血气检测结果分析前的影响因素研究

目的 探讨分析前因素对血气分析结果的影响.方法 针对送检时间、保存温度和血气针品牌等分析前因素设计3组实验,同一时间内采集患者两侧桡动脉血气标本,应用血气分析仪测定pH、PCO2、PO2、Na^＋、K^＋、Ca^2＋,比较不同的分析前因素对检测结果的影响.结果 室温条件下（18℃～28℃）血气标本延迟检测对pH、PCO2、PO2、Na^＋、Ca^2＋ 5项指标的影响差异有统计学意义（P＜0.05）,即刻检测与延时检测结果pH分别为（7.40±0.09）、（7.39±0.09）,PCO2分别为（45.55±10.46） mmHg、（44.55±9.87）mmHg,PO2分别为（98.70±18.48）mmHg、（118.30±25.36）mmHg,Na^＋分别为（137.20±5.16）mmol/L、（138.00±5.03） mmol/L,Ca2＋分别为（1.05±0.09） mmol/L、（0.99±0.09） mmol/L,延迟检测会导致PO2显著上升和Ca^2＋显著下降;冷藏条件下（2℃～8℃）血气标本延迟检测对pH、PCO2、PO2、Na^＋、K^＋、Ca^2＋ 6项指标的影响较小,差异无统计学意义（P＞0.05）;两种品牌的血气针对血气分析结果的影响差异无统计学意义（P＞0.05）.结论 血气标本应注意及时送检,以提高检测结果的准确性.

江西赣州市耕地碳效应时空特征分析

掌握江西赣州市近年来耕地碳效应基本演变趋势,了解耕地碳源碳汇主要来源,指导江西赣州市耕地低碳化发展。基于江西赣州市2006一2020年作物产量、农业投入等统计数据,估算赣州市耕地净碳汇量和净碳汇强度,并结合空间分析工具探究耕地碳效应时空分布格局。结果表明,(1)2006一2020年,赣州市耕地净碳汇量总体呈上升趋势,耕地碳效应以碳汇为主。(2)蔬菜和瓜果是赣州市碳汇贡献的主要农作物;碳源结构以翻耕、化肥为主,农药、农膜、农田有效灌溉面积为辅。(3)耕地碳效应区域差异明显,空间格局分布不均。(4)耕地净碳汇强度区域差异较明显,但区域差异有减小的趋势。

一个改进的电磁波传输激波管实验

在中国科学院力学研究所Φ800 mm高温低密度激波管上进行电磁波在等离子体中传输机理研究时,低密度和强激波条件下,由于气体解离和电离等非平衡过程,使得激波后2区宽度显著减小;同时由于边界层效应造成激波衰减和接触面加速,使得激波后2区长度进一步减小.这两个效应导致激波管2区实验观测时间减小,2区气体处于非平衡状态,增加了观察数据的不稳定性和数据分析的难度.本文提出在Φ800 mm高温低密度激波管中采用氩气(Ar)和空气(Air)混合气替代纯空气作为激波管实验介质气体.利用Ar不解离和难电离的特性,减小激波前后压缩比,从而增加激波后2区实验时间和气体长度.采用Langmuir静电探针和微波透射诊断技术测量激波后电子密度,同时利用探针测量激波后2区实验时间.结果显示,在Ar+Air混合气实验中,激波波后电子密度可达与纯Air同样的10^(13)cm^(-3)量级.在与纯Air相同的电子密度和碰撞频率条件下,采用95%Ar+5%Air和90%Ar+10%Air两种混合气,激波后2区实验时间和气体长度约为纯Air条件下的5～10倍,其中2区实验时间为300～800μs,2区气体长度1～1.5 m.在Φ800 mm激波管中采用Ar+Air介质气体进行电磁波传输实验,获得了比在纯Air介质中与理论预测更一致的结果.

Measurement of the current and spectral analysis on the continental shelf in the East China Sea

Direct measurements of current velocity and water temperature were undertaken at the mooring Sta. M (125°29.38' N, 31°49.70' E) on the continental shelf area in the East China Sea in June 1999 by R/V Xiangyanghong 14. The relationship between various time series of oceanic fluctuations is calculated by spectral analysis. The major results are as follows: (1) an average (u,v) of (6.9,-3.0 cm/s) at the 30 m depth is obtained during the 9-day observation, and that at the 45 m depth is (3.7,-1.1 cm/s), i. e., the mean flows are southeastward at both the 30 and 45 m depths;the currents become stronger gradually during the observation period; this may be mainly attributed to the transition of the tidal currents from neap to spring; (2)semidiurnal fluctuation is the most dominant in the current fluctuations, and rotates mainly clockwise; in the next place, there is also diurnal fluctuation;the local inertial period is close to the period of diurnal fluctuation, and an inertial motion is clockwise; thus, local inertial motion combines with diurnal fluctuation, and makes the spectral peaks in clockwise components much higher than those in counterclockwise ones; except for the fluctuations of above main periods, there is also the peak at 3 d period for counterclockwise compo-nents in the upper and lower layers; (3) the calculation of cross spectra between two time series of current velocities at the 30 and 45 m depths shows that both the current fluctuations at the 30 and 45 m depths are much alike, i. e., they are synchro; this shows that the flow field here is rather vertically homogeneous; (4)power spectra of tempera-ture time series at both the 30 and 45 m depths show that the semidiurnal peak is the most predominant, and the second highest peak is the diurnal period; besides spectral peaks at above periods, there are also obvious spectral peaks at 6.8 h and 2 d; (5)plots of temperature time series at 16 , 30 , 35 , 45 and 50 m depths show that the temporal variations of temperature at these depths are synchro, which are like those in the velocity field; temperature records also show a gradual rise in temperature, which are also like those in the velocity field.

Fluorescence and cofluorescence enhancement of Tb(Ⅲ) complexes with pyromellitic acid by M (M = Gd, La, Ca, and Sr ions)

Fluorescence and cofluorescence properties of Tb(Ⅲ) solid complexes werestudied using pyromellitic acid (PMA) as ligand and fluorescence inert ions as doping elements. Thecofluorescence enhancement, a result of ligand sensitized fluorescence, was observed in Tb(Ⅲ) solidcomplexes doped with fluorescent inert ions La(Ⅲ), Gd(Ⅲ), Ca(Ⅲ), and Sr(Ⅲ). The effect of thetype and content of doping elements on fluorescence enhancement was studied, and optimum conditionswere determined. The results show that Gd (La, Ca, Sr) has clear cofluorescence effect in solidcomplex Tb-M-PMA system, and in present work, rare earth complex fluorescent powder that emitsbright green fluorescence at ultraviolet excitation was obtained, which had potential application asfluorescent anti-counterfeit ink.

Characterization of the negative thermal expansion material Zr_(1-x)Hf_xW_2O_8

The oxide ZrW_2O_8 displays unusual property of isotropic negative thermalexpansion in a large wide temperature range, which makes it have a number of important potentialapplications. The cubic Zr_(1-x)Hf_xW_2O_8 (x velence 0,0.3, 0.5, 0.7, and 1.0) were synthesized bystandard solid state reaction technique. The high and low temperature X-ray diffraction analysisindicate that the substitution of the Hf^(4+) for Zr^(4+) only leads to reducing the latticeconstants, and the changes of negative thermal expansion coefficients are not obvious. The linearexpansion coefficients of Zr_(1-x)Hf_xW_2O_8 (x velence 0,0.3, 0.5, 0.7, and 1.0) are about -6 X 10^(-6) K^(-1) in the temperature range of 298 to 973 K, while that of Zr_(0.5)Hf_(0.5)W_2O_8 is -9.6X 10^(-6) K_(-1) from 83 to 298 K. The phase transition temperatures from alpha-ZrW_2O_8 tobeta-ZrW_2O_8 structure were also determined by X-ray diffraction method. Thermogravimetric analysis(TGA) exhibits that Zr_(1-x)Hf_xW_2O_8 is not hygroscopic in air.

Currents in the Luzon Strait during the spring of 2002: observation and computation by modified inverse model

On the basis of the current measurements at 200,500 and 800 m from moored current meters with the time series data from March 17 to April 15 at the mooring station (20°49′57″N, 120°48′ 12″E) and the hydrographic data obtained in the Luzon Strait during the spring of 2002 cruise, the circulation in the investigated area is computed by using the modified inverse method. The major observed results are as follows: (1) the average velocity and the flow direction in the observing days are (47.4 cm/s, 346°) at the 200 m level. The average velocity in the observing days is (20.3 cm/s, 350? at the 500 m level. These mean that the Kuroshio intrudes into the South Chin Sea to flow northwestward through the Luzon Strait at 200 and 500 m levels. (2) The average velocity in the observing days is (1.2 cm/s, 35°) at the 800 m level, i. e., its direction is northeastward. This means that the flow condition at the 800 m level very differs from mat at the 200 and 500 m levels. (3) There is the high density and cold water (HDCW) in the middle of western part of in the investigated region, and its center is located near the hydrological station 3 at Section A. (4) There is the lower density and warm water (LDWW) in the southeastern part of investigated region. (5) The currents in April 2002 are stronger than those in March 2002.The major computed results are as follows: (1) The northwestward and southeastward VTs through Section B are 32.48×106 m3/s (inclusive of VT of anticyclonic eddy) and 3.34×106m3/s, respectively. The net northwestward VT through Section B in the investigated area is about 29.14×106 m3/s. (2) The eastern and western VTs through Section A are about 16.71×106 and 8.57×106 m3/s, respectively. Thus, the net eastward VT through Section A is about 8.14×106 m3/s. (3) The net northward VT through Section M is about 24.68×106 m3/s. (4) After about 24.68×106 m3/s flows through Section M, most of it, about 16.54×106 m3/s, flows northward through the eastern part of Section C and then flows northward into the region east Taiwan Island. The other part of it, about 8.14×106 m3/s, branches out from the main Kuroshio and then flows meanderingly through the western part of Section C. Thus, the Kuroshio has the two cores of current at Section C. (5) The direction of the computed current near the mooring station M agrees with the direction of the current measurements at 200 and 500 m from moored current meters, i.e., their directions both are northwestward. (6) About 3.34×106 m3/s of the South Chin Sea water probably flows slowly from the northwest to the southeast in the layer below 550 m at the western part of Section B.

Electrochemistry of polyamidoamine dendrimers ester gel electrolytes

This paper described the first example of polyamidoamine dendrimers ester(PAMAM) used as a gel electrolyte with a short-chain polyethylene glycol (MPEG-400) as aplasticizer. The polymer films are solid and sticky. Background cyclic voltammetry (CV) shows apotential window between +0.7 and -0.7 V vs. Ag/AgCl. The voltammetry of ferrocene and7,7,8,8-tetracyanoquinodimethane (TCNQ) indicates that diffusion coefficients are in the range of10^(-8) -10^(-9) cm^2/s. Ionic conductivities are approximately 10^(-6) S/cm. Similar films usingdimethyl sulfoxide (DMSO) as a plasticizer instead of MPEG-400 have demonstrated ionicconductivities of 10^(-4) S/cm and reversible voltammetry. However, UV spectropho-tometry shows that70% of the DMSO is lost under vacuum, indicating the difficulty in quantifying the DMSO contentwhen exposed to vacuum.

Statistical Mechanics Approach for Uniform and Non—uniform Fluid with Hard Core and Interaction Tail

One recently proposed self-consistent hard sphere bridge functional was combined with an exponential function exp(-cr) and a re-normalized indirect correlation function to construct the bridge function for fluid with hard core and interaction tail. In the present approach, the adjustable parameter α was determined by the thermodynamic consistency realized on the compressibility modulus, the re-normalization of the indirect correlation function was realized by a modified Mayer function with the interaction potential replaced by the perturbative part of the interaction potential. As an example, the present bridge function was combined with the Ornstein-Zernike (OZ) equation to predict structure and thermodynamics properties in very good agreement with the simulation data available for Lennard-Jones (L J). Based on the universality principle of the free energy density functional and the test particle trick, the numerical solution of the OZ equation was employed to construct the first order direct correlation function of the non-uniform fluid as a functional of the density distribution by means of the indirect correlation function. In the framework of the density functional theory, the numerically obtained functional predicted the density distribution of LJ fluid confined in two planar hard walls that is in good agreement with the simulation data.

A New Uniform Phase Bridge Functional：Test and Its Application to Non—uniform Phase Fluid

A new bridge functional as a function of indirect correlation function was proposed, which was basedon analysis on the asymptotic behavior of the Ornstein-Zernike (OZ) equation system and a series expansion whoserenormalization resulted in an adjustable parameter determined by the thermodynamics consistency condition. Theproposed bridge functional was tested by applying it to bulk hard sphere and hard core Yukawa fluid for the predictionof structure and thermodynamics properties based on the OZ equation. As an application, the present bridge functionalwas employed for non-uniform fluid of the above two kinds by means of the density functional theory methodology, theresulting density distribution profiles were in good agreement with the available computer simulation data.

Instability of Non—Fermi Liquid Behavior in the Two—Channel Kondo Model

The effects of interchannel scattering of conduction electrons by the impu rity and repulsion of conduction electrons at the impurity site on the two-channel Kondo model are simultaneously considered in this paper.It is shown that these two perturbations will substantially modify the usual local non-Fermi liquid behavior of the two-channel Kondo model.With bosonization and unitary transformations we find that the system can be transformed into a single channel Kondo model with anisotropy between longitudinal and transverse exchange couplings.Whatever for originally antiferromagnetic or ferromagnetic isotropic coupling,the system always flows to strong-coupling limit,which exhibits local Fermi liquid behavior at low temperatures.

Effects of Mifepristone (RU_(486)) on Hypophysis, Ovary,Uterus and Placenta in Pregnant Rats

The effects of mifepristone (RU486) on the early and middle stage of pregnant rats were examined using light and electron microscopy. Two groups of pregnant rats were administered with RU486, at a dose of 1. 25 mg/rat on days 7 and 10 of pregnancy, respectively. Thereafter all the rats with middle stage had abortion with necroticdecidua at 48h post administration. However, uterus endometrium returns to normal. The number of the lipid droplets in the luteal cells increased. The level of serum progesterone was significantly lower than that of the control group. For rats with early stage pregnancy, the development of some embryos in two cases was similar to that of the control group at 48h post administration. The embryos of the remaining rats in the group were all disintegrated. Nevertheless, two rats had their uteri restored. There were no significant differences in the structure of corpus luteum, the levels of hypophyseal gonadotrophin nor the serum progesterone between the treated and the control groups. These results indicate that the anti-pregnant activity of RU486 is more effective during the middle stage pregnancy than in the early pregnancy in rats.

DENSENESS OF RADIAL-BASIS FUNCTIONS IN L^2(Rn) AND ITS APPLICATIONS IN NEURAL NETWORKS

The authors discuss problems of approximation to functions in L2(Rn) and operators fromL2(Rn1) to L2(Rn2) by Radial-Basis Functions. The results obtained solve the problem ofcapability of RBF neural networks, a basic problem in neural networks.

Origin and evolution of new genes

Organisms have variable genome sizes and contain different numbers of genes. This difference demon-strates that new gene origination is a fundamental process in evolutionary biology. Though the study of the origination of new genes dated back more than half a century ago, it is not until the 1990s when the first young gene jingwei was found that empirical investigation of the molecular mechanisms of origination of new genes became possible. In the recent years, several young genes were identified and the studies on these genes have greatly enriched the knowledge of this field. Yet more details in a general picture of new genes origination are to be clarified. We have developed a systematic approach to searching for young genes at the genomic level, in the hope to summarize a general pattern of the origination and evolution of new genes, such as the rate of new gene appearance, im-pact of new genes on their host genomes, etc.

Research of stability condition for time-invariant nonlinear system

We present here a stability condition and its verification method for the time\|invariant nonlinear system. This stability condition is based on the small gain theorem in regard to L\-2 gain, and its verification method is described by the Nyquist criterion and the modified M\|circle set(alike to Popov’s criterion). In order to verify the above system stability, we assume the system nonlinear part as a non\|linear subsystem with a free parameter q≥0, and focus on the change of some peak value of the relative position between the vector locus of the open loop frequency response characteristic and the modified M\|circle set, which may be available for stability analysis and robust design of the control system.