The Effects Induced by Turbulence and Dust Storms on Millimeter Waves

Dust storms and turbulence consist of a random medium system, its effects on milimeter waves propagation are studied. Attenuation of millimeter waves, its phase shift and cross- polar discrimination are presented. Results show that dust storms mainly effects XPD and phase shift of millimeter waves, turbulence chiefly produces attenuation, in mediocre fluctuation.     

Hydrogeochemical Characteristics and Formation Mechanisms of the Geothermal Water in the Qingdong Coal Mine,Northern Anhui Province,China

Mine Water and the Environment - The hydrogeochemistry of geothermal fluids provides insight into the occurrence, formation, and circulation of geothermal resources. We collected 13 geothermal...     

Effect of high oxygen modified atmosphere on post‐harvest physiology and sensorial qualities of mushroom

The changes in physiology and sensorial qualities of mushroom stored at 2 °C for 12 days under high oxygen (100% O₂, 80% O₂) atmosphere and air had been investigated. Respiration rate was suppressed in mushroom in 80% O₂ and 100% O₂. No significant differences were found between 80% O₂ and 100% O₂. Weight loss was not more than 1.5% in all treatments. Weight loss and firmness of mushroom held in high oxygen were significantly (P < 0.05) higher than in air. Total soluble solid (TSS) was only slightly affected by high oxygen treatment. High oxygen, especially 100% O₂ treatment was effective at reducing browning degree and electrolyte leakage of mushroom. The surface colour of mushroom changed slightly before tenth day under high oxygen treatment. From day 2 the L‐value of mushroom flesh was significantly (P < 0.05) lower under air atmosphere compared with high oxygen treated mushroom. High oxygen, especially 100% O₂ was effective at inhibiting discoloration. The PPO activity of mushroom was significantly (P < 0.05) higher in 100% O₂ compared with air treatment. The POD activity was highest in high oxygen at eighth day, then reduced. High oxygen, especially 100% O₂ was effective at maintaining the quality of mushroom.     

无耗均匀传输线的系统特性

对于以常系数偏微分方程描述的一维波动分布参数系统变换为以时间为独立变量的定常系统，用已知的常系数常微分方程系统的状态空间分析做了定性的判定。这种方法避免了直接处理分布系统的复杂数学方法。     

用品牌战略挑战未来

加入WTO的中国,市场全面开放,竞争将更加激烈。面对新形势、新挑战,必须把企业的品牌经营提到新的高度来对待,培育和塑造企业的品牌形象,提高市场认识度和竞争能力。现围我们绕企业的品牌经营,谈一点粗浅的认识。1品牌经营的探索与实践新钻公司是国家桩工机械行业骨干企业,原来品牌观念不浓,主要还是停留在商品销售层面。后来通过参加高层论坛和竞争体验,品牌意识逐步明朗,开始有意识的进行品牌经营运作。“新钻”牌工程钻机是1977年由国家建委主持鉴定并通过鉴定。1978年获全国科学大会奖,1988年获国优银质奖,1992、1998、1999有三项产品…     

Nonuniform sequential sampling for signal analysis

New electronic technologies for signal analysis raise the possibility of sampling very rapidly, with a time-varying density, and determining empirically both the sampling rate and the window width as the signal evolves in time. These opportunities also point to the possibility of sequentially sampling in a time-varying way in more traditional problems. Motivated by these ideas, we establish a sampling formula, valid in cases where both sampling rate and window width may be varied. The formula states that, in terms of the ways in which these quantities should alter with time, optimal performance is achieved when the window width is inversely proportional to squared sampling rate, and sampling rate is directly proportional to squared bias.     

舰载机有限可修复备件库存模型

为在舰载机可修复备件库存管理中保持合理的库存及必要的订货补充,提出有限可修复备件库存模型。分析舰载机有限可修复备件维修供应模式;基于储存理论,研究连续采购模型,给出适用于Vari-Metric理论的有限可修复备件适用性修改方法;研究有限可修复备件批量采购模型,给出批量采购的最优订购点和最优订购量,并进行实例分析。结果表明：该方法有较高的理论参考价值,对提高舰载机备件供应保障能力具有积极意义。     

海拉尔盆地查干诺尔凹陷大磨拐河组孢粉组合及其地质意义

海拉尔盆地查干诺尔凹陷大磨拐河组自下而上划分为2个孢粉组合.云杉粉Piceaepollenites sp.-单束松粉Abietineaepollenites sp.-三角粒面孢Granulatisporites sp.组合,分布于大磨拐河组一段;罗汉松粉Podocarpidites8p.-双束松粉Pinuspollen...     

大分子螯合剂在低压力低磨料条件下铜膜的化学机械抛光中的应用

The mechanism of the FA/O chelating agent in the process of chemical mechanical polishing （CMP） is introduced. CMP is carried on a φ300 mm copper film. The higher polishing rate and lower surface roughness are acquired due to the action of an FA/O chelating agent with an extremely strong chelating ability under the condition of low pressure and low abrasive concentration during the CMP process. According to the results of several kinds of additive interaction curves when the pressure is 13.78 kPa, flow rate is 150 mL/min, and the rotating speed is 55/60 rpm, it can be demonstrated that the FA/O chelating agent plays important role during the CMP process.     

闪光灯泵浦Cr：LiCAF激光器的实验研究

实现了闪光灯泵浦Ｃｒ：ＬｉＣＡＦ激光器的脉冲运转．在最佳耦合输出条件下获得斜率效率为２．２０％、转换效率为１．３６％的激光输出。研究结果表明．对于闪光灯泵浦的Ｃｒ：ＬＩＣＡＦ激光器．较高的掺杂浓度有利于降低激光阈值并提高输出能量和效率。实验中观察到激光脉冲尖峰振荡中的类自调Ｑ现象。