土法造纸木素降解之探索Ⅲ.嫩毛竹自然发酵过程中的细菌分离鉴定与嫩竹软化菌的筛选

试验证实,嫩毛竹自然发酵过程中的微生物主要是细菌。分离出并纯化了１００株细菌,其中６０株是芽胞杆菌。将分离出的１００株细菌分别接入石灰预处理过的嫩竹,从中筛选出能使嫩竹进一步软化的菌株３株,也均为芽胞杆菌。对这６０株芽胞杆菌进行了形态学及其生理生化特征的鉴定,按Ｐｒｉｅｓｔ氏等（１９８８年）的数值分类系统分类到组,将３株（３０８,３０９,３１０）对嫩竹软化有明显作用的芽胞杆菌的１株（３０８）鉴定到种,认为是短小芽胞杆菌（Ｂ．ｐｕｍｉｌｕｓ）。另外４０株非芽胞杆菌参阅《伯杰氏系统细菌学手册》第１卷和第２卷,鉴定到科或属,有微球菌、葡萄球菌、李氏杆菌、不动杆菌、肠杆菌科等。     

Dissolution of ionisable groups and lignocellulosic components during low-temperature kraft pulping of pinus radiata

A wide range of kraft pulps from radiata pine produced by low-temperature kraft pulping in flow-through reactors was assessed for carboxyl and hexenuronic acid (HexA) contents using the conductometric titrations and UV spectrophotometer, respectively. The Kappa number of pulps varied from 20.8 to 84.7 when using a cooking liquor of 1 M effective alkali as Na₂O, 25% sulfidity, and cooking time of 100–250 min. The experimental results showed that the carboxyl groups (including HexA) and HexA groups dissolved and their residual values in the pulp samples correlate linearly with Kappa number and pulp yield. The dissolving rate of all carboxyl groups is much faster than the loss of HexA. The HexA/lignin ratio decreased non-linearly with Kappa number.     

Brightness Reversion of Mechanical Pulps. Part XVII: Diffuse Reflectance Study on Brightness Stabilization by Additives Under Various Atmospheres

Brightness reversion of softwood (SW) and hardwood (HW) bleached chemithermomechanical pulps (BCTMP) with a 300–400nm light source under argon, oxygen, and air were studied in the absence and presence of UV-screens using UV–Vis reflectance difference spectroscopy. The UV-Vis difference absorption spectra of control SW and HW BCTMP testsheets indicate that as the concentration of atmospheric oxygen is increased, the absorption at max 360nm increases and a blue shift occurs. In all of the cases studied, brightness reversion was observed to occur under an argon atmosphere. The addition of benzophenone and benzotriazole additives to BCTMP testsheets resulted in a significant decrease in formation of chromophores absorbed at 400nm and 360nm. The possible mechanisms contributing to these effects are discussed in terms of the photoformation of lignin chromophoric structures.     

Sorption of spruce O-acetylated galactoglucomannans onto different pulp fibres

Sorption of spruce acetylated galactoglucomannans (GGM) onto different pulps, among which unbleached and peroxide-bleached mechanical pulps, and unbleached and bleached kraft (BK) pulps, was studied as a means of understanding the retention of acetylated GGMs in mechanical pulping and papermaking. The fibre surface coverage of lignin and carbohydrates was estimated by X-ray photoelectron spectroscopy (XPS) or electron spectroscopy for chemical analysis (ESCA). GGM sorption was clearly favoured on kraft pulps. Hardly any differences in sorption were, however, observed between unbleached and BK pulps, even if the surface coverage of lignin was lower on the bleached pulp. Neither thermomechanical pulp (TMP) nor chemithermomechanical pulp (CTMP) manufactured from spruce sorbed any acetylated GGMs. Peroxide bleaching of the pulp did not increase sorption. Only CTMP produced from aspen sorbed some GGMs. The anionic charge of neither chemical nor mechanical pulps influenced GGM sorption.     

Surface area of papermaking woodpulps used by the British paper industry

The surface area was determined for various papermaking woodpulps: bleached eucalyptus globulus sulphate pulp; bleached eucalyptus grandis sulphate pulp; bleached betula verrucosa sulphate pulp; bleached pine/spruce sulphate pulp; bleached pine/spruce sulphate pulp fines. The method of negative adsorption was used which gives an effective wet surface area. By looking at negative adsorption data more closely, some inference can be made about the morphology of the substrate.Glossary of symbols B (e²/2kT)^1/2 - ¯C concentration of fibre per unit volume of pulp - 1 - ¯¯c - h angle between pore and the axis of the bed in a permeable material - K permeability coefficient - k Boltzmann constant - k ₀ shape factor for pores in a permeable material - n _i concentration of co-ion in the bulk solution - n _i experimentally observed increase in concentration of co-ion in the bulk solution - S surface area - S _t wS - S ₀ surface area per unit volume of permeable material - V _t total volume of solution - V excluded volume - V _s excluded volume accessible to water but not to ions - V _obs experimentally observed excluded volume - w weight of dry fibre - ¯ effective volume of fibres in a permeable pad - surface potential at outer Helmholtz plane     

聚乙烯胺在CaCO3加填造纸中的作用效果

探讨了在弱碱性条件下聚乙烯胺(PVAm)对CaCO3加填的芦苇浆和废纸浆的助留助滤效果．实验结果表明：PVAm在两种浆中都有非常显著的助滤．助留效果，且在芦苇浆中的助滤效果大于废纸浆．PVAm在芦苇浆中对纤维的助留效果不如废纸浆，但对CaCO3的助留效果高于废纸浆．     

造纸废液用于水泥生产的研究

在实验室条件下研究了纸浆废液代水用于水泥生产成球对熟料煅烧及水泥性能的影响。结果表明，纸浆废液中的碱使生料的易烧性降低，使水泥各龄期强度降低；生料中配入适量石膏可减少或消除碱的不利影响     

在经纱上浆中如何实现浆液组分的等效替换

本文通过对各种变性淀粉、PAM、PVA及其混合浆对棉和涤棉的粘附性能及浆膜的机械性能测试分析，证实浆液组分变换的有效性可以通过检验对纤维的粘附力和浆膜的机械性能来判断，指出在浆纱工艺配方中能否少用或不用PVA的关键在于替代材料与淀粉混合后粘附力、浆膜的弹性和断裂功能否保持一致。     

ONP脱墨浆二氧化硫脲漂白研究

实验主要探讨了ONP脱墨浆FAS单段漂白的工艺条件,找出了FAS漂白的最佳工艺条件为:FAS用量0.6%,NaOH用量0.3%,漂白温度65℃,漂白时间30min,浆浓10%,在此条件下漂后浆白度达66.6%ISO。     

INFLUENCE OF NON-PROCESS ELEMENTS ON REED PULP''''S CHARACTERS DURING OXYGEN DELIGNIFICATION

INTRODUCTIONOxygen delignification is widely used in many bleached pulp-grade operation to diminish the levels of residual lignin in kraft[1]. The chemistry of oxygen delignification has undergone a renaissance in the last decade.Although the chemical structure and reactivity of residual lignin play a role in its effective removal, a variety of metal ions, frequently refers to as non-process elements(NPEs), they are either originated in pulp or introduced are also suggested to strongly a…