改性橡椀栲胶与非铬金属离子结合鞣

将国产橡Ｗａｎ栲胶进行水解,缩合得到渗透性好,收敛性小的栲胶产品,用其与金属离子ＲＥ＾３＋、Ａｌ＾３＋,Ｃｒ＾３＋,Ｔｉ＾４＋,Ｚｒ＾４＋构成结合鞣。结合鞣革的粒面平细度很好。耐湿热稳定性较各单独作用时有极大增加。实验表明改性栲胶有好的低ｐＨ分散性,缓冲区宽,使后继金属离子在改性植鞣革内较未改性时有更好的分布均匀性。     

广州市酸雨对不同森林冠层淋溶规律的研究

１９９８年４月至１９９９年３月对广州市白云山马尾松林和常绿阔叶林、广州市龙眼洞马尾松林两试验点进行了酸雨的监测,并测定和分析了林内穿透雨物理量及化学量,旨在探讨酸雨对不同森林冠层养分淋溶规律的影响。结果表明：（１）广州市酸雨占次数的７９．７％或占降雨量的９５．１％。（２）酸雨通过林冠层后,ｐＨ值明显增加。（３）在马尾松林和常绿阔叶林中,某些单次降雨出现ＳＯ４＾２－、ＮＯ３＾－、ＮＨ４＾＋Ａｌ＾３＋、Ｎａ＾＋的负淋溶现象,说明森林对这些离子（特别是ＮＯ３＾－、Ａａ＾３＋）具有吸收作用;阔叶林全年的ＮＯ３＾－和Ａｌ＾３＋净淋溶为负值,说明阔叶林比马尾松林对这两种离子具有更强的吸收能力。（４）雨水酸度增加（即ｐＨ值减小）,明显提高阳离子Ｃａ＾２＋、Ｍｇ＾２＋、Ｋ＾＋和Ｎａ＾＋冠层淋溶面分率。（５）ＮＨ４＾＋、ＳＯ４＾     

金属离子对纤维素酶制备的影响

在纤维素制备过程中,Ｃ＾２＋,Ｃｏ＾２＋,Ｆｅ＾２＋,Ｍｇ＾２＋,Ｍｎ＾２＋及Ｋ＾＋等金属离子对纤维素酶的合成均有一定的影响。金属离子过量或不足都会降低酶产率,在此基础上提出了纤维素酶制备的产酶培养基中较适宜的金属离子组成。     

漆酚金属盐聚合物催化合成缩酮

考察了漆酚金属盐聚合物在缩酮合成反应中的催化性能。实验表明,漆酚与Ｆｅ＾３＋、Ｓｎ＾４＋、Ａｌ＾３＋等金属盐的聚合物均能催化缩酮的合成反应。以环己酮和乙二醇为反应体系,在漆酚ＦｆＥ＾３＋盐聚合物催化剂存在下,环己酮缩乙二醇的得率为８１％,     

施肥对尾叶桉无性系MLA生长影响的研究

在雷州林业局两个试验点进行了尾叶桉无性系ＭＬＡ施肥试验,林龄３８个月生的结果表明：处理⑥（Ｐ３００ｇ／株＋Ｋ３００ｇ／株＋１５０ｇ／株）的平均蓄积生长量为２９．２４ｍ＾３／ｈｍ＾２．ａ,比处理⑦（常规施肥,滤泥５０００ｇ／株＋Ｐ２５０ｇ／株＋Ｋ１５０ｇ／株）的平均蓄积生长量２６．２６ｍ＾２／ｈｍ＾２．ａ大１１;３％,比ｃｋ（不施肥）的平均蓄积生长量６．３９ｍ＾３／ｈｍ＾２．ａ大３５７．５９％,比总     

杨梅果核中油脂抗氧化成分的研究

从杨梅果核中首次分离得到了三个黄酮类化合物，经ＵＶ、ＩＲ、＾１ＨＭＲ、＾１３Ｃ ＮＭＲ、ＥＩ－ＭＳ和ＦＡＢ－ＭＳ等波谱分离，鉴定为槲皮素（１）、杨梅素（２）和槲皮素－３－Ｏ－α－Ｄ－吡喃葡萄糖－（６→１）－Ｏ－α－Ｌ－吡喃鼠李糖苷（３）。用Ｒａｎｃｉｍａｔ法测定了它们的抗氧化性能，表明三个化合物对油脂都是优良的抗氧化剂，尤其是槲皮素和杨梅素对于猪油的抗氧化性比合成抗氧化剂ＢＨＴ（３，５－二叔丁基－     

空苞栗子房内源激素含量的变化与调节研究

应用酶联免疫吸附法（ＥＬＩＳＡ）测定了空苞栗子房和正常栗子房胚胎发育期的内源激素含量,并分析了ＢＲ、ＧＡ３、ＰＰ３３３对板栗子房和顶芽内源激素平衡的影响。结果表明,正常栗胚胎发育期子房内源ＧＡ１＋３、ｉＰＡｓ含量和（ＧＡ１＋３＋ｉＰＡｓ）／ＡＢＡ值呈现出“双峰”型变化模式;而子房内源ＡＢＡ含量变化趋势相反,且幅度较小。空苞栗子房内源激素含量及其比值在整个胚胎发育期未出现明显的峰值,且子房内源ＧＡ１＋３、ｉＰＡｓ含量和（ＧＡ１＋３＋ｉＰＡｓ）／ＡＢＡ值呈下降趋势,ＡＢＡ含量呈上升趋势。空苞栗子房内源激素ＧＡ１＋３、ｉＰＡｓ含量和（ＧＡ１＋３＋ｉＰＡｓ）／ＡＢＡ值在授粉期的低水平与授粉不良有关,而幼胚发育期的持续下降可能导致了子房营养物质供应不足及幼胚发育停滞。ＢＲ（ρ＝０．０１ｍｇ．Ｌ＾－１）喷布提高了子房和顶芽     

漆树酶在漆酚树脂上的固定化研究

介绍了漆酚树脂吸附金属离子后对漆树酶的固定化方法，比较了Ｆｅ＾３＋和Ａｌ＾３＋、漆酚树脂和漆酚－水杨酸接枝树脂对漆树酶的固定化结果显示，漆酚－水杨酸－Ａｌ螯合树脂对漆树酶的固定化活力最高，测定了溶液ＰＨ，环境温度对固定化漆树酶活性的航固定化漆酶的重作用性。另外，测定了固定化漆树酶的米氏常数，Ｋｍ＝４．９×１０＾－３，并讨论了Ｋｍ小于天然漆树酶的米氏常数的原因。     

重金属离子对有效微生物群处理污水能力的影响

在生活污水中添加不同种类不同体积质量的重金属离子, 研究了重金属离子对有效微生物群（Ｅｆｆｅｃｔｉｖｅ Ｍ ｉｃｒｏｏｒｇａｎｉｓｍ ｓ,简称ＥＭ ）去除生活污水化学需氧量（ＣＯＤｃｒ）的影响．结果表明：重金属对ＥＭ 有毒害作用,且体积质量越高,毒害作用越大;当其它条件保持不变时,ＣＯＤｃｒ 的去除率随重金属离子体积质量的增加而逐渐减少;另外,不同的重金属离子对ＥＭ 的降解能力影响也不同,其中,Ｈｇ２＋ ,Ａｓ３＋ 的毒性最大,Ｚｎ２＋ ,Ｐｂ２＋ 的毒性最小;ＥＭ 对污水中重金属离子的耐受体积质量分别是,对 Ａｓ３＋ 的耐受体积质量为０． ０５ ｍ ｇ ·Ｌ－ １, Ｈｇ ２＋ 为 ０． １０ ｍ ｇ · Ｌ－ １, Ｃｕ２＋ 为 ０． ５０ ｍ ｇ ·Ｌ－ １, Ｃｒ６＋ 为 ０． ５０ ｍ ｇ ·Ｌ－ １, Ｃｄ２＋ 为 ０． ５０ ｍ ｇ ·Ｌ－ １, Ｚｎ ２＋ 为１．００ ｍ ｇ·Ｌ－ １,Ｐｂ２＋ 为１．００ ｍ ｇ·Ｌ－ １．总之,用ＥＭ 处理生活污水时,保持较低水平的重金属离子体积质量是十分必要的     

试论科技成果的价值特点

试论科技成果的价值特点李宏伟（河北保定林学院社科部０７１０００）关键词科技成果，价值特点，时效性，多维性，客观性中图分类号ＦＯ６２．３ＯＮＴＨＥＶＡＬＵＥＣＨＡＲＡＣＴＥＲＳＯＦＳＣＩＥＮＴＩＦＩＣＲＥＳＥＡＲＣＨＡＣＨＩＥＶＥＭＥＮＴＳＬｉＨｏｎｇ...     

Sorption of metal ions from aqueous solution to spruce bark

The concentrations and protonation constants of the functional groups like carboxyl and phenolic hydroxyl groups in spruce bark were determined by a potentiometric acid–base titration method. The non-cellulosic carbohydrates in spruce bark were also characterized by acid methanolysis and GC, including determination of the uronic acid units, which are the key units involved in metal sorption. Sorption of metal ions to bark takes place by ion exchange, mainly by complexation to these functional groups. The sorption equilibrium time, studied by using a batch method, was approximately 5 min. The metal sorption capacity of spruce bark and the affinity order of metal ions were studied with four different metal ion mixtures using a column chromatographic method. Because a method of competition was used, concentration of metal ions adsorbed to bark depends on the metal ions present in the mixtures studied. In the sorption experiments with same metal ion mixtures, inner bark of spruce exhibited higher sorption capacity than outer bark. By combination of the results from several experiments, the following affinity order was obtained Fe³⁺ ? Pb²⁺ ? Cu²⁺ ? Cd²⁺ > Zn²⁺ > Ni²⁺ > Ba²⁺ > Ca²⁺ > Sr²⁺ > Mn²⁺ > Mg²⁺ ? K⁺ ~ Na⁺ ~ Li⁺. Bark has a great potential as an effective and inexpensive sorbent for removal of metal ions from, e.g., waste water.     

Decontamination of synthetic solutions containing heavy metals using chemically modified sawdusts bearing polyacrylic acid chains

New materials containing carboxylate groups have been synthesized by grafting polyacrylic acid onto sawdust. These new adsorbents were subjected to continuous extraction of different metal ions using packed columns to determine their maximum binding capacities. They exhibit binding capacities 15–40 times higher than unmodified sawdusts for removal of Cu²⁺, Ni²⁺, and Cd²⁺ chosen as representative heavy metal ions. Cation desorption and adsorbent regeneration could be effected by elution with a diluted HCl solution; water as an eluent has no effect on metal desorption.     

Mechanism of detoxification of aluminum ions by kraft lignin treated with alkaline oxygen

 Kraft lignins modified by radical sulfonation or alkaline oxygen treatment were rich in acidic groups, such as sulfonic acid, carboxylic acid, and phenolic hydroxyl groups, and were effective as soil-conditioning agents, especially because of their ability to trap aluminum ions eluted from soil under acidic conditions. Formation of complexes between aluminum ions and modified lignins was examined using potentiometric titration and ²⁷Al nuclear magnetic resonance (NMR) spectroscopy. Changes in the titration curve of a modified lignin by the addition of aluminum ions suggest the release of protons after the formation of complexes between them. Disappearance of ²⁷Al-NMR signals assigned to various aluminum ions by the addition of kraft lignin treated with alkaline oxygen was also attributed to the formation of complexes. The relative ease of proton release because of complex formation between a modified lignin and metal ions was as follows: Fe³⁺ > Al³⁺ > Cu²⁺ > Pb²⁺ > Mn²⁺ > Ca²⁺. This indicates that aluminum complexes are quite stable, and the aluminum ion is not exchanged with cations other than Fe³⁺. Received: October 24, 2001 / Accepted: January 16, 2002 Present address: Asian Natural Environmental Science Center, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan Tel. +81-3-5841-7506; Fax +81-3-5841-5230 e-mail: ukyoko@mail.ecc.u-tokyo.ac.jp Part of this study was presented at the 11th International Symposium on Wood and Pulping Chemistry, Nice, June 2001 Correspondence to:K.S. Katsumata     

Adsorption of metal and uranyl ions onto amidoximated Pinus densiflora bark

Pine (Pinus densiflora) bark was chemically modified by grafting with acrylonitrile (AN) through Fenton reaction and conversion of the cyano group to an amidoxime group by reaction with hydroxylamine. Treatments of pine bark with 160 mM H₂O₂ at 40°C yielded ~70% grafting in 6-h reaction. After alkali hydrolysis of amidoximated pine bark (AOPB), its adsorption capacity (q _e) for copper ions was largely increased from 0.5 to 1.8 mmol/g. Adsorption of the hydrolyzed AOPB (HAOPB) followed the pseudo-second-order kinetic model. Among the metal ions tested, the order of adsorption capacity (q _e) predicted by the kinetic model at equilibrium time was Hg²⁺ > UO₂ ²⁺ > Cd²⁺ > Cu²⁺ > Zn²⁺ > Ni²⁺. The adsorption process was pH-dependent, and the adsorption equilibrium was observed in the pH range of 6–7 for all the metal ions. Even though pine bark is a good adsorbent for Hg²⁺ and UO₂ ²⁺ ions, it had a poor affinity for the other ions tested. It was obviously found that HAOPB had very high adsorption abilities for heavy metal and uranyl ions.     

Removal of heavy metal ions from solutions by coniferous barks

Summary The abilities of 15 coniferous barks for removing toxic heavy metal ions were investigated. The barks considerably varied in the adsorption ability to each metal ion. Of the barks tested, high adsorption ability for heavy metal ions was found inPicea abies (Norway spruce). Equilibrium experiments usingP. jezoensis (Yezo spruce) bark showed that the adsorption of Cd²⁺ was greatly affected by the pH of solution and the initial Cd²⁺ concentration in solution. The adsorption of Cd²⁺ byP. jezoensis bark followed Freundlich isotherm in the concentration range 10–330 mg Cd²⁺/L. The continuous column experiments usingP. jezoensis bark indicated that the packing had retained 10.1–14.2 mg Cd²⁺/g adsorbent until the column broke through.     

碳量子点材料作为荧光探针检测离子的原理及应用进展

指出了作为碳纳米材料的新兴成员,碳量子点(CQDs)因其优异的荧光性能,在离子检测方面展现出潜在的应用价值。阐述了CQDs作为荧光探针检测离子的几种检测原理以及CQDs作为荧光探针检测Cu^2+、Fe^3+、Ag^+、Hg^2+等金属阳离子和P3O4^-、I^-、F^-等阴离子的方法,总结了其作为荧光探针的优缺点并进行了展望。     

Effects of Metal Ions and EDTA on Free Radical Reaction Intermediates of Laccase-catalyzed Oxidation of Wood Powder from Szemao Pine

INTRODUCTIONLaccase (EC 1.10.3.2) is multicopper oxidase catalyzing oxidation of various phenolic compounds, aromatic amines, and even certain inorganic compounds by a one-electron transfer mechanism. The electron withdrawn from the substrates is transferred via four copper atoms to molecular oxygen (Messerschmidt 1997). Laccase is very common in nature, especially in plants and fungi (Gianfreda et al. 1999). Fungal laccases participate in plant pathogenesis, pigment production and ligni…     

Afforestation method affects the isotopic composition of planted Pinus halepensis in a semiarid region of Spain

We used an isotopic approach to evaluate the effects of three afforestation methods on the ecophysiology of an Aleppo pine plantation in semiarid Spain. The site preparation methods tested were excavation of planting holes (H), subsoiling (S), and subsoiling with addition of urban solid refuse to soil (S + USR). Five years after plantation establishment, trees in the S + USR treatment were over three times larger than those in the S treatment, and nearly five-fold larger than those planted in holes. Differences in tree biomass per hectare were even greater due to disparities in initial planting density and pine tree mortality among treatments. Pine trees in the S + USR treatment showed higher foliar P concentration, δ¹³C and δ¹⁵N than those in the S or H treatments. Foliar δ¹⁵N data proved that trees in the S + USR treatment utilized USR as a source of nitrogen. Foliar δ¹³C and δ¹⁸O data suggest that improved nutrient status differentially stimulated photosynthesis over stomatal conductance in the pine trees of the S + USR treatment, thus enhancing water use efficiency and growth. In the spring of 2002, trees in the S + USR treatment exhibited the most negative predawn water potentials of all the treatments, indicating that the rapid early growth induced by USR accelerated the onset of intense intra-specific competition for water. The results of this study have implications for the establishment and management of Aleppo pine plantations on semiarid soils. Planting seedlings at low density and/or early thinning of pine stands are strongly recommended if fast tree growth is to be maintained beyond the first few years after USR addition to soil. Foliar C, O and N isotope measurements can provide much insight into how resource acquisition by trees is affected by afforestation techniques in pine plantations under dry climatic conditions.     

的吸附

以胶原纤维为基质,通过醛交联剂将杨梅单宁固化在胶原纤维上,制备固化杨梅单宁(IMT)吸附材料.研究该吸附材料对Pb2+、Cd2+ 和Hg2+的吸附性能.实验表明该吸附材料对这3种金属离子的吸附容量大小顺序为Hg2+>Pb2+ >Cd2+.吸附容量与pH值有关,pH值7时,对Hg2+的吸附容量最大;pH值3时,对Pb2+和Cd2+的吸附容量最大.在上述pH值条件下,当吸附剂用量为0.1 g,金属离子初始浓度为200 mg/L、体积为100 mL时,IMT对Hg2+、Pb2+、Cd2+的平衡吸附容量分别为198、87和24 mg/g.通过研究温度对吸附平衡的影响以及吸附动力学,发现IMT对Hg2+的吸附主要为化学吸附,对Pb2+的吸附可能包含物理吸附和化学吸附,对Cd2+的吸附以物理吸附为主,这与金属离子在水溶液中的状态有关.当水体中同时存在Hg2+和Pb2+时,IMT对每种金属离子的平衡吸附容量几乎不受其它金属离子的影响,即可以用于同时吸附除去这些金属离子.