ISSN 0253-2778

CN 34-1054/N

2009 Vol. 39, No. 1

Display Method:
The technological progress of synthesizing glycol using coal to replace petro-ethylene
CHEN Yi-dun, LI Guo-fang
2009, 39(1): 1-10.
The technique of synthesizing glycol using coal or natural gas to replace petro-ethylene is a major C1 chemical technology that is the most scientific route of raw materials, the most reasonable usage of resources, and thus an obviously more advanced technique than that using petroleum-based raw materials. The research and development were carried out, first in the world, with only industrial raw materials, and for more than 20 years we finally succeeded in obtaining three catalysts with excellent performance and six matching techniques. On the other hand, we have applied for four national patents for inventions and formed a full set of intellectual property rights of independent innovation with new techniques and new technologies by Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences. After a successful cooperative research and development with Jiangsu Danyang Chemical Technology Co.Ltd, a middle-scale pilot plant with an annual production capacity of 300 tons for synthetic glycol replacing petro-ethylene by coal has been set up successfully and a 10 000-ton model factory for synthetic glycol has been completed and put into production. A plant of ethylene glycol by using lignite to replace petro-ethylene is under construction in Tongliao, with a production capacity of 200 000 tons per year. These results demonstrate that the complete sets of engineering and technology have entered the industrialization stage of implementation and application. This technology conforms to Chinas coal-based resource characteristics and the reality that the lignite resources in China are in urgent need of development. This is a real resource-saving and energy-saving technology and recycling economy. At the same time, in the production process, very little waste pollution occurred so it can meet the requirement of environmental protection. This technology can also be used for the production of oxalete ester, oxalic acid, ethylene glycol, oxamide and other important chemical raw materials. A huge new industry group can be established by this technology and will create enormous economic and social benefits. Large-scale implementation of this technology will realize the strategic objectives of synthetic glycol replacing petro-ethylene by coal or natural gas and have a significant impact on Chinese energy and chemical industry.
Trends of Antarctic research
WU Yi-lin
2009, 39(1): 11-14.
The common areas and methodologies, including current tendencies and trends, as well as individual national characteristics, were analyzed, based on the Antarctic scientific research strategies of sovereign states such as the USA, Britain, Australia and New Zealand. This critique also examined the role that the Scientific Committee on Antarctic Research plays in international research cooperation and emphasized the importance of understanding Antarctic research strategy.
Relationship between stratospheric circulation anomalies and extended snow storm
CHEN Yue-juan, ZHOU Ren-jun, DENG Shu-mei, YI Ming-jian, LIU Yi
2009, 39(1): 15-22.
In order to investigate the relationship between the stratospheric circulation anomaly and the exceptionally serious snow storms which occurred in the southern part of China in 2008, the variation of the atmospheric circulation in the stratosphere from October, 2007 to February, 2008 was analyzed using NCEP data. The results show that before the occurrence of the snow storms the stratospheric north polar vortex abnormally strengthened and deformed, and the stratospheric circulation in the middle-lower latitudes changed significantly. These anomalies propagated downward and affected the troposphere. This means that the snow storms were connected not only with the changes of the tropospheric circulation, but also with the changes of the stratospheric circulation. Meaningfully, the changes of the stratospheric circulation were more than a month ahead of the snow storms. Therefore information of the stratospheric circulation is very conducive to improving the middle and long term weather forecast, especially the forecast of serious meteorological calamities.
Comprehensive observation research on urban atmospheric boundary layer — Description of field experiment and analysis of micrometeorological properties in the surface layer
LIU Gang, SUN Jian-ning, JIANG Wei-mei, LIU Hong-nian, YUAN Ren-min, LUO Tao
2009, 39(1): 23-32.
Two field observation experiments in Nanjing aimed at urban boundary layer researches were described. The observation data were analyzed and some micrometeorological properties in the urban surface layer were obtained. The main results are: Air temperature in the urban area is significantly higher than in the suburban area, which embodies the presence of urban heat island effect, and the differences of air temperature between the urban and suburban areas decrease with height. During the observation period in the winter of 2006, wind speed in the urban area is about 1 m/s less than in the suburban area, which reflects the damping, friction and drag effects of urban buildings on the airflow. Sensible heat flux in the daytime in the urban area is approximately equivalent to that in the suburban area, but latent heat flux in the urban area is far less than in the suburban area, thus the Bowen ratio in the urban area is far larger than in the suburban area. In the summer, friction velocity in the urban area is 34% larger than in the suburban area, and is 23% larger in the winter. In this paper, a new variable, normalized friction velocity, was introduced, of which the mean value was found a constant not varying with time and season. It is found that the proportion of vertical turbulent energy to total turbulent energy in the urban area is somewhat larger than in the suburban area during the winter of 2006.
Kelvin-Helmholtz instability of sheared electron flow at the magnetopause
XIE Tao, TAO Xin
2009, 39(1): 33-36.
Magnetopause is the boundary layer formed by the interaction of solar wind with magnetosphere, and current flows upon it. The current was considered as the sheared electron flow, and the Kelvin-Helmholtz (K-H) instability induced by the sheared electron flow of nightside magnetopause was discussed. Because of the effect of the electric field, instabilities of the shear electron flow are a little more complicated than those of the shear plasma flow. From the results obtained from the paper, K-H instability rising from sheared electron flow is easy to occur at the inner boundary of the magnetopause, and, it is likely that K-H instability happens when the velocity of sheared electron flow is between two thresholds. And, comparing the nightside near earth magnetopause with the magnetotail, we found that when the ratio of electron number densities of magnetopause is constant, and high electron number density can raise K-H instability. It is obvious that the variations of n2/n1 influenced the effective growth rates: K-H wave centralizes the lower velocity region with bigger n2/n1, and its effective growth rate is smaller.
The thermal control of minisized-electromotor in lunar environment
WANG Hai-tao, YE Hong
2009, 39(1): 37-42.
The thermal control problem of minisized-electromotors in a lunar detector was analyzed. Based on the actual parameters of some minisized-electromotors, a thermal control system using an umbrella-like radiation cooling surface was conceived. The key influencing factors, such as the operating torque of the minisized-electromotors, lunar surface temperature, lunar latitude, etc., were considered. And the variations of the thermal states of the system with the above-mentioned factors were simulated. The results show that, with the proposed thermal control system, the minisized-electromotors temperature can be controlled in the allowed upper limit of the lunar environment.
Influence of cover ratio of PV cells and glass cover on the performance of the PV solar assisted heat pump
HE Han-feng, JI Jie, PEI Gang, HE Wei, LIU Ke-liang
2009, 39(1): 43-49.
The PV solar assisted heat pump (PV-SAHP) can generate electricity and thermal energy from solar radiation simultaneously. Change in the cover ratio of PV cells leads to an opposite influence on the photovoltaic and thermal performance: the increase of the PV cells cover ratio is advantageous to the photovoltaic process but adverse to the photothermic process. Additionally, the use of glass cover also leads to a similar influence. To evaluate the performance of PV-SAHP, based on the dynamic distributed parameter model of the system and the second law of thermodynamics, the effects of PV cells cover ratio and glass cover were contrastively analyzed. The results show that the increase of the PV cells cover ratio is advantageous to the performance of the system, while the use of glass cover is adverse to the performance of the system.
Combustion of n-heptane in porous inert medium
LIN Bo-ying, CHEN Yi-liang, LIU Ming-hou
2009, 39(1): 50-56.
Application of porous inert medium (PIM) to internal combustion engines(ICE) promises high efficiency, low emissions and general practicability. The constant volume ignition of n-heptane droplets in PIM was simulated by a zero dimensional model using detailed chemical kinetics. Empirical relations for heat and mass transfer coefficients were used in the model, and Raoults law was employed to account for chemical equilibrium at the droplet surface. A homogeneous isotropic black-body radiation was assumed within PIM. Under normal conditions, PIM remained at a nearly constant temperature. Results show that PIM can drastically reduce the ignition delay time. This is of great benefit to ignition control of ICEs. Rate-of-pressure-rise can also be reduced, leading to a relatively low noise level. Emissions are, in general, relatively low.
Experimental and numerical study on the performances of mini-channel heat sinks
LIU Dong, LIU Ming-hou, XU Kan, WANG Ya-qing
2009, 39(1): 57-62.
Experimental and numerical investigation on the thermal performances of mini-channel heat sinks for cooling the integrated electronic chip with 50 W/cm2 power density using the liquid-cooling technology was conducted. The characteristics of total heat exchange and heat flux performance were obtained by measuring and simulating the heated surface temperature, the inlet and outlet temperature of coolant, under different flow rates and heating power conditions. The heat sinks can effectively remove the high density heat generated by the integrated electronic chip on the surface heat flux up to 56 W/cm2 and the pressure drop under 400 Pa with Reynolds number under 50 and surface temperature under 85 ℃. The friction factor of mini-channel heat sinks decreases with Reynolds number under the Reynolds number we checked and the heat flux increases with the surface temperature and flow rate. The convective heat transfer coefficient of the mini-channel heat sinks increases with Reynolds number, and the extent increases with power density.
Study on mini-channel structured radiator filled with porous media
XU Kan, LIU Ming-hou, LIU Dong, WANG Ya-qing
2009, 39(1): 63-68.
The mini-channel structured radiator filled with copper porous media was proposed for heat transfer enhancement. The performance of this radiator was studied in terms of heat flux, Nusselt number and thermal resistance through several measurements of the mass flux, temperature difference and pressure drop between inlet and outlet of the coolant. It is found that the mean volume heat flux of this radiator reaches up to 250 W/mm3. Compared with the Rj, in-Δp relationship of Zhangs results, it is found that lower consumption of pump and thermal resistance can be achieved. Additionally, numerical simulation indicates that the radiator with copper porous media may obtain more uniform temperature distribution.
Analysis and numerical simulation of microheater thermal field
TANG Qiong-hui, XU Jin-liang
2009, 39(1): 69-75.
The thermal response and distribution of microheaters were studied to further investigate the law of periodic bubble generation on the surface of microheaters, and dimensionless solid-liquid coupling heat conduction concerning microheaters and the surrounding liquid was thus analyzed. Based on the example of Pt film as the heating resister and water as the working liquid, it is concluded that the dimensionless time does not relate to the thickness of film heater, but varies with the dimensionless value of volume heating resource. Compared with current heating pulse, quadratic voltage heating pulse is more liable to incite periodic bubbles and more applicable as well. Besides, the thickness of superheated liquid layer and the affected zone was defined and discussed.
Performance of the mechanical vapor compression desalination system
JIAO Dong-sheng, WANG Jun
2009, 39(1): 76-82.
A mechanical vapor compression desalination system was set up, of which the designed capacity is 2 m3·d-1, and the evaporator temperature is 95 ℃. The system is composed of evaporator-condenser, compressor and preheaters. The performance of the components and the effects of the parameters on the energy consumption were analyzed experimentally and theoretically. The results indicate that the experimental system works well when the operating temperature is in the range from 89 ℃ to 97 ℃, and that the production rate increases with the evaporator temperature. When the salinity reduces from 40% to 20%, the production rate increases by about 72%. The least seawater separation work of the system is 594 kJ·kg-1.
Physiological characterization of a microbial consortium that reductively dechlorinates 1,1-dichloroethane to chloroethane
YANG Rui, SUN Bao-lin
2009, 39(1): 83-89.
An anaerobic microbial consortium reductively dechlorinating 1,1-dichloroethane (DCA) to chloroethane (CA) was enriched from the sediment of Hudson River, New York. The consortium used hydrogen, formate, acetate, benzoate and fumarate as electron donors for reductive dechlorination. Pyruvate fermentation occurred in the enrichment culture, although this compound was not used as an electron donor for dechlorination. Among other halogenated compounds tested, only DCA was reductively dechlorinated. Sulfite could completely inhibit DCA dechlorination, whereas sulfate, nitrate or fumarate had no effect. Growth by reductive dechlorination with hydrogen as electron donor was revealed by a cell yield of (4402±1241)g of cells (dry weight) per mole of chloride released. Sequence analysis of 16S rRNA gene amplified from a highly enriched culture with H2 as electron donor suggests that Dehalobacter species dominated the enrichment culture under dechlorination conditions.
Basic study on inactivation of phage in serum and its mechanism
MA Xiao-li, WU Qing-qing, WEN Long-ping
2009, 39(1): 90-94.
To investigate factors affecting the viability of phage in the blood and provide a basis for improving in vivo phage display applications, the percentages of active phage in serum and blood at various time points were measured, phage viabilities after various treatment conditions (washed by KSCN, high temperature which can inactive complement, injection of immune suppressor, and use of nude mice) were compared, and some preliminary solutions to overcome this problem were put forward. The results show that serum can cause rapid inactivation of phage. KSCN and cyclophosphamide can partially, while 60 ℃ treatment can almost completely, inhibit this inactivation effect. The inactivation profile in nude mice is comparable to that in normal mice. Tryptone and BSA can partially overcome the inactivation factor in the serum. It was concluded that a heat-labile serum factor, most likely a type of complement-mediated IgM reaction, is responsible for inactivating phage in the blood.
Effects of external noise on motion perception in amblyopia
ZHANG Yang, XU Peng-jing, QIU Zhu-ping, ZHOU Yi-feng
2009, 39(1): 95-100.
There are two conflicting opinions about the mechanism of the motion perception deficit in amblyopia. One is that the deficit observed in temporal detection test ought to be accounted for by the deficit of the visual spatial information input from the amblyopic eye, while the other focuses on the temporal detection deficit of amblyopes. So far, no systematic research with external noise has been performed on the temporal perception of visual stimuli in amblyopia. In this study, we used drifting vertical sine-wave gratings under different temporal frequencies as stimuli, and compared the motion direction discrimination performances between fifteen anisometropic amblyopes and nineteen normal controls in the conditions with and without external noise. It can be concluded that the contrast sensitivity ratios between amblyopic eyes and non-amblyopic eyes are independent on the temporal frequency, and the external noise has the equivalent impact on the temporal detection performance in amblyopes and normal controls. Thus, it reveals that the temporal perception pathway of amblyopes is intact. This study can help with understanding the impairment mechanisms of amblyopia and pursuing a suitable therapy for amblyopes.
Action of glycine, lysine, tyrosine and methionine in Micromonospora echinospora
GUAN Yu-xia, ZHANG Hong-xiu, LUO Hong, TANG Cui
2009, 39(1): 101-105.
The promoters (amino acids) were screened out by the orthogonal design in the course of biosynthesis micronomicin from the mutant strain (Fzu-707) of Micromonospora echinospora. Certain amount of glycine, lysine, tyrosine and methionine was added to the original medium in a flask on the rotary shaker 220 r/min and incubated at 36 ℃. It was propitious to biosynthesize micronomicin in cells of Micromonospora echinospora. The fermentation time was shortened from 144 h to 104 h, the yield of micronomicin (u·mL-1) was increased about 20% compared with the control group and the production rate of micronomicin was increased about 60%.
Preparation and crystallization behavior of polyoxymethylene/molybdenum disulfide nanocomposites
WANG Jin, HU Kun-hong, SHI Tie-jun, HU Xian-guo
2009, 39(1): 106-110.
Polyoxymethylene/molybdenum disulfide (POM/MoS2) nanocomposites were prepared by means of in situ intercalation/polymerization. The intercalation mechanism was discussed. The structure of composites was confirmed by means of X-Ray diffractometer (XRD), and the results indicate that the interlayer spacing of MoS2 increases from 0613 nm to 1118 nm. The morphologies of POM/MoS2 nanocomposite were observed by Transmission Electron Microscopy (TEM). This shows that the MoS2 has a good dispersion in the polymer matrix, and is still in a layer state. It can be concluded that POM/MoS2 is an intercalated nanocomposite. The nonisothermal crystallization kinetics of POM and POM/ MoS2 were also investigated by Differential Scanning Calorimetry (DSC) at various cooling rates. The Avrami analysis modified by Jeziorny was employed to describe the nonisothermal crystallization process of POM and POM/ MoS2. The results show that MoS2 plays a role of a nucleating agent for nonisothermal crystallization of POM. In comparison with pure POM, POM/MoS2 exhibits a faster crystallization rate and increases crystallization temperature.