水泵排量法测涌水量的改进

根据物理知识进行简单操作和计算,解决了部分工作面涌水量难以准确观测的问题,对完善水文日常工作起到一定的作用。

排量法测定密度方法的改进

排量法测定密度方法的改进梁宏斌，郝志峰，唐宗薰（西北大学化学系，西安７１００６９）测定盐、配合物等固体的密度，排量法是一种常用方法，传统的排量法存在一些局限，因而结合实际工作，我们对传统的排量法进行了改进。１传统排量法的局限采用传统的排量法测定固体密...

应用动脉压力波形心排量监测法监测妊娠合并重度肺动脉高压孕妇剖宫产术中血流动力学变化规律

目的:观察动脉压力波形心排量监测法(arterial pressure-based cardiac output,APCO)监测下,妊娠合并重度肺动脉高压孕妇剖宫产术中血流动力学变化规律及APCO在该类患者的临床应用。方法:妊娠合并先天性心脏病(先心病)重度肺动脉高压行择期剖宫产术患者30例,所有患者术中均采用APCO监测。均采用连续硬膜外麻醉,用药按照缓慢、分次给药、逐渐扩散麻醉平面的原则。记录各观察时点的脉搏氧饱和度(SpO2)、HR、中心静脉压(CVP)、SBP、DBP、平均动脉压(MAP)、心排量(CO)、心脏指数(CI)、每搏量(SV)、心搏指数(SVI)、体循环阻力(SVR)及体循环阻力指数(SVRI)。结果:与硬膜外给药前相比,硬膜外给药3min后HR、SpO2、CVP及CO无明显变化,但BP、SVR下降(P<0.05)。与胎儿娩出前相比,胎儿娩出后、子宫体注射缩宫素10U(T6)时,BP、SpO2、SVR降低及HR、CO增加等变化均差异有统计学意义(P<0.05),但CVP的变化并差异无统计学意义(P>0.05)。给予缩宫素2min后,以上变化更为明显。结论:该类患者剖宫产术血流动力学变化主要发生在连续硬膜外麻醉起效阶段以及胎儿娩出前后,主要表现为SVR和SpO2下降。APCO监测,因其微创及不受心内分流影响具有较高的可行性与可信度,适用于妊娠合并先心病重度肺动脉高压者的围术期监测。

排量控制循环压井工艺技术的实践与应用

随着勘探开发的难度加大,储层深度不断增加,给后期井筒作业增加了难度,向压井作业提出了新的三大挑战。压井在钻井、试油行业中起着举足轻重的作用,随着工艺技术进步,给压井作业带来了新的挑战,以往压井过程以节流压力为控制对象进行压井,而出口压力的影响因素很多,压力能否和入井压井液数量相匹配难以判断,因此提出一种以排量为控制对象进行节流循环压井的观点。

象山港溶解无机氮环境容量研究

综合考虑凫溪、颜公河、郭巨大碶等10个陆源污染物入海口的影响,建立了象山港三维水质模型并对该海域溶解无机氮(Dissolved Inorganic Nitrogen,DIN)时空分布进行了数值模拟。结合象山港海域功能区划要求,通过调整各入海口DIN最低排海浓度(Rmin)的取值范围设置了四类情境,基于排海通量最优化法计算了对应情境下象山港DIN的环境容量。结果表明,象山港DIN环境容量随Rmin的增大而减小,其范围介于127.16~274.17 t/a;同时Rmin的增大也导致各入海口DIN排海通量需要削减,按削减优先程度,可将各入海口划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四级,入海口所处海域水体半交换时间越长、DIN年排海通量越大,相应的削减优先程度越高。

小剂量容量负荷试验对脓毒性休克患者容量反应性的预测价值

目的:探讨小剂量容量负荷试验对脓毒性休克患者容量反应性的预测价值。方法:选择佛山市禅城区中心医院2017年1月至2019年12月收治的51例脓毒性休克患者为研究对象,对所有患者进行脉搏指示连续心排量测定法(PiCCO)监测血流动力学指标。记录每搏量(SV),分析输注100 mL胶体后SV(ΔSV100)与输注500 mL胶体后SV(ΔSV500)的相关性,ΔSV100的灵敏度与特异度使用受试者工作特征曲线(ROC)进行分析。结果:在接受100 mL及500 mL容量负荷试验后,ΔSV100与ΔSV500呈正相关性(r=0.843,P<0.01),ΔSV100预测容量反应性的ROC曲线下面积为0.779,95 % CI(0.652,0.907),P=0.000,以ΔSV100≥8.3 %为最佳截断值,灵敏度为0.778,特异度为0.603。结论:小剂量容量负荷试验可预测脓毒性休克患者的容量反应性,与传统容量负荷试验有良好的相关性。

脉搏指示连续心排血量法测定婴幼儿心内直视围手术期血流动力学变化的临床意义

目的临床应用脉搏指示连续心排血量法(PiCCO),初步研究和探索婴幼儿三种常见先天性心脏病(简称先心病)[室间隔缺损(VSD)、室间隔缺损合并肺动脉高压(PH)、法洛四联症(TOF)]患者围手术期心排血量、血管内容量、血管外肺水、肺血管通透性等血流动力学参数,为进一步提高危重先心病的手术成功率提供更为客观、直接的依据。方法前瞻性连续选取浙江大学附属儿童医院2010年8月至2011年6月经体外循环心内直视根治手术的0～3岁先心病患儿30例为研究对象。其中TOF10例,VSD10例,VSD+PH10例。连续测定和记录所有患儿术后0h、4h、8h、12h、24h、48h、72h的血流动力学变化,包括心指数(CI)、全心舒张末期容积指数(GEDVI)、血管外肺水指数(EVLWI)、肺血管通透性指数(PVPI)等。抽血检测术前、术后4h、24h、48h、72h的血浆CK-MB活性、CK-MB质量、肌钙蛋白水平,同时监测和记录左心房压(LAP)、中心静脉压(CVP)、平均肺动脉压(mPAP)、肺血管阻力指数(PVRI)、血管活性药评分、血乳酸和PaO2/FiO2。结果 (1)30例患儿中男18例,女12例,VSD、VSD+PH、TOF患者各10例,均顺利出院。(2)三组患者围手术期CK-MB活性、CK-MB质量、肌钙蛋白均于CPB术后4h达到最高值,后逐渐下降恢复。(3)三组患者术后8～12hCI相对最低,但与术后0h比较无统计学差异,VSD+PH组和TOF组术后48hCI值均较术后0h显著上升(P<0.05)。TOF组患者在术后各时点的CI均低于VSD组(P<0.05)和VSD+PH组(P<0.05)。(4)所有3组患者术后各时点的mPAP和PVRI与术前比较均无统计学差异;组间比较显示VSD+PH组患者术前和术后的mPAP和PVRI均显著高于VSD组和TOF组同时点的水平(P<0.05)。(5)TOF组、VSD+PH组患者术后早期GEDVI均显著低于VSD组(P<0.05)。与术后0h相比,VSD组患者术后12h的GEDVI显著增加恢复(P<0.05),TOF组术后24h的GEDVI开始显著增加(P<0.05),VSD+PH组患者GEDVI于术后48h显著增加恢复(P<0.05)。(6)组间比较显示术后48h时,VSD+PH组EVLWI显著高于TOF组(P<0.05),而TOF组EVLWI显著高于VSD组(P<0.05);VSD组术后24h和48h的PVPI显著低于VSD+PH组和TOF组(P<0.05)。结论微创的PiCCO法揭示了三种先心病心内直视根治术后的详细的血流动力学特征,包括CI、GEDVI、EVLW、SVRI、PVRI等参数,具有指导临床正确判断和有效治疗的意义。

Experimental study on the properties of CMTs-incorporated geopolymers prepared at low temperatures

Considering that copper mine tailings(CMTs)are commonly mixed with ordinary Portland cement,fly ash(FA),and kaolin to produce geopolymers,to make full use of CMTs,the properties of geopolymers manufactured under different material mass ratios and curing methods(standard curing,water bath curing,and 60℃curing)are evaluated with significantly increased dosage of CMTs.Porosity and unconfined compressive strength tests,X-ray diffraction,field emission scanning electron microscopy,and energy dispersive spectroscopy are used to determine the physical and mechanical properties,microstructure,and mineral composition of geopolymers.Finally,costs and CO 2 emissions of specimens with different material mass ratios during the preparation processes are compared.The results show that during the geopolymerization of low-calcium materials,various geopolymer gels,including calcium silicate,calcium silicoaluminate,and mainly sodium silicoaluminate gels,coexist.The solid waste,cost,and carbon dioxide emission reductions can reach 100%,166.3 yuan/t,and 73.3 kg/t,respectively.Under a curing condition of 60℃,the sample with a CMTs mass fraction of 70%and an FA mass fraction of 30%meets the requirements of porosity,compressive strength.The resource utilization of CMT and FA is realized in a more economical way.

Multi-attribute decision-making based on subjective and objective integrated eigenvector method

An integrated approach is proposed to investigate the fuzzy multi-attribute decision-making （MADM） problems, where subjective preferences are expressed by a pairwise comparison matrix on the relative weights of attributes and objective information is expressed by a decision matrix. An eigenvector method integrated the subjective fuzzy preference matrix and objective information is proposed. Two linear programming models based on subjective and objective information are introduced to assess the relative importance weights of attributes in an MADM problem. The simple additive weighting method is utilized to aggregate the decision information, and then all the alternatives are ranked. Finally, a numerical example is given to show the feasibility and effectiveness of the method. The result shows that it is easier than other methods of integrating subjective and objective information.

In-situ measurement and distribution of flue gas mercury for a utility PC boiler system

The in-situ instrumentation technique for measuring mercury and itsspeciation downstream a utility 100 MW pulverized coal (PC) fired boiler system was developed andconducted by the use of the Ontario hydro method (OHM) consistent with American standard test methodtogether with the semi-continuous emissions monitoring (SCEM) system as well as a mobile laboratoryfor mercury monitoring. The mercury and its speciation concentrations including participate mercuryat three locations of before air preheater, before electrostatic precipitator (ESP) and after ESPwere measured using the OHM and SCEM methods under normal operation conditions of the boiler systemas a result of firing a bituminous coal. The vapor-phase total mercury Hg(VT) concentration declinedwith the decrease of flue gas temperature because of mercury species transformation from oxidizedmercury to particulate mercury as the flue gas moved downstream from the air preheater to the ESPand after the ESP. A good agreement for Hg°, Hg^(2+) and Hg( VT) was obtained between the twomethods in the ash-free area. But in the dense particle-laden flue gas area, there appeared to be abig bias for mercury speciation owing to dust cake formed in the filter of OHM sampling probe. Theparticulateaffinity to the flue gas mercury and the impacts of sampling condition to accuracy ofmeasure were discussed.

PICCO监测下经尿道激光前列腺切除术的围术期护理

目的总结在持续脉波轮廓连续心排血量与经肺热稀释法联合监测(PICCO)下行经尿道2μm激光前列腺切除术患者的围手术期护理要点。方法回顾我科2010年1月-2014年1月收治的合并有心、脑、肺部疾病的80例高危前列腺增生患者,总结在PICCO监测下行经尿道2μm激光前列腺切除术围术期的护理措施,并进行分析。结果 80例患者手术过程顺利,未出现明显并发症,对治疗效果满意。结论对高危前列腺增生患者在行经尿道2μm激光前列腺切除术围手术期中应用PICCO监测,有针对性地给予护理干预及宣教,是患者手术成功和康复的重要条件。

重症超声对脓毒症休克患者血流动力学的监测价值

目的:探讨重症超声对脓毒症休克患者血流动力学的监测价值。方法:选取2017年1月-2020年1月期间在我院接受液体复苏治疗的60例脓毒症休克患者,采用随机数字表法将上述入选者进一步分为试验组(n=30)和常规组(n=30)。常规组患者使用脉波指示剂连续心排血量法(PiCCO)进行监测,试验组患者则使用重症超声进行监测,对比分析两组患者复苏前后血流动力学及复苏后复苏液量、尿量的变化情况。结果:复苏24h后,两组患者收缩压、舒张压均高于复苏前,心率低于复苏前,且试验组患者收缩压、舒张压均低于常规组患者,心率高于常规组,差异有统计学意义(P<0.05);试验组患者复苏液量少于常规组患者,尿量多于常规组患者,差异有统计学意义(P<0.05)。结论:重症超声对脓毒症休克患者的监测效果较好,其具有较高的监测价值,临床上可推广使用。

Analysis of Three-dimensional Crack Propagation by Using Displacement Discontinuity Method

A technique for modelling of three-dimensional(3D)quasi-statically propagating cracks in elastic bodies by the displacement discontinuity method(DDM)was described.When the crack is closed,the Mohr-coulomb rule on the two contacted surfaces of the crack must be satisfied.A simple iterative method was adopted in order to consider three different states of cracks.Under the assumption that the advance of the point on the crack front would occur only in the normal plane which is through this edge point,the maximum energy release rate criterion is modified to be used as the criterion for the crack growth.With discretization,the process of crack propagation can be seen as the advance of the vertices of the crack front.The program MCP3D was developed based on these theories to simulate the 3D quasi-static crack propagation.A numerical example of a penny-shaped crack subject to tension and compression in an infinite elastic media was analyzed with MCP3D,and the results in comparison with others' show that the present method for 3D crack propagation is effective.

MODIFIED LAYER REMOVAL METHOD FOR MEASUREMENT OF RESIDUAL STRESS DISTRIBUTION IN THICK PRE-STRETCHED ALUMINUM PLATE

The integrated structure parts are widely used in aircraft. The distortion caused by residual stresses in thick pre-stretched aluminum plates during machining integrated parts is a common and serious problem. To predict and control the machining distortion, the residual stress distribution in the thick plate must be measured firstly. The modified removal method for measuring residual stress in thick pre-stretched aluminum plates is proposed and the stress-strain relation matrix is deduced by elasticity theory. The residual stress distribution in specimen of 7050T7451 plate is measured by using the method, and measurement results are analyzed and compared with data obtained by other methods. The method is effective to measure the residual stress.

Seafarers＇ Current Awareness, Knowledge, Motivation and Ideas towards Low Carbon-Energy Efficient Operations

International and national concern about detrimental climate change has generated pressure for the shipping industry to play its＇ role in reducing the 3.3% of global carbon emission it emits. On the 1st January, 2013, the IMO （International Maritime Organisation） enforced regulations to support the reduction of shipping carbon emissions by improving energy efficiency. These measures directly and indirectly affect the daily operations of seafarers and onshore performance and managerial personnel. Whilst the industry has made efforts to raise the awareness of many stakeholders and research has been undertaken to investigate energy efficiency barriers, little has been done to capture the opinions, needs and knowledge of seafarers. A questionnaire was distributed in the last quarter of 2011 to investigate seafarers＇ awareness, knowledge and motivation towards carbon emissions in general and towards shipping carbon emissions. It also investigated opinions as to which personnel have the most influence over carbon reductions and what are the most important operational improvements that can be made. The authors have collected 317 questionnaire responses. The primary benefit of this study is to support the identification of an operational strategy to improve energy efficiency, including the development of LC-EE （low carbon-energy efficiency） MET （maritime education and training）, which is shown to be needed.

The research progress on carbon fixation and oxygen release of phytoremediation

To create evaluation methods in reclamation area according to specific conditions in coal mines, introduced the re- search trends both at home and abroad on plants＇ carbon fixation and oxygen release, offered, at the same time, several method models on carbon fixation and oxygen release by plants, and gave some suggestions in this field on the basis of reading the ex- periences of former experts. Finally, used biomass method and instrument measurement method to analyze carbon emission benefits in the study area.

On-line least squares support vector machine algorithm in gas prediction

Traditional coal mine safety prediction methods are off-line and do not have dynamic prediction functions.The Support Vector Machine(SVM) is a new machine learning algorithm that has excellent properties.The least squares support vector machine(LS-SVM) algorithm is an improved algorithm of SVM.But the common LS-SVM algorithm,used directly in safety predictions,has some problems.We have first studied gas prediction problems and the basic theory of LS-SVM.Given these problems,we have investigated the affect of the time factor about safety prediction and present an on-line prediction algorithm,based on LS-SVM.Finally,given our observed data,we used the on-line algorithm to predict gas emissions and used other related algorithm to compare its performance.The simulation results have verified the validity of the new algorithm.

Effective Solution Algorithm for Tomographic Inversion of Volume Emission Rate from Satellite-based Limb Measurement

The volume emission rate (VER) of airglow can be used to investigate atmospheric processes. Satellite-based limb measurement of atmosphere is able to obtain the VER profile of airglow with high vertical resolution. However, the traditional one-dimensional retrieval techniques for VER inversion fail to retrieve horizontal structure of VER profile. Thus, the tomographic technique based on the maximum probability is applied to retrieving two-dimensional VER profile of airglow from infrared limb measurement. This technique could process the observed data with low signal-to-noise ratio caused by the observation angle of less than 180° due to the solid nature of the Earth. For saving the processing time and improving the computing speed of VER inversion, serial tables for storing the large sparse matrix for radiance simulation and a large dataset during iterative estimate of VER are presented. The index and weighting factor of line of sight (LOS) through each grid are saved in initial estimate to avoid being computed repeatedly. Furthermore, the product of observed radiance and corresponding weighting factor obtained in initial iteration is stored as weighted observed radiance for the iterative calculation subsequently. Based on the improved algorithm, the VER of airglow is inversed through the tomographic technique. The full width of half maximum (FWHM) of error is 1.78% and the offset of the peak percentage error is 0.22% after 40 iterations for final VER. Comparison of assumed and retrieved VER profiles suggests that VER can be retrieved with a bias of 15% between 10 km and 90 km above the LayerMin (6384 km from the Earth center), and with a bias of 8% for altitude from 30 km to 60 km with vertical resolution of 1 km after 40 iterations. After improvements, the computation speed of VER inversion for once can be improved by 29.6 times for 700 images of 1/3 orbit, and accordingly, the processing time will be reduced from 3 hours and 11 minutes to only 6 minutes. In conclusion, the improvements to tomographic inversion of VER of airglow proposed in this paper are effective and significant.

Forward displacement analysis of a redundant parallel manipulator by approximation algorithms

This paper presents the forward displacement analysis of an 8-PSS(prismatic-spherical-spherical)redundant parallel manipulator whose moving platform is linked to the base platform by eight kinemtic chains consisting of a PSS joint and a strut with fixed length.A general approximation algorithm is used to solve the problem.To avoid the extraction of root in the approximation process,the forward displacement analysis of the 8-PSS redundant parallel manipulator is transformed into another equivalent problem on the assumption that the strut is extensible while the slider is fixed.The problem is solved by a modified approximation algorithm which predicates that the manipulator will move along a pose vector to reduce the difference between the desired configuration and an instantaneous one,and the best movement should be with minimum norm and least quadratic sum.The characteristic of this modified algorithm is that its convergence domain is larger than that of the general approximation algorithm.Simulation results show that the modelified algorithm is general and can be used for the forward displacement analysis of the redundant parallel manipulator actuated by a revolute joint.