Comparison between mainstream (Capnostat 5) and a low-flow sidestream capnometer (Capnostream) in mechanically ventilated,sevoflurane-anesthetized rabbits using a Bain coaxial delivery system

ObjectiveTo evaluate agreement between end-tidal carbon dioxide (Pe′CO₂) and PaCO₂ with sidestream and mainstream capnometers in mechanically ventilated anesthetized rabbits, with two ventilatory strategies.Study designProspective experimental study.AnimalsA total of 10 New Zealand White rabbits weighing 3.6 ± 0.3 kg (mean ± standard deviation).MethodsRabbits anesthetized with sevoflurane were intubated with an uncuffed endotracheal tube (3.0 mm internal diameter) and adequate seal. For Pe′CO₂, the sidestream capnometer sampling adapter or the mainstream capnometer was placed between the endotracheal tube and Bain breathing system (1.5 L minute^–1 oxygen). PaCO₂ was obtained from arterial blood collected every 5 minutes. A time-cycled ventilator delivered an inspiratory time of 1 second and 12 or 20 breaths minute^–1. Peak inspiratory pressure was initially set to achieve Pe′CO₂ normocapnia of 35–45 mmHg (4.6–6.0 kPa). A total of five paired Pe′CO₂ and PaCO₂ measurements were obtained with each ventilation mode for each capnometer. Anesthetic episodes were separated by 7 days. Agreement was assessed using Bland-Altman analysis and linear mixed models; p < 0.05.ResultsThere were 90 and 83 pairs for the mainstream and sidestream capnometers, respectively. The mainstream capnometer underestimated PaCO₂ by 12.6 ± 2.9 mmHg (proportional bias 0.44 ± 0.06 mmHg per 1 mmHg PaCO₂ increase). With the sidestream capnometer, ventilation mode had a significant effect on Pe′CO₂. At 12 breaths minute^–1, Pe′CO₂ underestimated PaCO₂ by 23.9 ± 8.2 mmHg (proportional bias: 0.81 ± 0.18 mmHg per 1 mmHg PaCO₂ increase). At 20 breaths minute^–1, Pe′CO₂ underestimated PaCO₂ by 38.8 ± 5.0 mmHg (proportional bias 1.13 ± 0.10 mmHg per 1 mmHg PaCO₂ increase).Conclusions and clinical relevanceBoth capnometers underestimated PaCO₂. The sidestream capnometer underestimated PaCO₂ more than the mainstream capnometer, and was affected by ventilation mode.     

活性炭吸附汽油机冷起动HC排放的实验

为控制汽油机的冷起动HC排放，开发了一个活性炭吸附器，用于吸附车用汽油机冷起动阶段排放的HC。吸附材料采用煤质蜂窝状定型活性炭块，吸附器外表面用薄钢板焊接封装，整个吸附器串接在排气管上。进行汽油机冷起动排放实验，测量起动后200s内的HC排放量，实验结果表明，在冷却水温度为20U、40℃、60℃和85℃时，活性炭吸附器对HC的吸附率分别达到86．64％、70．34％、79．69％、77．45％。     

PREDICTIVE INTELLIGENT CONTROL OF THE COLD STORAGE

The predictive intelligent control scheme is proposed, which is based on approximation theory and numerical method of Chcbyshev orthogonal polynomial. It has the practical value to the cold storge using widely electromagnetic valve and can be also applied similar systems in orther area.     

Land Storage System: Effect, Problem and Its Legal Regulation

The authors suggest that the land storage system is beneficial not only to strengthen the country's macroscopic regulation of city land market, accelerate healthy development of city economy and increase the financial income, it can also be advantageous to carry out the economic reform and public facilities construction without a hitch. On the basis of this, in this paper, the increment of the land price and house price as well as the high risk of fund due to lack of related laws is analyzed. Corresponding legal regulations, such as polishing the legislation of land right, implementing the land utilization planning, reinforcing the legislation of city development, land requisition and countryside residential land administration are put forward.     

CO2-O2混合喷吹对铁液中C、V元素氧化的影响

为了验证用CO2替代部分O2进行转炉氧化提钒的可行性,在实验室进行了CO2-O2混合喷吹提钒模拟实验。结果显示C的氧化量与C的氧化速率随CO2含量的增加而升高;V的氧化量随CO2含量的增加而降低,其中CO2含量为20%与纯O2对C、V的氧化量接近;纯O2喷吹时C的氧化量为34.56%,V的氧化量为96.85%;CO2含量为20%混合气体喷吹时C的氧化量为36.83%,V的氧化量为93.29%;以V的相对氧化量与C的相对氧化量的比值(ΔV/ΔC)来衡量提钒保碳能力,CO2含量为20%的最终ΔV/ΔC为5.96,CO2含量,40%、60%、80%的最终ΔV/ΔC均小于3.8;反应前期,V的氧化速率随CO2含量的增加而升高,反应后期V的氧化速率随CO2含量的增加而降低。     

A STUDY ON HEAT AND MOISTURE STATE OF HULL LAYER FOR THERMAL INSTULATION OF A COLD STORAGE

This paper analyses the thermal moist characteristics of the hull layer beside an air layer at lower temperature in an envelope for a cold storage and presents a new method of waterproof by air layer. With test data from engineering practice, the theory on the barrier of self moisture proof at the surface sublayer of the hull layer in an attic on a cold storage is proven. The dried zone about three phase point is confirmed. It is a new knowledge for thermophysics on thermal design of a cold storage with an optimum thermal performance.     

以粮温实测数据为例探讨低温储粮的可行性

通过对高大平房仓粮温进行跟踪检测，分析比较了粮温变化情况，并探讨了低温储粮的可行性。     

高氨氮厌氧消化液后处理技术研究

采用SBR-絮凝沉淀-Fenton氧化-活性炭吸附组合工艺对高氨氮厌氧消化液的后处理进行实验研究.结果表明,当进水COD浓度为4516 mg·L^-1时,SBR出水COD可降为1752 mg·L^-1,去除率达到61.2%;絮凝沉淀出水COD浓度为1189 mg·L^-1,去除率为32.1%;Fenton氧化和活性炭吸附出水COD浓度分别为452和216 mg·L^-1,去除率分别为61.7%和52.7%.当进水NH3-N浓度2162 mg·L^-1时,SBR出水NH3-N浓度降至13.8 mg·L^-1,去除率为99.4%,NH3-N主要在该段去除.整个组合工艺对COD和NH3-N的去除率分别达到95.2%和99.9%,达到了很好的有机物和氨氮去除效果,在技术上是可行的.     

温室地下贮热系统设计研究

为了降低温室环境调控能耗。根据育苗不同阶段对气温与土壤温度的要求，设计了温室地下贮热系统，并阐述了系统的组成和贮热原理；同时，分析了各设计参数对系统贮热性能的影响。这样不仅为系统设计与理论分析奠定了基础，对其它类似地下贮热系统的设计、研究也具有参考意义。