合成脂肪酶的影响

研究了碳源和氮源对白腐菌Sarcodon asparatus合成脂肪酶的影响。橄榄油是脂肪酶合成的最佳碳源，脂肪酶活力达0．65U／mL。蛋白胨、尿素和氯化铵对脂肪酶的合成有促进作用，它们的酶活力分别为0．65、0．67和0．62U／mL，而硫酸铵抑制脂肪酶的合成，其酶活力仅为0．08U／mL。C／N比对细胞生长和酶的合成影响很大，当C／N比从2增加到10时，脂肪酶活力从0．65下降到0．14U／mL，而细胞浓度从3．08升高到4．58mg／mL。在培养基初始pH值5．5、28℃下培养，S．asparatus合成的脂肪酶活力最高，脂肪酶活力和细胞浓度分别为0．65U／mL和3．08mg／mL。     

大豆秸秆纤维素固态发酵及酶解条件的研究

对经氨预处理的大豆秸秆纤维素固态发酵产酶及酶解产糖工艺过程进行了研究，影响康氏木霉(Trichoderma koningii)固态发酵的主要因素是温度、pH值、培养基液固质量比及培养时间，影响纤维素酶水解的条件主要是温度、pH值及时间，结果表明：较适宜的产酶条件为温度30℃，pH值5．0，培养基液固质量比2．5：1，时间96h，产纤维素酶活力为798．84FPU／mL，以所产纤维素酶进行酶水解，较适宜条件为温度55℃、pH值5．6、时间36h，酶解率为18．98％。由液相色谱分析可知酶解液的主要成分为葡萄糖、纤维二糖和木糖．为大豆秸秆的进一步综合利用提供了参考数据。     

氮源对里氏木霉木聚糖酶和纤维素酶生物合成的影响

研究了氮源种类和比例、碳氮比(C／N)等因素对里氏木霉木聚糖酶和纤维素酶生物合成的影响。在各种氮源中，蛋白胨是最好的氮源。复合氮源中当硫酸铵N和尿素N的比例为1：3时，木聚糖酶活力最高，达93．3IU／mL；当比例为1：1时，滤纸酶活力和羧甲基纤维素(CMC)酶活力达到最大值，分别为0．263FPIU／mL和0．026IU／mL。当控制培养基的C／N为8．0和6．0时，它们对木聚糖酶和纤维素酶的诱导作用最强，分别为95．1IU／mL和0．310FPIU／mL。     

纤维素酶和半纤维素酶改性对漂白针叶木浆性能的影响

分别采用复合纤维素酶、内切纤维素酶和木聚糖酶3种酶对漂白针叶木纤维进行改性处理,比较不同的酶对漂白针叶木浆性能的影响。结果表明:复合纤维素酶对漂白针叶木浆性能影响较大,随着酶用量的增加,浆料滤水性先增加后下降,纤维保水值(WRV)和Zeta电位绝对值先降低后增加,纤维表面亲水性降低,纤维长度急剧下降,手抄片抗张指数先增加后急剧下降;在酶用量5.0 U/g时,纤维平均长度较对照样降低了48.64%,抗张指数较对照样下降了23.23%;内切纤维素酶和木聚糖酶对漂白针叶木浆的影响都比较小,改性处理后WRV和Zeta电位绝对值逐渐降低,但纤维表面亲水性增加,手抄片抗张指数也有所增加。对于造纸工业而言,内切纤维素酶的改性效果较好,当其用量为5.0 U/g时,纤维表面亲水性增加,有利于对纤维进行打浆处理,同时手抄片抗张指数增加到22.04 N·m/g,较改性处理前增加了20.77%。     

纤维素酶预处理对杨木APMP浆配抄性能的影响

为了改善杨木高得率浆的配抄性能,扩大其应用范围,研究探讨了纤维素酶预处理对杨木碱性过氧化氢机械浆(APMP浆)配抄性能的影响。结果表明,与未经过酶预处理的杨木APMP浆相比,酶处理后APMP浆打浆能耗最大可降低19%,纤维吸水润胀程度增加,保水值增加12.6%;与不同比例针叶木漂白硫酸盐浆(BKP浆)配抄后,纸张的裂断长、耐破指数和撕裂指数均有所提高,最大可分别提高6.1%,44.6%和30.3%,纸张的松厚度、白度和不透明度稍有降低。纤维质量分析仪(FQA)、扫描电镜(SEM)和X射线衍射(XRD)分析结果显示,酶处理后纤维平均长度增加7.0个百分点,细小纤维组分减少10.0%,纤维卷曲指数降低22.4%,结晶度提高0.7%。可见,纤维素酶预处理可以改善杨木APMP浆的配抄性能,提高纸浆纤维质量,所配抄的纸张的物理强度性能指标有显著提高。     

分批添料半连续发酵制备纤维素酶

以淀粉水解液、纸浆为原料，分批添加底物制备纤维素酶，底物浓度为４０ｇ／Ｌ时，滤纸酶活力和纤维二糖酶活力分别达５１ＦＰＩＵ／ｍＬ和１５ＩＵ／ｍＬ，蛋白质浓度达２２９ｍｇ／ｍＬ；当底物浓度增加到７４ｇ／Ｌ时，滤纸酶活力几乎成正比例地提高到１４８ＦＰＩＵ／ｍＬ。以纸浆为原料分批添料产酶，添料速度以０３ｇ／ｄ较为适宜，底物浓度达７７ｇ／Ｌ时，滤纸酶活力达９９５ＦＰＩＵ／ｍＬ，酶产率和酶得率分别为３１８９ＦＰＩＵ／Ｌ·ｈ和１２９２ＦＰＩＵ／ｇ纤维素。通过分批添加底物，可实现在高浓度底物下制备纤维素酶而达到降低产酶成本的目的。     

低纤维素酶活的木聚糖酶对二次纤维AKD施胶效果的影响

低纤维素酶活木聚糖酶在合适的酶解条件下，能降低轻量涂布纸二次纤维中细小组分含量，增加浆料的滤水速度。原浆细小组分含量为37．5％，经过烷基烯酮二聚体（AKD）中性施胶，Cobb值为25．86g/m^2；经过木聚糖酶处理30min后，细小组分为28．4％，Cobb值为20．03g/m^3，细小组分含量的变化影响到AKD施胶效果，成纸的施胶度随着浆料中细小组分含量的增加而降低，细小组分含量高，吸附在细小组分表面的AKD在纸页的成形过程中易流失到白水中，降低了AKD的留着率，在合适的酶处理条件下，经过酶改性的二次纤维，能有效地提高二次纤维AKD的施胶效果，细小组分的含量对AKD的旋胶效果影响很大。     

产纤维素酶细菌的筛选及酶学特性研究

以腐烂的废纸浆为原料，经反复筛选及刚果红染色鉴定，获得一株高活力纤维素酶生产细菌。该菌形态杆状，可产芽孢，适宜在pH值为9．0－10．0、35－37℃条件下生长。摇瓶产酶试验结果表明：该菌的发酵液在中性和碱性条件下都可测得较高的纤维素酶活力，其CMC酶活力分别可达69．4U/mL（pH值为6．7和53．6U／mL（pH值9．5）。酶反应的适宜温度为50℃，适宜中性至碱性，Ca^ 2和Mn^＋2对酶反应有促进作用，Pb^ 2和Hg^ 2对酶反应有抑制作用。这种酶制剂在棉织品的水选整理及洗涤剂工业中具有良好的应用前景。     

二次纤维酶水解生成葡萄糖的研究

将回收的废纸脱墨、洗净即为二次纤维。脱去其中的木质素和半纤维素，得纤维素，用纤维素酶水解生成葡萄糖。对温度、pH值、酶用量、时间分别进行单因素试验，通过测定水解液葡萄糖含量，找出水解的适宜条件：温度45℃，pH值4．8，酶用量8IU／g(对绝干原料)，产率可达60％以上。     

碱性纤维素酶发酵条件的研究

采用芽孢杆菌Bacillus sp.AC-2作为碱性纤维素酶的生产菌株，对其发酵条件进行了研究。适宜的种子茵龄为24h；适于产酶的培养温度为37℃，培养基初始pH值10．5；在碳源和氮源分别为1％的淀粉和2％的豆饼粉时，碱性纤维素酶活力可达到76．04U／mL。该酶反应的最适温度为60℃；酶液在70℃以下、pH值6．0～10．0范围内稳定。该酶制剂在棉织物洗涤和纸浆脱墨方面具有良好的应用前景。     

越南甜竹纤维形态特征的研究

对甜竹原料、甜竹浆的纤维形态进行了研究。结果表明:甜竹原料纤维平均长度为2.37 mm、平均宽度17.91μm、长宽比值132.40;纤维平均壁厚为8.13μm、平均腔径为2.57μm、壁腔比值6.33。研究了在蒸煮过程中纤维形态的变化。结果表明,在蒸煮过程中甜竹纤维长度不断变小,从2.37 mm(原料)到1.79 mm(全浆),减少24%;蒸煮过程中纤维长宽比值也不断缩小,从132.40(原料)到98.89(全浆)。与青皮竹浆、桉木浆(阔叶木)、马尾松浆(针叶木)和麦草浆(草类)的纤维形态相比,甜竹浆纤维长度大于麦草浆纤维,小于马尾松浆纤维,与青皮竹浆和桉木浆纤维长度基本相近,因此甜竹浆纤维属于长纤维范围,是一种优良的造纸原料。     

Characterization of raffia palm fiber for use in polymer composites

Raffia palm fibers are potential reinforcement materials for making cost-effective polymer-based composite. This paper presents the results obtained from a study of physical, chemical, thermal and mechanical properties of raffia palm fibers (RPFs) derived from the raffia palm tree (Raphia farinifera). The as-received RPFs had their remnant binders manually removed and was subsequently cleaned in a 2% detergent solution before drying in an air oven at 70 °C for 24 h. Evaluation of the properties of the dried samples was carried out using a combination of characterization techniques including chemical composition determination, density measurement, moisture adsorption and water absorption measurements, tensile testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Raman spectroscopy, X-ray diffractometry, and Fourier transform infrared spectromicroscopy. The main constituents of RPFs were found to be cellulose, hemicellulose and lignin. The average diameter and average density were 1.53?±?0.29 mm and 1.50?±?0.01 g/cm³, respectively. The average breaking strength of the fibers ranged from 152?±?22 to 270?±?39 MPa; it did not vary significantly with fiber length and cross-head speed during tensile testing. The results of scanning electron microscopic investigation of the fibers showed that they comprise several elemental fibers which are tightly packed together with each having its own lumen. Synchrotron-based Fourier-transform infrared spectromicroscopy of a cross-section of the fiber showed that lignin is concentrated mostly on the outside while cellulose and pectin are concentrated in the mid-section. A two-stage water sorption behavior was observed for the fibers.     

福建柏优树子代苗期性状遗传变异和生长节律研究

福建柏 (Fokieniahodginsii)是柏科 (Cupressaceae)福建柏属的唯一种 ,为我国特有的第一批珍稀濒危二级保护植物。因其生长较快、材质较好、栽培管理较容易、病虫害较少 ,因此是值得推广的优良用材树种 (杨宗武等 ,1 998;中国树木志编辑委员会 ,1 983;高兆蔚 ,1 994)。近年来 ,福建柏作为珍贵建筑材树种和抗逆性强的造林树种已越来越被重视 ,在南方各省区已成为杉木二代更新不可多得的好树种 ,推广前景广阔 (盛炜彤等 ,1 992 )。因此 ,开展福建柏的遗传改良研究 ,选育优良的遗传材料供生产推广应用 ,具有重要的意义。鉴于此 ,笔者从 1 998年开始进行福建柏优树选择、子代测定等工作。目前有关这方面的研究仅有少量有关种源试验苗期阶段的报道 (曾志光等 ,1 998;侯伯鑫等 ,2 0 0 0 ;郑仁华等 ,2 0 0 1 ;杨宗武等 ,2 0 0 1 ) ,而对优树子代测定的研究未见报道。本文主要报道子代苗期性状遗传变异和生长节律 ,以期为进一步研究奠定基础。1　材料与方法1 999年 1 0月中旬至 1 1月上旬 ,对 1 998— 1 999年在福建省和湖南省选...     

Properties of gypsum particleboard reinforced with polypropylene fibers

This paper details the influence of the length and content of polypropylene (PP) fibers on the physical and mechanical properties of gypsum particleboard (GPB). The length and amount of PP fibers added had a significant effect on the internal bond strength (IB) and the modulus of rupture (MOR) of GPB. The highest IB value was shown at 9 mm length and 9% content of PP fibers. The MOR was highest when the board was made with PP of 12 mm fiber length and 12% content. Suitable contents of PP fibers were advantageous in that they reinforced the properties of GPB so it achieved high performance. In contrast, a high content of PP fibers reduced the IB, MOR, and modulus of elasticity (MOE) of GPB. The thickness swelling was reduced with an increase in PP length and content. It was concluded that the combination of 12 mm length and 12% content or 3mm length and 9% content was optimum for producing good performance of GPB.Part of this paper was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000     

马占相思的树龄和倍性对纤维性状的影响

近年来关于树龄对木材结构影响的研究越来越多,主要集中于研究年轮代表的树龄对木材结构的影响,并运用于林业的早期选育,但很少涉及纵向树龄和维管组织所反应的树龄（管宁,１９９６;姜笑梅,１９９７;刘元,１９９７;马灵飞,１９９７;Ｆａｈｎ,１９９０;崔克明,１９９２;１９９３;１９９５;１９９７;Ｂａｓｓ,１９８４;曾其蕴,１９９０;Ｄｏｎａｌｄｓｏｎ,１９９６）。马占相思（ＡｃａｃｉａｍａｎｇｉｕｍＷｉｌｌｄ．）是含羞草科（Ｍｉｍｏｓａｃｅａｅ）金合欢属（Ａｃａｃｉａ）中生长较快的一个种（Ｇｏｎｚａ…     

A method to determine lumen volume and collapse degree of pulp fibers by using bottleneck effect of mercury porosimetry

On applying mercury porosimetry to wood blocks or paper sheets, the “bottleneck” effect due to pits of fibers occurs and thus lumen volume can be determined from the weight increase due to the remaining mercury. However, in addition to the mercury in the lumen, some mercury drops may also remain in the space between fibers within a paper sheet. The mercury between fibers increased with an increase of basis weight. Thus, a large number of paper sheets of low basis weight, such as 10 g·m⁻², should be used to determine the lumen volume of pulp fibers. Furthermore, in the case of fibers from mechanical pulp with many open cut fibers, mercury can retract from the open lumen such that the bottleneck effect due to pits does not occur. Therefore, the degree to which fibers are cut should also be considered for lumen volume determination. Although quantitative estimation of open cut fibers is difficult, the percentage of open cut fibers is quite low for the long fiber fraction. Thus, the remaining mercury for the long fiber fraction can be adopted as the lumen volume at least for practical purposes. Compared with the original lumen volume of the wood, the volumetric degree of fiber collapse was also estimated. Plausible values of almost 100% for lightly beaten KP and about 85% for slabwood thermomechanical pulp were obtained for the degree of collapse. Part of this report was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, August 2006     

Production and harvest of fibers from Aphandra natalia (Palmae) in Ecuador

Aphandra natalia (Balslev & Henderson) Barfod is native to the western Amazon. It is exploited commercially for its leaf sheath and petiole fibers, which are used for brooms. Data from a 2 year study on production and harvest of fibers in the province of Morona-Santiago in Ecuador shows correlations to exist between the degree of the palm's exposure to light and leaf production, and between exposure to light and petiole length (maximum fiber length), while correlation is absent between exposure to light and fiber load per leaf. A linear relation was found between time and leaf production, with an overall average of 5.5 leaves produced per palm per year. No difference in leaf production of male and female palms was found among palms growing at low light intensities, while among palms in open, light-exposed areas, males were found to produce significantly more leaves than females. An average of 8.5 leaves are cut per palm per harvest, yielding 3.4 kg of fibers, while 6.9 leaves are left untouched. Average harvest time per palm is 33 min. Under optimal conditions (high densities of easy accessible palms), one harvester may harvest and clean about 20 kg of fibers in 1 day, selling at US$1.1 kg⁻¹. One hectare with high, but natural, densities of the palm may produce fibers worth US$460 per year, which can be harvested and prepared in 22 work days. Exploitation of the edible fruits may be combined with fiber extraction if female palms are left to produce fruits, while male palms are exploited for fibers, or if harvest frequency of fibers from female palms is lowered considerably below the average of once every 1.55 years. The exploitation practised in the study area appears sustainable.     

竹原纤维和竹粉纤维形态和化学成分分析

以3年生毛竹材为原料,研究了毛竹竹粉和竹原纤维的纤维形态和化学成分。纤维形态分析结果表明:竹原纤维的宽度(143μm)与竹粉(136μm)相当,长度(22.63 mm)远高于竹粉(0.61 mm),使其长宽比(158.25)远高于竹粉(4.49)。化学成分分析表明:竹原纤维的纤维素含量(65.6%)比竹粉(37.3%)高得多,聚戊糖含量(17.1%)略低于竹粉(20.1%)。竹粉中的木质素含量为24.5%,是竹原纤维中木质素含量(11.5%)的2倍多。竹原纤维的高纤维素含量和低木质素含量是其广泛应用于制浆造纸行业的重要原因。     

Medium-density fiberboard performance as affected by wood fiber acidity, bulk density, and size distribution

The properties of medium-density fiberboard (MDF) panels as affected by wood fiber characteristics were investigated. Wood chips from three softwood and one hardwood species were refined under the same refining conditions to make four different types of fibers. The resulting fibers were characterized by fiber size distribution, bulk density, pH value, and buffering capacity. Using the same resin system and hot-pressing parameters, MDF panels were produced and evaluated for internal bonding (IB), modulus of rupture (MOR), modulus of elasticity (MOE), thickness swelling, and linear expansion. The pH values and alkaline buffering capacities of raw materials were reduced considerably after refining. IB was strongly related to the pH value of fibers. The mechanical properties increased with alkaline buffering capacity. IB, MOR, and MOE increased with the bulk density of fibers. Increased proportions of coarse fibers had negative effects on the panel mechanical properties.     

杂种松扦插繁殖试验初报

通过近３年的杂种松扦插繁殖试验结果表明,选用黄泥心土基质、穗条采下后浸于５０ｍｇ／ｋｇ的台化牌植物生根促进剂溶液或１ｇ／ｋｇ多菌灵溶液各０．５ｈ或浸于１ｇ／ｋｇ多菌灵溶液０．５ｈ后蘸黄泥浆扦插等处理、在冬春季节光照充足的圃地、穗条长６～１４．５ｃｍ、顶端次生叶长５．５～１３ｃｍ等条件下扦插生根率高;并且在穗条、管理措施、扦插季节等条件合适的情况下,部分家系的扦插生根率较稳定,可达到７５％,最高达１００％。大规模扦插试验平均生根率达９１％。