浅析旱作农业技术在黄土高原退耕还林(草)之后的作用——为朱总理’99,8,7讲话而作

针对朱基总理 1 999年 8月 7日讲话精神和旱农技术在特殊的自然条件和社会条件下为了良化农田生态环境和持续增产所采取的一整套用地与养地相结合的技术体系。文章着重的分析了培肥地力、轮作倒茬、化学技术、选育品种、节水、立体种植、地膜覆盖、水土保持耕作法八种技术 ,充分利用光、热、水、气、土、肥资源而取得明显的社会效益、经济效益和生态效益 ,剖析了旱作技术在农业持续、稳定、健康发展中的作用和改善农业生态环境的显著地位 ,供同类地区的决策者和研究者借鉴

微波消解-ICP-AES法同时测定蛹虫草中8种微量元素

选用硝酸和过氧化氢作为消解剂,采用微波技术消解蛹虫草样品,用电感耦合等离子体发射光谱(ICP-AES)法同时测定其中K、P、Ca、Mg、Cu、Fe、Zn、Mn共8种微量元素的含量。进行微波消解条件的优化选择及分析线性、精密度和回收率等实验,建立同时测定蛹虫草中多种微量元素的微波消解-ICP-AES方法。本方法所测元素的标准曲线均有良好的线性关系,以猪肉粉国家标准物质GBW08522为对照进行验证,其回收率为91%～106%,相对标准偏差(RSD)<3.0%;该法加标回收率为90%～108%,RSD<3.0%,具有较好的准确度和精密度,是一种快速、准确而高效的分析方法。测定结果表明,蛹虫草富含有K、P、Mg、Ca、Zn元素。

中国东北8种藓类植物染色体数目

本文对中国东北 8种藓类植物染色体数目进行了报道。其中赤茎藓Pleuroziumschreberi (Brid .)Mitt.,n =5 ;塔藓Hylocomiumsplendens (Hedw .)B .S .G .,n =11;粗肋羽藓Thuidiumrecognitum (Hedw .)Lindb .,n =11;绿羽藓T .assimile (Mitt.)Jaeg .,n =11;四齿藓TetraphispellucidaHedw .,n =8;侧枝匐灯藓Plagiomniummaximoviczii (Lindb .)Kop .,n =6 ;尖叶匐灯藓P .cuspidatum (Hedw .)Kop .,n =12 ;具缘提灯藓Mniummarginatum (With .)Beauv .,n =6。绿羽藓的染色体数目为首次报道 ,赤茎藓 ,塔藓 ,粗肋羽藓和四齿藓为国内首次报道

Mo的掺杂对Ce_(0.8)Gd_(0.2)O_(1.9)烧结温度及电性能的影响

掺杂的CeO2基固体电解质因其在中低温条件下(500￣700℃)具有高氧离子电导率而成为有希望的IT-SOFCs(intermediate temperature-solid oxide fuel

Microstructure and mechanical property of Mg-8.31Gd-1.12Dy-0.38Zr alloy

The Mg-8.31Gd-1.12Dy-0.38Zr (mass%) alloy was prepared by casting technology, and the microstructure, age hardening behavior and mechanical property have been investigated. It is noted that the alpha-Mg and the different Mg-RE (RE = Gd/Dy) compounds are subsistent in the as-cast and annealed state samples. The age hardening behavior is observed during the investigated temperature range, and the alloy exhibits high Vickers hardness, excellent ultimate tensile strength and yield strength at peak hardness.

Design and synthesis of near-IR luminescent mesoporous materials covalently linked with tris(8-hydroxyquinolinate) lanthanide(III) complexes

By using the bifunctional ligand, 8-hydroxyquinoline-functionalized organosilane (Q-Si), the new mesoporous material Q-MCM-41 covalently bonded with 8-hydroxyquinoline was synthesized. Through the ligand exchange reaction, the new near-infrared (NIR) luminescent mesoporous LnQ(3)-MCM-41 (Ln = Er, Nd, Yb) materials were prepared by linking the lanthanide quinolinate complexes to the ordered mesoporous Q-MCM-41 material. The LnQ(3)-MCM-41 materials were characterized by powder X-ray diffraction and N-2 adsorption/desorption, and they all show the characteristic mesoporous structure of MCM-41 with highly uniform pore size distributions.