A small sample-size automated adiabatic calorimeter from 70 to 580 K——Molar heat capacities of α-Al_2O_3

An automatic adiabatic calorimeter for measuring heat capacities in the temperature range 70—580 K, equipped with a small sample cell of 7.4 cm~3 in the internal volume has been developed. In order to obtain a good adiabatic condition of the calorimeter at high temperature, the calorimeter was surrounded in sequence by two adiabatic shields, three radiation shields and an auxiliary temperature-controlled sheath. The main body of the cell made of copper and the lid made of brass are silver-soldered and the cell is sealed with a copper screw cap. A sealing gasket made of Pb-Sn alloy is put between the cap and the lid to ensure a high vacuum sealing of the cell in the whole experimental temperature range. All the leads are insulated and fixed with W30-11 varnish, thus a good electric insulation is obtained at high temperature. All the experimental data, including those for energy and temperature are collected and processed automatically with a personal computer using a predetermined program. To verify the     

AN ADIABATIC CALORIMETER FOR HEAT- CAPACITY MEASUREMENTS FROM 80 TO 400K——HEAT CAPACITIES OF a-ALUMINA AND n-HEPTANE

An improved automatic adiabatic calorimeter for precision measurement of heat capacities of solid and liquid phases in the temperature range 80-400 K is described. Temperature control of the shield and electrical energy measurement are automated; data processing is performed by an electronic computer. The calorimeter proper has thin L-shaped vanes which make no contact with its inner wall and a device for helium filling, which greatly improves the internal thermal equilibration and effectively reduces the surface temperature gradient. Measurements of the heat capacities of a-alumina and n-heptane, two internationally accepted heat-capacity standards, show a precision of±0.1%, agree with those of the National Bureau of Standards (NBS) within ±0.2%, and demonstrate the reliability of the apparatus.     

THE STUDY OF ADAPTABILITY OF Drepanopus bispinosus TO TEMPERATURE AND SALINITY IN THE ANTARCTIC BURTON LAKE

The tolerance to temperautre and salinity of a Calanoida copepod: Drepanopus bispinosus from the Burton Lake in the Vestfold Hills, Antarctica, was tested in each season. The results obtained show that the copepod has a marked physiological property of tolerance to low temperature and high salinity, and this property could be strengthened after winter. The response to different temperature and salinity of the copepod evidently expressed the tardy characteristics contrasted with seasons. This means that for a long term in early winter(lower temperature and higher salinity) the animal still has higher tolerance to lower salinity and higher temperature; and it is opposite in early summer. These physiological features are possibly caused by natural acclimatization in the lake. The experimental data were processed and plotted by computer. The correlation of animal's survival rate with the changes of temperature and salinity presented an approximately smooth surface of a three-degree elliptic sphere.     

AN AUTOMATED ADIABATIC CALORIMETER FOR USE FROM 80 TO 600 K——HEAT CAPACITIES OF α-ALUMINA

The construction of an automated adiabatic calorimeter for use from 80 to 600 K is reported. The main feature of the calorimoter is to mount three radiation shields in the cryostat for advancing the working tomperature. The molar heat capacity of α-Al_2O_3 has been measured in order to assess the reliability of the calorimeter. Deviations of the experimental heat capacities of α-Al_2O_3 from the smoothed curve are within ±0.3% except for a few experimental points. Our smoothed results agree with those of tho National Bureau of Standards. USA, within ±0.3% over the entire working temperature range.     

LOW-TEMPERATURE HEAT CAPACITIES AND THERMODYNAMIC PROPERTIES OF LANTHANUM AND CERIUM TRIISOTHIOCYANATE HYDRATESI (Ⅰ)——La(NCS)_3, 7H_2O AND Ce(NCS)_3. 7H_2O

The heat capacities of La(NCS)_3. 7H_2O and Ce(NCS)_3. 7H_2O have been measured from 13 to 300K with a fully-automated adiabatic calorimeter. The construction and procedures of the calorimetric system are described in detail. No obvious thermal anomaly was observed for both compounds in the experimental temperature range. The polynomial equations for calculating the heat capacity values of the two compounds in the range 13—300K were obtained by the least-squares fitting based on the experimental C_p data. The C_p values below 13K were estimated by using the Debye and Einstein heat Capacity functions. The standard molar thermodynamic functions were calculated from 0 to 300K. Gibbs energies of formation were also calculated.     

THEORETICAL AND COMPUTATIONAL INVESTIGATIONS OF NONLINEAR WAVE PROPAGATIONS IN ARTERIES (Ⅰ)——A THEORETICAL MODEL OF NONLINEAR PULSE WAVE PROPAGATIONS

In this paper, a new theoretical model of nonlinear wave propagations in arteries with surrounding tissues was put forward. The equations of motion for the blood vessels and their peripheral tissues as a system have been derived. These equations were expressed in terms of the stresses of the vessel wall and fluid, and the geometry of the blood vessel. They can be used to solve numerically the problems for the propagations of nonlinear pulse waves in arteries together with the momentum and continuity equations of incompressible-viscous flow, as well as the constitutive equations of fluid and vessel wall. The numerical solutions can involve pressure, velocities and flowrate of the blood flow, as well as displacements, velocities and stresses of the vessel wall. These physical variables of propagations of pulse waves in arteries are all of significance physiologically and clinically.     

A DYNAMIC MECHANICAL ANALYSIS STUDY OF THE TRANSITION BEHAVIOUR OF I-PP/EPDM BLENDS

The transition behaviour of the blends of isotactic polypropylene (i-PP) with ethylene-propylene terpolymer (EPDM) containing 42 wt% propylene was investigated by dynamic mechanical analysis technique (DMA). Owing to its high propylene content, EPDM is compatible with i-PP to some degree. The interaction between the two components was strengthened. As expected, for partially compatible system the glass transition temperature of i-PP in the blends shifted to lower temperature. It was found that there existed two transitions, αEPDM and βEPDM, for the EPDM used in this work. The former was considered to be the glass transition of the random chain segments of EPDM, while the latter the local motion of the long ethylene sequences in EPDM. The unusual transition behaviour of αEPDM in the blends was explained in terms of the greater thermal expansion of EPDM and the compatibility of the two components. On the other hand, the βEPDM changed with the composition of the blends in a regular manner.     

MAGNETIC SUSCEPTIBILITY OF CHINESE LOESS AS A PALAEOCLIMATIC INDICATOR

Through the studies on low temperature susceptibility, frequency dependent susceptibility, isothermal remanent magnetization, low temperature magnetization and demagnetization for loess and palaeosols one can easily reveal some significant characters of rock magnetism for the magnetic minerals of ultrafine grain sizes, those are very difficult to identify by general geological methods. It is shown in the present study that both loess and palaeosols cover magnetic grain size from superparamagnetism, single domain to multidomain. Loess samples with relative high peramagnetic minerals are dominantly of thermally stable characteristics while palaeosols have relatively high percentage of superparamagnetic grain (0.01—0.03μm). The relative grain size of magnetite is always finer in palaeosol with higher susceptibility than in loess, indicating that many tiny ferri-ferromagnetic minerals formed during the process of soll formation, which has caused a higher susceptibility in palaeosols than in loess. The cli     

EXPERIMENTAL STUDY ON REMOTE SENSING OF ATMOSPHERIC SOUNDING BY MEANS OF MULTIFREQUENCY MICROWAVE RADIOMETERS

In this paper, the principle and method of microwave remote sensing atmospheric sounding are described. In order to carry out the experimental study, the 4 channels in 5mm—1.35 cm band microwave radiometers have been constructed. The field experiment in September-October 1981 was carried out. In this paper, the results obtained by different inversion methods are compared with each other. The experimental result shows that it will be satisfactory, if the temperature profile and inversion of lower atmosphere are derived from remote sensing of 2 channels (frequencies: 52.8 Gc and 54.4. Gc) in 5 mm band. The atmospheric humidity can be obtained from the remote sensing of 1.35 cm band. While the change of air mass exists, signal reveals itself significantly in the atmospheric microwave radiation. The variations of atmospheric temperature and humidity have been analysed and compared with those obtained from radiosonde.     

SYNTHESIS OF DI（ETHYLMERCAPTOETHYL） AMINO GROUP—CONTAINING POLYSESQUISILOXANE PLATINUM COMPLEX AND ITS CATALYSIS IN HYDROSIL YLATION OF OLEFINS WITH TRIETHOXYSILANE

Three new polysesquisiloxane-bound platinum complexes were synthesized via hydrolysis of N,N-di(β-ethylmercaptoethyl)γ-(triethoxysilyl)propylamine or cohydrolysis of the monomer with dodecyltriethoxysilane or with phenylpropylthiethoxysilane and immobilixation on fumed silica,followed by reacting with potassium platinite in acetone under argon atmosphere.The platinum complexes exhibited high catalytic activity for the hydrosilylation of olefins by triethoxysilane. The effects of temperature and the amount of complex on the catalytic activity,as well as the recovery and reusability of the catalysts were investigated.     

STUDIES ON THE KINETICS OF PHASE TRANSITIONS OF A MAIN CHAIN THERMOTROPIC POLYESTER

The kinetics of phase transitions including a transition between mesophases were studied for a main-chain thermotropic polyester by means of DSC and depolarizing transmittance techniques. The isothermal process of these transitions was found to be described by the Avrami equation to high conversions. The Avrami exponents n are about 2,4, 5.3 and 2.2 for liquid crystallization, transition between mesophases and crystallization from mesophase respectively. The liquid crystallization from isotropic liquid phase occurs at very low undercoolings with high transformation rate. This behavior is explained as the results of the smaller value of the surface free energy for mesophase than that for crystallites which is evidenced by the very weak temperature dependence of liquid crystallization rate.     

Recent Progress in Low Temperature Calorimetry

The paper gives a review on recent progress on new methods, instrumental innovations and new trends in low temperature calorimetry as reported in the last five years in the literature. The paper refers to establishing strictly adiabatic conditions, improved analysis of quasi-adiabatic experiments, high resolution adiabatic and isoperibol scanning calorimeters and microcalorimeters for the study of μ-samples. This revised version was published online in August 2006 with corrections to the Cover Date.     

DETERMINATION OF VOLATILE PHENOLS IN CHINESE LIQUORS BY GC-MS

A new method for determining volatile phenols in Chinese liquors is proposed.Phenols are sorbed on a macroporous anion-exchange resin after the liquors were brought toa pH value of 12.5,then eluted with HCl-acetone,extracted with methylene dichloride andconcentrated to a suitable concentration for derivatization with pentafluorobenzyl bromide(PFB).The PFB derivatives of phenols were successfully separated by gas chromatography ona 30 m SE-54 elastic glass capillary column and detected with Ni-63 electron capture detec-tor.The characteristics of this method are:high sensitivity,low interference and 95%average recovery of phenols.The method was used successfully in the determination of vola-tile phenols in eight kinds of Chinese liquors.     

KINETICS STUDIES OF MINERAL-WATER REACTIONS IN HYDROTHERMAL FLOW SYSTEMS AT ELEVATED TEMPERATURES AND PRESSURES

This paper describes new experimental results on mlneral-water reaction kinetics obtained in plug-flow systems at high temperatures and pressures. As an example, the rates of reaction between calcite, fluorite, albite and water in the continuous flowing system have been measured in three separate studies. All experiments are carried out by suspending a sample bag in the plug-flow vessel, by pumping water at carefully controlled rates through the vessel, and by collecting and analyzing the reacted solution. In addition, the reaction mechanisms of fluorite and albite in a packed bed reactor have been studied with the aid of an axial dispersion model. The main factors controlling the effective dissolution rate with respect to temperature, solvent flow rate, and chemistry of the input solutions have been evaluated. It is also found that a non-steady state process is, in some cases, still observed, even under conditions where steady state conditions should have been attained. These results provide informatio     

LOW-TEMPERATURE HEAT CAPACITY AND THERMODYNAMIC FUNCTIONS OF 2-CHLORO-6-(TRICHLOROMETHYL)PYRIDINE

The heat capacity of 2- chloro- 6- (trichloromethyl)pyridine has heen measured with anadiabatic calorimeter in the range from 13 to 316K. There is no indication of any phasetransition or thermal anomaly in this temperature region for the present compound. Theresults have been compared with those reported in [1] in the overlapping temperaturerange. The experimental heat capacity data have been fitted to a smoothed curve by the aidof the effective frequency distribution method, and the heat capacities below 13K have beenobtained by extrapolating the fitting curve down to 0K. The standard molar thermodynamicfunctions between 0 and 400 K have been derived by combining the present heat capacitymeasurements with the previous ones. The values of C_p~o (T), S~o(T) - S~o(0), [H~o(T) -H~o(0)]/T, and - [G~o(T) - H~o(0)]/T at T = 298.15 K are 189.35, 244.60, 112 .45 and 132.15J·K~(-1)·mol~(-1), respectively.     

HEAT SHRINKING BEHAVIOUR OF γ-RADIATION CROSSLINKED POLYETHYLENE

Heat shrinking material of γ-radiation erosslinked polyethylene is widely used for various application in industry. In this study, DSC, TMA, WAXD and density measurement techniques were used to investigate the influence of MI and thermal history of LDPE on the effectiveness of network formation. Based on the results of heat stretching and heat shrinkage tests, it is found that the formation of a network as perfect as possible is indispensable to the irradiated material if good heat shrinkage property is desired. To this end, quenching technique and polyethylene with appropriate MI must be used so that an effective radiation effect will be obtained with a minimum amount of radiation dose. In spite of that the mechanical property of the irradiated polyethylene in the rubbery state is basically in agreement with the classical expression of the theory of high elasticity, only about 90% shrinkage can be reached. Besides, the heat shrinkage temperature T_s and the % shrinkage Sare both related to the radiation dose.     

THE STRUCTURE OF AGGREGATION STATE AND ISOTHERMAL CRYSTALLIZATION KINETICS OF NYLON-1010

The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD, DSE, Variance-Range Function and density measurement. The results show that crystallization of Nylon-1010 has the most suitable annealing temperature, the crystals of the Nxlon-1010 are two-dimension heterogeneous nucleation. Both low treatment temperature and high crystallization te, temperature are disadvantageous for Nylon-1010 crystal growth.     

STUDIES ON BIO-ANTIOXIDANTS——MICELLAR EFFECTS ON THE REDUCTION OF NITROXIDES BY VITAMIN C

The kinetics of reduction of nitroxides including 4-hydroxy-TEMPO, 4-methoxy-TEMPOand 4-hexanoyloxy-TEMPO, which are of different lipophilicities, by vitamin C in cationic,non-ionic and anionic micelles, i. e. CTAB, Triton X-100 and SDS, respectively, have beenstudied by ESR spectroscopy by a stopped-flow technique. A mechanism for the reactionconducted in micelles is proposed and the rate constants for the elementary reactions areevaluated. It is found that the rates of single electron transfer reactions involving the ni-troxides are dependent on the nature of the micelle and the lipophilicity of the nitroxide.The rates are increased in CTAB, decreased in SDS, whereas unaffected in Triton X-100.And the greater the lipophilicity of the nitroxide, the more pronounced the rate variation.As high as a 3600-fold increase in the rate was observed for 4-hexanoyloxy-TEMPO in CTABover that in SDS. The micellar effects are rationalized on the basis of analysis of parame-ters and line shape of the ESR spectra for     

STUDIES ON PREPARATION OF INACTIVATED VACCINES FROM CELL CULTURES OF MINK ENTERITIS VIRUS (MEV) AND THEIR IMMUNITY

In this paper, superhigh reproductive rate strains of MEV with titre more than HA8192* or TCID50 log9.7 10 have been achieved both by cultivation in cell lines with different susceptibility to MEV and by isolating and identifying in field by the author. The systematic tests proved that S18 and L12 strains of MEV are the best strains for vaccine preparation. In this study, the best means for the tissue cultivation of MEV and the most advanced technological process for the production and detection of serum-free cell-cultured MEV fluids with super-high HA titre in batches in large quantities have been established for the first time. Optimum conditions for MEV inactivation were determined, and safe and effective inactivated vaccines with mineral oil or A1(OH)3 gel adjuvant were successfully prepared with serum-free cell-cultured MEV fluids. Both vaccines with different adjuvants can be manufactured in batches in large quantities and have been widely used all over China since 1986. The change laws of the imm     

CARBONACEOUS PRODUCTS OF POLYMER-PALLADIUM COMPLEXES AS CATALYSTS FOR THE HYDROGENATION OF METHYL ACRYLATE

Many catalysts were pcrpared by carbonization of ion exchange resin-PdCl_2 complexes at high temperature in nitrogen, hydrogen atmosphere. The rates for the hydrogenation of methyl acrylate and the amounts of Pd elution of the carbonaceous products were measured and compared with those of commercial Pd/C catalyst. It indicates that the carbonaceous products are less active than Pd/C. However, the leaching of Pd from carbonaceous products is very small and much less than that from Pd/C.