simulations were performed using a limited PT2 Block, i.e. 2nd-order transfer function with limitation of slope and signal output to determine suitable velocity of the cylinder which will match high performance and system stability. A mathematical model suited to the simulation of the hydraulic accumulator both in an open-or close-loop system is presented. The quest for improvement of lower energy capacity storage, saving and re-utilization of the conventional accumulator resulting in the short cycle time usage of hydraulic accumulators both in domestic and industrial purposes necessitates this research. The outcome of the research appears to be very efficient for generating fluctuation free electricity, power quality and reliability, energy saving/reutilization and system noise reduction.

A Method for Calculating Blast Pressure of Failed Lithium-Ion Cells with C-H-O Solvents

Blast pressure of C-H-O solvents on failed lithium-ion cells at the voltage range between 3.8 V and 4.18 V may be calculated by means of the simple semi-empirical equation, y = （Ia ＋ Jb）/（Ka ＋ Lb ＋ Me）, p is the initial density of solvent, Q is the chemical energy of explosion, v is the voltage. The values of a, b, c depend on C-H-O composition. Value of I, J, K, L, Mmay be estimated from the H20-CO2 arbitrary decomposition assumption. Blast pressure derived in this manner can provide preliminary protective estimation and it is compared with experiment results by adiabatic calorimeter.

Photovoltaic Powered Reverse Osmosis Plant for Brackish Water without Batteries with Self Acting Pressure Valve and MPPT

This paper presents a PV （photovoltaic） powered RO （reverse osmosis） plant for brackish water without batteries and a self-regulating pressure valve. The aim is to extract the maximum power from the PV module using an MPPT （maximum power point tracking） technique for powering a solar water pump and maintain constant the pressure in the RO membranes by using the self-operated valve. A Buck type converter using the InCond （incremental conductance） MPPT was developed for this application. The MPPT chosen was simulated, tested and validated, showing an efficiency of 86.8%. The technical feasibility of the RO plant was made by PLC （programmable logic controller） and was tested for two salinity levels （1,000 and 1,500 mg/L of TDS （total dissolved solids））. These salinity levels chosen are commonly found in most brackish water wells of the semi-arid region of Northeastern Brazil. The RO plant could permeate 175.3 L/day of drinking water with 120 mg/L of TDS and specific energy consumption of 2.56 kWh/m3.

Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle--Steam Cycle

A SOFC （solid oxide fuel cell） cycle running on natural gas was integrated with a ST （steam turbine） cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce steam in a HRSG （heat recovery steam generator）. The bottoming steam cycle was modeled with two configurations： （1） a simple single pressure level and （2） a dual pressure level with both a reheat and a pre-heater. The SOFC stacks in the present SOFC-ST hybrid cycles were not pressurized. The dual pressure configuration steam cycle combined with SOFC cycle （SOFC-ST） was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each other to reveal the most superior concept with respect to plant efficiency and power. It was found that in order to increase the plant efficiency considerably, it was enough to use a single pressure with a hybrid recuperator instead of a dual pressure Rankine cycle.

Experimental research on charging characteristics of a pressure-controlled VRLA battery in high-temperature environments

Valve-regulated-lead-acid (VRLA) battery charging performed in high-temperature environments is extremely risky under overcharge conditions, and may lead to a subsequent thermal runaway. A new pressure-controlled charging method was adopted and the charging characteristics of the pressure-controlled VRLA battery in high-temperature environments were ex-perimentally studied. The concept was tested in a large temperature gradient to obtain more details about the effects of users' accustomed charging and discharging modes on battery capacity. The premature capacity loss (PCL) phenomenon under high temperature exposure was analyzed. The results showed that the capacity loss could be recovered by charging using a large current.

Study on performance of PVDF piezoelectric film for the separator in Li-ion rechargeable cell

The properties of piezoelectric PVDF films as separators are studied in NiO/Li electrodes Li-ion power cell.The results show that the PVDF piezoelectric film with excellent insulation is suitable for the environmental energy harvesting application.This is attributable to the compact structure of the piezoelectric PVDF film,and which make it has low leakage current and low charge-discharge current characteristics.

Investigation on Active Thermal Control Method with Pool Boiling Heat Transfer at Low Pressure

In order to maintain a desirable temperature level of electronic equipment at low pressure, the thermal control performance with pool boiling heat transfer of water was examined based on experimental measurement. The total setup was designed and performed to accomplish the experiment with the pressure range from 4.5 kPa to 20 kPa and the heat flux between 6 kW/m^2 and 20 kW/m^2. The chosen material of the heat surface was alu- minium alloy and the test cavity had the capability of varying the direction for the heat surface from vertical to horizontal directions. Through this study, the steady and transient temperature of the heat surface at different pressures and directions were obtained. Although the temperature non-uniformity of the heat surface from the centre to the edge could reach 10℃ for the aluminium alloy due to the varying pressures, the whole temperature results successfully satisfied with the thermal control requirements for electronic equipment, and the temperature control effect of the vertically oriented direction was better than that of the borizontally oriented direction. Moreover, the behaviour of bubbles generating and detaching from the heat surface was recorded by a high-resolution camera, so as to understand the pool boiling heat transfer mechanism at low-load heat flux. These pictures showed that the bubbles departure diameter becomes larger, and departure frequency was slower at low pressure, in contrast to 1.0 atm.