改性大豆分离蛋白可生物降解材料的降解性研究

用邻苯二甲酸酐改性大豆分离蛋白(SPI)制备了SPI可生物降解材料。采用霉菌生长法、水性土壤培养液法和自然土埋法对SPI可生物降解材料的降解性能进行了表征。结果表明:SPI材料在3种降解方法中都表现出良好的降解性,其中霉菌生长法的降解率最大,水性土壤培养液法次之,自然土埋法降解率最小。     

改性农用保水剂生物降解性能研究

以淀粉、海藻酸钠、羽毛蛋白、4A沸石等为原料通过对丙烯酸-丙烯酰胺类保水剂进行改性,制备一系列不同天然产物改性的农用保水剂,并对保水剂进行几种不同生物降解方式实验。微生物生长实验表明:单纯PAA/AM生物降解性能较差,淀粉接枝AA/AM、海藻酸钠接枝AA/AM、羽毛蛋白接枝AA/AM和矿物质改性均可大大提高树脂的降解性能;土壤掩埋降解实验和细菌培养液降解实验表明:细菌培养液降解法比土壤掩埋降解法得到的降解率高。     

聚丙烯酸-海藻酸钠吸水树脂的降解研究

通过土壤掩埋法和菌类生长法研究了聚丙烯酸-海藻酸钠高吸水树脂的降解性能。实验结果表明,聚丙烯酸—海藻酸钠高吸水性树脂具有较好的生物降解性能,能够被土壤以及特定菌类降解,聚丙烯酸—海藻酸钠高吸水性树脂在土壤中埋置65天后降解率达43%,通过菌类降解,50天后降解率达60%。     

明胶-乙烯接枝共聚物生物降解性能和溶胀性能研究

本文研究了明胶-乙烯接枝共聚物的生物降解性能和溶胀/溶解行为。以过氧化二苯甲酰为自由基引发剂合成明胶-乙烯接枝共聚物。采用土壤(含或不含尿素)掩埋实验对共聚物的生物降解性能进行表征。实验中,观察重量损失率随时间的变化。结果表明,共聚物的重量损失率随时间的延长而增大,且在含有尿素的土壤中样品的重量损失率较大。数天后,对包含样品的土壤进行微量分析。实验结果发现,随着时间的延长,土壤样品中微生物量增加。这表明,聚集在共聚物材料上的微生物导致了共聚物的重量损失率增加。数天后,对掩埋在土壤中的样品进行水解测试。观察发现,样品在土壤中掩埋的时间越长,其水解重量损失率越大。在富含和不含尿素的土壤中研究共聚物降解产物对植物生长的影响。结果表明,植物在含有共聚物降解产物的土壤中能够正常生长。并通过溶胀实验,考察了共聚物在水-乙醇二元体系和水-乙醇-二甲基亚砜三元体系中的最大溶胀度和溶解行为。     

聚（α-羟基酸）的表面侵蚀动力学行为

可生物降解高分子材料的降解机理可以是主体降解也可以是表面侵蚀。目前的表面侵蚀研究主要集中在降解过程中材料表面的化学组成、结构信息、表面形貌的改变及对表面侵蚀过程进行定量分析等。综述了几种重要的可生物降解聚（α-羟基酸）的表面水解降解动力学及对药物控制释放行为的影响。这对于药物控制释放体系的研究及设计制备新型可生物降解高分子材料具有重大意义。     

ABS增韧PLA生物降解材料的制备与性能研究

采用丙烯腈-丁二烯-苯乙烯共聚物(ABS)弹性体对聚乳酸(PLA)进行熔融共混改性,制备出具有一定韧性的PLA/ABS生物降解材料,并研究了该共混体系的热性能、力学性能和生物降解性能。结果表明:ABS弹性体的加入降低了PLA/ABS共混材料的玻璃化转变温度、冷结晶温度和熔点,提高了共混材料的高温分解温度和断裂伸长率,改善了PLA的热稳定性和韧性。土壤掩埋实验表明,纯PLA和ABS含量为10%的PLA/ABS共混薄片具有良好的生物降解性能。     

天然纤维素基生物降解塑料研究进展

综述了纤维素基生物降解塑料共混法、化学改性法及微生物法三种典型制备方法,介绍了C02释放量检测、生物降解半衰期检测、生物降解塑料分子量检测、微生物侵蚀形貌观察及生物降解性能指标检测等生物降解性评价机制。纤维素基生物降解塑料是未来新材料发展的重要领域,将会朝着低成本、广应用、降解速度可控和完全降解的方向发展。     

醇胺类的生物降解动力学及其对活性污泥法影响研究

实验研究了醇胺类有机物的可生物降解性、降解反应动力学及其对活性污泥法的影响。结果表明:乙醇胺的生物降解反应速率常数(k)为0.155 0,去除率达到90%以上;二乙醇胺和N-甲基二乙醇胺的生物降解反应速率常数分别为0.064 1和0.053 9,去除率均达到60%以上;三乙醇胺的生物降解反应速率常数为0.012 4,去除率仅为23%。少量N-甲基二乙醇胺的冲击不会对活性污泥法的出水水质造成明显影响,大量冲击虽然会在短期内影响出水水质,但不会对活性污泥法产生不可逆转的破坏作用。     

科技纵横

三菱树脂公司以玉米等植物为原料开发出可在土壤中生物降解的聚乳酸塑料管 ,具有与PVC管相同的强度 ,一般掩埋在土壤中 3～ 5年便可经过土壤中微生物、水和二氧化碳作用而分解。这种PVC管通常用于难以回收的配管或临时管道 ,也可用于薄膜、容器、包装、标签和卡片等。开发者正在对未来的市场前景进行调研。 (张东生 )日本开发新型PET啤酒瓶最近朝日啤酒公司开发出一种优于清凉饮料包装瓶的聚酯瓶 ,该聚酯瓶的阻气性能和遮光性能大幅提高。在瓶内蒸涂一层氧化硅膜可将阻气性能提高约 2 0倍 ,对碳酸气的阻挡作用约提高了 4倍。由于普通聚…     

EVA废品回收和生物降解性研究

据（PolymerDegradation00dStabil…）1997，57，183－186报道，马西的学者研究了乙烯——醋酸乙烯共聚物（EVA）废品的回收加工过程。由添加多酚到EVA中去来制备生物降解混合物，并得到混合物薄膜。这些薄膜用热重分析法（TG和DTG），差示扫描量热法（DSC）和扫描电子显微镜（SEM）法等来分析。在热稳定性和生物降解性方面讨论了所得到的结果。文中给出EVA、可生物降解EVA和经微生物侵蚀后的EVA三种薄膜的扫描电子显微镜的照片，后者显示出十分严重的破坏现象。EVA废品回收和生物降解性研究…     

Effect of aggregate size on liquid absorption characteristics of konjac glucomannan superabsorbent

In this article, four kinds of konjac glucomannan based superabsorbent polymers (KSAPs) with different aggregate sizes were obtained by sieving the KSAP powders manually. They were characterized by scanning electronic microscopy (SEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and optical contact angle (OCA), and the effects of aggregate size on liquid absorption characteristics of KSAP were studied in detail. The results show that the coarse KSAP particles were aggregated by many microspheres, while the fine particles were well dispersed with 50–150 µm particle size. OCA dynamic images showed the enhanced hydrophilicity for the finer particles. The liquid absorption measurements demonstrated that water and physiological saline absorption velocity of KSAP increased for the finer particles, while their ultimate water holding capacity decreased accordingly. The liquid absorption capacity of the finest sample (75 µm) could reach its maximum value (332.5 ± 5.6 g/g) in 0.5 min, while the coarsest sample (850 µm) reached the maximum value (532.5 ± 1.2 g/g) in 16 min. The reason for this phenomenon was discussed, and a new model was proposed to explain it. We believe that the results of this article would be meaningful in application of KSAP as superabsorbent materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45416.     

塑料模具表面粗糙度变化机理及影响因素分析

高温高压下塑料颗粒对模具表面的冲蚀,引起模具表面粗糙度发生变化,是造成塑料模具失效的重要原因。针对这个原因,分析了塑料模具表面粗糙度的变化机理;总结了影响塑料模具表面粗糙度变化的因素,主要包括冲蚀速率、冲蚀角度和塑料颗粒的形状与硬度;指出可以通过粒子注入技术、激光熔覆技术、碳氮共渗等技术来降低塑料模具表面粗糙度。     

Organic matter management for soil conservation and productivity restoration in Africa: a contribution from Francophone research

Soil fertility is closely linked to soil organic matter (SOM), whose status depends on input, i.e., mainly biomass management, and output, i.e., mineralization, erosion and leaching. Preliminary results from runoff plots and lysimeters on hillslopes in West Africa indicated that carbon losses by erosion and leaching ranged between 10 and 100 kg C ha^?1 yr^?1, depending on annual rainfall and vegetal cover. Under natural conditions, losses may be low enough to be compensated by aerial deposits. But together with mineralization, erosion can locally be an important cause of SOM decrease in cropping systems where there is poor soil cover, steep slopes and erosive rain conditions. The effect of previous erosion on cereal production was assessed in case studies from Rwanda, Burundi, Cameroon, and Burkina Faso. On the densely populated hillslopes of Rwanda, hedges and manure reduced runoff and erosion efficiently, but did not succeed in improving grain yields due to P-deficiency of these ferrallitic soils. In Burundi, under similar conditions but under banana plantation, tree density and mulch cover had a strong influence on erosion; this previous erosion had an important effect on the next maize yield, even when the soils were amended with manure, mineral fertilizers and lime. On sandy ferruginous soils of North Cameroon, erosion increased with increasing tillage intensity. Manure application increased grain yield, but burying organic residues did not improve SOM levels and soil resistance to erosion. Mulching and tillage limited to the plant rows protected the topsoil against erosion, but did not clearly increase the yield. Manuring permitted the restoration of soil productivity, but additional mineral fertilizers (P, N) were needed to reach rapidly a high level of grain production. In the same way, experiments conducted with traditional Zaï system for restoring a degraded Entisol in Burkina Faso showed that runoff harvesting and organic matter input were not sufficient with no additional N and P fertilizers. Complementary experiments in Cameroon showed that a 4-mm selective sheet erosion and a 50-mm non-selective de-surfacing resulted in similar yield decline. Long fallowing, burning and grazing are traditional ways to utilize available biomass in Africa. Considering social habits and technical realities, it seems useful to balance ‘grazing-manuring’ and mulching in order to protect the soil and maintain its productive capacity. Minimum tillage with mulch (crop residues, weeds or legume fallow) is the new trend used for increasing crop production, with the help of herbicides. Agroforestry that produces good-quality litter is also a part of the solution.     

关于埋地塑料管的受力情况研究分析

本文介绍了埋地塑料管道的施工运用及塑料管道在土壤下的受力分析;重点介绍了埋地排水管道与土壤共同作用下的指标确定、影响埋地管道的重要参数,并研究分析管道的埋填要求,包括埋填材料要求,尺寸要求等。     

Effect of natural biomass fillers on the stability,degradability, and elasticity of crop straws liquefied polyols-based polyurethane foams

Oilseed rape straw (OS), rice straw (RS), wheat straw (WS), and corn stover (CS) particles were used to reinforce bio-polyols based polyurethane (PU) foams. The influence of crop straws (XS) fillers on the stability in water, degradability in soil, thermal stability, and elasticity of foams were investigated. The incorporation of OS and CS particles in the PU matrix increased the stability of reinforced foams in water, while the addition of WS and RS particles made foams lower stability in water. PU foams reinforced by XS particles displayed mass reductions up to 53.8% after burying in soil for 250 days. The reinforced foams were more stable under heating but the enhancement of thermal stability trended to disappear after water immersion or soil burying. The reinforced foams showed better elasticity that incorporations of OS and CS made PU foams higher height recovery percentage, while RS and WS made the recovery percentage decline firstly and then enhance during three times compressions. All these four XS particles are suitable to modify bio-based PU foams, especially OS and CS particles appear to be more outstanding in preparing foams with higher stability in water, degradability in soil, thermal stability, and elasticity than RS and WS particles.     

长输管道土壤腐蚀特性分析

基于长输管道658处土壤取样点的腐蚀等级及变化趋势,选取30处典型土壤腐蚀点开展埋片试验,建立土壤腐蚀数据样本。采用BP神经网络评价法,进行多因素分析30处埋片点的测试结果,并预测其他628处取样点的土壤腐蚀特性。该方法可为今后长输管道土壤腐蚀特性分析提供依据和标准。     

模具污垢与清洗

本文介绍了模具污染因素、污垢成份和四种清洗方法。     

临近冲击载荷的埋地聚乙烯燃气管道有限元分析

运用Abaqus有限元分析软件,构建冲击作用下管土相互作用有限元分析模型,分析聚乙烯管道的应力变化,研究聚乙烯管道的材料模型、土体性能、冲击速度对聚乙烯管应力及变形的影响规律。结果表明,由于冲击作用时间较短,冲击速度对聚乙烯管道没有明显影响;管道覆土的性质及埋深对管道有明显的保护作用;聚乙烯管道的最大应力随着聚乙烯管道内压的增大而增大,近似成线性关系;在冲击载荷作用下,距离冲击区域越近的聚乙烯管道越容易达到强度失效极限;研究结果可以为埋地聚乙烯燃气管道的安全运行及第三方施工活动提供技术支持。     

Using a GIS system in mapping risks of nitrate leaching and erosion on the basis of SOIL/SOIL-N and USLE simulations

An assessment system that combines digital information on soil types, climates, slopes and crops with simulated values of nitrate leaching and erosion within a geographical information system was developed. The system was used for assessing risks of nitrate leaching and erosion on the regional as well as national scale, having municipalities as the level of aggregation. In Denmark the system has been used for assessing risks of erosion at a catchment scale.     

TBPAM应用于防治水土流失的试验结果

本文介绍了TBPAM(阴离子型聚丙烯酸胺)聚丙烯酰胺类产品应用于防治田间水土流失的研究,其保水、保土、保肥、增产的效果十分明显,对国内“三北”地区水土流失的治理将起到十分积极的作用.