液氮

The theoretical analysis of the work cycle is made for the pressed air engine and liquid nitrogen engine.

从理论分析的角度，对压缩空气发动机和液氮发动机的工作循环进行了分析讨论，采用不同概念计算了两者的可用能，并着重分析了膨胀初始压力和温度对输出功的影响，还探讨了液氮发动机工作循环的优化途径。

The influences of heat exchanger and engine on system efficiency are distinguished. The thesis also analysis the efficiency of the compound cycle of liquid nitrogen engine operating on open Rankin cycle together with the liquid nitrogen refrigeration cycle and economy in detail.

首次采用变质量系统热力学原理探讨了通过对进气温度与缸内残余质量温度的控制有助于实现准等温膨胀的可行性；首次采用有限时间热力学对具有压降不可逆液氮发动机开式朗肯循环进行了工作过程分析，研究了漏气和压降对液氮发动机效率和功率的影响关系。

In the clip above we see an attempt to "cool" the thermite reaction by dumping it in a vat of liquid nitrogen.

液氮的温度大约为-196℃，偶实验室要用的，灌液氮的场面也很壮观，有时间发图给大家看下！

The healing process and histological behavior of the tendon transplantation group were similar with those of the autografting group, however, which was better by liquid nitrogen after program freezing than by -80℃ deepfreezing.

结论经程序冷冻液氮保存和-80℃深低温保存方法冻存的兔异体髌腱重建膝关节交叉韧带后愈合过程和自体韧带移植重建过程相似，但程序冷冻液氮保存法优于传统的-80℃深低温保存法。

A set of in situ infrared apparatus which can beoperated at liquid nitrogen temperature is established. The structuralstudies of polyhydride of Ruthenium is carried out from roomtemperature to liquid nitrogen temperature. The structural conversion of〓 between dihydrogen and dihydride is observed firstly. It issuggested that with temperature changing, a fluxional structureconversion between terminal and bridged hydrogen appears. NMR studyand DV-Xα calculation are performed in this paper.

建立了可至液氮温度的原位红外测试装置，进行了室温至液氮温度区间钌多氢化合物的结构研究，首次发现了〓在室温存在分子氢与原子氢的结构流变，发现了新化合物存在随温度变化而出现桥氢与端氢的结构转化；进行了NMR测试及DV—〓计算。

Cryogenic two-phase flow and boiling heat transfer characteristics are studied by means of visualized experiment in lunate narrow channel.

采用可视化实验方法研究液氮在弦月形狭缝通道内两相流流动和传热现象。利用精心设计和制作的试件，借助高速摄影仪和3CCD 数码摄像机，获得了液氮在弦月形狭缝通道热虹吸沸腾时的气泡行为及两相流动的真实信息。

The genomic DNA of Nosema bombycis was isolated from it's spores, using two methods, ie, Alkaline-Germination and Liquid-nitrogen.

分别用碱发芽法及液氮法抽提了家蚕微孢子虫基因组DNA，其中碱发芽法抽提的DNA质量及数量上好于液氮法抽提的DNA。

Three weeks afer the allografting,there was no significant difference between the two al lografting groups in maximum load(P＞0.05),Eight weeks later,the maximum load of the group that was preserved by liquid nitrogen after program freezing(76.60±4.67)N was better than the group that was preserved by －80℃ deepfrozen(75.99±4.20) and similar with the autografting group(76.72±2.55).4.The healing process and histological behavior of the two deepfrozen groups are similar with the autografting group,and the program freezing group is better.

结果 a经程序冷冻液氮保存方法处理后，髌腱的最大载荷无明显下降，细胞活性得到了较好的保存，组织学观察冷冻损伤较－80℃深低温保存方法轻微；b程序冷冻液氮保存处理的移植物在术后未表现明显的排斥反应，且免疫反应随时间的推移而下降；c移植后3周，各组移植物的最大载荷无显著差异(P＞0.05)，移植后8周，程序冷冻液氮保存组移植物的最大载荷(55.87±1.86)N优于－80℃深低温保存组(52.14±2.79)，而和自体移植组相近(57.70±2.76)N；d从组织学观察看，－80℃深低温保存组和程序冷冻液氮保存组移植后的愈合过程均和自体移植组相似，而程序冷冻液氮保存组的愈合过程和组织学行为更接近于自体移植组。

Results 1.After treated by:program freezing,the maximum load of the allografts has no evident decrease and the cell activity of allografts was preserved well,the frozen hurt after program freezing was more slight than －80℃ deepfrozen,2.No evident reject reaction can be seen during the healing process after deep frozen and the reject reaction declined as the time pass by.3.Three weeks afer the allografting,there was no significant difference between the two al lografting groups in maximum load(P＞0.05),Eight weeks later,the maximum load of the group that was preserved by liquid nitrogen after program freezing(76.60±4.67)N was better than the group that was preserved by －80℃ deepfrozen(75.99±4.20) and similar with the autografting group(76.72±2.55).4.The healing process and histological behavior of the two deepfrozen groups are similar with the autografting group,and the program freezing group is better.

结果 a经程序冷冻液氮保存方法处理后，髌腱的最大载荷无明显下降，细胞活性得到了较好的保存，组织学观察冷冻损伤较－80℃深低温保存方法轻微；b程序冷冻液氮保存处理的移植物在术后未表现明显的排斥反应，且免疫反应随时间的推移而下降；c移植后3周，各组移植物的最大载荷无显著差异(P＞0.05)，移植后8周，程序冷冻液氮保存组移植物的最大载荷(55.87±1.86)N优于－80℃深低温保存组(52.14±2.79)，而和自体移植组相近(57.70±2.76)N；d从组织学观察看，－80℃深低温保存组和程序冷冻液氮保存组移植后的愈合过程均和自体移植组相似，而程序冷冻液氮保存组的愈合过程和组织学行为更接近于自体移植组。

During the fracturing for low pressure and low permeability gas reservoirs, there are some main problems in conventional hydroxypropylguar - organic boron cross-linking system: Firstly, the water-lock damage to low pressure and low permeability gas formations by filter liquor; Secondly, the reason for alkali-sensitive damage in alkali-sensitive reservoirs is that conventional hydroxypropylguar - organic boron cross-linking fracturing fluids were cross-linked under alkaline environment, while the permeability of reservoirs is reduced greatly; Thirdly, the formation pressure is low, and the energy of flow back is not enough, at present, the main measure in oil fields is "injecting with liquid nitrogen", but this technique increased the cost of fracturing, making great troubles in operating, and leaving the liquid nitrogen also is a big problem.

在低压低渗透气藏的压裂改造过程中，常规羟丙基胍胶-有机硼交联压裂液体系存在的主要问题，一是压裂液滤液对低压低渗透气层造成的水锁损害；二是常规羟丙基胍胶-有机硼压裂液是在碱性条件下交联的，对碱敏性储层造成碱敏损害，降低储层渗流能力；三是地层压力低，压裂液返排能量不足，当前各油田采取的措施主要是&液氮伴注&技术，但是&液氮伴注&技术增加了压裂的费用，而且液氮存放也存在较大问题。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新