Thermal Behavior of the Fluorescence Lines of Ho~(3 ) in Cr,Tm,Ho∶YAG

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｃｒ,Ｔｍ ,Ｈｏ∶ＹＡＧｉｓａｋｉｎｄｏｆｖｅｒｙｉｍｐｏｒｔａｎｔ 2 μｍｌａｓｅｒｃｒｙｓｔａｌ,ｗｈｏｓｅ 2 .1 μｍｌａｓｅｒｉｓａｂｓｏｒｂｅｄｓｔｒｏｎｇｌｙｂｙｗａｔｅｒｃｏｍｐｏｎｅｎｔｏｆｔｉｓｓｕｅ,ｒｅｓｕｌｔｉｎｇｉｎｓｈａｌｌｏｗｔｉｓｓｕｅｐｅｎｅｔｒａｔｉｏｎａｎｄｇｏｏｄｓｕｒｇｉｃａｌｐｒｅｃｉｓｉｏｎｉｎｍｏｓｔｔｙｐｅｓｏｆｓｏｆｔａｎｄｈａｒｄｔｉｓｓｕｅ .Ｈｏ∶ＹＡＧｌａｓｅｒｈａｓｂｅｃｏｍｅａｎｉｍｐｏｒｔａｎｔｓｏｕｒｃｅ…     

All solid-state passively Q-switched frequency-doubled intra-cavity Nd: GdVO4/KTP laser

In this paper, laser frequency-double and passive Q-switching are studied. The optimum coupling at endpump and optimum design of resonator are also investigated. The maximum output power of TEM00 is 1.68 W at 1.06-μm wavelength. Optic-optic conversion efficiency is 48.6%, and the slope efficiency is 56.3%. The maximum output of green light is 0.235 W. The smallest pulse-width of green light is 27.42 ns, optic-optic conversion efficiency of green light is 7%, and beam quality factor M2 ＜ 1.2. Thermal lens effect is discussed.     

Tunable and Passively Mode-Locking Nd0.01:Gd0.89La0.1NbO4 Picosecond Laser

A high-quality Nd_0.01:Gd_0.89La_0.1NbO₄ (Nd:GLNO) crystal is grown by the Czochralski method, demonstrating wide absorption and fluorescence spectra and advantage for producing ultrafast laser pulses. In this paper, the tunable and passively mode-locking Nd:GLNO lasers are characterized for the first time. The tuning coverage is 34.87 nm ranging from 1058.05 to 1092.92 nm with a maximum output power of 4.6 W at 1065.29 nm. A stable continuous-wave (CW) passively mode-locking Nd:GLNO laser is achieved at 1065.26 nm, delivering a pulse width of 9.1 ps and a maximum CW mode-locking output power of 0.27 W.     

碳氮复合材料负载镍甲醇羰基化催化剂的研究

通过碳化由偏氯乙烯和丙烯腈悬浮共聚得到的前体,制得碳氮复合材料,将其负载金属镍后即得气相甲醇羰基化反应的催化剂。分别采用扫描电镜(SEM)、氮气吸附、XPS、电子探针(EPMA)等方法对该材料及由其制得的催化剂进行表征,证明该催化剂中的镍呈高度分散的纳米粒子状态。采用固定床反应器对该催化剂进行催化性能测试,结果表明该催化剂在较低金属镍负载量及较温和的条件下即可具有较好的催化性能。该催化剂的最佳镍负载量为1.5%左右。     

Concentration distribution of Nd3+ In Nd:Gd3Ga5O12 crystals studied by optical absorption method

Nd:Gd₃Ga₅O₁₂ crystals with different concentrations of Nd³⁺ were grown by Czochralski method, their absorption spectra were measured at room temperature. By using the optical absorption method, the effective distribution coefficient k_eff for Nd³⁺ in GGG was fitted to be 0.40±0.01, which is higher than that of Nd³⁺ in YAG. The 808nm absorption cross‐section was calculated to be 4.0±0.2×10^‐20cm^‐2. The lengthways and radial concentration distribution of Nd³⁺ in the crystals were also analyzed and discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

高效液相色谱-紫外/荧光检测方法测定河豚毒素

河豚毒素（TTX）的准确定性及定量测定一直是人们研究的重点,其检测方法有多种。小鼠法是最常用和最简便的方法,但具有定量不准确且重复性差等缺点。由于河豚毒素在NaOH溶液中加热具有产生荧光的特性,可以利用荧光检测器测定TTX的含量,因此,本文利用反相高效液相色谱法（RP-HPLC）,采用紫外和荧光两套检测系统对TTX的准确定量进行了初步探索。     

尿素抑制甲烷爆炸过程中爆炸压力与自由基变化耦合分析

为建立抑爆过程中,尿素对甲烷宏观抑爆效果与微观抑爆机理之间的联系,利用20 L球型爆炸测试装置开展实验,测量了尿素粉体抑制甲烷爆炸过程中爆炸压力,利用光栅光谱仪采集火焰发射光谱数据;采用光谱分析和数据同步分析方法,分析该抑爆过程中爆炸压力和NO、CN、CHO、HNO、OH等关键自由基或分子的变化,得出甲烷爆炸压力发展过程与相关自由基含量之间的耦合变化关系。研究表明,加入尿素能有效地降低甲烷的爆炸压力,延长甲烷的爆炸感应期;在尿素的作用条件,NO、HNO含量的升高和CN、CHO、OH含量的降低,可以抑制甲烷爆炸;NO、CN、CHO、HNO自由基分子与甲烷爆炸升压过程有较大联系;OH自由基一直存在于甲烷爆炸的整个过程中且含量较高;对以上自由基的干预,可以在相应阶段发挥抑爆作用。

     

A Review of Selenium (Se) Nanoparticles: From Synthesis to Applications

Selenium is an essential trace element that plays a crucial role in various physiological activities, exerting a significant impact on human health. Selenium deficiency can lead to the development of several diseases, while excessive doses can be toxic. In recent years, there is a growing interest in elemental selenium nanoparticles (SeNPs) due to their good biocompatibility, low toxicity, and high antioxidant activity, making them suitable for numerous applications. The quest for enhancing efficacy and reducing toxicity has driven extensive research on SeNPs. This review aims to provide a comprehensive summary of the recent advancements made in the synthesis, characterization, properties, and applications of SeNPs. Moreover, the challenges associated with SeNPs research, as well as the future trends in the field, are thoroughly discussed. This review aims to provide an insight into the current state of research on SeNPs and highlight areas that require further exploration and development.