半导体激光器列阵器件光束复合研究

文中针对半导体激光器列阵的波长复合和偏振复合技术开展了设计和实验研究。首先利用半导体材料波长易调节的特点,设计了AlGaInAs/GaAs/AlGaAs压应变量子阱结构,得到了760nm、800nm、860nm、930nm、976nm五个波长激射的半导体列阵激光器,同时设计了四个短波通滤波片参数,开展了半导体列阵激光器的多波长光束复合技术的实验研究;其次利用1/2波片和偏振复合棱镜将两束不同偏振状态的光束进行了复合,并设计了光束聚焦系统。最终实现了5个波长,10条半导体激光器列阵的光束复合,得到了196W的激光功率输出,总体效率为76%,其中,波长复合效率可以达到92.4%,输出聚焦光斑尺寸为144μm×1 330μm,聚焦光功率密度达到1.02×105W/cm2,与单条半导体激光器列阵相比,合束光的光功率密度提高了4.3倍。     

SmarTrunk通信系统无线终端的功能实现

要使对讲机能在SmarTrunk系统中使用，实现信道的集群化管理，拥有其提供的诸多先进功能，必须在现有常规模式对讲机的基础上进行一些改造。具体方法是在其中增设逻辑附件板，作为系统控制器和对讲主机之间通信的桥梁。建立附件板与主机之间的硬件接口，并通过软件设计实现信息交换。此设计方案已在实践中验证合理正确。     

喜庆欢乐情不减 电子鞭炮趣味添

无论是中华民族的传统节日,还是民间的婚嫁等喜期,人们总爱以放鞭炮、点烟花的方式来庆祝。然而,鞭炮、烟花产生的爆力、噪声及硝烟严重危及了人们的安全、健康及环境保护。1992年除夕夜,仅合肥地区就有近10名儿童爆伤了皮、炸伤了眼,留下了终生残     

磺酸化磁珠富集鱼塘水中的孔雀石绿

采用1-乙基-(3-甲氨基丙基)碳酰二亚胺及N-羟基硫代琥珀酰亚胺活化磁珠表面羧基,将对氨基苯磺酸偶联在磁珠表面,获得磺酸化磁珠.以此磺酸化磁珠为吸附剂,建立了分散固相萃取富集鱼塘水中孔雀石绿的新方法,并对水体样本的最佳吸附pH值及解吸附条件进行了考察.结果表明:当水体样本pH值在3.0～0.6之间,磺酸化磁珠对水体中...     

低能N+ 离子预处理对水稻UV-B辐射的当代损伤效应的影响

采用3种不同注量的N离子对供试材料进行了离子注入预处理, 再用10.08 kJ/(m2d1)增强UV-B辐射对其幼苗进行辐照试验, 测定了过氧化物酶（POD）活性、 过氧化物歧化酶（SOD）活性、 过氧化氢酶（CAT）活性、 丙二醛（MDA）含量、 还原型谷胱甘肽（GSH）含量和可溶性糖含量的变化。 研究结果表明: 经N离子注入预处理的水稻材料受到UV-B辐射时其POD和SOD活性明显升高, 并在注量为2.0×1017 ions/cm2时活性达到最强; CAT活性和MDA含量明显降低, GSH含量显著增加, 而可溶性糖的含量则变化程度很小。 从这些研究结果可以看出, 经过一定注量离子注入预处理的水稻材料当受到UV B辐射时能产生较强的抗氧化能力和防御能力,而且抗氧化系统优于碳水化合物系统而先于表达。 由此可见, 离子注入预处理对水稻UV-B辐射的生物学效应的影响相当明显。 The seedlings of rice (xindao18) were exposed to UV B (10.08 kJ/(m2d1 )) irradiation follo wing the pretreatment with three different implantation dosages of low energy N+ ions. Changes in the levels of the superoxide (POD),superoxide dismutase (SOD),catalase (CAT), malondialdehyde (MDA),glutathione (GSH) and soluble sugar were measured. The result showed that the UV-B irradiation on the seedlings of rice pretreated with low energy ions implantation could lead to increase activities in POD and SOD,and the maximum appeared on the dose of 2.0×1017 ions/cm2. Meanwhile,it made the content of GSH increased, and caused the activity of CAT and the content of MDA to be decreased. But there was no obvious change in soluble sugar. It was suggested that the rice pretreated by low energy ion implantation could enhance the antioxidation capacity and defensive ability when irradiated by UV-B, and the antioxidation system could be induced earlier than carbohydrate system. Therefore, the biological effects of UV-B irradiation on rice pretreated by low energy ion implantation were quite obvious.     

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.     

一种带阈值的EPON动态带宽分配算法

文章提出一种适用于千兆以太网无源光网络(EPON)的支持多业务的动态带宽分配(DBA)算法,该算法采用单阈值整帧上报和阈值动态调整解决了EPON中存在的时隙碎片和队头阻塞问题.同时,文章对算法中的关键参数--设定周期的大小与算法性能的关系进行了深入的研究分析,以指导算法设定周期的确定.     

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.     

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.     

E1 over EPON的实现

提出一种在基于以太网的无源光网络(E-PON)上传输电路业务的方法——E1overEPON,此方法能够确保电路业务的服务质量,电路业务接口的技术性能指标满足国内外相关规范要求。阐述了E1overEPON的设计方案,包括主要模块组成和功能;对时延进行了分析;介绍了实现同步的方法。E1接口的性能测试结果表明,所提出的E1overEPON方案很好地满足了电路业务的QoS要求。