低聚反应

The effects of different factors on the laser-induced graft polymerization on the PET surface were analyzed, and the mechanisms were discussed. The factors were: 1 Monomers with smaller molecules resulted in better modification than polymeric monomers. Acrylamide monomer was chosen as hydrophilic modifier finally; 2 Higher concentration of the monomer solution favored the graft reaction; 3 With the increasing laser fluence, the surface hydrophilicity of PET films increased at first, then decreased. More laser pulses led to a more hydrophilic surface; 4 Benzophenone as a photosensitizer hindered the graft polymerization; 5 The homopolymer retardant of ammonium iron sulfate hexahydrate in a proper concentration retarded the formation of homopolymers and promotes the graft copolymerization; 6 The solvent of monomer solution also affected the graft reaction. Different solvents functioned in different ways. Ethanol can promote the graft reaction because of the activity of hydrogen in its structure; 7 pH value of the monomer solution affects the polymerization rate, and a lower pH value was favorable to the graft reaction.

这些影响因素的作用分别为：1小分子单体的表面改性效果好，确定以丙烯酰胺为亲水性改性单体；2较高的单体溶液浓度有利于接枝反应；3激光能量密度增大，薄膜表面亲水性先显著增强，后又减弱；激光脉冲次数越多，改性后表面亲水性越强；4光敏剂BP对PET表面接枝聚合反应有阻碍作用；5适当浓度的均聚物抑制剂六水合硫酸铁铵能减少单体均聚物的生成，促进接枝聚合；6单体溶液的溶剂也影响接枝聚合的反应进程，不同溶剂的影响作用原理不同，含较活泼氢的乙醇能促进接枝反应；7溶液pH值影响单体聚合速率，pH值较低有利于接枝反应。

The biomechanical tests showed that two kinds of artificial bones had not significant difference on compressive strength and Young\'s modulus(P＞0.05),while the flexural strength of nano-nacre artificial bone was less than the control group(P＜0.05).3.The results of CCK-8 showed that the difference were not significant in each group,the proliferation of osteoblast reached the peak at the 5th day;7 days after being co-cultured,the total protein content of study group was higher than control group and blank group(P＜0.05),while the difference between control group and blank group was not significantP＞0.05The difference of alkaline phosphatase activities among three groups was not significant(P＞0.05The SEM view showed that osteoblast attached and grew well in two kinds of artificial bone.4.X-ray photography showed that two kinds of powder started to degrade in 2 weeks;this phenomenon became more appear in 4 weeks,nano-nacre powder degraded faster than micron-nacre powder,while the hole shadow was easy to be found;in 8 weeks,all the femoral holes recovered and returned to normal bone mineral density in all groups.Analysis of tetracycline fluorescent double marks in the hard tissue grinding slices indicated that new bone grew fastest around the bone defect area in study group,while most slowly in blank groupP＜0.05 SEM(scanning electron microscope observation showed that nano-nacre powder degraded more quickly.The same result can be found through the demineralized sections morphometric analysis,and both of the composite artificial bones made from those two kinds of nacre powder had the good connection with the adjacent tissue in rats body without apparent inflammatory response.5.X-ray photography showed that rabbit\'s bone defects healed faster in study group since NNAB implanted than in control group since MNAB implanted.At 24 weeks after operation,bone density in radial defects had nearly accessed to the normal area,while lower in control group,and turned up nonunion in blank group;The checking of BMD showed that results in study group were higher than those in control group at 8,16 and 24 week(P＜0.05), and the difference between the BMD values in study group at 24 week and those in blank group was not significant(P＞0.05).The gross specimens showed satisfactory histocompatibility both in study group and in control group,with bone tissue growing from two sides into the center of implanted materials; Normal slices in HE stain and hard tissue grinding slices in Stevenel\'s blue/Van Geison\'s picro-fuchsin stain showed that the bone growth tendency was better in study group than that in control group,and the medullary cavity had been penetrated to the implanted materials in study group at 24 week;Analysis of tetracycline fluorescent double marks in the hard tissue grinding slices indicated that new bone in both groups grew fastest 8 weeks after surgery,while slow down at 16 week.

纳米珍珠层/消旋聚乳酸复合人工骨与微米珍珠层/消旋聚乳酸复合人工骨分别与成骨细胞共培养后，其各时间点CCK-8法检测值与空白对照无显著差异(P＞0.05)，成骨细胞均在第5天达到增殖高峰期；培养7天后，实验组细胞蛋白含量高于对照组及空白组(P＜0.05)，后两者之间则无显著差异P＞0.05碱性磷酸酶活性在三组间均无显著差异(P＞0.05电镜下可见成骨细胞在两种人工骨上都有良好生长贴附能力。4.X-ray显示两种粉体在大鼠股骨骨洞植入第2周时都开始出现了降解，第4周时更为明显，纳米珍珠层粉较之微米珍珠层粉降解更快，而空白对照组骨洞阴影仍可见，至8周时，则所有组骨洞均己闭合修复，X-ray下已不可见原钻孔痕迹，恢复正常骨质密度；硬组织磨片四环素荧光双标记结果显示纳米珍珠层粉植入组较其余两组在骨缺损区周围新骨生长速度更快，空白组速度最慢P＜0.05电镜观察及常规脱钙切片亦可见到纳米粉体降解较快；由以上两种原材料制得的纳米珍珠层/消旋聚乳酸复合人工骨与微米珍珠层/消旋聚乳酸复合人工骨在大鼠体内均与周围组织结合良好，无明显炎症反应。5.X-ray显示纳米珍珠层/消旋聚乳酸复合人工骨植入兔桡骨缺损区后其骨愈合速度较对照组微米珍珠层/消旋聚乳酸复合人工骨植入的快，至植入术后24周，实验组骨缺损区接近正常骨密度，对照组骨缺损区密度较低，空白组则呈现骨不连状态；骨密度测量结果显示术后8周、16周、24周实验组的骨密度值高于对照组(P＜0.05，24周实验组的骨密度值与术前所测得的正常值无显著性差异P＞0.05动物取材大体所见均显示组织相容性良好，骨组织逐渐由植入材料两端向中央生长；常规切片HE染色及硬组织磨片Stevenel\'s blue/Van Geison\'s picro-fuchsin联合染色均可见实验组骨缺损区长势优于对照组，至术后24周，实验组骨髓腔与材料已呈相交通状；硬组织磨片荧光显微镜下观察，两组材料在术后8周处于骨生长最快速时期，16周时速度开始减慢，术后4、8、16周时实验组的新骨生长速度均较对照组的快

The kinetic behaviors of ethylene homo- olymerization and ethylene / l-hexene co-polymerization , catalyzed by the metallocene catalyst PS-DVB-MC in an 0.5 L stainless steel reactor , were studied. The effects of polymerization conditions on ethylene polymerization , such as concentration of catalyst , temperature of polymerization , pressure of ethylene , molar ratio of AI / Z r , etc ., were also investigated . Some leading results were as follows : the activity of the catalyst PS–DVB- MC for ethylene homo-polymerization was high ( 1.053 x 107 gPE / mol Zr·h ), but the molar ratio of AI / Zr was low ( 350:1 ); the catalytic ability for ethyleneα-olefin ( such as l hexene etc .) co-olymerization was great , and the corresponding activity come up to a maximum of 1.753 x 107 gPE / mol Zr·h while concenlration of l-hexene was 0.080 mol / L ; the molecular weight of polyethylene was about 180,000 , meanwhile the molecular weight distribution was narrow ( 2.19 ); the bulk density of polyethylene and ethylene / l-hexene co -polymer were 0.25 and 0.34 respectively .

采用0.5L高压不锈钢反应釜，对催化剂PS–DVB-MC催化乙烯均聚和乙烯/ l-己烯共聚合的动力学行为进行了研究，详细考察了催化剂浓度、反应温度、压力、Al/ Zr比、1-己烯浓度等因素对乙烯聚合反应的影响，得到如下主要结论：催化剂PS-DVB-MC具有催化乙烯均聚的高活性(1.053×107g PE / mo1 zr.hr)，低Al / Zr比( 350：1 )；具有良好的催化乙烯与α-烯烃(如1-己烯等)共聚的能力，在1-己烯浓度为0.080 mol / L时，催化活性达到最大(1.783×107 g PE / molZr.hr)；乙烯均聚产物的分子量在18万左右，分子量分布窄( 2.19 )。

By GC-MS analysis, the liquefied products contained oligomers of polyhydric alcohols, carboxylic acids and their esters because of oxidation and esterification of polyhydric alcohols and the decomposed cornstalk components.

GC-MS分析表明，液化产物中主要含有多元醇的低聚合体，以及多元醇和玉米秸秆降解产物的氧化和酯化反应产生的羧酸及其酯。

The p-tert-butyl calix arene (n=4,6,8) were synthesized by p-tert-butyl phenol, formaldehyde aqueous solution as raw materials. Six kinds of calixarene oligomeric surfactants were prepared by etherification of the calix arene with 1,3-propane sultone and 1,4-butane sultone.

以对叔丁基苯酚、甲醛为主要原料合成杯芳烃母体对叔丁基杯芳烃(n=4，6，8)；以1，3-丙烷磺内酯、1，4-丁烷磺内酯为醚化试剂，经Williamson醚化反应，合成出6种杯芳烃基低聚表面活性剂。

The polymerization of preparing PDA could be impacted by allyl chloride, allyl alcohol and allyl aldehyde. The content of allyl chloride, allyl alcohol and allyl aldehyde in the DMDAAC monomer solution varied from 0mg/kg to 1000mg/kg, their intrinsic viscosity of PDA descended from 10.3dL/g to 8.0dL/g, 6.8dL/g and 8.8dL/g respectively. The polymerization of preparing PDA could be carried out well in the case the content of NaCl, active carbon, yellow residua and low molecular polymer of DMDAAC were less than 10000mg/kg, 1000mg/kg, 1000mg/kg and 50000mg/kg respectively.

单一杂质含量变化对聚合产物PDA特征粘度影响的研究结果表明：在DMDAAC单体溶液聚合反应过程中，当Fe~(3+)、Fe~(2+)和Cu~(2+)含量分别达到7mg／kg、9mg／kg和5mg／kg时无法得到聚合产物PDA胶体；当烯丙基氯、烯丙醇、烯丙醛含量分别从0mg／kg增加到1000mg／kg时，聚合产物PDA的特征粘度从10.3dL／g分别下降到8.0dL／g，6.8dL／g和8.8dL／g；活性炭和黄色物质含量在1000mg／kg以下，低聚物含量在50000mg／kg以下以及氯化钠含量在10000mg／kg以下时产物PDA的特征粘度降低变化量不超过0.2dL／g。

Purpose:The aim is to study the optimal co reaction condition of producing high content fructooligosaccharides for immobilized cells and glucose isomerase.

目的 ：研究固定化黑曲霉细胞与葡萄糖异构酶协同反应生产高含量低聚果糖的优化条件。

Then the surface of the star polymer was intramolecularly crosslinked using octa(3-azidopropyl)polyhedral oligomeric silsesquioxane, POSS-(N_3)_8,as the inorganic multifunctional crosslinker at high dilution concentration via click chemistry,forming a novel POSS/polymer hybrid nanostructure.Thermogravimetric analysis shows that after surface crosslinking, the thermostability of the core crosslinked PS can be remarkably improved.In the second work,we synthesized of a novel polymer with quatrefoil-shaped topology.

接着，我们合成了一种结构规整的含八个叠氮功能团的无机分子—多面低聚倍半硅氧烷，以其为交联剂，我们通过Click反应在即稀浓度下实现了前驱体星型聚合物的分子内表面交联，得到了外层为无机分子交联，内层为有机高分子的星状高分子，这种新型的星状聚合物表现出了优良的热稳定性能。

The results indicate that water and metal ions can promote the development of fly ash from vitreous body to low polymer in the process of wet milling and placement, so as to improve the second-hydration capability of mineral admixture slurry.

研究表明，在湿磨及放置过程中，粉煤灰玻璃体表面可向低聚度方向转化，结构变疏松，可促进其二次水化反应。

The concrete steps are: the lactic acid and small-molecule dicarboxylic acid react under the condition with the presence of the catalyst to directly polymerize the carboxyl-terminated lactic acid prepolymer; then the aliphatic polycarbonate diol and the catalyst are added; with the presence of the N2, the reaction is kept for 1 to 10 hours at the temperature of 150 to 200 Celsius system to get the poly lactic acid and polycarbonate copolymer of the low molecular weight; then the reaction is done in the twin-screw extruder at the temperature of 150 to 190 Celsius system to screw out the extension chain; finally the polylactic copolymer of the high molecular weight, toughness and heat resistance is made.

具体步骤是：乳酸和小分子二元酸在催化剂条件下反应直接缩聚合成羧基封端的乳酸预聚物，然后加入脂肪族的聚碳酸酯二元醇和催化剂，在N 2 气氛下，抽真空，在150～200℃温度下，反应1～10小时，得到低分子量聚乳酸/聚碳酸酯共聚物，然后在双螺杆挤出机中在140～190℃下，进行反应挤出扩链，最终得到高分子量的、韧性与耐热性较好的聚乳酸共聚物。

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。