Atmospheric Hexachlorocyclohexanes in the North Pacific Ocean and the adjacent Arctic region: spatial patterns, chiral signatures, and sea-air exchanges

During the 2003 Chinese Arctic Research Expedition (CHINARE2003) from the Bohai Sea to the high Arctic (37 degrees N to 80 degrees N) aboard the icebreaker Xuelong (Snow Dragon), air samples were collected for the analysis of hexachlorocyclohexanes (HCHs) in the North Pacific Ocean and adjacent Arctic region. The sigma HCHs (alpha-HCH + gamma-HCH) ranged from 2.3 to 95.1 pg/m3 with the highest levels observed in Far East Asia (32.5 pg/m3), followed by the North Pacific Ocean (17.0 pg/m3) and the Arctic (7.3 pg/ m3). Compared to previous studies in the same areas in 1990s, our measurements were approximately 1 order of magnitude lower. Because of disproportionate chemical reduction and physical fractioning during long-range transport, the ratios of alpha-HCH to gamma-HCH (alpha/gamma-HCH) showed a significant increasing trend from low to high latitudes, suggesting thatthe alpha/gamma-HCH range of 4-7 could not be used to identify sources of technical HCHs especially in remote areas. The ratios of (+)-alpha-HCH to the sum of (+)-alpha-HCH and (-)-alpha-HCH were on average much more biased from 0.5 compared to previous observations in mid-1990s, indicating the exchange of atmospheric alpha-HCH with those in the oceans, where (+)-alpha-HCH was selectively depleted in biological degradation processes. Estimated fugacity ratios based on available data for both alpha-HCH and gamma-HCH further implied their net volatilization from seawater to air in the Arctic Ocean.     

小比例混纺精梳色纱的生产

为生产小比例混纺精梳色纱,分析了小比例混纺精梳色纱的特点及加工难点.并通过生产实践,探讨了生产精梳棉/黑白涤/粘胶18.2 tex小比例精梳混纺纱的工艺参数及生产技术措施.从而加工出了质量较好的小比例混纺精梳色纱.提高了企业的经济效益.     

用weibull理论评价表面处理对碳纤维拉伸强度的影响

采用常压等离子体对碳纤维表面进行改性处理,用weibull理论评价了等离子体处理前后碳纤维抗拉强度及其离散性的变化,验证了形状参数和强度离散的关系.结果表明常压等离子体处理在改善碳纤维表面性能时,基本不会影响碳纤维强度及其离散性.     

酸性普鲁兰酶基因在地衣芽孢杆菌中的表达

根据Genbank公布的来源于Bacillus deramificans的普鲁兰酶基因突变体序列(AX203843)合成普鲁兰酶成熟肽基因。将该基因插入芽孢杆菌分泌型表达载体pHY-WZX,重组质粒转化地衣芽孢杆菌B60608,重组地衣芽孢杆菌实现普鲁兰酶分泌表达。对重组菌产普鲁兰酶的条件进行优化,以含2%药媒和8%甘油的培养基最适合普鲁兰酶表达。     

一种橄榄果酒的发酵工艺研究

以新鲜橄榄为原料,榨汁后采用果酒酿造工艺进行发酵,获得具有橄榄独特风味的橄榄酒。考察了酵母接种量、初始糖度、初始pH值、发酵温度、SO2添加量对橄榄酒感官评价的影度21℃,酵母接种量7%,SO2添加量70 mg/L,初始pH值3.7,初始糖度18°Bx。     

磁化处理对甘蔗混合汁物理特性的影响研究

该文研究了电磁场和永磁场强化处理甘蔗混合汁物理特性的变化规律,以电导率、粘度和表面张力为指标,确定了实验条件下较好的磁场强化工艺参数。结果表明:电磁铁磁化操作条件为磁场强度0.30 T、循环时间40 min和流速为1.30 m/s;永磁铁磁化操作条件为磁场强度(0.30~0.32)T、循环时间40 min和流速为1.30 m/s。     

魔芋葡甘聚糖可食性涂膜处理荔枝的保鲜效果

采用魔芋可食性膜处理荔枝，用PF塑料袋包装，在常温下进行保鲜试验。结果表明：经该膜保鲜后的荔枝，在贮藏过程中果皮褐变率和好果率较好的控制，基本上防止了果皮失水、腐烂变质，保持荔枝原有品质，延长了保鲜期和货架寿命。     

改性涤纶纤维的抄造性能研究

用碱处理方法对涤纶进行了亲水化改性。探讨了亲水化处理对纤维的亲水性、分散行为及与木浆纤维混抄时对抄造性能的影响。研究结果表明:碱处理后涤纶纤维的亲水性得到明显改善,纤维保水值增大;处理后的涤纶纤维与木浆纤维混抄时有较好的分散性能和抄造性能,纸页的匀度指数、抗张强度、撕裂指数、耐破指数都有较大程度提高。其较适宜的处理条件是:(1)温度95℃、NaOH浓度3％、处理时间1h,混合抄片匀度指数138,裂断长4270m,撕裂指数24.2mN·m2/g,耐破指数2.95 kPa·m2/g;(2)处理温度75℃,NaOH浓度3％,处理时间2h,混合抄片匀度指数89,裂断长4130m,撕裂指数23.0mN·m2/g,耐破指数3.01 kPa·m2/g。     

蒸煮过程纸浆卡伯值近红外光谱法在线测定

利用近红外光谱法测量蒸煮过程黑液中木素含量的变化，从而在线测定出纸浆卡伯值。通过一元线性回归、多元线性回归和主成分回归分析显示：3种测量模型均具有较好的学习和预测精度，其中主成分回归模型具有较高的预测鲁棒性。     

科技档案在盐行业的利用与探索

阐述科技档案业务建设，基础服务功能，法制建设，制度建设。通过科技档案在企业技术管理，生产管理，设备管理，环境保护等方面的应用，显示出其独特的功能。