Seizure activity and lesions of neuronal cells by intrahippocampal injection of guanidinosuccinic acid in rats]

Intrahippocampal injection(ihci) of guanidinosuccinic acid (GSA) to rats, induced typical generarized clonic seizures and epileptiform discharges in electrohippocampogram (EHG) and electrocorticogram (ECoG), degenerative changes of neuronal cells in the injected side hippocampus. The pyramidal cells in CA1 area were found to be more vulnerable to GSA than the granular cells. Phenobarbital and phenytoin are typical antiepiletics, but in no case did they successfully protect against GSA induced convulsions, epileptiform discharges in the EHG and ECoG and neurolysis. Ketamine, a selective noncompetitive NMDA receptor antagonist, was shown to protect against not only seizures, but also neuronal cell damage induced by GSA. All these results indicate that GSA very like the endogenous excitatory amino acid, glutamic acid, it also has such effects mentioned above. Therefore, the NMDA receptor may mediate both effects of GSA.     

用于微流控荧光PCR的高分辨率温度控制系统

微流控荧光PCR产物在高分辨率熔解（HRM）曲线分析的过程中,随着DNA的解链荧光强度发生突变,而能否检测到该突变点则依赖于温控的精度。提出了多阈值PID算法,设计了一种适用于高分辨率熔解曲线分析的FPGA温度控制系统。根据测得温度值与设定值之间的差异,改变FPGA电路系统输出的脉冲宽度调制(pulse width modulation, PWM)波占空比和算法的调节频率实现对温度的准确控制。经过温度标定后,系统温度控制精度优于0.1℃,分辨率达到±0.01℃。HRM分析实验结果表明,本方法成功地辨别出了DNA序列的单碱基差异,温度控制系统达到了设计的要求。     

A/O-MBR处理PTA综合废水中试研究

试验研究对象为辽宁省某石化公司PTA综合废水。中试采用了缺氧好氧一体式膜生物反应器(A/O-MBR)工艺。经过60 d左右的运行,试验结果表明,系统处理效果理想。在进水COD为291～713 mg/L、总氮为19～51mg/L的情况下,系统出水COD<30 mg/L、氨氮<0.2 mg/L、总氮<10 mg/L,而且MBR出水浊度<0.2 NTU、SS<5 mg/L、含油量<0.3 mg/L,因此系统出水指标优于《辽宁省污水综合排放标准》(DB 21/1627—2008),同时达到可回用于国家工业循环冷却水系统补水的水质要求。     

17-4PH不锈钢纳米析出物的磁小角中子散射研究

本文充分发挥中子对磁灵敏、穿透力强等技术优势,利用加载磁场小角中子散射实验技术研究核电站实际服役14年的阀杆17 4PH不锈钢样品。结果表明,与不加磁场时相比,加载磁场条件下二维散射图谱呈明显各向异性,在散射矢量垂直于磁场方向上散射强度显著增强。利用多分散球模型对数据进行拟合,结合原子探针实验结果分析得出,衬度的增加降低了Cu析出物周围元素分布不均匀对散射的相对贡献,从而有助于更加准确地获得Cu纳米析出物的尺寸。     

CaC_2在低碳含铝钢脱氧工艺中的应用

针对河北敬业集团板坯连铸生产低碳含铝钢铝消耗高的问题,通过试验确定了用廉价的脱氧剂电石（CaC2）替代铝粉造白渣的技术方案。采用新工艺后,吨钢降低铝制品消耗0.32 kg,节约成本2元,LF工序可减少钢水吸氮2～3 ppm,提高了产品质量。从CaC2在该工艺中的应用原理以及使用效果证明：CaC2能够有效降低铝的消耗,减少钢水的吸氮。     

Enhanced properties of pure alumina ceramics by oscillatory pressure sintering

A novel oscillatory pressure sintering (OPS) process to consolidate high-quality pure alumina ceramics is reported. The microstructure of the ceramics prepared by OPS develops into a higher final density, a smaller and a narrower distribution of grain sizes compared with those prepared by conventional pressureless sintering (PS) and hot-pressing (HP) processes. Enhanced mechanical properties of alumina ceramics were investigated by OPS process. The bending strength, hardness and elastic modulus of the OPS specimen reached about 546 MPa, 19.1 GPa and 374 GPa, respectively, i.e values significantly higher than that of the specimens by PS and HP. XRD analysis indicates the strengthening of atomic bonds aided by oscillatory pressure. The results suggest OPS to be an effective technique for preparing high-quality pure alumina ceramics.     

Surfactant-free hydrothermal synthesis and characterization of single-crystal K2V8O21 nanobelts

Single-crystal K₂V₈O₂₁ nanobelts were prepared from the reaction between V₂O₅ and KHSO₄ under hydrothermal condition using no surfactant or template. The synthesized nanobelts were characterized by X-ray diffraction, X-ray photon-electron spectrometry, scanning electron microscopy, and transmission electron microscopy. The nanobelts are single-crystalline in nature, and have typical width of 100–500 nm, thickness of less than 100 nm and length up to a few tens of microns. The effects of solution concentration, reaction temperature and molar ratio of K and V on the morphology and phase component of the obtained products have been investigated. The possible formation mechanism was also discussed.     

Facile and rapid synthesis of multiferroic TbMnO3 single crystalline

The pure single phase of multiferroic material TbMnO₃ powders were successfully synthesized by one-step molten salt synthesis (MSS) method in the NaCl–Na₂SO₄ eutectic salts at the temperature as low as 800 °C for 1 h. The temperature of synthesized high purity TbMnO₃ is limited in a very narrow range. Prolonging the sintering time will not have an effect on the purity of samples, and either lower or higher salt concentration is not conducive to form pure TbMnO₃. The obtained TbMnO₃ was indexed to an orthorhombically distorted perovskite phase. The as-prepared crystals exhibit uniform and regular rhombic-like morphology with an average size of about 2 μm in edge length and 1–2 μm in thickness. The elements Mn and Tb in TbMnO₃ exist dominantly as Mn³⁺ and Tb³⁺, respectively. The magnetic measurements of the TbMnO₃ powders exhibit antiferromagnetism. Because of the simplicity and generalizability of the MSS method, it is reasonable to expect that the MSS method could also be exploited in future works which involves the nanoscale investigation of ferroelectric, ferromagnetic and multiferroic materials.