Study on Preparation of Agricultural low-cost Super Absorbent Resins

合成类吸水树脂是近几十年发展起来的一种新型功能高分子材料，其吸水能力远远超越于一般传统吸水材料，还具有保水性能好、吸水速度快、无毒环保等优点。可广泛应用于农业园林、医药卫生、日用化工、油水分离、建筑材料、污泥固化等领域。它的广阔市场促使研究者们对超强吸水剂进行了更多的深入研究与改性。 本文概述了合成类吸水树脂在农用方面的进展，提出采用低成本且工艺较成熟的水溶液聚合法，以丙烯酸（AA）、丙烯酰胺（AM）为基体、接枝可溶性淀粉进行三元单体共聚，经钠基膨润土改性，复合引发剂、复合交联剂制备低成本、易降解的农用合成类吸水性树脂。 本实验首先进行正交实验考察各工艺因素的影响主次，并在此基础上进行单因...The synthetic absorbent resins are the new functional polymer materials developed in recent decades. Their water absorption capacity is far beyond the traditional absorbent materials. In addition, they have the advantages of good water retention, fast absorption rate, non-toxic and environmentally friendly. They can be widely used in areas, such as agriculture and horticulture, medicine and health...学位：工程硕士院系专业：化学化工学院化学工程与生物工程系_化学工程学号：2062010115145

Preparation of agricultural low-cost super water absorbent

概述了合成类吸水树脂在农用上的进展,提出采用低成本且工艺成熟的水溶液法,以丙烯酸(AA)、丙烯酰胺(AM)为基体、接枝可溶性淀粉进行三元单体共聚,经钠基膨润土改性,复合引发剂、复合交联剂制备低成本、易降解的合成类吸水性树脂。经实验改进和工艺条件优化后,树脂吸去离子水倍率可达1 940.9 g/g,吸自来水899.8g/g。采用红外光谱仪、热重分析仪、扫描电镜、X射线衍射仪等分析手段对合成树脂进行了分析表征,证实了产物为淀粉、丙烯酸及丙烯酰胺的共聚物。The utilization status of the synthetic absorbent resin in agricultural applications was summarized.An improved process of three monomer copolymer system was proposed by using an aqueous solution polymerization.These three monomers are soluble starch,acrylic acid and acrylamide,which are modified by sodium bentonite,using a composite initiator and cross-linker.By improving the experiments and optimizing the process conditions,the absorption rate of the synthetic absorbent resins is up to 1 940.9 g/g in deionized water,and 899.8 g/g in tap water.In addition,the structure and performance of the synthetic absorbent resin were characterized by using infrared spectroscopy,thermal gravimetric analysis,scanning electron microscopy and X-ray diffraction,which shows that it is an copolymer of starch,acrylic acid and acrylamide

Study on the risk factors for intrauterine infection of hepatitis B virus among pregnant women

目的探讨厦门市孕妇乙型肝炎病毒(hepatitis B virus,HBV)感染情况和HBV宫内感染的影响因素。方法在1; 064名孕妇第一次到医院建立孕产妇保健卡时进行问卷调查并检测其血清乙肝标志物,根据检测结果选择外周血乙型肝炎表面抗原(hepatitis B; surface antigen,HBsAg)阳性的产妇179例随访至其分娩,并采集其分娩时的脐血和胎盘组织。对脐血进行HBsAg和HBV; DNA的检测,对胎盘组织进行HBsAg的检测。采用chi~2检验和非条件Logistic回归分析相关因素与HBV宫内感染的关系。结果被调查的1; 064名孕妇中,HBsAg阳性的孕妇共179名,感染率为16.8%。对179名HBsAg阳性的孕妇的脐血进行检测发现,发生HBV宫内感染的孕妇共; 34名,感染率为19.0%。孕妇HBV宫内感染的危险因素为胎盘HBsAg阳性、孕妇血清乙型肝炎E抗原(hepatitis B e; antigen,HBeAg)阳性、孕前超重,OR分别为5.123(95% CI:1.422 ~ 18.413)、4.619(95%; CI:1.225 ~ 17.534)、 3.343(95% CI:1.233 ~; 9.092)。结论对于HBsAg和HBeAg双阳性的超重/肥胖孕妇,其新生儿可能发生HBV宫内感染,应加强自身防护措施,合理规避HBV宫内感染风; 险。Objective To investigate the prevalence of hepatitis B virus (HBV); infection in pregnant women and the risk factors for Intrauterine; infection of HBV among pregnant women in Xiamen. Methods Total 1 064; pregnant women were included in this study. A questionnaire was; performed to collect the general information of the subjects and HBV; infection status was tested on the first day when they came to the; hospital. Then HBsAg positive pregnant women were selected and followed; until delivery. We collected their cord blood and placenta tissue when; they delivery. HBsAg and HBV DNA in cord blood and HBsAg in placental; tissue were detected. Chi-square test and the non-conditional Logistic; regression analysis were conducted to investigate the correlation; between HBV intrauterine infection and risk factors. Results 179 out of; the 1 064 pregnant women were HBsAg positive. The infection rate was; 16.8%. 34 out of 179 HBsAg positive pregnant women were found; intrauterine transmission with a rate of 19.0%. The risk factors for the; occurrence of HBV intrauterine transmission were placenta HBsAg positive; (OR = 5.123, 95% CI:1.422-18.413),mothers with hepatitis B e; antigen(HBeAg) positive (OR = 4.619, 95% CI:1.225-17.534) and; overweight(OR = 3.343, 95% CI:1.233-9.092), respectively. Conclusions; Placenta HBsAg positive,mothers with HBeAg positive and overweight are; independent risk factors for the occurrence of HBV intrauterine; transmission.国家自然科学基金; 厦门市科技计划项

Optimization of Hydrometallurgical Purification for SiO_2 in the Process of Preparing Solar-grade Silicon

考察了Hf质量分数、H2C2O4质量分数、HnO3质量分数、酸浸时间、粒径、液体质量与固体质量的比值(简称液固比,下同)等因素对混酸法提纯SIO2工艺过程的影响,利用电感耦合等离子体发射光谱仪(ICP-OES)、场发射扫描电子显微镜(SEM)进行表征。结果表明,最佳工艺条件为:W(Hf)=2%、W(H2C2O4)=3%、W(HnO3)=30%、酸浸时间4 H、粒径100~120目、液固比4∶1、酸浸温度30℃。fE、Al、CA、P杂质的去除率分别达到99.99%、14.02%、73.27%、60.00%,经混酸法处理后SIO2中杂质总量的质量分数降至1.465x10-4。As a pre-treatment unit for preparing solar-grade silicon,hydrometallurgical route could remove most metallic impurities in silicon dioxide(SiO2) and raise the yield of the final product.Acid leaching of SiO2 could reduce the cost and energy consumption of industrialized development.Combined with high purity of reducing agent,the successor process of pyrometallurgy can also achieve "continuous casting".Factors such as the mass fraction of leaching agent,time,the particle size of SiO2,and the liquid-solid ratio were investigated,and the samples were characterized by means of ICP-OES,SEM,etc.The optimal reaction conditions were as follows:w(HF)=2%,w(H2C2O4)=3%,w(HNO3)=30%,reaction time 4 h,the average size of SiO2 powder particle 100～120 mesh,the liquid-solid ratio 4∶1,and room temperature 30 ℃.It was found that the final removal rates of impurities of Fe,Al,Ca,P could reach 99.99%,14.02%,73.27%,and 60.00% respectively and the mass fraction of total amount of impurities could be reduced to 1.465×10-4

SARS的激素治疗与胸片所见

【目的】探讨严重急性呼吸综合征（SARS）的糖皮质激素治疗与胸片所见的关系。【方法】收集广州市458例SARS患者的一般临床资料及每次胸片资料。所有患者都临床确诊并经免疫学检查证实,临床资料及胸片资料同时较齐全才作为研究对象。根据应用激素与否将其分为两组。【结果】应用激素组257例,未用激素组201例。两组在首次见到肺内病变时间之差异无统计学意义（t=1.417,P=0.157）;激素用于临床表现较严重的病例,胸片上肺内病变达高峰时间较未用激素组长（t=3.242,P=0.001）,所累及的肺小区个数较多（t=3.982,P〈0.001）,住院时间较长（F=2.731,P〈0.001）。始用激素于病程10d之内及10d之后比较,后者肺内病变达高峰时所累及的肺小区个数较多。最大日剂量较大者,其病变存留较久、住院时间较多（F=3.040,7.044;P〈0.001,〈0.001）。【结论】激素用于症状较重的SARS患者的情况下,病死率不高,提示激素在SARS治疗中有重要意义

环孢素治疗中重度干眼症的对照研究

【目的】观察0．2％（2g/L）环孢素滴眼液对中重度干眼症的效果。【方法】将中重度干眼症134例随机分为对照组（65例）和实验组（69例）。对照组应用10g/L羧甲基纤维素钠，4次／d，实验组应用10g/L羧甲基纤维素钠和2g／L环孢素滴眼液，4次/d。两组均连续用药1个月。用药前后均进行荧光素染色检查、泪液分泌检查（STT）、泪膜破裂时间检测（BUT）、结膜印迹细胞检查。【结果】两组比较在治疗前差异无统计学意义（P〉0．05），治疗后实验组SIT、BUT比对照组的结果有统计学意义（P〈0．01），实验组治疗前后结果比较有统计学意义（P〈0．01）。对照组的治疗前后比较差异无统计学意义（P〉0．05）。【结论】2g/L环孢素滴眼液治疗中重度干眼确有良好的效果

Study of Preparation of Silica with High Specific Surface Area Using Precipitation Method

以nA2SIO3·9H2O、H2SO4为原料,沉淀法路线合成高比表面积SIO2.实验考察了反应温度、H2SO4溶液浓度、nA2SIO3溶液浓度、反应终点PH值、表面活性剂添加量、后处理试剂、干燥方式等因素对SIO2比表面积的影响.采用bET低温液氮吸附比表面分析仪、热重分析仪、场发射扫描电镜、激光粒度分析仪、傅里叶变换红外光谱仪等分析仪器对SIO2样品进行表征.结果表明,在C(H2SO4)=1.5MOl/l、W(nA2SIO3)=6.3%、反应温度T=60℃、PH值为5,用正丁醇置换水等实验条件下,可制得SIO2粉末比表面积为841M2/g,相较于一般沉淀SIO2300~400M2/g的比表面积有明显提高.Silica with high specific surface area was successfully prepared from sodium silicate solution and sulfuric acid using precipitation method.The aim was to study the effects of various factors in the preparation process,which include temperature,concentration of sulfuric acid,mass fraction of sodium silicate,pH of the reaction system,surfactants,post-processing reagent and the drying method.The silica samples prepared in different conditions were characterized by BET,thermogravimetric analysis(TG),scanning electron microscope(SEM),laser particle size analyzer(LDSA) and Fourier transform infrared(FT-IR).Optimum condition was established for carrying out the precipitation process of silica.The specific surface area of silica can reach up to 841 m2/g with the optimum condition of c(H2SO4)=1.5 mol/L,w(Na2SiO3)=6.3%,t =60 ℃,pH 5.The specific surface area is improved remarkably compared with the regular value of 300-400 m2/g using precipitation method.福建省科技计划项目(2010H6024

Desarrollo de pastos Cerrados

在室外通过人工构建静态模拟生态系统，研究冬季不同底质、水深、水质条件下，菹草对水体营养盐的吸收净化效果。结果表明，在不同水深或水质污染程度的相应组实验中，添加土壤改良剂的各组实验的TN、TP、NO3--N、高锰酸盐指数去除率均高于相应的未添加组，而NH^4＋-N去除情况相反；添加土壤改良剂有助于菹草对水体营养盐的综合去除，菹草在水深较深且营养盐负荷较高的水体中对营养盐的去除效果更好；水深35cm比水深25cm更适宜菹草的生长；菹草在实验设计的水质条件下能正常生长和对水质进行高效净化，适合在冬季运用于一般河道的水体修复