基于磁性纳米复合棒的“咖啡环”效应

研究了含有不溶性纳米复合棒的液滴在蒸发过程中出现的咖啡环效应,证实了咖啡环现象的形成和抑制与液滴体积、液滴浓度、基底温度、表面活性剂添加量及外加磁场等因素有关,并根据实验数据拟合咖啡环宽度与实验参量间的关系.证实了减小液滴体积、增大液滴浓度或升高基底温度,导致咖啡环变宽,而添加表面活性剂或施加外磁场则能够抑制咖啡环效应的出现.建立了磁性纳米复合棒在液滴蒸发过程中的受力模型,探讨了液滴重力、毛细流引起的牵引力、马兰戈尼流引起的牵引力及外加磁场提供的牵引力对咖啡环的形成及其宽度的调控影响规律.     

经济新常态下的专家论述与广东创新发展

分析经济新常态下知名专家学者对宏观经济、政府管理、创新驱动等方面的观点和建议,结合广东发展现状,提出若干创新发展建议,以供相关部门参考和借鉴.     

Facile fabrication of highly flexible,porous PEDOT: PSS/SWCNTs films for thermoelectric applications

High-performance organic composite thermoelectric(TE)materials are considered as a promising alternative for harvesting heat energy.Herein,composite films of poly(3,4-ethyienedioxythiophene):poly(styrene sulfonate)/single-walled carbon nanotubes(PEDOT:PSS/SWCNTs)were fabricated by utilizing a convenient solution mixing method.Thereafter,the as-prepared hybrid films were treated using sulfuric acid(H₂SO₄)to further optimize the TE performance.Film morphological studies revealed that the sulfuric acid treated PEDOT:PSS/SWCNTs composite samples all possessed porous structures.Due to the successful fabrication of highly conductive networks,the porous nano-architecture also exhibited much more excellent TE properties when compared with the dense structure of the pristine samples.For the post-treated sample,a high power factor of 156.43μW·m^-1·K^-2can be achieved by adjusting the content of CNTs,which is approximately 3 orders of magnitude higher than that of the corresponding untreated samples(0.23μW·m^-1·K^-2).Besides,the obtained films also showed excellent mechanical flexibility,owing to the porous nanostructure and the strong p–p interactions between the two components.This work indicates that the H₂SO₄ treatment could be a promising strategy for fabricating highly-flexible and porous PEDOT:PSS/SWCNTs films with high TE performances.     

辐照诱变对小麦生理学效应的影响

以小麦品种小偃81为材料, 利用低能N+离子, 60Co-γ射线以及紫外线UV-C等为诱变源, 对种子胚部进行辐照处理。 研究其对小麦发芽势、 发芽率、 根长及苗高等生理指标的影响。 以辐照后的幼苗为材料研究了低能N+注入对过氧化氢酶（CAT）、 过氧化物酶（POD）、 超氧化物歧化酶（SOD）活性及还原型谷胱甘肽（GSH）含量的影响。 研究结果表明: N+注入后种子活力先升高后降低, 苗高在5×1017 N+/cm2时显著低于对照; 60Co和紫外线辐照对种子活力有较显著的影响, 辐照后的根长和苗高均显著低于对照; N+束辐照后的幼苗CAT酶活随剂量的变化规律性不明显, POD和SOD酶活总体趋势随剂量的增加先升高后降低, GSH含量随剂量的增大先降低后升高。 由此可知, 辐照诱变可以诱导小麦一系列的生理变化。60Co-γ射线和紫外线UV C对小麦胚根的伤害较大, 导致幼苗在后期大量死亡。N+注入对小麦的损伤效应较60Co和紫外线γ射线和紫外线UV-C小, 一定注量的N+注入处理可促进小麦生长。 In this paper, the biological effects,such as germination percentage, germination index and the length of seedlings and roots were investigated by using low energy N+, 60Co- γ rays and ultraviolet UV C to irradiate the embryos of wheat seeds （Xiaoyan81）. The anti oxidative enzyme system (CAT,POD, SOD) and GSH content were studied as well. The results show that the vitality of seed increased and then reduced with increasing the dosage of N+ ion implantation. The length of roots and seedlings were significantly higher than control. The seed vigor was significant effected after irradiated by 60Co-γ rays and ultraviolet UV-C, but the length of roots and seedlings were significantly lower than control. After N+ implantation, the changing pattern of CAT was not obviously. The enzymatic activity of POD and SOD were increased at low dosage and reduced at high dosage. The content of GSH was reduced and then raised. The results proved that the damage induced by γ ray and UV C to the radicle of wheat was severe that result in a large number of seedling died. However the damage induced by N+ implantation was lower than that by rays and UV C irradiation. Certain dosage of ion implantation can promote the growth of wheat.     

聚乙二醇二甲基丙烯酸酯整体柱固相萃取-高效液相色谱法测定血清中卡马西平和10-羟基卡马西平

使用乙二醇二甲基丙烯酸酯（EDMA）在注射器中构筑固相萃取整体柱,并结合高效液相色谱法,建立了测定血清中卡马西平（CBZ）和10-羟基卡马西平（MHD）的分析方法。实验考察了反应温度和反应时间对整体柱萃取性能的影响和淋洗溶液种类、洗脱溶液种类及体积对固相萃取的影响。在优化条件下,该固相萃取柱对血清中CBZ和MHD能够有效富集、净化。对0.02~40 μg/mL CBZ和0.05~100 μg/mL MHD标准溶液进行分析,结果表明,在各自的范围内CBZ和MHD线性关系良好,相关系数（r）均为0.999。CBZ和MHD的检出限分别为0.004 μg/mL和0.01 μg/mL;在3个加标水平下,CBZ和MHD的平均回收率分别为92.7%和94.2%,日内（n=3）和日间（n=3） RSD≤6.1%。该固相萃取柱批内（n=3）和批间（n=5） RSD≤5.3%,反复使用8次的RSD≤5.8%。该法简单、高效,适用于癫痫患者血清中CBZ和MHD的测定。     

Research Progress on the Continuous Cropping Obstacles of Ginseng from Soil Improvement北大核心CSCD

The unique black soil resources and natural environment of Jilin province provide the proper conditions for the growth of ginseng-the king of herb. Ginseng industry has effectively promoted the development of medical and health industry,and brought considerable economic income for ginseng farmers. However,long-term continuous cropping of ginseng causes the chemical,biological,and physical properties deterioration of soil,which influences the yield and the quanlity of ginseng,and results in the occurrence of replant obstacle. Identifying the malignant soil factors in continuous cropping obstacles,then analyzing the evolution process,and putting forward the improvement strategies is the primary task of ginseng research at present. This paper reviews the influence of ginseng cultivation on the physicochemical property,nutrient, enzyme activity,microecology and ecotoxicity of the soil,and the achievements of improving ginseng soil by chemical and biological techniques and methods in recent 10 years. © 2022, Science Press (China). All rights reserved.     

反相/亲水色谱法分析糖苷类化合物

根据皂苷、黄酮苷等糖苷类化合物的结构特点,采用亲水色谱模式分析该类化合物,以弥补反相色谱模式分离结构类似糖苷类化合物选择性的不足。首先选择14个糖苷类化合物,比较了反相色谱柱(XAqua C18)和亲水色谱柱(Click XIon)的分离效果,评价了反相/亲水色谱的正交性,并构建了反相/亲水二维体系用于西洋参样品的分离。结果表明,糖苷类化合物在反相及亲水色谱柱上均有很好的保留,但两者具有不同的分离选择性,14种物质在反相和亲水柱的出峰顺序有较大差异,在反相色谱中不易分离的人参皂苷Rg1和Re在亲水色谱柱可获得很好的分离,反相/亲水模式分离糖苷化合物具有很好的正交性。以构建的RPLC/HILIC二维色谱体系分离西洋参样品,有效地提高了分离能力及峰容量,有利于后续更多极性及微量化合物的制备、结构表征与活性研究,且该方法操作简便、流动相兼容性好,可作为糖苷分离分析、制备的有效手段,也可以为其他中药复杂体系的分析提供参考。     

交互环境、质量支持对企业员工持续使用意愿的影响

员工对E-learning培训系统这一新兴培训方式的持续使用意愿是影响培训效果最重要的因素之一。以信息系统持续使用模型（ECM IS）为基础,结合E-learning系统特有的体系结构,构建影响企业员工E-learning持续系统使用意愿的理论模型并进行实证研究。研究结果表明：交互环境、质量支持中的信息质量、服务质量正向影响感知有用性;系统质量、服务质量、交互环境正向影响期望确认度;感知有用性、期望确认度、满意度对企业员工E-learning持续使用意愿均具有显著的正向影响。     

羧基微珠表面化学与生物活化方法及表征

研究了微珠阵列芯片传感单元的生物分子固定化方法.运用羰基二咪唑(CDI)法进行羧基微珠表面化学活化研究及表征.结果表明微珠表面咪唑基团的有效活化率为30.1%.活化微珠表面固定化抗体后,采用荧光显微成像分析,CDI法活化的微珠比未活化的微珠荧光强度提高60倍,活化效果显著.     

Fifty-five km reach,bidirectional, 400 Gb/s(40×10 Gb/s), channel-reuse DWDM–PON employing a self-wavelength managed tunable laser

We experimentally demonstrate a channel-reuse bidirectional 10 Gb∕s∕λ long-reach dense wavelength-division multiplexing passive optical network(DWDM-PON) and an optical beat-noise-based automatic wavelength control method for a tunable laser used in a colorless optical network unit(where λ· wavelength). A55 km, bidirectional, 400 Gb/s(40 × 10 Gb∕s) capacity channel-reuse transmission with 100 GHz channel spacing is achieved. The transmission performance is also measured with different optical signal to Rayleigh backscattering noise ratios and different central wavelength shifts between upstream and downstream in the channel-reuse system.