基于离心作用的齿轮泵容积效率和困油现象分析

为了解高速时工作油液的离心作用对泵容积效率和困油现象的影响,将离心作用对两者的影响归结于对泵进油侧原始含气比的修正。基于仅考虑工作油液中混入空气的可压缩性和含气、纯净工作油液分别累积在齿槽内、外侧的假设,建立了基于油液离心作用的下容积效率、困油区间内含气比和进油侧修正含气比的计算公式。两组数据的仿真结果表明离心应用对容积效率和困油现象的影响相反,转速越高,对容积效率越不利;出口压力越低,离心作用对困油现象的影响越有利;齿形参数的选择存在优化的问题;该研究为泵的高速化发展提供一定的依据。     

Numerical simulation of the mechanism of atypical dynamic phenomena in mines

An atypical dynamic phenomenon of mines, including its action forms and definition, were put forward, based on the mining accident at the Furong Mining Group Company in Sichuan, P. R. China. The mechanism of the atypical dynamic phenomenon was revealed by analyzing rock stress distribution, calculating the first and cycle broken distance of each thick and hard roof, and analyzing the balance structure of broken rock based on the three dimensional finite element software. The first stratum of the bent, sunken, aged strip was influenced by the geological conformation and the coal mining activity. This created the first break of the key stratum and led to the atypical dynamic phenomenon. We show that the key factors affecting the phenomena are the roof and floor structures, surrounding rock, and initial stress and rock burst tendency of the key stratum.     

一类二阶半线性椭圆方程边值问题正解的熄灭现象

讨论了一类二阶半线性椭圆方程u″（t）＋ρ（t）f（u（t））=0的第一类边值问题：μ″（t）＋ρ（t）f（u（t））=0,u（t0）=u（t1）=0,0〈t0〈t1〈＋∞的径向正解的熄灭现象。在假设条件f∈C1（0＋∞）,f（t）／tλ在（0＋∞）上非增,λ∈[0,1）下通过变量代换与构造积分等式得到该问题的径向正解出现熄灭现象的充要条件。     

城市化发展对相对湿度的影响——以济宁市为例

为了研究济宁城市化发展对相对湿度的影响,利用1981—2010年济宁及周边郊区3县（兖州、汶上、嘉祥）台站的相对湿度资料,研究分析了济宁城区、郊区的相对湿度变化趋势和特点。在此基础上,探讨了城市化发展对济宁城郊相对湿度的影响。研究发现：（1）济宁城区、郊区1981—2010年相对湿度有相同的年际变化趋势,均呈现减少趋势。其中,相对湿度在春季和秋季减幅最大,且郊区相对湿度的降低速度高于城区,意味着济宁城区和郊区正逐步暖干化。（2）近30年来,济宁市在年平均相对湿度上表现为明显的干岛现象,且呈上升趋势,在20世纪90年代较为突出,2000年以后城市干岛现象虽高于平均值,但呈现明显的下降趋势。（3）济宁城市干岛效应具有明显的月季变化特征和四季变化特征：即冬半年明显高于夏半年。四季干岛强度均有加强的趋势,春秋季节最强,夏季最弱,冬季居中,四季均表现为1991—2000年热岛强度较强,2000年以后热岛效应有所减缓,与年度变化一致。济宁在2时、8时、14时、20时4个时刻的年平均上都反映了干岛效应,2时的干岛强度最大,而在午后14时干岛强度是最小。     

Mine transient electromagnetic field multiples phenomenon

In order to accurately calculate the magnetic field parameters of mine transient electromagnetic field based on the former research theory of transient electromagnetic field full-space and half-space combined with transient electromagnetic space applications in mines this article studies the relationship of transient electromagnetic field intensity and half-space transient electromagnetic field and proposes the multiple phenomenon of transient electromagnetic. Research results show that full-space transient electromagnetic field intensity and half-space transient electromagnetic field intensity has multiple phenomenon. They have 2 times relationship in the early stage and have 2.5 times relationship in the late stage. Similarly mine transient electromagnetic field intensity electric field intensity and apparent resistivity calculations also have multiple relationships. Putting forward the multiple phenomenon has important reference value in theory and practice for researching the mine transient electromagnetic field.     

囚徒困境与高校图书馆占座现象

通过博弈论的囚徒困境模型分析了高校图书馆占座严重这一现象,并对占座现象产生的原因加以分析,同时提出应对方案。     

费约果开花物候特性的研究

以费约果实生树为试验材料观测其花期物候，以期为费约果花期调控、栽培管理和生产实践方面提供理论支撑。结果表明：不同年份费约果种群花期长短相近，其花期持续时间为36~37天；株间开花时间不同，但是开花持续天数相差不大，为29~32d；单花开花持续时间约为7天。费约果的花瓣多为4瓣，多反卷，雄蕊众多，易于昆虫和鸟类传粉。     

断根方法对高山巨峰葡萄旺树的控制及物候期延迟的效果研究

本研究以巨峰葡萄为研究对象，探索在高海拔山区运用不同断根方式对旺树枝叶生长及物候期的影响。结果表明：不同断根处理较对照组（未断根），其物候期、生长势、果实品质均有显著差异。其中离植株40 cm处挖30 cm宽环状沟，沟深40 cm处理，萌芽期推迟16 d、新梢粗度下降39.4 %、叶面积下降66.5 %、小果率下降47.5 %，显著低于对照；可溶性固形物提升至21.9 %，花色苷提升1.2 %，总糖提升至122.2 mg/ml，显著高于对照。断根处理可有效推迟物候期，削弱地上部生长，提高果实品质。本试验结果可为高海拔山区种植的巨峰葡萄在控制长势，推迟物候期以及提高果实品质提供理论依据。     

沙地樟子松天然林和人工林中针叶养分含量比较

为了诊断沙地樟子松人工林的衰退原因,我们比较分析了沙地樟子松天然林和人工林中的叶片养分含量。结果表明,天然林中的樟子松叶片内氮、磷含量均比人工林中低,而钾含量比人工林高。樟子松人工林叶片中 N:P, P: K 和N: K在45年前随年龄增加而增加,从植物养分含量的角度来看,这一结果表明氮或磷可能不是沙地樟子松生长的绝对限制因子。然而,天然林和人工林叶片中的钾含量比以前报道过的松属植物中的含量都要低。天然林叶片中的N: P比值在正常的范围内,但人工林的则在该范围以外。这些结果表明天然林具有比人工林更好的养分平衡状况。如果只从樟子松的生长地来考虑,我们可以认为樟子松人工林的衰退现象可能是因其它的矿物元素或者氮和磷的有效性,而不是氮和磷的绝对含量不足造成的。养分的不平衡状况和人工林内针叶快速分解可能也是衰退的重要因素。图3表3参42。     

Relationships between blacking phenomenon and norlignans of sugi (Cryptomeria japonica) heartwood III: Coloration of norlignans with alkaline treatment

We investigated norlignan coloration with alkaline treatment to clarify the relationship between the blackening of sugi (Cryptomeria japonica D. Don) heartwood and norlignans in the heartwood. Of the four main norlignans (agatharesinol, sequirin-C, sugiresinol, hydroxysugiresinol) of sugi heartwood, only sequirin-C was clearly colored with alkaline treatment (0.4% potassium hydrogencarbonate solution, pH 8.6). Sequirin-C changed color to deep purple with alkaline treatment. The absorbance spectrum of colored sequirin-C had two peaks (450 and 525nm) and one shoulder (626nm). Coloration began at pH 6.2.). The spectrum of blackened sugi heartwood was similar to that of sequirin-C treated with alkali. A catechol nucleus and a double bond conjugated with a benzene nucleus play important roles in norlignan coloration with alkaline treatment. The number of hydroxyl groups is related to solubility in alkaline solution, and, therefore, whether a norlignan changes color also depends on the number of hydroxyl groups. Based on these results, we concluded that sugi heartwood turns black because sequirin-C, which is readily soluble in alkaline solution and can form a large intramolecular conjugation system when alkalized, is converted to products with a deep purple color as the heartwood is basified.