外施脱落酸对镉胁迫下青萍生理特性的影响

采用营养液水培方式,研究5mg·L^-1镉（Cd²⁺）对青萍生长、光合色素、渗透调节物质含量、抗氧化酶活性和细胞膜脂过氧化反应的影响及外施不同质量浓度脱落酸（ABA）对镉胁迫下青萍的缓解效应. 结果表明：与空白组（CK）相比,镉能显著抑制青萍的生长,减少光合色素含量,降低超氧化物酶（SOD）活性,增加可溶性蛋白、可溶性糖和脯氨酸的含量,提高过氧化物酶（POD）和过氧化氢酶（CAT）活性及丙二醛（MDA）含量. ABA的叶面喷施能促进青萍的生长,随着ABA质量浓度的增大,青萍生长指标呈先上升后下降的趋势,另外,ABA的添加降低了青萍POD活性及MDA含量,并在质量浓度为1×10^-4mg·L^-1或1×10^-3mg·L^-1时可回到CK水平,为本试验的最佳处理质量浓度.     

药物中半胱氨酸的流动注射荧光测定方法研究

 在近中性介质及聚乙烯醇(PVA)存在下,半胱氨酸能熄灭一个新的荧光试剂5-(4-氯苯基)-8-苯磺酰氨基喹啉(CPBSQ)与Cu(Ⅱ)络合体系的荧光的反应.基于此现象,本文建立了一个测定半胱氨酸的流动注射荧光熄灭方法.结果表明,在λ_ex/λ_em=327/368nm处测定,方法的进样频率为64h-1,检测范围为0.05～5.5μg·mL^-1,检出下限为0.01μg·mL^-1,对4.0μg·mL^-1半胱氨酸平行测定11次的相对标准偏差为1.52%.大量存在的常见金属离子、蛋白质及很多不带巯基的氨基酸不干扰测定.应用此方法测定了某些注射液针剂中半胱氨酸的含量,结果满意.     

乙烯利对绿豆芽前期生长和品质的影响

为研究乙烯对绿豆芽前期生长与品质的影响，采用4种不同质量浓度的乙烯利（30，60，90，120 mg·L^-1）对种子萌发前和萌发后进行处理，用以评价绿豆芽各项生长指标。结果表明：在萌发前和萌发后施加不同质量浓度乙烯利溶液对绿豆芽生长和品质有不同程度的影响。一方面，萌发前用30 mg·L^-1的乙烯利溶液处理8 h后，种子萌发率达到62.2%，与对照组存在显著差异，而高质量浓度的乙烯利溶液120 mg·L^-1则抑制萌发；此外，用30 mg·L^-1乙烯利处理，种子侧根生长被显著抑制，超氧物歧化酶（SOD）和过氧化物酶（POD）活性提高，而用较高质量浓度乙烯利溶液处理时，下胚轴长度减小和粗度增加，相同时间产量减小。另一方面，在种子萌发后用乙烯利溶液处理，除30 mg·L^-1乙烯利处理外，其他质量浓度在发芽30 h内产量显著降低；而用90 mg·L^-1乙烯利处理后，在培养50 h时产量出现显著增加，抗氧化性有所提升。研究结果发现：30 mg·L^-1乙烯利对绿豆芽萌发与质量来说是最佳选择，本研究为绿豆芽高效安全的生产提供了一定的理论和技术支持。     

光电器件中有机半导体薄膜的光学和电学性质研究

采用真空热蒸发制备了 AlQ， BAlQ 和 NPB 有机半导体薄膜样品， 探讨了薄膜的透射、吸收和光学性质．制备了有机薄膜样品的夹心结构器件，研究了其电流-电压特性．结果表明: 有机薄膜的透明性能良好， AlQ 和 BAlQ 具有几乎相同的直接光学能隙(4.46 eV) ，大于 NPB 的能隙值(3.11 eV) ． AlQ， BAlQ 和 NPB 内部自由载流子浓度具有相同的数量级(10²² m^-3) ，但NPB 具有最高的零电场迁移率(1.75×10^-8 cm·V^-1·s^-1) 和电导率(1.45×10^-10 S·cm^-1)     

Ce-MOF/CB纳米复合材料的合成及其对5-羟色胺的电化学检测

制备了一种铈-金属有机框架/炭黑（Ce-MOF/CB）纳米复合材料,将其修饰于玻碳电极（GCE）上,用于对5-羟色胺（5-HT）的电化学测定. 通过扫描电子显微镜（SEM）、能量色散X射线谱仪（EDS）和傅里叶变换红外光谱（FTIR）对Ce-MOF/CB进行了表征. 电化学实验结果表明：Ce-MOF/CB对5-HT的电化学氧化具有良好的电催化活性. 5-HT的峰电流与该物质的量浓度在6.77×10^-8~1.00×10^-5 mol·L^-1内呈线性关系,检测限（LOD）达1.0×10^-8 mol·L^-1（信噪比S/N=3）.     

阳极氧化Ti-6Al-4V合金表面TiO2多孔膜的制备及研究

在一定浓度的H₂SO₄溶液中对Ti-6Al-4V合金表面进行阳极氧化处理,通过改变阳极氧化处理的电压、氧化时间和电解液浓度,研究了预处理工艺参数对钛合金表面形貌、物相、润湿性及粗糙度的影响.试验结果表明：钛合金经过阳极氧化处理后,表面出现了二氧化钛（TiO₂）纳米多孔结构,多孔氧化膜由锐钛矿型和金红石型TiO₂组成;在0.5 mol·L^-1 H₂SO₄溶液中,随着阳极氧化电压的增加,多孔膜的孔径逐渐增大,基体表面与模拟体液（SBF）的接触角明显降低,经120 V氧化处理的试样表面接触角由预处理前的52.8°降至16.9°左右,具有良好的润湿性;并且试样表面的粗糙度明显增加,在电压为120 V时粗糙度达到0.56 μm.在电压120 V时,随着阳极氧化时间或电解液浓度的增加,TiO₂多孔膜的含量和孔径尺寸逐渐增大,试样表面的润湿性和粗糙度也不断增加,在氧化时间10 min或电解液浓度0.5 mol·L^-1时达到最大,氧化时间大于10 min或电解液浓度高于0.5 mol·L^-1时,试样表面出现裂纹,多孔结构被破坏.     

光照强度对西藏虎头兰幼苗生长及光合特性的影响

探究西藏虎头兰(Cymbidium tracyanum L.Castle)幼苗对不同光照强度的适应性,明确其生长的适宜光照强度,为该物种资源保育及驯化提供科学依据。以苗龄为2 a的西藏虎头兰为研究对象,测定了不同光照强度下(8%、20%、45%、100%全光照)西藏虎头兰的生长状况、叶绿素含量和光合参数等的变化。结果表明：西藏虎头兰在20%光照强度下长势最好,其株高、分株基径、冠幅和最大叶长最大。随着光照强度的升高,西藏虎头兰叶片的叶绿素a (Chl a)、叶绿素b (Chl b)、类胡萝卜素(Car)和叶绿素(a+b)[Chl (a+b)]含量均显著降低,Car/Chl(a+b)升高,Chl a/ Chl b无明显变化。8%和20%光照强度下西藏虎头兰的净光合速率(P_n)呈现“单峰”曲线,45%光照强度下呈现“双峰”曲线;日均P_n大小表现为20%光照强度(0.78 μmol·m^-2·s^-1)＞8%光照强度(0.55 μmol·m^-2·s^-1)＞45%光照强度(0.23 μmol·m^-2·s^-1)。20%光照强度下西藏虎头兰的光补偿点(LCP,8.86 μmol·m^-2·s^-1)最低,光饱和点(LSP,607.67 μmol·m^-2·s^-1)、表观量子效率(AQY,0.041)和最大净光合速率(P_max,2.91 μmol·m^-2·s^-1)最高。本研究中,西藏虎头兰在20%光照强度下植株长势最好、光合作用能力最强,因此在进行引种栽培时应提供适当的光照,有助于其生长。     

臭氧水对草莓及拟盘多毛孢影响的研究

通过组织分离纯化和分子生物学鉴定,明确了引起草莓叶部新病的致病菌为拟盘多毛孢。以喷洒清水为空白对照,利用不同质量浓度的臭氧水直接喷洒致病菌和生长期的草莓植株,研究臭氧水对致病菌和草莓植株的浓度效应,结果显示：低浓度臭氧水（0.5~0.8 mg·L^-1）对草莓植株的生理生态变化和致病菌的生长影响较小;中浓度臭氧水（2.2~2.5 mg·L^-1）可以显著抑制致病菌的生长,并促进草莓植株的生长;高浓度臭氧水（4.0~4.3 mg·L^-1）可以很好地抑制致病菌的生长,但对草莓叶片有较严重的腐蚀作用。因此,中浓度（2.2~2.5 mg·L^-1）是喷洒草莓的最适臭氧水浓度。     

Alkalibacterium sp. SL3中α-半乳糖苷酶基因的克隆、表达和性质研究

以大布苏盐碱湖分离菌Alkalibacterium sp. SL3的DNA为模板,利用PCR扩增α-半乳糖苷酶基因(galSL3),构建重组质粒pET-22b-galSL3,转化至大肠杆菌BL21（DE3）诱导表达重组酶（rGalSL3）. 通过镍柱亲和层析分离纯化重组酶,并对纯化的重组酶进行性质研究. 研究表明,纯酶rGalSL3最适pH值为5.5,最适温度为55℃;该酶在pH值 5.0~10.0保持90%以上的剩余酶活,在50℃有非常好的热稳定性. 在0~1.5mol·L^-1 NaCl溶液中该酶的酶活基本不受影响,在3.0mol·L^-1 NaCl溶液中有很好的稳定性. Pb²⁺、Ca²⁺、Co²⁺、Li⁺、Na⁺、K⁺、Triton-100和β-mercaptoethanol等对重组酶的活性有明显的促进作用. 该酶水解对硝基苯基-α-D-吡喃葡萄糖苷的K_m、v_max和k_cat分别为(2.64±0.02)μmol·mL^-1、(454.55±0.59)μmol·(mg·min)^-1和(347.73±1.27)s^-1. 重组酶可水解蜜二糖和棉籽糖,不能水解瓜尔豆胶.     

Effects of lanthanum and gadolinium on proliferation and differentiation of primary osteoblasts

The effects of La³⁺ and Gd³⁺ on the proliferation, differentiation and adipogenic transdifferentiation of rat calvarial osteoblast-like cells (ROB cells) were evaluated by MTT method， measuring the activity of alkaline phosphatase (ALP) and Oil red O measurement. Both of La³⁺ and Gd³⁺ inhibited the proliferation of ROB cells at all concentrations (1×10^-5, 1×10^-6, 1×10^-7, 1×10^-8, 1×10^-9 mol?L^-1). La³⁺ at concentration of 1×10^-5 mol?L^-1 significantly increased the alkaline phosphatase activity of ROB cells up to 3 folds (P<0.01). However, the effects reversed to inhibit at other concentrations. Gd³⁺ played a negative role in the alkaline phosphatase activity. La³⁺ inhibited the adipogenic transdifferentiation of ROB cells at all concentrations in a dose-dependent way. However, Gd³⁺ promoted the adipogenic transdifferentiation of ROB cells at 1×10^-8 and 1×10^-9 mol?L^-1. These findings suggested that the effects of rare earth elements on the proliferation, differentiation and adipogenic transdifferentiation of ROB cells were dependent on their concentrations and species     

Effect of exogenous lanthanum on accumulation of cadmium and its chemical form in Tomatoes

In the condition that soil is polluted by Cd(20 mg·L-1),two varieties of tomato(Lycopersicon esculintum Mill.)(plant high Cd-enriched variety(Yufen109)and plant low Cd-enriched variety(4641))treated with LaCl3 of different concentration(0,10 and 20mg·L-1)were determined for their effect on plant dry weight,anti-oxidase activity(CAT,SOD and POD),tomato fruit Cd chemical form and Cd accumulation.The results show that 10 mg?L-1LaCl3 can increase dry weight of plant at various positions and can reduce the concentration of Cd of different forms.Spraying with LaCl3(10,20 mg·L-1)can reduce Cd concentration in leaves,stems,roots and fruits of tomato plants with lowering rates of 13.7%-31.9%,9.5%-30.6%,10.8%-44.5%and 19.4%-37.0%,respectively.Suitable amount of lanthanum(10 mg·L-1 LaCl3)can increase yield of tomatoes,reduce Cd accumulation in the fruit.In the two tomato varieties,Lanthanum and Cadmium react interactively,expressing to be coexisting of both synergism and antagonistic.     

Application of Nanometer-Size Titanium Dioxide in Extreme-Trace V（Ⅴ） Analysis

0Introduction Vanadiumplaysanimportantroleinmodernindustry,es peciallyinsteelandchemicalindustry.Forinstance,itscompoundsarewidelyappliedintheproceduresofvitrioland petroleumchemicalmanufactureascatalyzers[14].Vanadium hasseveralvalences,butgenerallyitslowvalencesturnintohighoneseasilyinenvironment[5].BecauseV(Ⅴ)isthemost stableandpoisonousone,weoftenlayemphasisonitinenvi ronmentalpollutioncontrol.Vanadiumexistsinenvironmentalwaterwithextremelylowconcentration.Inseawateritscontentislessthan…     

Investigation of Ru （ phen ）3^2＋-Hydrazine-Ce（Ⅳ） Chemiluminescence System and Its Analytical Application

0 IntroductionThbiep ycroidmipnlee)xru ctahteinoinu mof(Ⅱ r)u t(he Rniuu(mbip,y m)3ai2n +ly) atrnids- t(r2is -,(21’ -,10-phenanthroline)ruthenium(Ⅱ) (Ru(phen)32 +) ,is a kindof sensitive analytical reagent for electrogenerated chemilumi-nescence(ECL) and chemiluminescence(CL) ,on which a par-ticular review has been presented[1]. The earliest publicationon the synthesis of Ru(bipy)32 +appeared in 1936[2], andduringthefollowing30 years ,theinvestigations relatedtothissubstance were only in…     

Third-order optical nonlinearities for lanthanum (III) complexes with 1, 10-phenanthroline components

The nonlinear refractive indexesn ₂ for the ethanol solutions of 1, 10-phenanthroline (2.0 × 10⁻³ mol · L⁻¹), [bis(l, 10-phenanthroline) lanthanum (III)] nitrate (1.0 × 10⁻³ mol · L⁻¹), and [nitrato-fluoracil-bis (1, 10_{-phenanthroline}) lanthanum (III) ] nitrate (1.0 × 10⁻³ mol · L⁻¹) are first measured, the third-order nonlinear optical susceptibilities χ(³) and 〈γ〉 are calculated, and the mechanisms of the third-order optical nonlinearities enhanced by lanthanum (III) are discussed preliminarily.     

外源AHLs信号物质对蓝藻生长代谢的影响

 研究了外加AHLs(acyl-HSLs)信号物质对滇池铜绿微囊藻(Microcystis aeruginosa)FACHB905以及集胞藻(Synechocysti sp.)FACHB898生长和代谢的影响.结果表明:AHLs类信号物质对2种藻具有明显的生长抑制作用.在10~80μmol·L^-1浓度范围内,2种供试藻的生物量,藻蓝蛋白(phycocyanin,PC)含量都受到了一定程度的抑制,而2种藻的可溶性糖含量和Car/Chl a却有明显地提高.随AHLs浓度的增加,铜绿微囊藻藻液中超氧自由基含量明显地增加,而集胞藻藻液中超氧自由基含量随AHLs物质浓度的增加呈下降趋势,反映出两者在适应性上是有差异的.     

Preconcentration of vanadium(V) on crosslinked chitosan and determination by graphite furnace atomic absorption spectrometry

A new method is proposed for the preconcentration of vanadium(V) with crosslinked chitosan (CCTS) and determination by graphite furnace atomic absorption spectrometry (GFAAS). The adsorption rate of vanadium(V) by CCTS was 97% at pH 4.0, and vanadium(V) was eluted from crosslinked chitosan with 2 mL 2.0 mol·L⁻¹ chlorhydric acid and determined by GFAAS. The detection limit (3σ,n=7) for vanadium (V) was 4.8×10⁻¹²g and the relative standard deviation (R.S.D) at concentration level of 2.6 μg·L⁻¹ is less than 3.6%. The method shows a good selectivity and high sensity, and it was applied to determination of vanadium(V) in oyster and water samples. The analytic recoveries are (97±5)%. Biography: Wu Wei (1975-), female, Master candidate, research direction: environmental & analytical chemistry.     

Reductive recovery of manganese from low-grade manganese dioxide ore using toxic nitrocellulose acid wastewater as reductant

The hydrometallurgical strategy of extracting Mn from low-grade Mn ores has attracted attention for the production of electrolytic manganese metal (EMM). In this work, the reductive dissolution of low-grade MnO₂ ores using toxic nitrocellulose acidic wastewater (NAW) as a reductant was investigated for the first time. Under the optimized conditions of an MnO₂ ore dosage of 100 g·L-1, an ore particle size of -200 mesh, concentrated H₂SO₄-to-NAW volume ratio of 0.12, reaction temperature of 90℃, stirring speed at 160 r·min-1, and a contact time of 120 min, the reductive leaching efficiency of Mn and the total organic carbon (TOC) removal efficiency of NAW reached 97.4% and 98.5%, respectively. The residual TOC of 31.6 mg·L-1 did not adversely affect the preparation of EMM. The current process offers a feasible route for the concurrent realization of the reductive leaching of Mn and the treatment of toxic wastewater via a simple one-step process.