2004 Volume 15 Issue 7

Efficient Synthesis of the C1-C7 Fragment of Didemnaketal A
Xue Qiang LI , Xue Zhi ZHAO , Pei Nian LIU , Yong Qiang TU
2004, 15(7): 757-758
[Abstract](192) [FullText HTML] [PDF 681KB](6)
The stereoselective synthesis of the C1-C7fragment (3R,4S,6R)-3,4-di[(tert-butyl-dimethylsilyl)oxy]-7-hydroxy-6-methylheptan-2-one, which is the crucial intermediate for synthesis of the HIV-1 protease inhibitive didemnaketals, was developed via 12 steps from the natural (+)-pulegone.
New Approach to Synthesis of Tetrahydroisoquino[2,1-c][1,3]-benzodiazepine
Hong Min MA , Zhan Zhu LIU , Shi Zhi CHEN , Xiao Tian LIANG
2004, 15(7): 759-761
[Abstract](169) [FullText HTML] [PDF 1145KB](0)
A concise and efficient synthesis of the new compounds tetrahydroisoquino[2,1-c] [1,3] benzodiazepine 5 and 7 is reported.
A Concise and Stereoselective Synthesis of the Cathasterone's Side Chain
Tian Sheng MEI , Li Zeng PENG , Tao ZHANG , Yu Lin LI
2004, 15(7): 762-764
[Abstract](184) [FullText HTML] [PDF 874KB](0)
A concise and stereoselective synthesis of cathasterone's side chain using methyl isopropyl ketone 3 as the fragment is described.
Synthesis of New 13-O-Acylavermectin B1 Aglycones
Qing An WU , Zhen Yuan XU , Mei ZHENG , Dan Qian XU , Jun XU , Yin Chu SHEN
2004, 15(7): 765-767
[Abstract](178) [FullText HTML] [PDF 853KB](0)
Six new 13-O-acylavermectin B1 aglycones(3~8) were synthesized from avermectin B1 aglycone and their bioactivities were evaluated against Spodoptera exigua, Spodoptera eridania, Tetranychus urticae and Aphis fabae.
Enzymatic Synthesis of a CCK-8 Tetrapeptide Fragment
Guang Ya XIANG , Heiner ECKSTEIN
2004, 15(7): 768-770
[Abstract](180) [FullText HTML] [PDF 1195KB](0)
The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt is reported. It was synthesized by coupling Phac-Met-OEt with Gly-OMe·HCl, Trp-OMe and Met-OEt successively, catalyzed by α-chymotrypsin, papain and α-chymotrypsin respectively. The results of FAB-MS showed that the products had the correct molecular mass.
Photoaffinity Probe Candidates for Gamma-aminobutyric Acid (GABAA)-Gated Chloride Channel
Shang Zhong LIU , Qing Xiao LI
2004, 15(7): 771-773
[Abstract](194) [FullText HTML] [PDF 1111KB](0)
New photoaffinity ligand candidates were synthesized based on 5-t-butyl-2-(4-(substituted-ethynyl)phenyl)-1, 3-dithiane for the noncompetitive blocker site on the gamma-aminobutyric acid-gated chloride channel. Their half-maximal inhibition concentrations ranged from 4 to 32 nmol/L as measured by 4'-ethynyl-4-n-[2,3-3H2]-propylbicycloorthobenzoate (3H EBOB) assay.
Hydroaminomethylation of 1-Dodecene Catalyzed by Water-soluble Rhodium Complex
Ying Yong WANG , Mei Ming LUO , Yao Zhong LI , Hua CHEN , Xian Jun LI
2004, 15(7): 774-776
[Abstract](185) [FullText HTML] [PDF 941KB](0)
The hydroaminomethylation of 1-dodecene catalyzed by water soluble rhodium complex RhCl(CO)(TPPTS)2 in the presence of surfactant CTAB was investigated. High reactivity and selectivity for tertiary amine were achieved under relatively mild conditions.
An Unusual Reductive Ring-opening Reaction of Phthalimide with Sodium Hydride in DMF
Xiang Bao MENG , Hui LI , Qing LI , Zhong Jun LI
2004, 15(7): 777-778
[Abstract](180) [FullText HTML] [PDF 645KB](0)
An unusual reductive ring-opening reaction of phthalimide with sodium hydride in anhydrous DMF was observed for the first time. The presumed mechanism was described in detail.
Direct Synthesis of Oxygenates from Water and Methane via Dielectric-barrier Discharge
Bao Wei WANG , Gen Hui XU
2004, 15(7): 779-780
[Abstract](188) [FullText HTML] [PDF 753KB](0)
In this investigation, a clean, atomic economic and direct synthesis of oxygenates (methanol, ethanol) form water and methane via dielectric-barrier discharge was developed at room temperature and under atmospheric pressure. The effect of discharge voltage on this process was studied. The results showed that the conversion of water can be as high as 7%, the selectivity of methanol and ethanol can be as high as 100%.
Synthesis of Tigogenyl 2-Deoxy-2-phthalimido-D-glucopyranoside Derivatives and Study of their 1H-NMR Spectrum
Shu Jie HOU , Chuan Chun ZOU , Ping Sheng LEI , De Quan YU
2004, 15(7): 781-784
[Abstract](175) [FullText HTML] [PDF 1497KB](0)
Two protected tigogenyl glycosides were synthesized via parallel synthesis of oligosaccharide. Using chemical synthesis and conformational analysis the reason of the proton signal of 2" acetyl group shifted up field in 1H-NMR was discussed.
Synthesis of Novel Nucleoside Analog (3R)-2,3-Dideoxy-3-(N-hydroxy-N-methylamino)-L-arabinofuranosyl Uracil
Ji Cheng CHU , Hong Sheng GUO , Jun Biao CHANG , Kang ZHAO
2004, 15(7): 785-786
[Abstract](176) [FullText HTML] [PDF 771KB](0)
The synthesis of novel nucleoside analog (3R)-2,3-dideoxy-3-(N-hydroxy-N-methylamino)-L-arabinofuranosyl uracil was studied. A twelve-step synthetic route, started from L-ascorbic acid, was designed, and the final product was obtained in 20.8% yield.
A Facile Synthetic Method for Biphenyltetracarboxylic Dianhydrides
Xue E WU , Chang Lu GAO , Meng Xian DING , Suo Bo ZHANG , Lian Xun GAO
2004, 15(7): 787-790
[Abstract](199) [FullText HTML] [PDF 1451KB](1)
We report a facile and high-yielding procedure for preparing biphenyltetracarboxylic dianhydrides (BPDAs). This method relies on a nickel-catalyzed electroreductive coupling reaction of dimethyl 3-chorophthalate (3-DMCP) and/or dimethyl 4-chorophthalate (4-DMCP) with subsequent hydrolysis of tetra-ester and dehydration of tetra-acid.
A New Sesquiterpenoid from Magnolia delavayi
Jian Xin CAO , Guo Fang LAI , Yi Feng WANG , Yuan Feng HUANG , Shi De LUO
2004, 15(7): 791-793
[Abstract](191) [FullText HTML] [PDF 944KB](0)
A new sesquiterpenoid was obstained from the leaves of Magnolia delavayi. Its structure was determined as 8β-acetoxy-10α-ethyloxy-guaia-4α, 11-diol on the basis of spectral evidence.
New Sesquiterpenes from Cacalia ainsliaeflora
Man Jun MAO , Cheng Shan YUAN , Zhong Jian JIA
2004, 15(7): 794-796
[Abstract](188) [FullText HTML] [PDF 954KB](0)
Two new eremophilane sesquiterpenes, 3β-angeloyloxy-8-oxo-eremophil-6(7)-en-12-oic acid 1 and 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en-12-oic acid 2, and a novel nor-eremophilane derivative, 3β-angeloyloxy-10β-hydroxy-8-oxo-eremophil-6(7)-en 3 were iso-lated from the roots of Cacalia ainsliaeflora. Their structures were elucidated by spectroscopic methods, including 2D NMR.
A Novel Cardiac Glycoside from Parepigynum funingesis
Jian Xin CAO , Yi Feng WANG , Guo Fang LAI , Shi De LUO
2004, 15(7): 797-800
[Abstract](175) [FullText HTML] [PDF 1230KB](0)
From the dried aerial part of Parepigynum funingesis Tsiang et P. T. Li (Apocynaceae), a new cardiac glucoside, named parefuningoside (1) had been isolated. Its structure was determined by means of hydrolysis and spectral analysis.
Reaction of Nitrosonium (NO+) with Schiff Bases
Yu Lu ZHOU , Cong De HUO , Shu MIAO , Long Min WU
2004, 15(7): 801-804
[Abstract](206) [FullText HTML] [PDF 1257KB](6)
The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate
Electrochemical Reduction of Oxygen on Multi-walled Carbon Nanotubes Electrode in Alkaline Solution
You Qun CHU , Chun An MA , Feng Ming ZHAO , Hui HUANG
2004, 15(7): 805-807
[Abstract](182) [FullText HTML] [PDF 1220KB](0)
The multi-walled carbon nanotubes (MWNTs) electrode was constructed using poly-tetrafluoroethylene as binder, and the electrochemical reductive behavior of oxygen in alkaline solution was first examined on this electrode. Compared with other carbon materials, MWNTs show higher electrocatalytic activity, and the reversibility of O2 reduction reaction is greatly improved. The experiments reveal that the electrochemical reduction of O2 to HO2- is controlled by adsorption. The preliminary results illustrate the potential application of MWNTs in fuel cells.
Superoxide Anion Radical Scavenging Ability of Quaternary Ammonium Salt of Chitosan
Xiao Yan ZHU , Jian Min WU , Zhi Shen JIA
2004, 15(7): 808-810
[Abstract](194) [FullText HTML] [PDF 1191KB](0)
A series of N-alkyl or N-aryl chitosan quaternary ammonium salt were prepared using 96% deacetylated chitosan. Their scavenging activities against superoxide anion radical were investigated by chemiluminescence. The IC50 values of these compounds range from 280 to 880 μg/mL, which should be attributed to their different substitutes.
Purification and Structure Identification of Hyaluronic Acid
Shui Sheng HONG , Jia CHEN , Jian Guo ZHANG , Yan Chun TAO , Lan Ying LIU
2004, 15(7): 811-812
[Abstract](197) [FullText HTML] [PDF 818KB](2)
Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis, 13C NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16×106D, which was measured by viscosity method.
Promotion of the Direct Electron Transfer of Hemoglobin by the Carbon Nanotube
Jing CHEN , Chen Xin CAI
2004, 15(7): 813-816
[Abstract](189) [FullText HTML] [PDF 1757KB](0)
It is reported that the direct electron transfer of hemoglobin (Hb) can be effectively promoted by carbon nanotubes when Hb was immobilized on the surface of the carbon nanotubes modified electrode. The results indicated that the conversion of Hb-Fe(Ⅲ)/Hb-Fe(Ⅱ) is a one-electron coupled one-proton reaction process. The method presented can be easily extended to study the direct electrochemistry of other proteins or enzymes.
Analysis of Hydrolysis Reaction of N-Phosphoryl Phenylalanine by HPLC-ESI-MS/MS
Shu Xia CAO , Jian Chen ZHANG , Jun XU , Xin Cheng LIAO , Yu Fen ZHAO
2004, 15(7): 817-820
[Abstract](185) [FullText HTML] [PDF 1184KB](0)
Hydrolysis procedure of N-phosphoryl phenylalanine (DIPP-Phe) was studied by HPLC-ESI-MS/MS. The results showed that (HO)(i-PrO)P(O)Phe was the main intermediate and the hydrolysis of DIPP-Phe also occurred through a penta-coordinate transition state.
The Electrooxidation of Tetracycline at Acetylene Black Electrode in the Presence of Sodium Dodecyl Sulfate
Xue Ping DANG , Cheng Guo HU , Ying Liang WEI , Sheng Shui HU
2004, 15(7): 821-822
[Abstract](184) [FullText HTML] [PDF 766KB](1)
The electrooxidation of tetracycline (TC) at acetylene black electrode has been studied in the presence of sodium dodecyl sulfate (SDS). Tetracycline (TC) exhibited very sensitive oxidation peak in this system. The peak current was proportional to TC concentration, and the detection limit was 1.2×10-8 mol/L. The system was used to the determination of TC in pharmaceuticals.
Noninvasive Detection of the Gases Inside the Sealed Batteries by the On-line Mass Spectrometry
Xiao Rong ZHOU , Pei Fang LIU , Lin ZHUANG , Jun Tao LU
2004, 15(7): 823-826
[Abstract](198) [FullText HTML] [PDF 1324KB](0)
Mass spectrometer is connected through an adaptor to a sealed small battery to probe the gas phase changes inside the battery. The factors influencing the response time are analyzed with a simplified model. The feasibility of the new technique is demonstrated with a Ni-Cd battery, showing different profiles of MS intensities for O2 and H2. Compared with gas chromatography, this technique has the advantage of being noninvasive and should be useful for the study and diagnostic examination of small sealed batteries.
Determination of Surface pKa of Pure Mercaptoacetic Acid and 2-Mercaptobenzothiazole Mixed Monolayers by Impedance Titration
Guang Han LU , Chuan Yin LIU , Hong Yan ZHAO , Wei LIU , Li Ping JIANG , Ling Yan JIANG
2004, 15(7): 827-830
[Abstract](201) [FullText HTML] [PDF 1350KB](4)
Interfacial proton transfer reactions of pure mercaptoacetic acid (MA) and 2-mercaptobenzothiazole (Mbz) mixed self-assembled monolayers (SAMs) have been studied using a.c. impedance titration method. The charge-transfer resistance (Rct) is measured with the monolayer composition and the ionic strength of pH solution. The surface pKa can be obtained by the plots of Rct and pH, the reasons of shifts of surface pKa are also explained.
Separation of Felted Explosives by Pressurized Microemulsion Electrokinetic Chromatography
Jing JIANG , Su Xuan GONG , Hu Wei LIU , Yong ZHANG , Yu Lin DENG , Jun Ling GU , Ai Qin LUO , Li Xin WANG
2004, 15(7): 831-833
[Abstract](180) [FullText HTML] [PDF 1127KB](0)
A new MEEKC method assisted with pressure-driven mobile phase was presented for the separation of felted explosives. Microemulsion solution was composed of 80 mmol/L heptane-120 mmol/L SDS (sodium dodecyl sulphate)-900 mmol/L butanol-10 mmol/L borate at pH 9.4 and a pressure-driven flow of 0.020 mL/min under 1.3 MPa was employed to manipulate the separation. Explosives HMX (1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazacyclooctane) and TATB (triamino-trinitrobenzene), which were felted on fluorine rubber F2311(polytrifluorochlorethylene and polyvinylidene fluoride 1/1 co-polymerization)and F2314(polytrifluorochlorethylene and polyvinylidene fluoride 4/1 co-polymerization)were well separated with very good peak shapes.
Synthesis of Bowl-like Particles by Emulsion Polymerization and Release Behavior of Solvent from the Particles
Guang Jie HAO , Xiao Yi SHEN , Zhi Wu LIANG , Tian Ying GUO , Bang Hua ZHANG
2004, 15(7): 834-836
[Abstract](173) [FullText HTML] [PDF 961KB](1)
Bowl-like poly (styrene-co-glycidyl methacrylate) was synthesized by swollen seeded emulsion polymerization. The polymerization was carried out in PS seed emulsion swollen by toluene, whereby the bowl-like particles formed at last. The shape was observed by SEM. These particles became ball-like when swollen by toluene, observed by optical microscope, and the release behavior of solvent from them was examined.
A Novel Substrate for in situ Synthesis of Oligonucleotides:Hydrolyzed Microporous Polyamide-6 Membrane
Song LI , Jian Xin TANG , Mei Ju JI , Peng HOU , Peng Feng XIAO , Nong Yue HE
2004, 15(7): 837-840
[Abstract](176) [FullText HTML] [PDF 1520KB](0)
A novel substrate for in situ synthesis of oligonucleotide was prepared by hydrolyzing microporous polyamide-6 membranes in a 0.01mol/L NaOH/(H2O-CH3OH) mixture medium. The formation of amines (NH2) on the surface was proved by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The treated membrane was applied for in situ synthesis of oligonucleotide and a single step coupling efficiency determined by ultraviolet (UV) spectra was above 98%.
A Novel Approach for Observing Morphology of Polypropylene under Ultrasonic Vibration by SALS
Li Fang TONG , Ye SHEN , Qiang ZHENG , Yong Gang SHANGGUAN
2004, 15(7): 841-844
[Abstract](175) [FullText HTML] [PDF 1241KB](0)
In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for verifying polypropylene(PP) indicated that ultrasonic vibration resulted in the decrease of the crystallization rate and made PP crystallizable at low temperature.
A Nano-scale Study on Film Stability
Cheng TAO , Gen Lin TIAN , Regine V. KLITZING , Peter BEHRENBRUCH
2004, 15(7): 845-848
[Abstract](195) [FullText HTML] [PDF 1678KB](0)
Thickness and stability of films formed by different surfactants are studied by means of thin film balance (TFB) technique to observe the formation and stability of the films. It is demonstrated that stable Newton black films (NBFs) can be easily obtained with non-ionic surfactants (C12E5, C12G2) than ionic surfactants (C12TAB, C16TAB). Common black film (CBF) was obtained with C16TAB at 5×10-3 mol/L, while the film of C12TAB is unstable. It has been demonstrated that the horizontal forces should also be taken into consideration for explaining film stability.
Effect of Sodium Alginate Concentration on Membrane Strength and Permeating Property of Poly-l-arginine Group Microcapsule
Shi Bin WANG , Yuan Gang LIU , Lian Jin WENG , Xiao Jun MA
2004, 15(7): 849-852
[Abstract](169) [FullText HTML] [PDF 1504KB](0)
A novel poly-l-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.
The Preparation of B-type Starch Spherocrystals by Freezing Crystallization
Yan Qi LIU , Jiu Gao YU , Xiu Ping SUN
2004, 15(7): 853-855
[Abstract](184) [FullText HTML] [PDF 1150KB](0)
The B-typed starch spherocrystals were prepared by the dissolution and freezing crystallization of acid-hydrolyzed starch obtained by the mild hydrolysis of maize starch. The spherocrystals were characterized with scanning electron microscope (SEM), X-ray diffraction, thermogravimetry (TG) and gel pervasion chromatogram (GPC). The results show that the preparation was a B-type spherocrystal with the average degree of polymerization of 14 glucose units, and the average diameter of crystal particles was about 7μm.
Silica-supported Poly-γ-aminopropylsilane Cu2+-Pd2+ Complex:A New Catalyst System for Heck Vinylation Reaction
Ren Xian ZHOU , Shao Fen ZHAO
2004, 15(7): 856-858
[Abstract](188) [FullText HTML] [PDF 955KB](0)
In this paper, a new silica-supported poly-γ-aminopropylsilane Cu2+-Pd2+ complex was studied in Heck vinylation reaction of aryl iodide with olefins. The catalyst is highly active and stereoselective at 70-100℃, and can be resused after washing without loss in activity.
Synthesis and Crystal Structure of a Novel Compound of (C2N2H8O2) H6V10O28
Ju Tao LIU , Xiao Hong WANG , Jing Fu LIU
2004, 15(7): 859-862
[Abstract](179) [FullText HTML] [PDF 1407KB](0)
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pī, a=8.4960 (17), b=10.447 (2), c=11.299 (2)Å, α=68.82 (3)°,β=87.35 (3)°, γ=66.97 (3)°. V=855.3(3)Å3, Z=8, R1=0.0857, wR2=0.2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid.
A Novel Borophosphate Coordination Polymer with Sandwich-type Supramolecular Architecture
Mao Feng LI , Heng Zhen SHI , Yong Kui SHAN , Ming Yuan HE
2004, 15(7): 863-866
[Abstract](161) [FullText HTML] [PDF 1483KB](0)
A novel borophosphate (Hmel)3{Co2[(mel)2(HPO4)2(PO4)]·(H3BO3·H2O} (mel=melamine) has been synthesized under mild solvothermal conditions. The structure of the compound exists a high ordered organic-inorganic sandwich-type supramolecular architecture via metal-coordination, hydrogen bonds and π-π stacking interactions.
Preparation of PO43-,P2O74- Anion-Pillared Nanocrystalline Mg-Al and Zn-Al Layered Double Hydroxides in Microwave Fields
Ze Jiang ZHANG , Xiu Juan MEI , Liang Rong FEN , Shao Jie LU , Fa Li QIU
2004, 15(7): 867-870
[Abstract](203) [FullText HTML] [PDF 1388KB](1)
Using nanocrystalline[Mg-Al-CO3] and[Zn-Al-CO3] as precursors,[Mg-Al-PO4],[Zn-Al-PO4],[Mg-Al-P2O7] and[Zn-Al-P2O7] have been successfully synthesized by a direct reaction with the free PO43- or P2O74- using the microwave techniques and the anion-exchange method. And the samples thus obtained were characterized by TEM, FT-IR and XRD. The results show that the initial interlayer carbonate ions can be completely replaced by the free PO43- or P2O74- under controlled microwave conditions employed for a short time.
Study on Synthesis and Intercalation Behavior of Layered Zirconium Proline-N-methylphosphonate-phosphate
Xiao Ping RAO , Xiang Kai FU , Kai RAO
2004, 15(7): 871-874
[Abstract](186) [FullText HTML] [PDF 1506KB](0)
Zirconium proline-N-methylphosphonate-phosphate (α-ZPMPP) was prepared in the presence of HF for the first time. The α-ZPMPP sample is highly crystallized with interlayer distance of 1.52 nm. The interlayer distance of complex of α-ZPMPP with n-butylamine (α-ZPMPP-BA) is in 0.45 nm larger than that of α-ZPMPP. The α-ZPMPP possesses different intercalation behavior of host-guest compound from α-ZP.
Preparation of Pt/C Catalyst with a New and Simple Organic Sol Method
Ya Wen TANG , Gang LI , Chang Peng LIU , Wei XING , Tian Hong LU
2004, 15(7): 875-878
[Abstract](176) [FullText HTML] [PDF 1314KB](0)
It is reported for the first time that the Pt/C catalyst can be prepared with a new and simple organic sol method using SnCl2 as the reductant. It was found that the average size of the Pt particles in the Pt/C catalysts could be controlled with controlling the preparation conditions. The effect of the average sizes of the Pt particles in the Pt/C catalysts obtained with this method on the electrocatalytical activity of the oxidation of methanol was investigated.
Molecular Simulation on Transport Properties of Confined Water
Ying Chun LIU , Guo Zhen XIAO , Qi WANG
2004, 15(7): 879-882
[Abstract](190) [FullText HTML] [PDF 1449KB](0)
The diffusivity and viscosity of water confined in micropores were studied by molecular dynamics simulations. The effects of pore width and density were analyzed at pore widths from 0.9 to 2.6 nm. The diffusivity in micropores is lower than that of the bulk, and it decreases as pore width decreases and as density increases. But the viscosity in micropores is much larger than that of the bulk, and it increases as pore width decreases and as density increases. The diffusivity in channel parallel direction is obviously larger than that in channel perpendicular directions.
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