基于ADCP测量的钱塘江主要断面污染物通量研究

用声学多普勒流速剖面仪（Acoustic Doppler Current Profiler，ADCP）获取河流断面的流量资料，结合水质分析所得的高锰酸盐、氨氮、总磷、石油类等污染物浓度资料，分析了钱塘江主要断面的污染物通量。结果表明，污染物通量研究将水质和水量统一起来考虑，很好的反映了污染负荷大小，是全面了解和评价河流主要断面污染物输送量和贡献量的有效手段，今后在治理流域水污染时应重视对河流污染物通量的研究。     

PKI和PMI安全方案在电力数据申报系统中的实现

电力市场技术支持系统中存在冒充、越权、否认和泄密等威胁,因此安全方案对电力数据申报系统至关重要。文章首先提出通过公钥证书和采用数字签名技术来验证系统用户的合法性,然后根据电力市场技术支持系统用户的分布性和业务操作的时间性,提出了一种具有时空约束的基于角色的访问控制模型,使用属性证书作为用户角色和权限的分配载体,以保证用户的合法操作。最后将上述的安全方法应用于电力市场数据申报子系统中,验证了安全方案的有效性。     

基于TCP/IP网络的集中控制式电能表检定装置

介绍了一种新型的基于TCP/IP网络的集中控制式电能表检定装置,由通讯转换设备和网络交换设备,将多台电能表检定装置组建成网,通过一台计算机进行控制,实现网络化校表.该系统已在杭州电力公司计量中心建成投入运行,成功地解决了校表量大、实验室场地和人员受限的局面,在同样的实验室场在地和人员配置下,通过技术升级,提高了检定人员工作效率,简化了配置,并为安全生产提供了保障;整套系统实施方案为目前组建新型的省市级电力计量中心提供了新思路与模式.     

温州鞋业集群成长驱动演变研究

通过对温州鞋业集群成长路径和不同阶段驱动演变机制的分析,提出集群层次提升和集群网络联系柔性化是驱动温州鞋业集群持续成长的关键.同时,指出积极而适当的外力干预(政府政策)是实现集群演进跃迁的重要力量.     

Production of Beer with a Genetically Engineered Strain of S. cerevisiae with Modified Beta Glucanase Expression

This study used a recombinant Saccharomyces cerevisiae strain, which expressed both β‐glucanase enzyme and reduced Pro‐teinase A expression during wort fermentations. The genetic stability and fermentation features of the strain were examined. The recombinant strain's proteinase A activity was reduced compared to the parent strain; β‐glucanase was produced throughout the fermentation. The fermentation with the recombinant S. cerevisiae strain exhibited a larger reduction in β‐glucan content than what was observed with the control strain, with β‐glucan degradation above 80%. The foam stability period was reduced when the beer produced by the recombinant S. cerevisiae was stored for 3 months. SDS‐PAGE analysis of the beer proteins indicated that lipid transfer protein 1 had disappeared. Fermentation studies indicated that based on the parameters examined, this recombinant strain was suitable for industrial beer production.     

不对称小电流接地电网单相接地电流的测量

介绍了简单易用、测量精度高的不对称小电流接地系统单相接地电流的测量方法。该法分别将三相经电阻接地,测得经电阻接地的接地电流值、相电压值和零序电压值即可方便地计算出电网的单相接地电流大小,还可区分出其有、无功分量,无功分量为容性或感性。现场测量结果证实了该法的有效性。     

A first-principles thermodynamic approach to ordering in Ni-Mo alloys

There is a competition between several face centered cubic (FCC)-based ordered inter-metallic phases in Ni-Mo alloys containing 8-33 at% Mo. The transformation behavior of these alloys in terms of ordering instabilities has been studied. First-principles tight-binding-linear muffin-tin orbital (TB-LMTO) method coupled with augmented space recursion (ASR) in conjunction with orbital peeling (OP) technique has been employed to extract the concentration dependent effective pair interactions. Further, the mean-field statistical mechanics based static concentration wave (SCW) model has been used to determine the free energies of these ordered phases as functions of temperature, composition and order parameter. This ASR-OP-SCW approach, applied to Ni-Mo alloy system, gives the correct ground state stability sequence as observed experimentally. Furthermore, it has been shown that such an approach can be used to study the complex transformation behavior involving several competing superstructures as well as competing first order and second order ordering processes.     

Optical properties of semiconducting and metallic single wall carbon nanotubes: effects of doping and high pressure

We demonstrated that optical absorption spectra of single wall carbon nanotubes (SWNT) changed drastically by the doping of halogens and alkali metals. From disappearance of absorption peaks attributable to interband optical transitions, it was established that the semiconducting phase of SWNT can be doped amphoterically. Emergence of new absorption peaks induced by heavy doping are explained by invoking the involvement of low-lying valence states (or high-lying conduction states) in the optical transition. We also found that the interband absorption peaks considerably and reversibly broadened and shifted under high pressure up to 4.1 GPa. Good correspondence of the present results to recent theoretical works suggests that this change may reflect a semiconductor–metal transition induced by intertube interactions and/or by symmetry breaking.     

雌激素对卒中后抑郁大鼠血清单胺类递质的影响

目的 探讨雌激素对卒中后抑郁(PSD) 大鼠的血清单胺类递质的影响。方法 选用雌性SD大鼠, 经Open-Field 行为学评分后随机分成对照组、卒中组、PSD 组、药物治疗组和雌激素干预组,所有大鼠均行卵巢切除术。对照组为常规饲养;卒中组去卵巢后7 d 采用线栓法制备局灶性脑缺血大鼠模型;PSD 组为卒中大鼠结合孤养、束缚应激制备PSD 大鼠模型;药物治疗组对PSD 大鼠模型行帕罗西汀灌胃治疗;雌激素干预组对PSD 大鼠模型皮下包埋雌激素释放管。观察雌激素对PSD 大鼠自发性行为和外周血去甲肾上腺素(NE) 和5-羟色胺(5-HT) 的影响。结果 与对照组比较, PSD 组大鼠旷场实验水平和垂直得分明显减少, 外周血NE 和5-HT 浓度明显降低, 差异有统计学意义(P <0.05)。与PSD 组比较, 雌激素干预组大鼠旷场实验得分增加, 外周血5-HT 和NE 浓度明显升高, 差异有统计学意义(P <0.05)。与药物治疗组相较, 雌激素干预组大鼠旷场实验得分、外周血5-HT 浓度差异无统计学意义(P >0.05)。结论 雌激素能够改善PSD 大鼠的行为学、增加血清5-HT 浓度, 提示对PSD 大鼠有脑保护作用。     

纳洛酮对兔心肌缺血-再灌注损伤β-内啡肽的影响

目的: 探讨纳洛酮在心肌缺血-再灌损伤时对血浆及心肌匀浆β-内啡肽(β-EP) 的影响。方法: 新西兰兔45 只, 随机分成5 组:正常组5 只, 心肌缺血组、缺血再灌注组、纳洛酮保护组和纳洛酮治疗组,每组10 只。制作心肌缺血模型和缺血再灌注损伤模型, 并抽取不同时间点的静脉血, 在心肌缺血、缺血再灌注、纳洛酮保护和纳洛酮治疗后6 h 制作缺血心肌匀浆, 采用放射免疫法分别测定β-EP 的含量。结果: 心肌缺血2 h 后血浆β-EP 含量逐渐下降, 较缺血前显著降低(P<0.05) ;而心肌匀浆上清液β-EP 含量也降低。缺血再灌注后各时段β-EP 含量明显高于缺血前(P<0.05或P<0.01) ;纳洛酮保护组在4 h 后血浆β-EP 含量逐渐下降, 与缺血前比较无显著性差异(P >0.05) ;纳洛酮治疗组β-EP在缺血后各时间点与缺血前比较均无显著性差异(P >0.05) 。3 组心肌匀浆上清液β-EP 含量与缺血前的含量比较无明显变化。结论: 纳洛酮可有效降低心肌缺血及缺血再灌注损伤时血浆β-EP 水平;从而减轻β-EP 对血管和心肌组织的损伤作用。