用MAH改性PE和EPDM增韧PA-66及增韧机理分析

用马来酸酐（ＭＡＨ）熔融接枝聚乙烯（ＬＤＰＥ）和三元乙丙胶（ＥＰＤＭ）改善了与基体ＰＡ－６６的相溶性，继而大幅度地提高了ＰＡ－６６／（ＰＥ）／ＥＰＤＭ）－ｇ－ＭＡＨ的冲击强度。当共混物中ＥＰＤＭ－ｇ－ＭＡＨ为９％、ＰＥ－ｇ－ＭＡＨ为３０％时，共混材料的冲击强度是ＰＡ－６６的３．３５倍，成本降低约１５％。同时对增韧机理进行了分析     

用MAH改性PE和EPDM增韧PA—66及增韧机理分析

用马来酸酐ＭＡＨ熔接枝聚乙烯（ＬＤＰＥ）和三元乙丙胶（ＥＰＤＭ）改善了与基体ＰＡ－６６的相溶性、继而大幅度地提高了ＰＡ－６６／（ＰＥ／ＥＰＤＭ）－ｇ－ＭＡＨ的冲击强度。当共混物中ＥＰＤＭ－ｇ－ＭＡＨ为９％、ＰＥ－ｇ－ＭＡＨ为３０％时，共混材料的冲击强度为ＰＡ－６６的３．３５倍，成本降低约１５％。同时对增韧机理进行了分析。     

烷基苯磺酸盐与聚丙烯酰胺混合水溶液的测定

本文提出了用双长紫外法－新洁尔灭浊度法来分析烷基苯磺酸盐（ＡＢＳ）和聚丙烯酰胺（ＰＡＭ）混合术溶液中各组分的合量，以解决用常规分析方法时因组分间相互干扰而逅成的测定偏差．首先，双波长紫外法利用２１５ｎｍ、２２５ｎｍ两个波长下溶液吸光度的差值（２Ａ２２５－Ａ２１５），消除ＰＡＭ的吸光影响，测出ＡＢＳ的浓度，精度达０．５％；然后，根据部分水解聚丙烯酰胺与阳离子型表面活性剂新洁尔灭反应产生白色沉淀，利用浊度大小测定ＰＡＭ的浓度，此法可检测出０．１ｍｇ／ｋｇ的ＰＡＭ．     

ICP－AES的超声雾化进样系统

本文报导了超声雾化器改装后作为电感耦合等离子体发射光谱分析（ＩＣＰ－ＡＥＳ）的进样系统，考察了该系统的有关性能。用空气一氩ＩＣＰ－ＡＥＳ直接测试毛线中的微量钕，获得了满意的结果，加标回收率在９５％～１００％之间。     

聚丙烯腈水解过程的红外光谱考察

通过自由基接枝聚合方法由丙烯腈（ＡＮ）单体和纤维素纤维（ＣＦ）制取一种具有聚丙烯腈（ＰＡＮ）表层的改履纤维素纤维（ＰＡＮ－ＣＦ）,将ＡＮ接枝率７０％的ＰＡＮ－ＣＦ用２．０ｇ／ｄＬＮａＯＨ溶液进行水解,制得反应程度不同的系列水解ＰＡＮ－ＣＦ（Ｈｙｄ．ＰＡＮ－ＣＦ）样品,运用红外光谱法分析上述试样。以考察水解反应过程。结果表明,ＰＡＮ的碱水解过程是由反应速度不同的三个阶段构成;前期增速缓慢,中期增速争     

酶法合成DHA／EPA型卵磷脂的研究

为了合成二十二碳六烯酸（ＤＨＡ）和二十碳五烯酸（ＥＰＡ）的卵磷脂（ＰＣ）,筛选得到了一株产脂肪酶的少根根霉Ｍ－０１。用该菌株的处理菌体催化多烯不饱和脂肪酸与卵磷脂进行酸解反应,制备ＤＨＡ／ＥＰＡ型卵磷脂。结果显示反应后的卵磷脂中ＤＨＡ与ＥＰＡ含量分别达到５．３５％和６．７６％。     

添加剂对流动沸腾压降的影响

研究了添加剂对垂直铜管内流动沸腾压降的影响，实验介质为水，所用添加剂为分子量２５６万的聚丙烯酰胺胶乳（ＰＡＭ）及十八烷胺，测定了添加剂溶液流动沸腾两相流压降，并且用Ｍａｒｔｉｎｅｌｌｉ分离流模型回归不同添加剂浓度下的液相摩擦因子ｆ１与液相雷诺数Ｒｅｌ间的函数关系，根据回归的模型方程计算两相流压降，与实验值比较其相对误差为１５％左右，研究结果表明，在一定热通量和一定浓度范围内，加入少量添加剂ＰＡＭ可     

奈福泮对豚鼠心肌电生理的影响

奈福泮（Ｎｅｆ）１～１００μｍｏｌ／Ｌ可降低豚鼠心室肌细胞动作电位振幅（ＡＰＡ）和０相上升最大速率Ｖｍａｘ；Ｎｅｆ还可延长复极９０％时动作电位时程（ＡＰＤ_（９０））和有效不应期（ＥＲＰ），同时升高ＥＲＰ／ＡＰＤ_（９０）比值，但使复极２０％时的动作电位时程（ＡＰＤ_（２０））缩短。本实验结果提示：Ｎｅｆ对Ｎａ￣＋、Ｋ￣＋和Ｃａ￣（２＋）的跨膜转运均有抑制作用，与第Ⅰ类抗心律失常药奎尼丁类似。     

一类双重时间序列模型平稳解的存在性

讨论了双重时间序列模型ｘｔ＝θｔｘｔ－１＋εｔ（１）的平稳解存在的条件，这里，θｔ是平稳的自回归滑动平均ＡＲＭＡ（Ｐ，ｑ）序列。并且，在θｔ是一阶自回归序列ＡＲ（１）时，给出模型（１）有平稳解的显式条件。     

多级用户的竞争-冲突系统模型的建立及分析

分析了只有多级用户的Ｓ－ＡＬＯＨＡ协议,并建立了基于该协议的离散时间排队网络模型,分别用离散时间排队网络系统中的递归ＥＰＡ法（ＲＥＰＡ）及迭代ＥＰＡ法（ＥＥＰＡ）完成了对具有多级用尸的Ｓ－ＡＬＯＨＡ网络的吞吐量（Ｓ）及等待时间（Ｗ）的性能分析。最后对２种算法的时间复杂度进行了比较。     

谈建筑工程施工图结算的审核

建筑工程结算应从工程量计算 ,定额的套用、合同的履行等方面予以审核 ,使工程造价客观　　　　　真实的反映出来。     

Coagulation enhanced electrokinetic settling of mature fine oil sands tailings

The mature fine oil sand tailings(MFT) remain as slurry in the tailings pond for long time. The dewatering and consolidation of MFT for sustainable management is an important task for the mining industry. The objective of this study is to accelerate electrokinetic settling of MFT solids in suspensions in presence of optimal coagulant. In the first phase, optimal coagulant and coagulant dosage for settling of suspension are identified, i.e., ferric chloride at 350 mg/L. It is found that the chemical treatment is not much effective; the final solid content of the sediment is only 6.48% from an initial of 5%. In the second phase,combined coagulation and electrokinetic treatment is carried out to enhance the settling effect. The direct electric current is applied in continuous and intermittent modes on MFT suspensions placed in electrokinetic cell. The results show the final solid content reaches 23.74% under the combined application of350 mg/L ferric chloride and 218.75 V/m applied voltage gradient in the continuous mode. The intermittent current mode with 40% save in power consumption produces a settled sediment having 20.84% final solid content.     

堵口土工包沉落试验研究

对抢险土工包这种新型的抢险堵口材料进行了抛掷沉降运动的概化模拟试验研究 ,建立了土工包沉降速度的计算模式 .针对黄河一般的堵口水流特点及现实施工条件 ,根据设计水流条件和土工包的几何、材料特性 ,进行了不同条件、多组次的水槽概化试验 .通过试验观察与实测资料整理 ,分析了土工包沉降力学机理、落地稳定性及偏移运动过程 ;给出了不同条件下的土工包沉落速度、横向偏移量以及用于土工包沉降计算的有关参数 .水槽概化模拟试验中得出的有关数据 ,可供土工包抢险设计、施工预案时参考     

Effects of intense magnetic field on digestion and settling performances of bauxite

The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.     

高校结算中心风险管理

高校结算中心是管理高校货币资金的特殊部门，特殊部门具有特殊风险，结合高校实际探讨了该部门风险管理的意义和方法，对其发展具有指导作用．     

以粗组分泥沙为主的高浊度水正交混凝沉淀实验研究

以PAM为混凝剂 ,通过烧杯静水正交混凝沉淀实验 ,研究了原水含沙量 (ρ)、PAM投加量(a)、混凝搅拌强度 (G)、混凝搅拌时间 (T)和沉淀时间 (t)五个主要因素对以粗组分泥沙为主的高浊度水混凝沉淀影响的程度 ;实验表明五个主要因素的影响强度从大到小依次为原水含沙量、混凝搅拌强度、PAM投加量、沉淀时间和混凝搅拌时间 ;同时 ,通过实验得出的澄清水层残余浊度 (Ty)—实验因素 (如ρ、a、G、T、t)曲线 ,指出了每个因素对沉淀效果影响的趋势     

Numerical simulation of flocculation and settling behavior of whole-tailings particles in deep-cone thickener

Rapid dewatering and thickening of whole-tailings with ultrafine particles is one of the most important processes for the whole-tailings paste preparation. Deep-cone thickener, a kind of such process for the flocculation and settling of whole-tailings, is particularly necessary to study. However, there exist many problems in observing the flocculation and settling process of whole-tailings, as well as the particle size distribution(PSD) of whole-tailings floccules in deep-cone thickener. Population balance model(PBM) is applied to predict the PSD in deep-cone thickener, and LUO model and GHADIRI model are employed to study the aggregation and fragmentation mechanism of the whole-tailings particles, respectively. Through three-dimensional numerical simulation on the whole-tailings flocculation and settling in deep-cone thickener using computational fluid dynamics(CFD)-PBM, the distribution of density and turbulent kinetic energy in deep-cone thickener were obtained, at the same time the spatio-temporal changes of whole-tailings floccules particle size distribution are analyzed. Finally, the major flocculation position in deep-cone thickener is found and the flocculation settling rules of whole-tailings are achieved.     

基于负反馈原理的功放电路交越失真解决方法研究

为解决功放电路交越失真的问题,本论文首先阐述了交越失真产生的原理,并对传统常见的解决方法进行了讨论,然后把负反馈原理应用在解决交越失真中。此法操作简单,效果好,仿真和实验结果验证了该方法的可行性和正确性。     

Synthesis of modified polyacrylamide with high content of hydroxamate groups and settling performance of red mud

Hydroxamated polyacrylamide(HPAM) was synthesized from polyacrylamide(PAM) with high relative molecular mass under the optimum reaction conditions(p H 12 and a molar ratio of hydroxylamine to amide groups of 1.5 at 50 °C for 12 h). The hydroxamate groups of HPAM were verified by Fourier transform infrared spectrum(FT-IR). 46%(molar fration) hydroxamate groups and 23%(molar fraction) carbonyl groups on HPAM were determined by conductometric titration combined with Kjeldahl's microanalysis method. The settling performance achieved at different flocculant dosages was investigated with high goethite-containing red mud slurry of simulated Bayer process synthesized in laboratory. It turns out that the settling performance of high goethite-containing red mud was better with HPAM. The average settling rate of red mud in the first 5 min and the turbidity of supernatant after settling for 30 min are 2.36 m/h and 507 NTU, respectively, at a flocculant dosage of 120 g/t, which is similar to that achieved with Hx-600.     

Negative effect of dissolved organic compounds on settling behavior of synthetic monominerals in red mud

Hydration grossular and hematite monominerals were synthesized. The effects of dissolved organic compounds(including sodium formate, sodium acetate, sodium oxalate, sodium salicylate or disodium phthalate) on the settling performance of hydration grossular or hematite slurries were studied. The settling of the slurries was also investigated with the addition of sodium polyacrylate(PAAS) or hydroxamated polyacrylamide flocculant(HCPAM). The adsorption mechanism of organic compounds on monominerals surfaces was studied by FT-IR and XPS, respectively. A deterioration in settling is observed in order of disodium phthalatesodium salicylatesodium oxalatesodium formate(or sodium acetate). Moreover, PAAS can efficiently eliminate the negative effects of organic compounds on the settling performance of the hydration grossular slurry. HCPAM can efficiently eliminate the negative effects of sodium formate, sodium acetate and sodium oxalate on the settling performance of the hematite slurry, but it only partially improves the settling performance of hematite slurry containing sodium salicylate or disodium phthalate. FT-IR and XPS results show that organic compounds are physically adsorbed on hydration grossular surface, and chemisorptions of organic compounds occur on hematite surface with a bidentate chelating complex.