EXAMINATION OF SILICATE LIMITATION OF PRIMARY PRODUCTION IN JIAOZHOU BAY, CHINA I. SILICATE BEING A LIMITING FACTOR OF PHYTOPLANKTON PRIMARY PRODUCTION

Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou Bay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO - 3 N, NO - 2 N, NH + 4 N, SiO 2- 3 Si, PO 3- 4 P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq.(1) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temperature; that the main factor controlling the primary production is Si; that water temperature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecological niches for C , the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D , the coefficient of water temperature’s effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay, the biogeochemical sediment process of the silicon, the phytoplankton predominant species and the phytoplankton structure. The authors considered silicate a limiting factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and uptake by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrinsic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant nutrient concentrations but low phytoplankton biomass in some waters is reasonably explained in this paper.

The effects of spring-neap tide on the phytoplankton community development in the Jiaozhou Bay, China

The development of the phytoplankton community was studied in the Jiaozhou Bay during the spring to neap tide in August2001, through three cruises and a 15 d continuous observation. This investigation indicates that diatom cell abundance increasedsharply following the end of a spring tide, from 9 cells/cm3 to a peak of 94 cells/cm3. The dominant species composition andabundance show a quick species sequence from spring to neap tide, and the dominant species at the start phase is Skeletomenacostatum, then changes to Chaetoceros curvisetus, finally it changes to Eucampia zodiacus. Silicate concentration increasesduring spring tide, as a result of nutrient replenishment from the watersediment interface, its initial average concentration inneap tide is 1.39 mmol/dm3 and reached the peak average concentration of 8.40 mmol/dm3 in spring tide. But the nitrogenconcentration dropped due to dilution by the low nitrogen seawater from the Huanghai Sea, its initial average concentration inneap tide is 67 mmol/dm3 and decreased to the average concentration of 54 mmol/dm3 in spring tide. The degree of siliconlimitation was decreased and phytoplankton, especially diatoms, responds immediately after nutrient replenishment in thewater column. Skeletonmea costatum, as one of the dominant species in the Jiaozhou Bay, shows a quicker response tonutrient availability than Eucampia zodiacus and Chaetoceros curvisetus. It is proposed that dominant species compositionand water column stability synchronously determine the development of phytoplankton summer blooms in the Jiaozhou bay.

Effect of Nano-anatase TiO_2 on Spectral Characterization of PhotosystemⅡParticles from Spinach

The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.

A New Sesquiterpene Lactone from Scorzonera austriaca

A new guaianolide was isolated from the roots of Scorzonera austriaca. The structure was elucidated on the basis of spectral methods including 2D NMR.

Synthesis and Crystal Structure of 1,2Bis（2-benzimidazolyl） benzene

The title compound C6H4(C7H5N2)2 was prepared by the condensation of o-phenyl- enediamine with o-phthalic acid and characterized by elemental analysis, IR, UV and H NMR 1 spectra, and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic system, space group Pbcn with a = 17.928(8), b = 8.828(4), c = 9.752(4)?, Z = 4, V = 1543.4(12) ?3, Dc = 1.336 g/cm3, Mr = 310.35, λ(MoKα) = 0.71073 ?, μ = 0.082 mm-1, F(000) = 648, R = 0.0405 and wR = 0.1092. A total of 1693 unique reflections were collected, of which 1319 with I > 2σ(I) were observed. It is shown that the compound molecule belongs to C2 point group. A one-dimensional chain structure was formed by the intermolecular hydrogen bonds (N(2)–H… N(1)).

Effects of Precursors for Preparing Intermediate Layer on the Performance of Ti/SnO_2+Sb_2O_3/PbO_2 Anode

The Ti/SnO2+Sb2O3/PbO2 anode with SnO2+Sb2O3 intermediate layer obtained by the polymeric precursor method (PPM) and with the conventional route was studied. The morphology and microstructure of SnO2+Sb2O3 intermediate layer derived from different precursors and the top PbO2 active layer were examined by means of ESEM and XRD. The lifetime and electrocatalytic activity of the anode were also assessed by the cyclic voltammetry and accelerated lifetime test in 1.0 mol/L H2SO4 solution. It was found that precursor solvents affected lifetime, microstructure and morphology of the anode, and had little influence on electrocatalysis activity of the electrodes. The accelerated lifetime of Ti/SnO2+Sb2O3/PbO2 anode with intermediate layer prepared by PPM was 29.5 h in 1.0 mol/L H2SO4 solution, which was respectively about four times and twice that of the anode prepared with ethylene glycol and ethanol. After the anode was subjected to thermal corrosion, the lifetime still reached 27 h in contrast to the others.

Analysis of α, β, γ-hexachlorocyclohexanes in water by novel activated carbon fiber-solid phase microextraction coupled with gas chromatography—mass spectrometry

A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water.

Synthesis and Adsorption Property of Two Polymeric Adsorbents with Pendent Ether Bonds

Two polymeric adsorbents, poly(methyl p-vinylbenzyl ether) and poly(phenyl p-vinylbenzyl ether), were synthesized from chloromethylated polystyrene. Their adsorption property for phenol in hexane solution was investigated. The results showed that the two adsorbents adsorb phenol from hexane solution through hydrogen-bonding and π-π stacking interaction.

Synthesis and Luminescence of Complexes Eu_x Y_(1-x)(phen)L_3

A series of binuclear complexes with different molar ratio of europium to yttrium with cinnamic acid and o phenanthroline were synthesized in anhydrous alcohol. Elemental analysis shows that the composition of the complexes are Eu x Y 1- x (phen)L 3 (L: C 6H 5CH=CHCOO, x =1.0, 0.7, 0.5, 0.3 and 0.1). The IR absorption spectra indicate that cinnamate is coordinated to the rare earth ions and chemical bonds are formed between rare earth ions and nitrogen atoms of o phenanthroline. Fluorescent spectra show that the emission of Eu 3+ ion can be greatly enhanced if some of europium ions in the complexes are substituted by yttrium ions.

SEDIMENT TRANSPORT IN YALU RIVER ESTUARY

Tidal cycle measurements of tidal currents, salinity and water tempe rature, and suspended sediment concentrations were measured at four stations, to gether with surveys along two profiles short core collection within the Yalu Riv er estuary. Grain size analysis of the three core sediment showed that: 1) the s ediment from B1 to B3 became finer, worse sorting and positively skewed; 2) the diversification of matter origin became more and more evident from east to west; 3) the sediments over the region were of the same origin, as indicated by their similar colors and grain sizes. The data indicated that stratification occurred in the flood season, from upstream to downstream, and a salt wedge was formed. The water column was well mixed, but the longitudinal gradient of the salinity w as larger on spring tide. The results also showed that the dominating mechanism of suspended sediment transport in the Yalu River estuary was T1, T2, T3 and T5. The non-tidal steady advection transport was restricted by the net transport o f suspended sediment induced by mass Stoked drift directed to landwards, then th e net sediment transport rate were decreased and the turbidity maxima was also f avored to forming and extending.

Syntheses, characteristics, and fluorescence properties of complexes of europium with benzoic acid and its derivatives

The binary complexes of europium with benzoic acid and its derivatives(phthalic acid, m-phthalic acid, o-aminobenzoic acid, salicylic acid, and sulfosalicylic acid) weresynthesized and their compositions were identified by elemental analyses. UV and IR of the complexeshave been investigated. The UV spectra indicated that the complexes' ultraviolet absorption weremainly the ligands' absorption. The IR spectra showed that the IR spectra of complexes are differentfrom those of free ligands. The fluorescence properties of them were investigated by usingluminescence spectroscopy, the results showed that only three complexes appear as betterluminescence, they were Eu-benzoic acid, Eu-m-phthalic acid and Eu-phthalic acid, while the othersexhibited the ligands' wideband emission.

Isolation and Identification of Capillarin from Artemisia Ordosica Kraschen

Capillarin was isolated from Artemisia Ordosica Kraschen and characterized by IR, 1H-NMR, 13C-NMR, 1H-1HCOSY, HMQC, HMBC and EIMS, and its crystal structure was determined by single-crystal X-ray diffraction analysis with the following data: triclinic, space group P1, Z = 2, a = 7.226(6), b = 7.297(6), c = 11.042(8) ?, α = 74.695(12), β = 78.479(12), γ = 62.063(10)°, V = 494.2(6) ?3, Mr = 198.21, Dc = 1.332 g/cm3, F(000) = 208, μ = 0.089 mm-1, S = 1.023, (?/σ)max = 0.000, the final R = 0.0408 and wR = 0.1110. The largest peak and deepest hole on the final difference Fourier map are 0.219 and –0.161 e/?3, respectively. The bond lengths and bond angles of the molecule are also given.

Synthesis and Crystal Structure of Lanthanum Nitrate with Methyl-2-pyridyl Ketone Benzoyl Hydrazone

A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions.

Synthesis and Properties of Gemini Cationic Surfactants with Amide Spacers

Four gemini cationic surfactants {N,N′-di[2-(lauryldimethylamino)acetyl]polymethylenediamine dichloride, LAA-s-LAA, s=2,3,4,6} were synthesized by using four bis(α-chloroacetamide)s and N,N-dimethyllaurylamine, respectively. The molecular structures were characterized by means of IR, ~ 1H NMR, \{~ ~13 C NMR\} and MS, and the behavior of their aqueous solutions was studied. The critical micell concentrations(CMC) of LAA-s-LAA were one order of magnitude lower than that of dodecyltrimethyl ammonium chloride(DTAC). With the change of the length of spacer chain(s), their CMC values change, and CMC reaches the top value at s=4.

Preparation of Polystyrenylphosphonous Acid of Low Polymerization Degree and Influence of Initiators upon the Free Radical Reaction Mechanism

The polystyrenylphosphonous acid (PSPA) of low polymerization degree was prepared with one step reaction. The reaction mechanism was changed with different initiators. For the reaction with AIBN or BPO as the initiator, there are 2 or 3 series of radical reaction chains and 5 or 9 series of polystyrenyl products. The main products are PSPA without or with the fragment of the initiator H[CH(C6H5)-CH2]n-PO2H2 and C6H5CO2-[CH2CH (C6H5)]n-PO2H2 respectively.

Two-stage pH Control Mode in Batch Fermentation of a Novel Bioflocculant from Corynebacterium Glutamicum

The effect of pH of the fermentation medium on cell growth and the production of a novel bioflocculant(named REA-11) by Corynebacterium glutamicum CCTCC M201005 were investigated. The maximum biomass(2.23 g/L) and flocculating activity(142.2 U/mL) were simultaneously obtained at the 14th hour when the pH value of the culture medium was maintained at 7.0 during the whole fermentation process. The production of REA-11 kept on a trend of increase till the later phase of fermentation process, which resulted in the ultimate flocculating activity of the culture broth to enhance to nearly 100 U/mL at pH 6.0. A two-stage pH control mode was adopted in REA-11 production in which the pH value of the culture medium was controlled at 7.0 during the first 14 h, then decreased to 6.0 that was maintained until the end of the fermentation process. With the two-stage pH control mode, the maximum flocculating activity reached 178.8 U/mL which was 30% higher than that obtained under the condition of pH 7.0 and the biomass enhanced about 15%. Compared with the fermentation process without pH control, REA-11 production and cell growth via the two-stage pH control mode increased 80% and 25%, respectively.

Aliphatic Hyperbranched Poly(amido amine)s (PAMAMs): Preparation and Modification

A series of water soluble aliphatic hyperbranched poly(amido amine)s(PAMAMs) with the same or similar chemical structure of poly(amido amine) dendrimer was successfully synthesized from commercially available AB and C_n types of monomers by one-pot polymerization via the couple-monomer methodology(CMM). The AB type monomer used in this paper was methyl acrylate, and C_n monomers were multi-amino compounds such as ethylenediamine(EDA), diethylenetriamine(DETA), triethylenetetraamine(TETA), tetraethylenepentaamine(TEPA) and pentaethylenehexamine(PEHA). The reaction mechanism was investigated by means of the mass spectra of the reaction intermediates. Adjusting the feed ratio of AB to C_n, hyperbranched polymers with different terminal groups and properties were obtained. FTIR, NMR, DSC, and TGA were used to characterize the polymers. It was found that the polymers′ properties such as solubility, thermal behaviour and encapsulation capability varied with changing the feed ratio of AB to C_n. Benzoyl and palmitoyl groups were introduced into these macromolecules by acidylation to form amphiphilic hyperbranched polymers which have a high capability to encapsulate water soluble dyes such as Congo red. It is expected that the hyperbranched PAMAMs can play an important role in the industrial applications, such as coatings, cross-linking and phase-transferring agents because of their versatility and availability.

A New Steroid from Polygonum nodosum Pers

A new steroid named as Zhonghualiaoine I (1) was isolated from Polygonum nodosum Pers (Chinese name 揨honghualiao? Berberidaceae). Its structure was deduced on the basis of its spectral data.

The New-generation of Green Surfactant (Alkylpolyglucoside) as an Inhibitor to the Corrosion of 907 Steel in Seawater

Weight-loss trials and potentiodynamic polarization curves have been used to study the inhibitive properties of alkylpolyglucoside (APG) towards the 907 steel in seawater. The inhibition was different, if the length of alkyl chain APG was different. As the result, calcium gluconate, zinc sulfate and APG can protect 907 steel from being corrupted in static seawater. The compound corrosion inhibitor was found to control both the anodic process and the cathodic procesa