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养兰经验点滴
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作者 马明 《花卉》 2009年第10期35-35,共1页
弱株与老头的培养及管理 培养弱株与老头,因其水分挥发力弱。故不可浇水过多,否则,植料过湿便会引致芦头或兰根腐烂,至于所用植料,可用如绿豆大小的轻石粒,以利疏水,盆面再盖一层薄薄的水草以保持盆面湿润,植后置放阴凉而又通... 弱株与老头的培养及管理 培养弱株与老头,因其水分挥发力弱。故不可浇水过多,否则,植料过湿便会引致芦头或兰根腐烂,至于所用植料,可用如绿豆大小的轻石粒,以利疏水,盆面再盖一层薄薄的水草以保持盆面湿润,植后置放阴凉而又通风处,日后如见盆面之水草呈干状时, 展开更多
关键词 点滴 挥发力 培养 植料 水草 水分 浇水 兰根
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Chemical component analysis of volatile oil in drug pair Herba Ephedrae-Ramulus Cinnamomi by GC-MS and CRM 被引量:12
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作者 陈勇 李晓如 +2 位作者 赵君 周涛 邹桥 《Journal of Central South University of Technology》 EI 2007年第4期509-513,共5页
Active volatile components in drug pair(DP)Herba Ephedrae-Ramulus Cinnamomi(HE-RC),single drug HE and RC were analyzed by gas chromatography/mass spectrometry(GC/MS),chemometric resolution method(CRM)and overall volum... Active volatile components in drug pair(DP)Herba Ephedrae-Ramulus Cinnamomi(HE-RC),single drug HE and RC were analyzed by gas chromatography/mass spectrometry(GC/MS),chemometric resolution method(CRM)and overall volume integration.By means of CRM,the two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound.In total,97,62,and 78 volatile chemical components in volatile oil of HE,RC,and DP HE-RC,were respectively determined qualitatively and quantitatively,accounting for 90.08%,91.62%,and 89.76% total contents of volatile oil of HE,RC,and DP HE-RC respectively.It is further demonstrated that the numbers of volatile components of DP HE-RC are almost the sum of those of two single drugs,but some relative contents of them are changed.Some new components,such as 1,6-dimethylhepta-1,3,5-triene,tetracyclo[4.2.1.1(2,5).0(9,10)]deca-3,7-diene,globulol and(E,E)-6,10,14-trimethyl-5,9,13-pentadecatrien-2-one are found in DP HE-RC because of chemical reactions and physical changes during decoction. 展开更多
关键词 drug pair (DP) Herba Ephedrae-Ramulus Cinnamomi chemometric resolution method (CRM) volatile oil gas chromatography/mass spectrometry (GC-MS)
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Purification of indium by vacuum distillation and its analysis 被引量:3
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作者 李冬生 戴永年 +2 位作者 杨斌 刘大春 邓勇 《Journal of Central South University》 SCIE EI CAS 2013年第2期337-341,共5页
High purity (99.999% or 5N, mass fraction) indium (In) was obtained through vacuum distillation using a 2N (99%) In as input material under a dynamic vacuum of 5 Pa. The glow discharge mass spectrometry (GDMS)... High purity (99.999% or 5N, mass fraction) indium (In) was obtained through vacuum distillation using a 2N (99%) In as input material under a dynamic vacuum of 5 Pa. The glow discharge mass spectrometry (GDMS) was applied for the analysis of input material and the distilled indium. The results indicate that high-volatile impurities namely Cd, Zn, T1 and Pb can be removed from the indium matrix at the low fraction stage of 1 223 K for 120 min; Low-volatile impurities such as Fe, Ni, Cu, Sn can be reduced at the high fraction stage of 1 323 K for 120 min. The separation coefficient ,8i and activity coefficient Yi of impurities are calculated according to the experiments to fill the inadequate data of the thermodynamics. 展开更多
关键词 vacuum distillation INDIUM SEPARATION REFINING
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Correlation and Prediction of Salt Effect on Vapor Liquid Equilibrium for the System of 2-Propanol/Water 被引量:3
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作者 Fu Jiquan 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2008年第2期35-44,共10页
Binary vapor liquid equilibrium (VLE) data were measured for the systems of 2-propanol/ ethanediol and ethanediol/potassium acetate (KAc). VLE data for the system of propanol/ethanediol was tested using thermodyna... Binary vapor liquid equilibrium (VLE) data were measured for the systems of 2-propanol/ ethanediol and ethanediol/potassium acetate (KAc). VLE data for the system of propanol/ethanediol was tested using thermodynamic consistency test. The average values of Ayj and A P were 0.0776 and 0.1542 kPa, respectively. The above two sets of VLE data were correlated with the NRTL model. Ternary VLE data for the system of 2-propanol/water/KAc was used to obtain the more suitable parameters of NRTL model for binary systems of 2-propanol/KAc and water/KAc (called TDCM). For multicomponent systems, ternary and quaternary, the VLE values predicted by the NRTL model agreed well with the literature data. Influence of KAc, ethanediol, and the mixture of KAc and ethanediol on volatility between 2- propanol and water was investigated respectively. The results showed that the above-mentioned materials and mixture had different influence on volatility between 2-propanol and water. The method for correlation and prediction of salt-containing VLE is simple and effective for the said system. 展开更多
关键词 salt effect vapor-liquid equilibrium 2-propanol extractive distillation
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Desorption Kinetics of Volatile in Condensed Mode Polyethylene Process
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作者 王兆林 陈伟 +1 位作者 阳永荣 戎顺熙 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1999年第3期243-251,共9页
In this paper the desorption kinetics of volatile in condensed mode polyethylene process is studied through experiments. It is found that though the residual volatile in particles at the later stage of desorption acco... In this paper the desorption kinetics of volatile in condensed mode polyethylene process is studied through experiments. It is found that though the residual volatile in particles at the later stage of desorption accounts for a relatively small portion of the total quantity, the desorption of this part of volatile requires much longer time than at the earlier stage. For high requirement of devolatilization, the total time needed will be predominately determined by the residual amount of volatile in particles. Temperature has greater effect on the desorption rate than other influence factors, especially in the later period of desorption. A model is proposed to calculate the volatile desorption rate for condensed mode polyethylene process. 展开更多
关键词 desorption model mass transfer rate POLYETHYLENE
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Perceived Indoor Discomfort, Performance and Productivity
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作者 Ingrid Senitkova Miroslav Badida 《Journal of Civil Engineering and Architecture》 2012年第11期1514-1522,共9页
Even all indoor environmental standards are met the users are usually not satisfied and perceived discomfort is occurred in the smart office buildings. The most frequently cause of discomfort in smart buildings is ove... Even all indoor environmental standards are met the users are usually not satisfied and perceived discomfort is occurred in the smart office buildings. The most frequently cause of discomfort in smart buildings is overrun of intelligence. There are physical and psychological factors that influenced building users' comfort. An indoor air quality seems to be one of the main problems of smart office buildings. In Slovakia the office buildings relating to indoor environment European standard are mostly evaluated as the non-low polluting buildings. The pollution from building as well as the pollution from occupancy and using was respected. The odor intensity and indoor air acceptability were assessed by a sensory panel. The concentrations of total volatile organic compounds and carbon dioxide were measured. The odors from building materials studied under different air change rate are presented in this paper. The case study of indoor air acceptability concerning to indoor odors under occupancy and its affect on perceived air quality influenced by air change rate are also presented in this paper. 展开更多
关键词 Office buildings perceived discomfort air quality work performance productivity.
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Understanding Photolysis of CH_(3)ONO_(2) with on-the-fly Nonadiabatic Dynamics Simulation at the ADC(2) Level
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作者 Juanjuan Zhang Jiawei Peng +2 位作者 Deping Hu Chao Xu Zhenggang Lan 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第3期451-460,I0002,共11页
The nonadiabatic dynamics of methyl nitrate(CH_(3)ONO_(2))is studied with the on-the-fy trajectory surface hopping dynamics at the ADC(2)level.The results confirmed the existence of the ultrafast nonadiabatic decay to... The nonadiabatic dynamics of methyl nitrate(CH_(3)ONO_(2))is studied with the on-the-fy trajectory surface hopping dynamics at the ADC(2)level.The results confirmed the existence of the ultrafast nonadiabatic decay to the electronic ground state.When the dynamics starts from S_(1) and S_(2),the photoproducts are CH_(3)O+NO_(2),consistent with previous results obtained from the experimental studies and theoretical dynamics simulations at more accurate XMS-CASPT2 level.The photolysis products are CH_(3)O+NO_(2) at the ADC(2)level when the dynamics starts from S3,while different photolysis products were obtained in previous experimental and theoretical works.These results demonstrate that the ADC(2)method may still be useful for treating the photolysis mechanism of CH_(3)ONO_(2) at the long-wavelength UV excitation,while great caution should be paid due to its inaccurate performance in the description of the photolysis dynamics at the short-wavelength UV excitation.This gives valuable information to access the accuracy when other alkyl nitrates are treated at the ADC(2)level. 展开更多
关键词 Alkyl nitrate Nonadiabatic dynamics PHOTOLYSIS Conical intersection Volatile organic compound
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Impact of human motion on TVOCs inhalation dose under side re-circulated ventilation
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作者 张泉 曾丽萍 +2 位作者 谢更新 张国强 牛建磊 《Journal of Central South University》 SCIE EI CAS 2009年第4期599-607,共9页
The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly ... The main objectives were to (1) calculate the total volatile organic compounds (TVOCs) inhalation dose, (2) analyze the proportions of human’s inhaled contaminant dose from different sources, and (3) present a newly defined ratio of relative inhalation dose level (RIDL) to assess indoor air quality (IAQ). A user defined function based on CFD (computational fluid dynamics) was developed, which integrated human motion model with TVOCs emission model in a high sidewall air supply ventilation mode. Based on simulation results of 10 cases, it is shown that the spatial concentration distribution of TVOCs is affected by human motion. TVOCs diffusion characteristic of building material is the most effective way to impact the TVOCs inhalation dose. From the RIDL index, case A-2 has the most serious IAQ problem, while case D-1 is of the best IAQ. 展开更多
关键词 indoor air quality (IAQ) human motion computational fluid dynamics (CFD) simulation volatile organic compounds(VOCs) CONTAMINANT relative inhalation dose level (RIDL) index
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Thermodynamic analysis of liquid bridge for fixed volume in atomic force microscope 被引量:5
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作者 WEI Zheng HE MengFu +1 位作者 ZHAO WenBin LI Yang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第10期1962-1969,共8页
In ambient condition,capillary forces are the major contributors to the adhesive forces between the tip of an atomic force microscope(AFM) and the sample.In general,capillary forces are thought to be related to water ... In ambient condition,capillary forces are the major contributors to the adhesive forces between the tip of an atomic force microscope(AFM) and the sample.In general,capillary forces are thought to be related to water film thickness,contact time and relative humidity and so on.In this paper,an original analysis regarding the liquid bridge,based on the surface and interface thermodynamic theory,is proposed.The cases covered in the study include the capillary forces and temperature of liquid bridge for quickly drawn liquid bridge,and for nonvolatile liquid bridge.The study results show that variation in temperature may occur in the liquid bridge when it is stretched. 展开更多
关键词 liquid bridge atomic force microscope THERMODYNAMIC
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Secondary aerosol formation and oxidation capacity in photooxidation in the presence of Al_2O_3 seed particles and SO_2 被引量:3
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作者 Biwu Chu Tengyu Liu +7 位作者 Xiao Zhang Yongchun Liu Qingxin Ma Jinzhu Ma Hong He Xinming Wang Junhua Li Jiming Hao 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第9期1426-1434,共9页
To investigate the sensitivity of secondary aerosol formation and oxidation capacity to NOx in homogeneous and heterogeneous reactions, a series of irradiated toluene/NOx/air and ?-pinene/NOx/air experiments were cond... To investigate the sensitivity of secondary aerosol formation and oxidation capacity to NOx in homogeneous and heterogeneous reactions, a series of irradiated toluene/NOx/air and ?-pinene/NOx/air experiments were conducted in smog chambers in the absence or presence of Al2O3 seed particles. Various concentrations of NOx and volatile organic compounds(VOCs) were designed to simulate secondary aerosol formation under different scenarios for NOx. Under "VOC-limited" conditions, the increasing NOx concentration suppressed secondary aerosol formation, while the increasing toluene concentration not only contributed to the increase in secondary aerosol formation, but also led to the elevated oxidation degree for the organic aerosol. Sulfate formation was suppressed with the increasing NOx due to a decreased oxidation capacity of the photooxidation system. Secondary organic aerosol(SOA) formation also decreased with the presence of high concentration of NOx, because organo-peroxy radicals(RO2) react with NOx instead of with peroxy radicals(RO2 or HO2), resulting in the formation of volatile organic products. The increasing concentration of NOx enhanced the formation of sulfate, nitrate and SOA under "NOx-limited" conditions, in which the heterogeneous reactions played an important role. In the presence of Al2O3 seed particles, a synergetic promoting effect of mineral dust and NOx on secondary aerosol formation in heterogeneous reactions was observed in the photooxidation. This synergetic effect strengthened the positive relationship between NOx and secondary aerosol formation under "NOx-limited" conditions but weakened or even overturned the negative relationship between NOx and secondary aerosol formation under "VOC-limited" conditions. Sensitivity of secondary aerosol formation to NOx seemed different in homogeneous and heterogeneous reactions, and should be both taken into account in the sensitivity study. The sensitivity of secondary aerosol formation to NOx was further investigated under "winter-like" and NH3-rich conditions. No obvious difference for the sensitivity of secondary aerosol formation except nitrate to NOx was observed. 展开更多
关键词 secondary aerosol oxidation capacity synergetic promoting effect Al2O3 seed particles sensitivity
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Electrochemical impedance spectra of CdSe quantume dots sensitized nanocrystalline TiO_2 solar cells 被引量:3
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作者 XU XueQing XU Gang 《Science China Chemistry》 SCIE EI CAS 2011年第1期205-210,共6页
Quantum dots sensitized nanocrystalline Tit2 solar cells (QDSSCs) are promising third-generation pbotovoltalc devices. In comparison with conventional dye-sensitized solar cells (DSSCs), the efficiency of QDSSCs i... Quantum dots sensitized nanocrystalline Tit2 solar cells (QDSSCs) are promising third-generation pbotovoltalc devices. In comparison with conventional dye-sensitized solar cells (DSSCs), the efficiency of QDSSCs is still very low (about 3%). In this paper, the electrochemical impedance spectroscopy technology has been adopted to investigate the quasi-Fermi level and the cartier dynamics of the colloidal CdSe QDs sensitized Tit2 eletrode with S2-/Sf redox electrolytes and the series resistance of the QDSSCs. In comparison with the conventional DSSCs with I^-3/Г as redox electrolytes, the energy difference between the conduction band edge and the quasi-Fermi levels of the Tit2 films (or the Fermi levels of the redox electrolytes) in QDSSCs has been decreased by about 0.3 V, resulting in the decrease of Voc by this value. The increases of the electrolyte dif- fussion resistance and the charge transfer resistance between Pt counter electrodes and S2-/Sx redox electrolytes were attributed to the decrease of the fill factors. However, the electron lifetime and electron diffussion length for QDSSCs are longer than those for DSSCs due to the retardation of the electron recombination by the adsorbed cysteine at the surfaces of the TiO2 films. It is indicated that electron recombination at the TiO2/electrolyte interface is not the main reason for the lower Jsc of the colloidal QDs sensitized QDSSCs. Improving light harvesting efficiency and photoelectron injection efficiency should be considered in the future for such kind of QDSSCs. 展开更多
关键词 Quantum dots nanocrystalline TiO2 polysulfide redox electrochemical impedance spectroscopy solar cells
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