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研究了粉煤灰联产新型活性硅酸钙填料的填料性能及其作为填料在纸张中的加填性能,探讨了活性硅酸钙不同加填量对纸张性能的影响,并与商品轻质碳酸钙(PCC)填料进行了对比。结果表明,活性硅酸钙粒子呈蜂窝状,具有多孔性,比表面积较大,平均粒径为10.63μm,吸油值为2.178 g/g,沉降体积为4.0 mL/(10 g.24 h),白度为90.5%,较适于作为造纸填料。活性硅酸钙加填纸性能检测发现,随着活性硅酸钙用量的增加,纸张白度和不透明度都有较大程度的提高,纸张的抗张指数有较大降低,加填量不超过30%时,撕裂指数基本上保持不变。与商品PCC相比,加填量均为30%时,纸张白度和抗张指数基本相当,不透明度低5.1个百分点,撕裂指数高1.3 mN.m2/g,从加填后纸张的SEM图可以看出,活性硅酸钙与纤维之间有较好的交织。 相似文献
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探讨了2种CaSiO3加填印刷纸的脱墨性能。结果表明,以CaSiO3为填料的1#纸样和以CaSiO3/滑石粉为填料的2#纸样均具有较好的脱墨效果,二者浮选脱墨浆料得率相同,1#浮选脱墨浆的白度为77.5% ISO,略高于2#浮选脱墨浆的73.9% ISO,1#浮选脱墨浆有效残余油墨浓度为81.24 mm2/m2,略低于2#浮选脱墨浆的115.96 mm2/m2;在脱墨过程中,1#纸样胶黏物去除效果略优于2#纸样,2种纸样初始胶黏物含量均较低,不会对生产造成影响;2种纸样的碎解浆经浮选脱墨后纤维长度均有所降低,细小纤维含量增加,1#浮选脱墨浆的纤维长度下降幅度略高于2#浮选脱墨浆;受灰分影响,1#浮选脱墨浆手抄片的强度指标较2#浮选脱墨浆手抄片略差。 相似文献
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填料经预絮聚后以絮聚体的形式加填纸张中,絮聚体在湿部的尺寸及稳定性对纸张性能有着重要影响。采用不同用量的阳离子聚丙烯酰胺(CPAM)对沉淀碳酸钙(PCC)进行预絮聚,通过絮聚体粒径的变化,研究了不同剪切条件下PCC絮聚体抗剪切与再絮聚效果,并考查了所得絮聚体对成纸性能的影响。结果表明,随着CPAM用量从1%增加至7%,絮聚体粒径由23.37μm增大至31.92μm。与常规PCC加填方法相比,当CPAM用量为3%~7%且加填量55%时,预絮聚加填纸张留着率均可提高约3个百分点左右。当CPAM用量为3%,填料含量为30%时,预絮聚加填比常规加填纸张抗张指数提升了约16%,而CPAM用量高于3%时所得的大粒径絮聚体对成纸抗张指数反而不利,且纸张白度有所降低。 相似文献
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采用3种合成聚合物(PDADMAC、PVAm和PNVF)分别对TiO2进行改性,并用球磨机进行机械研磨,将改性后的TiO2作为填料用于装饰原纸的抄造中,探究了不同改性剂用量下获得的改性TiO2对加填后装饰原纸主要性能的影响。结果表明:改性剂PDADMAC用量为2.5%进行TiO2改性时,与未改性TiO2加填纸相比,改性TiO2加填纸的抗张指数和填料留着率分别提高了21.0%和9.5%;PVAm用量为2.0%时,改性TiO2加填纸的抗张指数和填料留着率比未改性TiO2加填纸分别提高了24.7%和5.5%;PNVF用量为1.5%时,改性TiO2加填纸强度性能和填料留着情况较优。 相似文献
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针对造纸常用填料沉淀碳酸钙(PCC)加填量较大时纸张强度严重下降的问题,利用淀粉-硬脂酸复合物同时添加交联剂六偏磷酸钠的方法对PCC进行表面改性,研究改性PCC制备工艺及改性PCC和未改性PCC对纸张物理性能的影响.结果表明,当淀粉用量为PCC质繁的25%,淀粉质量分数为3.0%.硬脂酸用量为PCC质量的4.0%,交联剂用量为PCC质量的1.0%时,制得的改性PCC性能较好.相同灰分含最下,与加填未改性PCC纸张相比,加填改性PCC纸张的抗张指数、耐破指数、撕裂指数和白度性能更佳. 相似文献
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本研究对粉煤灰基多孔硅酸钙填料的物理性能进行了分析,并对多孔硅酸钙加填轻型纸的脱墨性能进行了研究。结果表明,多孔硅酸钙填料密度小、比表面积大、孔隙率高,呈现“蜂窝状”结构,且白度高,磨耗低;多孔硅酸钙加填轻型纸的脱墨性能好,脱墨浆白度增值高,经浮选脱墨后其油墨去除率、残余油墨浓度和脱墨浆ISO白度增值分别为84.3%、159.9 mg/kg和17.1%,明显优于轻质碳酸钙(轻钙)加填轻型纸(分别为68.9%、230.2 mg/kg和10.4%),但其浮选脱墨浆渣率略高于轻钙填料,两者分别为3.44%、2.32%。与轻钙加填轻型纸的脱墨浆相比,多孔硅酸钙加填轻型纸的脱墨浆纸张松厚度好、裂断长和耐折度高,有助于生产高松厚度、高强度纸张。 相似文献
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研究取自不同厂家白泥碳酸钙的基本物化特性和加填应用性能,并将其与商品沉淀碳酸钙(PCC)和研磨碳酸钙(GCC)填料进行性能对比。实验结果表明,碱回收白泥精制碳酸钙的活性氧化钙和残碱含量与商品碳酸钙相当,但其白度和碳酸钙含量低,杂质含量高。白泥碳酸钙具有较高的比表面积,白泥颗粒呈不规则状且粒径分布较宽,其表面带负电而且具有较高的电导率。白泥加填后成纸的光学性能介于商品PCC与GCC之间,强度性能与商品碳酸钙相当,且白泥加填具有较高的留着率,但是白泥对AKD施胶会产生明显的负面影响,要达到常规填料的施胶度水平,白泥加填纸对AKD的消耗量是商品碳酸钙的2倍甚至更高。 相似文献
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纺织产业集群的经济景气研究在国内处于起步阶段,本文依据产品价格调查方法、企业景气调查方法和企业财务数据构建了专业市场型产业集群经济景气的指标体系,该景气指标体系由产品综合价格指数、市场景气指数和企业现金流指数构成。这一体系在中国东方丝绸市场发布的丝绸化纤指数中得到了运用。 相似文献
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A new selection index percent emphasis method using subindex weights and genetic evaluation accuracy
The current international standard methodology to quantify trait percent emphasis in selection indexes is based on a simple multiplication of the relative contribution of each trait's economic value (converted to absolute value) and its genetic standard deviation. This method does not reflect the actual selection emphasis applied when the index is used in practice. The economic value does not reflect selection effort when traits differ considerably in their accuracy of evaluation, and no account is taken for either favorable or antagonistic correlations among traits. A new emphasis method adjusted by both accuracy and genetic correlation is proposed. Genetically highly correlated traits are grouped into subindexes by applying a hierarchical clustering method to the genetic correlation matrix. Then each trait's subindex emphasis is calculated within its subindex group, with a weighting included for trait accuracy. Finally, each subindex emphasis is converted to a full index emphasis according to the conventional relative emphasis of its corresponding subgroup. The method can also be applied to sets of breeding values and their economic weights. When applied to a New Zealand sheep breeding selection index where trait genetic correlations are distinct across subindex groups, the new method shrank the emphasis on low-heritability traits, including survival, from 51% to 19%; and expanded that on growth traits from 30% to 49%, better reflecting the selection pressure applied in reality. When genetic correlations across traits were similar, clustering became difficult. Accounting for accuracy affected traits' within-subindex group rankings, whereas the clustering to account for correlations affected all traits within a subgroup equally. Accounting for differences in trait accuracy when describing percent emphasis within selection indexes gives a more practical indication of the likely outcome of selecting on the index. Accounting for correlations among traits when defining percent emphasis made a significant difference only in a subset of case study examples. 相似文献
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本文从整体和分类两个层面分别计算了植物油籽1999-2008年的G-L产业内贸易指数、Brulhart边际产业内贸易指数、Thom&McDowell边际产业内贸易指数,发现我国植物油籽的整体产业内贸易水平非常低,Brulhart边际产业内贸易指数显示我国植物油籽10年来贸易的增量主要来自于产业间贸易,Thom&McDowell指数表明我国植物油籽产业内贸易主要由水平产业内贸易引发。文章认为应该加快科技兴农步伐,提升我国植物油籽的质量,实施产品差异化战略,促进植物油籽品种的多元化,并争取WTO的特别保障条款,减少进口大豆、油菜籽对我国大豆、油菜产业的冲击。 相似文献
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Isabelle Travers Alain Jacquet Adlaïde Brisset Claire Maite 《Journal of the science of food and agriculture》2002,82(9):983-989
Monitoring the hydrolysis or disappearance of starch by the starch iodine test is a simple procedure for determining the maturity of cider apples, but it does not indicate the exact amount of starch present. So far, studies of starch in apples have dealt exclusively with dessert apples. In this paper the relationship between the visual starch index, the dark‐coloured surface area and the real starch content was studied in two varieties of cider apple commonly used in Normandy (France). Starch determination in cider apples required adapting the protocol provided by the Boehringer enzymatic kit. The work led to proposing a simplified index with five scales instead of 10. This index gives the correspondences between the new and old scales as well as the probable starch contents for each new scale. © 2002 Society of Chemical Industry 相似文献