宇宙临界减速因子

本文证明了如果中微子具有质量,那么膨胀宇宙的临界减速因子q_c就不是通常所说的1/2而是等于1。     

培养“四有”新人是历史赋予我们的神圣使命

本文对如何落实邓小平提出的要把青少年一代培养成为有理想、有道德、有文化、有纪律的社会主义建设者和接班人问题，结合当代大学生的情况进行了探讨。     

45钢固体粉末法稀土、硼、铬、铝共渗工艺研究

研究了RE_Mg合金对固体粉末法硼、铬、铝共渗层成分、组织和性能的影响 .发现随着RE_Mg合金加入量的增加 ,渗层中Al2 O3的量不断增多 ,当RE_Mg合金加入量为 5 %时 ,渗层中出现连续致密分布的Al2 O3黑区组织 ,对此进行了性能测试和机理探讨     

一类图的强最大亏格嵌入

图的嵌入理论是拓扑图论中一个中心课题.图的最大亏格嵌入的刻画和研究已较完善.但对于强嵌入,这方面的讨论却很少.本文对于平面上的不含不交(指无公共节点)圈的图以及完全图K5,利用构造强最大亏格嵌入的方法,给出了强最大亏格.同时,也给出了完全二部图K3,k(k≥3)的不可定向强最大亏格的一个下界.     

关于Herstein定理的逆问题研究

设R是一个环,如果存在n>1使f:x→xn为R的一个环同态,则映射f:R→R称为一个幂自同态。本文将完全刻划出无零因子环的所有幂自同态。     

通州区：金鱼、锦鲤大赛暨鉴赏会举行

近日，北京市第二届中国金鱼、锦鲤大赛暨鉴赏会在北京市通州区张家湾镇北京鑫淼水产总公司隆重举行。     

陇西：农民利用塑料薄膜覆盖点种玉米

入春以来，我市大部分县区降水偏少．土壤墒情较差，各地农村采取多种措施抗旱保苗夺丰收。     

The controlling factors and distribution prediction of H2S formation in marine carbonate gas reservoir, China

Generally, there are some anhydrites in carbonate reservoir, as H2S is also familiar in carbonate oil and gas reservoirs. Nowadays, natural gas with high H2S concentration is usually considered as TSR origin, so there is close relationship between H2S and anhydrite. On the contrary, some carbonate rocks with anhydrite do not contain H2S. Recently, researches show that H2S is only a necessary condition of H2S formation. The reservoir porosity, sulfate ion content within formation water, reservoir temperature, oil/gas and water interface, hydrocarbon and some elements of reservoir rock have great controlling effects on the TSR occurrence. TSR deoxidizes hydrocarbon into the acidic gas such as H2S and CO2, and the H2S formation is controlled by TSR occurrence, so the relationship among reaction room, the contact chance of sulfate ion and hydrocarbon, the reservoir temperature has great influence on the TSR reaction. H2S has relatively active chemical quality, so it is still controlled by the content of heavy metal ion. Good conditions of TSR reaction and H2S preservation are the prerequisite of H2S distribu- tion prediction. This paper builds a predictive model based on the characteristic of natural gas reservoir with high H2S-bearing. In the porosity reservoir with anhydrite, the formation water is rich in sulfate and poor in heavy metal ion. Oil and gas fill and accumulate in the gas reservoir with good preservation conditions, and they suffered high temperature later, which indicates the profitable area of natural gas with high H2S-bearing.     

试谈大学英语四、六级考试改革对高职高专院校英语专业教学的影响

本文探讨了目前高职高专院校以大学英语四、六级考试,作为三年制英语专业学生终结性评估标准的必要性,通过对该考试改革趋势的分析,浅析其对学生听力和口语表达能力教学的指导作用。     

维生素D

维生素D是一种脂溶性维生素，也被看作是一种作用于钙、磷代谢的激素前体，它与阳光有密切关系。维生素D在人类中的主要生理功能是维持血清钙和磷的浓度在正常范围内，维持神经肌肉功能正常和骨骼的健全，它是生命必需的营养素和钙代谢的最重要生物调节因子。