HCO_3~-碱度增加对铜绿微囊藻光合活性和超微结构的影响

研究了不同重碳酸盐(HCO3-)碱度2.3mmol/L(ALK2.3)和12.4mmol/L(ALK12.4)对铜绿微囊藻(Mi-crocystis aeruginosa FACHB 905)生长、光合特性、丙二醛(MDA)含量和超微结构的影响。实验结果表明,与对照相比碱度增加对铜绿微囊藻生物量抑制率分别为7%(ALK2.3)和55%(ALK12.4)。对光合色素Chla含量的抑制率分别为22%(ALK2.3)和88%(ALK12.4)。Chla/PC与对照相比先升高后降低。ALK2.3前期显著抑制光合活

酿酒酵母和运动发酵单胞菌木薯乙醇发酵条件研究

本文结合我国燃料乙醇发展的方针政策，以酿酒酵母和运动发酵单胞菌为菌种研究其在非粮能源作物木薯中乙醇发酵的情况，为木薯原料更好地应用于生产中提供了理论依据。 酿酒酵母木薯高浓度乙醇发酵的研究。实验采用的木薯干淀粉含量约70-75%。以酿酒酵母为菌种进行高浓度乙醇发酵的工艺条件研究，最佳条件为：木薯干粉碎细度为35目，料水比1：2，α-淀粉酶用量0.09 KNU/g淀粉，蒸煮温度85 ℃，蒸煮时间15 min。采用30 ℃同步糖化发酵工艺，糖化酶用量为3.4 AGU/g淀粉，发酵时间30 h。在10 L发酵罐中，乙醇质量比达127.88 g/kg，发酵效率为88.28%，发酵强度4.263 g/kg/h，100 L中试研究中乙醇浓度为127.75 g/kg，发酵强度4.258 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析，证明葡萄糖、果糖等单糖已完全被菌体利用，剩余糖为二糖，三糖等不可发酵的低聚糖。 运动发酵单胞菌快速乙醇发酵的研究。对实验室保藏的8株运动发酵单胞菌进行比较，选择发酵速度最快的Zymomonas mobilis232B进行研究。该菌在纯葡萄糖中的最佳发酵条件为：葡萄糖浓度18%，起始pH 6-7，发酵温度30 ℃，发酵时间18 h，乙醇浓度88 g/kg。在以木薯为底物同步糖化快速乙醇发酵中，采用Full Factorial设计和最速上升实验确定了培养基成分中的2个显著性因子及其最适浓度：酵母粉4 g/kg，硫酸铵0.8 g/kg。在最适培养基条件下，对木薯料水比和糖化酶用量进行了优化，得到Z.mobilis232B木薯乙醇发酵最佳料水比1：3，糖化酶浓度4 AGU/g淀粉，乙醇发酵4.915 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析，剩余糖为二糖，三糖等，但成分较酵母发酵后复杂。 According to the fuel ethanol development plans and policies in our country, the ethanol production from cassava by Saccharomyces cerevisiae and Zymomonas mobilis was studied. It provided theoretical basis for ethanol fermentation by cassava in industry. Part 1 is the study of VHG (very high gravity) ethanol fermentation by Saccharomyces cerevisiae. The content of starch in cassava was 70-75%. Compared with the performances under different experimental conditions, the following optimal conditions for VHG fermentation were obtained: Granule size of dry cassava 35 mashes, hydromodulus of cassava to water at 1:2, α-amylase enzyme dosage 0.09 KNU/g starch, cooking temperature 85 ℃ for 15 min, using the SSF process (simultaneous saccharification and fermentation) and the amount of glucoamylase 3.4 AGU/g starch. Accordingly, the final ethanol concentration was up to 127.88 g/kg; the ethanol yield reached 88.28%, and ethanol productivity was 4.263 g/kg/h after 30 h. When the fermentation scale expanded to 100 L, the final ethanol concentration was 127.75 g/kg, and the ethanol productivity was 4.258 g/kg/h in 30 h. The residual sugar was analyzed by high performance liquid chromatography, and proved that there was no glucose and fructose. The residual reducing sugar was some unfermentable oligosaccharide Part 2 is the study of the rapid ethanol production by Zymomonas mobilis. Compare with other seven stains, Zymomonas mobilis 232B was selected for research. The optimum condition in glucose medium was as follow: glucose concentration 18%, initial pH 6-7, and fermentation temperature 30 ℃. The ethanol concentration was 88g/kg in 18 h. After that, rapid ethanol production from cassava in SSF by Zymomonas mobilis 232B was studied. Through a series of experiments aided by Full Factorial Design and steepest ascent search, the optimal concentration yeast extract and ammonium sulfate were determined: 4 g/kg and 0.8 g/kg, each. Under optimum medium conditions, the optimal hydromodulus of cassava to water and glucoamylase dosages were obtained: hydromodulus of cassava to water at 1:3 and glucoamylase dosages 4 AGU/g starch. The ethanol production reached 4.915 g/kg/h. The residual sugar was analyzed by HPLC, and proved that the residual reducing sugar was some unfermentable oligosaccharide，but the components were more complex than that fermentation by Saccharomyces cerevisiae.

Climatology and trends of wet spells in China

IEECAS SKLLQG

The beta decay of N-21

The beta-delayed neutron and gamma energy spectra taken from the decay of neutron-rich nucleus N-21 were measured by using the beta - gamma and beta - n coincidence detection method. Thirteen new neutron groups ranging from 0.28MeV to 4.98 MeV and with a total branching ratio of 88.7 +/- 4.2% were observed and presented. One gamma transition with an energy of 1222 keV emitted from the excited state of O-21, and four gamma transitions with energies of 1674, 2397, 2780, and 3175 keV emitted from the excited states of O-20 were identified in the 3 decay chain of N-21. The beta decay half-life for N-21 is determined to be 82.9 +/- 1.9 ms. The uncertainty of half-life is much smaller than the previous result.

beta-delayed neutron decay of N-21

The beta-delayed neutron and gamma spectra of neutron-rich nucleus N-21 using beta-gamma and beta-n coincidence measurements were presented in this paper. Thirteen new neutron groups ranging from 0.28 MeV to 4.98 MeV and with a total branching ratio 88.7 +/- 4.2% were observed. One gamma transition among the excited states of O-21 and foury transitions among the excited states of O-20 were identified in the beta decay chain of N-21. The ungated half-life of 83.8 +/- 2.1 ms was also determined for N-21.

长期轮作施肥对土壤固定态铵释放动力学的影响研究

土壤中的固定态铵和水溶性铵、代换性铵之间处于动态平衡状态[1] 。作物吸收后 ,两种形态的铵或淋失、硝化促使土壤中固定态铵的释放。有研究表明 ,好气条件下 ,通过硝化培养 ,不同待培土壤 6周可释放出 6 %～ 88% (新固定态铵 ) [2 ] 。培养 4个月期间 ,固定态铵的平均释放为 2 0 %。固定态铵必须释放出来才能被作物吸收利用。固定态铵释放动力学研究有助于进一步揭示其释放机制及生物有效性。本研究在长期试验的基础上 ,对不同轮作施肥系统土壤的固定态铵释放动力学特征进行研究。1　材料与方法1 1　试验设计长期试验位于陕西长武县十里铺南 1ｋｍ处未进行灌溉的旱作农耕地上 ,1984年开始进行。土壤为黄盖黑垆土 ,耕层土壤有机质含量为 8 9ｇ/ｋｇ ,全Ｎ含量为 0 8ｇ/ｋｇ ,有效Ｐ含量为 2 8ｍｇ/ｋｇ。该地区气候温和 ,降雨量为 584 1ｍｍ。1997年秋 ,在选择的 5个处理区采样 ,即 :裸地、粮草 8年轮作 (苜蓿 苜蓿 苜蓿 苜蓿 马铃薯 小麦 小麦 小麦 )、粮草 3年轮作 (红豆草 小麦 小麦 )、粮饲豆 4年轮作 (豌豆 小麦 小麦 玉米 )、玉...

落地原油对芦苇湿地生态工程净化系统影响

以芦苇湿地为介质净化石油开采过程中落于地面的原油 ,研究了中试条件下芦苇湿地的净化效果及落地原油对土壤和芦苇介质的影响。结果表明 :芦苇湿地对不同施入剂量的落地原油都有较好的净化率 ,在试验运行期内 ,芦苇湿地对矿物油的净化率高达 88%～ 96 %。落地原油对土壤的污染基本局限于表层 ,对深层土壤的污染趋势并不明显 ,一般 4 0～6 0 cm土层的矿物油含量已接近或低于对照区表层土的背景值 ;落地原油对芦苇生长指标的影响表现出两面性 ,一方面抑制芦苇的叶龄指数和株高生长量 ,另一方面又能刺激芦苇的长粗、增加芦苇的生物量 ;落地原油对纤维素、木质素、戊糖、纤维素宽及纤维素长宽比等芦苇品质指标的影响很小 ,一些指标甚至优于对照区。

内蒙古陈巴尔虎旗饮茶型氟铝联合中毒调查

目的查明内蒙古陈巴尔虎旗饮茶型氟、铝联合中毒原因。方法在陈巴尔虎旗3个牧区嘎查随机抽取93名20~50岁牧民进行发、血清、尿含氟、铝水平测定,并拍摄前臂、小腿、骨盆正位及腰椎正侧位X线片,同时检测饮水、牛奶、砖茶等氟和铝水平,以扎兰屯市地方病防治研究所的34名23~50岁职工为对照组。结果陈巴尔虎旗牧民发、血清、尿及饮用的奶茶含铝量分别是(22.34±8.06)mg/kg、(1.13±0.48)mg/L、(3.78±1.62)mg/L、(6.02±1.77)mg/L,含氟量分别是(1.21±0.63)mg/kg、(0.092±0.042)mg/L、(2.08±1.16)mg/L、(3.00±1.11)mg/L,饮水、牛奶含铝量分别是(39±16)μg/L、(0.553±0.179)mg/L,含氟量分别是(0.50±0.39)、(0.063±0.032)mg/L;对照组发、血清、尿铝分别是(5.80±2.14)mg/kg,(0.203±0.101)mg/L、(2.19±1.34)mg/L,含氟量分别是(1.17±0.68)mg/kg、(0.033±0.008)mg/L、(0.57±0.32)mg/L,牧民发、血清、尿铝及血清、尿氟均高于对照组(P<0.001)。牧民X线改变硬化型22.2%(20/88),疏松型37.5%(33/88),退行性变86.4%(79/88),对照组退行性变13.3%(4/30),其余改变未检出。结论陈巴尔虎旗牧区饮茶型氟中毒实际为饮茶型氟、铝联合中毒。

双菱体λ/4消色差相位延迟器的设计

根据菲涅尔全内反射相变理论,给出了双菱体λ/4消色差器的结构设计、性能分析和测量方法.由有效通光孔径和光线追迹设计出BK7玻璃在波长532 nm时相位延迟λ/4的双菱体的结构,用作532 nm至1 064 nm波长范围的标准λ/4相位延迟器.理论分析了入射角变化和波长变化对双菱体相位延迟的影响,当入射角变化限制在±4.3°以内时,其影响得到补偿；波长从532 nm到1 064 nm产生的误差为－0.65°.采用椭偏法中的消光技术,分别实测了双菱体在532 nm和1 064 nm波长下的相位延迟为：90.08±0.14°和88.99±0.1°,可知两不同波长产生的相位延迟误差为－1.09°.

Metal dependent control of cis-/trans-1,4 regioselectivity in 1,3-butadiene polymerization catalyzed by transition metal complexes supported by 2,6-bis[1-(iminophenyl)ethyl]pyridine

Fe(III), Cr(III), Fe(II), Co(II) and Ni(II) chloride complexes supported by 2,6-bis[1-(iminophenyl)ethyl]pyridine have been synthesized and characterized along with single crystal X-ray diffraction. These complexes, in combination with MAO, have been examined in butadiene polymerization. The catalytic activity and regioselectivity are strongly controlled by metal center and cocatalyst (MAO/Co ratio dependent in the case of Co(II) complex). The activity decreases in the order of Fe(III) > Co(II) > Cr(III) approximate to Ni (II) complexes, in consistent with the space around the metal center. Polybutadiene with different microstructure content, from high trans-1,4 units (88-95% for iron(III) and Cr(III)), medium trans-1,4 and cis-1,4 units (55% and 35%, respectively, for iron(II)) to high cis-1,4 units 79% for Co(II) and 97% for Ni(II) call be easily achieved by varying of the metal center.

Syntheses and crystal structures of [Mn(H2O)(4)(bpy)]L center dot 4H(2)O, [Mn(H2O)(4)(bpy)]L ' center dot 4H(2)O (H2L = SUCCINIC ACID, H2L ' = FUMARIC ACID)

Reactions of freshly prepared M(OH)(2-2x)(CO3)(x) (.) yH(2)O (M = Mn, Zn) and 4,4'-bipyridine (bpy) with succinic acid (H2L) or famaric acid (H2L') in CH3OH-H2O afforded [Mn(H2O)(4)(bpy)]L (.) 4H(2)O, 1, [Mn(H2O)(4)(bpy)]L' (.) 4H(2)O, 2 and [Zn(H2O)(4)(bpy)]L (.) 4H(2)O, 3. The three coordination polymers are isostructural and consist of (1)(infinity)[M(H2O)(4)(bpy)(2/2)](2+) cationic chains, crystal H2O molecules and dicarboxylate anions (succinate or fumarate anions). Within the chains, the metal atoms are each octahedrally coordinated by four aqua oxygen atoms and two pyridyl nitrogen atoms from two 4,4'-bipyridine ligands. The crystal H2O molecules are hydrogen bonded to dicarboxylate anions to form ribbon-like anionic chains. The cationic and anionic chains are interconnected via hyqrogen bonds to generate a 3D network. Crystal data: 1 triclinic, P (1) over bar, a = 7.235(1), b = 7.749(2), c = 10.020(2) Angstrom, alpha = 79.95(3), beta = 88.79(3), gamma = 71.39(3)degrees, V = 523.9(2) Angstrom(3) and D-cal = 1.494 g cm(-3) for Z = 1; 2 triclinic, P (1) over bar, a = 7.127(1), b = 7.800(2), c = 9.945(2) Angstrom, alpha = 80.26(3), beta = 87.86(3), gamma = 72.69(3)degrees, V = 520.2(2) Angstrom(3) and D-cal = 1.498 g cm(-3) for Z = 1; 3 triclinic, P (1) over bar, a = 7.189(1), b = 7.764(2), c = 9.843(2) Angstrom, alpha = 79.16(3), beta = 87.80(3), gamma = 71.29(3)degrees, V = 510.9(2) Angstrom(3) and D-cal = 1.559 g cm(-3) for Z = 1.

Preliminary research on microporous membrane from F2.4 for membrane distillation

An asymmetric hydrophobic microporous membrane from the copolymer of tetrafluoroethylene and vinyliden fluoride (F2.4) has been fabricated by phase inversion process. Some characteristics, such as mechanical properties and hydrophobicity, have been examined and compared with polyvinylidenefluoride (PVDF) membrane. Experimental data exhibit F2.4 membrane excellent mechanical properties and hydrophobicity. F2.4 microporous membrane was approximately 6-8 times as high as PVDF membrane in stretching strain and extension ratio at break, and contact angle to distilled water of the fore (88.5degrees) was larger than the latter (80.0degrees), too. The results from membrane distillation (MD) process were well agreed with the fundamental laws of membrane distillation.

Blue light-emitting polymer with polyfluorene as the host and highly fluorescent 4-dimethylamino-1,8-naphthalimide as the dopant in the sidechain

The dopant/host concept, which is an efficient approach to enhance the electroluminescence (EL) efficiency and stability for organic light-emitting diodes (OLEDs) devices, has been applied to design efficient and stable blue light-emitting polymers. By covalently attaching 0.2 mol % highly fluorescent 4-dimethylamino-1,8-naphthalimide (DMAN) unit (photoluminescence quantum efficiency: Phi(PL)=0.84) to the pendant chain of polyfluorene, an efficient and colorfast blue light-emitting polymer with a dopant/host system and a molecular dispersion feature was developed. The single-layer device (indium tin oxide/PEDOT/polymer/Ca/Al) exhibited the maximum luminance efficiency of 6.85 cd/A and maximum power efficiency of 5.38 lm/W with the CIE coordinates of (0.15, 0.19). Moreover, no undesired long-wavelength green emission was observed in the EL spectra when the device was thermal annealed in air at 180 degrees C for 1 h before cathode deposition. These significant improvements in both efficiency and color stability are due to the charge trapping and energy transfer from polyfluorene host to highly fluorescent DMAN dopant in the molecular level.

A novel one-dimensional manganese phosphomolybdate with rectangular cavities: [H3N(CH2)(4)NH3] (H3O)(2){[Mn(phen)(2)](4) [(MnMo12O30)-O-v(HPO4)(6)(H2PO4)2} center dot 4H(2)O

A novel manganese phosphomolybdate, [H3N(CH2)(4)NH3](H3O)(2){[Mn(phen)(2)](4)[(MnMovO30)-O-12(HPO4)(6)(H2PO4)(2)]} . 4H(2)O 1, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. The crystal data: triclinic, P (1) over bar, a = 14.172(7) Angstrom, b = 16.547(2) Angstrom, c = 16.679(3) Angstrom, alpha = 62.881(12)degrees, beta = 73.83(3)degrees, gamma = 88.81(3)degrees. X-ray crystallography shows that the [Mn(phen)(2)] fragments are covalently bonded to the [Mn(Mo6P4)(2)] dimers leading to a one-dimensional chain with rectangular cavities occupied by tetramethylene-diamine cations and water molecules. (C) 2002 Elsevier Science B.V. All rights reserved.

Synthesis and crystal structure of triphenyltin-2-(1,2-ethylenedithio) methylene-3-oxo-5-aryl-4-pentenicate

Nine triphenyltin - 2 - (1,2 - ethylenedithio) methylene - 3 - oxo - 5 - aryl - 4 - pentenicates were synthesized. The crystal structure of the title compound 3b (C33H28O3S2Sn) was determined by X - ray diffraction analysis. The crystal belongs to triclinic system, space group P(1)overbar with a = 0.9074 (2) nm, b = 1.6809(3)nm, c = 2.1834(4)nm, alpha =77.57(3)degrees, beta = 88.04(3)degrees, gamma = 89.47(3)degrees, V = 3.2503nm(3), Z = 2, R = 0.0592. In crystal of 3b, there exist intramolecular 0-Sn coordination bonds, with carboxylate group acting as a bidentate ligand: Sn(1)-0(1) = 0.2086(5) and Sn(1)-0(2) = 0.2594nm, having a deformed trigonal bipyramidal geometry.