Analysis of Pesticide Raid^(█) in Feed of Wistar Rat by High-Pressure Liquid Chromatography (HPLC)

The distribution of pesticide by-product in tissues of wistar rats were analyzed using high pressure liquid chromatography. The limit of detection of the HPLC was 0.1 μg. Results show bioaccumulation factor of pesticide “Raid?” in lipid, up to three times that of the feed at the first concentration and gradually decreased as the concentration increased in the muscle > (0.7), brain > (0.5) and liver > (0.3) as indicated in the text. At higher concentration of 961 μg/g, bioaccumulation factor decreased in the lipid to 1.2 and 0.6 in the muscle, 0.03 in the brain and 0.08 in the liver respectively. High Pressure Liquid Chromatography (HPLC) analysis of raid extract suggests the presence of micprothrin and palethrin. The implications are numerous, but simply put that accidental ingestion of chlorinated hydrocarbon as in “Raid?” may involve convulsions, collapse and coma after only brief excitation and ataxia at the onset.

Pressure induced insulator to metal transition in quantum spin liquid candidate NaYbS_(2)

Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of isostructural compound NaYbS_(2)under pressure.It is found that the resistance of Na YbS_(2)single crystal exhibits an insulating state below 82.9 GPa,but with a drop of more than six orders of magnitude at room temperature.Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression.Finally,a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K.The insulator to metal transition,non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS_(2)under pressure are similar to those of NaYbSe_(2),suggesting that these phenomena might be the universal properties in NaLnCh_(2)(Ln=rare earth,Ch=O,S,Se)system.

Gas-Liquid Mass Transfer in a Slurry Bubble Column Reactor under High Temperature and High Pressure

The gas-liquid mass transfer of H2 and CO in a high temperature and high-pressure three-phase slurry bubble column reactor is studied. The gas-liquid volumetric mass transfer coefficients kLa are obtained by measuring the dissolution rate of H2 and CO. The influences of the main operation conditions, such as temperature, pressure,superficial gas velocity and solid concentration, are studied systematically. Two empirical correlations are proposed to predict kLa values for H2 and CO in liquid paraffln/solid particles slurry bubble column reactors.

EVOLUTION OF LIQUID WATER CONTENT IN A SEA FOG CONTROLLED BY A HIGH-PRESSURE PATTERN

On March 16–17, 2008, a sea fog occurred in Dianbai in the west of Guangdong Province and was accompanied by a high-pressure synoptic system. Using comprehensive observation datasets, this study analyzes the evolution of liquid water content during this sea fog and investigates the relationships between liquid water content and the average diameters and count densities of fog droplets, air temperature, wind speed and turbulence exchanges. The main results are presented as follows. (1) The sea fog showed a quasi-periodic oscillation characteristic, i.e., it developed, disappeared and then developed again. (2) During the sea fog, the number of fog droplets changed significantly while the changes in average diameter of the fog droplets were relatively small. The development and disappearance of the sea fog correlated significantly with the fog droplet numbers. (3) The air-cooling mechanism played a significant role in sea fog formation and development. However, the influences of this mechanism were not evident during fog persistence. (4) During sea fog formation, weak turbulence exchanges were helpful for fog formation. During sea fog development and persistence, liquid water content increased when turbulence exchanges weakened, and vice versa. The changes in turbulence exchanges were closely related to the quasi-periodic oscillations observed in sea fog presence.

Properties of Liquid Nickel along Melting Lines under High Pressure

We report a molecular dynamics study of structural and transport properties of liquid nickel under high pres- sures. Pressure dependencies of pair distribution function and pair correlation entropy along the melting line indicate that the configuration change along melting lines decreases with increasing pressure. The calculated diffusion coefficients and viscosity by using entropy-scaling laws with modified parameters and ideal parameters are compared with those extracted from mean-square displacement or the Stokes-Einstein relation. The results suggest that the entropy-scaling laws hold well for coefficients and viscosity increase moderately with liquid nickel under high-pressure conditions, and the diffusion pressure along melting lines.

Experimental study on liquid immiscibility of lamprophyre-sulfide melt at high temperature and high pressure and its geological significance

With lamprophyre and pyrite from the Laowangzhai gold deposit, Yunnan Province, China, as starting materials, and at pressures from 1.5 to 3.0 GPa and temperatures from 1160 to 1560℃ , an experimental study was carried out on the liquid immiscibility of lamprophyre-sulfide melt at high temperature and ultra-high pressure in the DS-29A cubic 3600T/6-type high pressure apparatus. Results showed that the liquid immiscibility of lampro-pyre-sulfide melt in the magmatic system would happen during the early magmatic evolution (high temperature and high pressure conditions) and was controlled by temperature and pressure. The sulfide melt which was separated from the lamprophyric melt would make directional movement in the temperature and pressure field and assemble in the low-temperature and low-pressure region. Because the density of SM is higher than that of the lamprophyric melt, the former would gather together at the bottom of the magma chamber and there would exist a striking boundary between the two melts. On the other hand, the results also suggested that there would be little possibility for lampro-phyric magma to carry massive gold, and lamprophyres can't provide many of oreforming materials (Au) in the processes of gold mineralization.

A Generalized Equation of State for High-Pressure Liquids

An equation of state (EOS) for high-pressure liquids, i.e., Tait EOS, is deduced according to isothermal compressibility Based on the equation, a generalized EOS for high pressure-liquids is established by using the reduced state principle and introducing a characteristic parameter-configuration factor ζ. Reasonably satisfactory P-V-T data for many organic compounds, including some polar components, were calculated by using the equation.

Public debate on metallic hydrogen to boost high pressure research

Instead of praises from colleagues,the claim of observation of metallic hydrogen at 495 GPa by Dias and Silvera met much skepticism,and grew into a public debate at the International Conference on High-Pressure Science and Technology,AIRAPT26.We briefly review this debate,and extend the topic to show that this disputation could be an opportunity to benefit the whole high pressure community.

Homogeneous Isolation of Nanocellulose from Cotton Cellulose by High Pressure Homogenization

Nano-cellulose materials are widely believed to have the potential to push polymer mechanical properties. The cotton cellulose was dissolved in ionic liquid (1-butyl-3-methylimidazolium chloride ([Bmim]Cl)), and then was isolated by high pressure homogenization in a homogeneous media. The nano-cellulose was obtained at 80MPa for 30 cycles. The geometry and microstructure of the cellulose nano-fibres were observed by SEM and their particle size analysis. FTIR, XRD and TGA were used to characterize changes to chemical functionality. Particular emphasis is given to the physical and chemical characterization of these nano-fibres together with their thermal stability and crystallinity, in order to develop their suitability.

Solid-liquid state pressure bonding of Si_3N_4 ceramics with aluminum based alloys and its mechanism

Solid liquid state pressure bonding of Si 3N 4 ceramics with aluminum based alloys, which contain a small amount of intermetallic compounds Al 3Ti or Al 3Zr, was investigated. With this new method, the heat resistant properties of the bonding zone metal are improved, and the joints’ strengths at high temperature is increased. The joints’ shear strength at room temperature and at 600 ℃ reach 126～133 MPa and 32～34 MPa, respectively, with suitable bonding pressure. The reaction between aluminum and Si 3N 4 ceramics, which produces Al Si N O type compounds is the dominant interfacial reaction, while the reactions between the second active element Ti or Zr in the aluminum based alloys and Si 3N 4 ceramics also occur to some extend. [

激光轰击金属液面溅射过程的数值模拟

目前,极紫外光被认为是制备特征尺寸小于7 nm芯片所必备的光源,激光轰击液态金属锡靶是其产生的主要方式之一.采用体积分数(volurne of fluid,VOF)方法建立了激光轰击金属锡液面产生溅射的模型,并对液料溅射和雾化的演化过程进行了数值模拟,研究了冠状水花的产生机制以及雾化时的流场变化.在此基础上,进一步研究了金属液态锡在不同的能量、光斑直径和脉宽的激光轰击下溅射产生的冠的宽度和高度随时间演化情况.研究表明:在激光辐照产生的高压等离子体的高速冲击下,液膜经历快速运动、冠状射流和雾化3个阶段,液膜生长主要原因是惯性力作用;液膜上下两端存在较大的速度梯度是射流形状发生变化的主要原因;冠边缘处雾化现象的产生是由Rayleigh-Taylor和Plateau-Rayleigh不稳定性共同作用的结果.在激光轰击下,冠的高度和宽度随激光能量增加而增大,但随着时间推移,冠宽和冠高的增长速率逐渐减小;激光光斑和脉宽对冠宽及冠高的影响较为复杂,在前期影响较小,在后期冠宽及冠高随它们数值增加而减小.

盾尾刷更换时液氮冻结温度场及冻结参数影响的数值模拟分析

为合理确定高水压下液氮冻结止水更换盾尾刷的冻结设计参数及掌握温度场变化规律,结合某过江通道长距离盾构掘进过程中盾尾刷更换时的液氮冻结止水工程,利用ADINA大型有限元分析软件建立液氮冻结止水及盾尾刷更换数值模型,模拟温度-时间变化曲线与现场实测数据对比,验证模型的合理性,并对土层、去路液氮温度、冻结管长度、冻结管间距、冻结方式进行敏感性因素分析。结果表明:1)冻结效果随土层的不同而发生改变,在卵石层、砾砂层、粉细砂层3种土层中,粉细砂层的冻结效果最差,卵石层最好;2)在有限的冻结时间内,去路液氮温度的不同,只影响土体从开始冻结至越过0℃完成相变这期间的降温速度,不影响完成冻结以后的土体降温速率;3)冻结管长度对土层冻结的影响较小,可以采用较短的冻结管,以降低施工成本和液氮消耗量,但不能过短,应保证其纵向有足够的支撑范围,经计算分析,当冻结管长度为1.52 m时,能在轴面处满足2.0 m的冻结壁厚度要求;4)冻结管间距对冻结效果影响大,冻结管越密,冻结速度越快,效果越好;5)在相同条件下,双环预埋冻结管液氮冻结效果优于管片上直接打孔液氮冻结。

基于液相敏感性与加卸载机制的泥岩地层压力预测方法

地层压力是井壁稳定分析的重要参数,尤其在异常高压泥岩段的高压机制复杂,且泥岩具有强液相敏感性,不利于地层压力预测,钻井风险高。基于此,以准噶尔盆地南缘安集海河组泥岩层段为例,考虑流体作用对泥岩物性参数的干扰,建立了泥岩地层物性参数的测井校正方法。结合声速-密度版图法与综合压实曲线法,揭示了泥岩地层异常高压的成因机制;基于高压成因机制,依据加卸载理论与有效应力原理构建了南缘泥岩段地层压力预测方法。结果表明:由于泥岩地层高黏土含量与油水两亲性,水相与油相介质均对泥岩物性具有显著影响,必须开展校正工作;在测井校正后,明确了泥岩段具有加载与卸载的高压成因机制,阐明了加卸载条件下泥岩有效应力与岩石物性的相关性;本文方法较Eaton法、等效深度法、加卸载预测方法、多参数综合预测法等地层压力预测方法具有较高精度。本文建立的泥岩段地层压力预测方法已在准噶尔盆地南缘地层压力预测中取得成功应用,预测地层压力与实测地层压力吻合度高,可为异常压力泥岩段的地层压力预测和泥岩地层安全高效钻井提供借鉴。

高压液氨预热器管板环焊缝主副加热局部热处理

管板环焊缝局部热处理是影响高压液氨预热器服役安全的关键制造技术,传统局部热处理时温度分布不均匀、管板约束大,导致残余应力难以消除。对此,采用主副加热局部热处理方法,并验证该方法在高压液氨预热器局部热处理时的有效性。计算与测试结果表明,传统局部热处理仅可降低外表面的轴向和环向残余应力,而内表面轴向应力会略微增大,环向应力降幅较小;主副加热局部热处理使内表面轴向应力由283 MPa降低至100 MPa以下,降幅约64%,环向应力由324 MPa降低至206 MPa,降幅约37%,显著降低了设备内表面应力腐蚀开裂的敏感性。

压裂双弯头液固两相流冲蚀影响数值分析

在水力压裂过程中,地面高压管汇受管内携砂压裂液的复杂流动影响,长期承受着严峻的冲蚀破坏。在各类高压管汇构件中,弯管的冲蚀损伤最为严重。为改善压裂双弯头冲蚀磨损状况,采用DPM模型、RNG k-ε湍流模型,综合分析了斯托克斯数(St)、重力方向、粒径及流速对串联双弯头冲蚀磨损的影响。结果表明:冲蚀磨损区域主要由St和重力方向共同决定;St<1时,最大冲蚀率随颗粒尺寸增大呈线性增加,St>1时呈指数增长;St相同时,速度对冲蚀磨损程度的影响远比颗粒尺寸强烈;向下流重力方向下,损伤区域随St增加完全转移至第二弯头的临界粒径显著小于向上流临界粒径;重力方向对同向冲击颗粒的冲蚀损伤虽有增强效应,其对冲蚀磨损程度影响远不及颗粒尺寸因素作用大。

考虑载荷模拟作用的高压弯头冲蚀数值仿真

在水力压裂过程中,地面高压管汇在管内复杂固液两相流冲击和管体恶劣载荷的耦合作用下,弯头、三通及接头等薄弱部件长期遭受严重的冲蚀磨损,极易导致管件发生断裂破坏,对现场人员及设备构成严重威胁。开展载荷作用下的高压管汇典型材料冲蚀磨损试验,根据试验结果,基于E/CRC冲蚀模型构建一种考虑应力状态影响的新型冲蚀数学模型,所构建的新模型与冲蚀试验数据之间的准确度可达95%以上。采用计算流体力学离散相模型(CFD-DPM),开展高压管汇件冲蚀性能的三维数值模拟,考察高压弯头在不同压裂工况下的冲蚀磨损程度及空间分布情况。结果表明:在固液两相流冲击下,主要冲蚀区位于靠近弯头出口处的弯头外侧,且管件的最大冲蚀率也位于该处;在弯头内侧二次流涡流的影响下,部分颗粒在流经弯头后会在下游直管内侧积聚,从而在这个区域造成次要冲蚀区;随着流动颗粒斯托克斯系数增加,主要冲蚀区面积增大,次要冲蚀区面积减小;此外,在嵌入新型冲蚀数学模型后,可观察到随着操作压力增大,高压管汇弯头部位的冲蚀磨损率明显增加。

基于多组分定量联合主成分分析正交偏最小二乘法-判别分析及熵权优劣解距离法的抗菌消炎胶囊质量差异性评价

目的建立主成分分析(PCA)、正交偏最小二乘法-判别分析(OPLS-DA)及熵权优劣解距离法(EW-TOPSIS)评价抗菌消炎胶囊的多组分质量差异。方法采用高效液相色谱法(HPLC)同时测定15批抗菌消炎胶囊中獐牙菜苦苷、獐牙菜苷、绿原酸、3,5-二-O-咖啡酰奎宁酸、知母皂苷BⅡ、知母皂苷AⅢ、原百部碱、对叶百部碱、黄芩苷、汉黄芩苷、黄芩素和汉黄芩素的含量,借助PCA、OPLS-DA及EW-TOPSIS模型对15批消炎胶囊样品进行质量差异分析,筛选出导致差异的特征成分,并进行质量排序。结果12种成分在各自范围内呈现良好的线性关系(r>0.999),平均加样回收率(n=9)96.90%~100.23%(RSD<2.0%)。化学计量学筛选出2个主成分,方差贡献率累计达95.172%;OPLS-DA发掘出黄芩苷、绿原酸、知母皂苷BⅡ和对叶百部碱对抗菌消炎胶囊质量有显著影响;EW-TOPSIS分析结果显示Ci值0.0827~0.8495,15批样品质量差异较大。结论所建立的方法可用于抗菌消炎胶囊质量的综合评价。

黑参炮制工艺优化及成分变化分析

以人参为原料,采用高温高压法炮制黑参,加工过程中使用蒸制与焖制结合的方法,缩短黑参的炮制时间,利用单因素试验和正交法优化黑参的炮制工艺,以感官评价为参考值,考查蒸制时间、烘干时间、烘干温度3个因素对黑参品质的影响。结果表明,在蒸制时间120 min,烘干时间8 h,烘干温度60℃时,炮制出的黑参的品质最佳;其含水量平均为10.132 513%,人参皂苷含量分别为0.033 g/100 g (Re),0.141 g/100 g (20(S)-Rg3);0.256 g/100 g(20(R)-Rg3)。与原参相比,黑参的稀有人参皂苷Rg3含量增加,人参皂苷Re含量减少。

高温高压超声波流量计研制及不确定度评定

针对国内压水堆核电机组主给水高温高压(高温为240℃、高压为12.2 MPa)的工况特点,基于超声波时差法的测量原理,研制了一种满足现场工况质量流量测量、不确定度不大于0.3%的高精度超声波流量计。介绍了高温高压超声波流量计的工作原理、整机组成及各部件的设计参数,总结了适合高温高压环境的超声波流量计装置的设计思路。研究了超声波流量计测量结果不确定度分量来源,分析了各个不确定度的分量值,并进行了试验验证。结果表明,通过利用国内现有条件的流量标准装置进行试验,引入的不确定度分量评估方法得到了验证,符合高温高压超声波流量计测量的不确定度指标,实现了超声波流量计的研制目标。

高压集输气井井筒积液量与流压计算方法

针对采用高压集输工艺气水同出的天然气井,为准确计算其井筒积液量及井底流压,以指导泡排工艺的实施,建立了一种井筒积液量与流压计算方法。通过简化油管与环空内气水两相分布,并以套压折算流压等于油压折算流压为基本原则,推导出包含油管等效液面处压力p_(1)、环空等效液面处压力p_(2)、环空与油管等效液柱高度比值k等3个关键参数的计算方程,并结合动态监测数据,给出了3个关键参数的求解方法,从而通过迭代方式计算得出井筒积液量与井底流压。经45口气井实测数据验证,流压计算平均误差4.4%,积液量计算平均误差14.8%。同时,该方法主要利用生产数据和少量流压测试数据进行并行迭代计算,具有成本低、计算速度快的优点。