酸雨对杨树生长和木材化学性质的影响

对受酸雨危害和未受酸雨危害杨树的年轮宽度和木材化学性质的对比研究表明：酸雨对杨树生长和木材化学性质产生了明显的影响。酸雨会导致树木生长减缓,年轮宽度变窄,受害材的年轮宽度较健康材相对降低１２．６７％。受害材与健康材的ｐＨ值无明显差异,酸、碱缓冲容量有显著差异。与健康材相比,受害材的戊聚糖和木质素含量相对升高１．４３％和３．７２％,而综纤维素的含量相对减少３．４５％,灰分的含量相对减少８．３４％。受     

脂肪酸酰化位置对营养代谢影响的研究进展

常用脂类中８０％ ～９０ ％ 的组分为三酰甘油（ＴＡＧ）。研究结果表明：在三酰甘油上不同酰化位置的脂肪酸影响三酰甘油消化吸收;并进一步影响体内的代谢。本文综述了三酰甘油中脂肪酸酰化位置对于三酰甘油的消化吸收及代谢的影响。     

酸水法及其它方法提取穿心莲总内酯的比较

为提高以水为溶媒提取穿心莲总内酯的收率,根据穿心莲内酯可以同亚硫酸氢钠起加成反应的原理,在常温条件下,用酸水法同乙醇回流法、碱水法、乙醇冷浸法、冷水浸渍法提取穿心莲总内酯,用比色法测定其含量,结果显示酸水法提取穿心莲总内酯可达乙醇冷浸法的７５％ 以上,与乙醇回流法相当,而远远超过其它方法。酸水法可为目前以水为溶媒提取穿心莲总内酯的可行方法     

Symbiotic effectiveness of Bradyrhizobium japonicum in acid soils can be predicted from their sensitivity to acid soil stress factors in acidic agar media

In acid soil, low pH, reduced availability of nutrients, and toxicity of Al and Mn limit plant growth and the survival and effectiveness of rhizobia. The symbiosis between legumes and rhizobia is particularly sensitive to acid soil stress. A pot experiment evaluated whether Bradyrhizobium japonicum strain growth on acidic agar media would predict ability to colonize the rhizosphere and form effective nodules in acidic soils. Three Indonesian strains of B. japonicum with similar effectiveness at neutral pH in sand culture but with different tolerance of acid soil stress factors in agar media, and an acid-tolerant commercial strain (CB1809) of comparable effectiveness, were tested in three acid soils using the Al tolerant soybean (Glycine max cv PI 416937). At 7 days after inoculation all strains had achieved large rhizosphere populations, but by day 14 the rhizosphere population of the acid-sensitive strain had decreased, while the more acid-tolerant strains increased. The acid-tolerant strains had significantly greater nodulation and symbiotic effectiveness than plants inoculated with the acid-sensitive strain. Laboratory prescreening of B. japonicum for acid, Al and Mn tolerance in acid media successfully identified strains which were symbiotically competent in low pH soils.     

沙棘中糖、酸、维生素C和SOD的动态变化

对中国沙棘、俄罗斯沙棘和蒙古国沙棘果实的总糖和可溶性固形物、总酸、维生素C和SOD以及叶中维生素C在年生长周期中的变化规律进行了比较研究。结果表明,果实着色前含糖量和可溶性固形物的变化一直下降,着色后呈上升趋势;有机酸含量在果实发育前期至中期一直呈增加趋势,至果实着色期后迅速下降,但中国沙棘在着色期后有机酸含量变化不大,成熟前才迅速下降;维生素C含量变化是中国沙棘在成熟时达到最大,成熟后迅速下降,俄蒙沙棘叶中维生素C则高于中国沙棘;SOD是先升后降,在成熟前达到最大值,成熟时下降。     

猪微卫星座位杂合度与肌肉肌苷酸含量的关系

英系大白猪和梅山猪产生的139头F2代个体用作试验猪。分析猪1、2和6号染色体的24个微卫星座位与肌肉肌苷酸的关系,发现5个座位与肌苷酸含量显著关联(P<0 05)。它们分别是1号染色体的Sw2185、2号染色体的Sw2516、S0170、Sw1883和Sw2192。6号染色体9个微卫星座位均没有显著的相关(P>0 05)。这提示2号染色体的一些基因或QTL对肌苷酸含量有较大的遗传作用。分别以24个座位分类、以5个显著关联座位分类和以19个中性座位分类来研究基因杂合度与肌苷酸含量的关系,结果均表明随着基因杂合度增加,肌苷酸含量呈下降趋势。其中前两者分析结果大体一致。基因杂合度在0 5～0 8范围内,每增加0 05则肌苷酸含量下降幅度大约是群体肌苷酸均值的1 2%～7 5%。提示显著关联座位在肌苷酸的杂种优势中可能具有重要的遗传效应。同时,在应用微卫星标记估计基因杂合度与肌苷酸含量的关系时,尽可能选用显著关联座位,可以作到多快好省。     

Effect of Intravenously Administered Crystalloid Solutions on Acid‐Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid‐base balance. The Stewart approach to acid‐base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [] increases plasma pH (alkalosis); SID < [] decreases plasma pH (alkalosis); and SID = [] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid‐base equilibrium. The ideal balanced crystalloid should (1) contain species‐specific concentrations of key electrolytes (Na⁺, Cl^?, K⁺, Ca⁺⁺, Mg⁺⁺), particularly Na⁺ and Cl^?; (2) maintain or normalize acid‐base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.     

绿盲蝽卵的染色方法及其在棉花和苜蓿上的分布

为了明确绿盲蝽在棉花和苜蓿植株上的产卵特性,采用改进的酸性品红染色法,调查了绿盲蝽在棉花和苜蓿植株不同部位上的产卵情况。结果表明:绿盲蝽在棉花植株上的产卵部位与其趋嫩特性密切相关,主要产卵部位是嫩叶和腋芽,其次是幼蕾和嫩叶柄,这4个幼嫩部位上的产卵量占棉花植株总卵量的79.57%,而在其他部位上的产卵量较少;但是在苜蓿植株上,绿盲蝽的主要产卵部位是刚收割后的新茬和嫩尖,2个部位的产卵量分别占苜蓿植株总卵量的43.90%和25.30%,并且在旧茬上也有11.59%的产卵量,而在嫩叶上产卵量却很少(仅占总卵量的0.91%)。绿盲蝽在植株上的产卵部位与其趋嫩习性有关,但也会因寄主种类的不同而存在差异。     

PLA沙障对土壤硬度的影响

 为了解新材料聚酯纤维(PLA)沙障对沙丘土壤硬度的影响,通过测定铺设PLA沙障沙丘表层的土壤硬度,并以铺设麦草沙障沙丘及裸沙丘为对照,对比研究各种规格、迎风坡、坡顶及背风坡土壤硬度的差异。结果表明:铺设PLA沙障沙丘表层土壤硬度显著高于麦草沙障沙丘(P<0.001),且2者土壤硬度均显著高于未铺设沙障的裸沙丘(P<0.001);2 m×2 m和1 m×1 m PLA沙障土壤硬度比较接近,均显著小于3 m×3m规格的(P<0.01),而麦草沙障3种规格的土壤硬度差异较小;2种沙障所在沙丘不同部位土壤硬度变化趋势相似,均是迎风坡的最大,坡顶次之,背风坡的最小;PLA沙障及麦草沙障单个障格内的土壤硬度分布都是不均匀的,并且二者的土壤硬度分布规律存在差异。     

Cu-Ce-O/γ-Al_2O_3催化剂的制备及CWPO法处理酸性大红-3R废水

以γ-Al2O3为载体,采用分层浸渍法制备Cu-Ce-O/γ-Al2O3催化剂,将其用于常温常压条件下催化湿式过氧化氢氧化法(Catalytic Wet Hydrogen Peroxide Oxidation,CWPO)降解质量浓度为1 000 mg/L的酸性大红-3R染料废水,并探讨催化剂制备过程中Ce(NO3)3溶液浓度、Cu(NO3)2溶液浓度、吸附次数、焙烧温度和时间、升温速率等因素对催化剂活性的影响。结果表明,Cu-Ce-O/γ-Al2O3催化剂最佳制备工艺为0.2mol/L Ce(NO3)3溶液浸渍吸附2次、450℃下焙烧4 h预处理、1.0 mol/L Cu(NO3)2溶液浸渍吸附1次、550℃下焙烧3 h、升温速率为8℃/min;处理工艺为常压、反应温度30℃、进水pH3.0、双氧水投加量0.18mol/L、催化剂用量0.18 mol/L、反应3 h,可使酸性大红-3R的降解率达到98.16%,铜流失量控制在2.76mg/L以下。