多体系统动力学微分／代数方程组的一类缩并算法

提出了多体系统动力学微分／代数组初值问题的一类缩并数值积分方法，首先通过矩阵正交分解法对增广系统转化为非超定系统，然后用Ｔａｙｌｏｒ展开法将其改写为可交替失代的格式，并用Ｎｅｗｔｏｎ迭代与差分修正求得系统响应，文末通过对平面二连杆操作手仿真验证了算法有有效性。     

斜交堰的水力特性

根据系列模型试验资料的分析，提出了不同交角的斜交堰的流量系数公式。叙述了它的主要水力特性。     

烷基化装置在生产运行中的节能优化措施

本文主要介绍了东营市亚通石化有限公司烷基化装置在日常生产运行中针对装置蒸汽使用方面实行的节能减耗措施,并列出措施实施前后的部分对比数据.     

垦西稠油的降粘研究

垦西稠油是超稠油,开采的关键在于降粘。探索了温度、溶剂和乳化剂对垦西稠油的降粘效果。升温降粘法是稀释降粘法和乳化降粘法的基础。温度每升高１０℃,垦西７３１ 井稠油粘度降低在３８％ —５０ ％ 范围。稀释降粘法效果明显,加入５ ％ —１０％ 的芳烃溶剂即可将垦西７３１ 井稠油的粘度降低到可在５２—７８ ℃下顺利开采的程度。而乳化降粘法必须在升温降粘法和（或）稀释降粘法配合下使用。     

碱法造纸黑液在稠油开采中的应用研究

本文通过室内实验研究,证实碱法造纸黑液对稠油有明显的降粘作用,用降粘相图法考察了温度、稠油粘度、水的矿化度和不同来源的黑液对稠油降粘作用的影响,提出了用黑液使稠油降粘的工艺技术参数,作为油田试验的参考。由于不同造纸厂的黑液对不同油田的稠油都有好的降粘作用,因此黑液最好就近使用,以减少运输成本。     

聚合物泥浆降粘剂PT－1降粘作用研究

ＰＴ－１降粘剂是顺丁烯二酸（酐）与乙烯基单体的共聚物。本文通过扫描电镜、粒度分析、Ｘ射线衍射等分析测定，研究了ＰＴ－１在膨润土泥浆和聚合物泥浆中的降粘作用，探讨了ＰＴ－１的降粘机理。     

Inactivation of aflatoxigenic fungi and the reduction of aflatoxin B1 in vitro and in situ using gamma irradiation

Detailed investigation on the effect of gamma (γ) irradiation on germination, sporulation, and growth of aflatoxigenic moulds (Aspergillus parasiticus 2999, Aspergillus flavus 305, and Aspergillus niger 388), as well as on the reduction of aflatoxin B₁ (AFB₁) level in artificially and naturally contaminated maize/feed samples was performed. The results of in vitro and in situ experiments with aflatoxigenic moulds demonstrated that 5 kGy-γ irradiation manages to prevent sporulation, germination and growth of the tested moulds both when in form of a pure and when in form of a mixed culture. In the feed samples artificially contaminated with AFB₁ (50 μg kg⁻¹) 5 kGy-γ irradiation reduced AFB₁ level by around 60%, while 10 kGy-dose reduce it for around 85%. Similarly, in feed samples spiked with AFB₁ in the concentrations of 100 μg kg⁻¹ 5 kGy-dose reduced the AFB₁ level by approximately 70%, while the dose of 10 kGy reduced it by approximately 90%. The experiments on naturally contaminated maize samples (n = 30) confirmed these observations; following a 5 kGy-irradiation, the overall mean AFB₁ reduction equalled to 69.8%, while the irradiation with a 10 kGy-dose achieved the overall mean toxin reduction of 94.5%. The obtained results indicate that γ irradiation can be used to prevent the growth of aflatoxigenic moulds and to reduce the AFB₁ levels in various goods intended for animal and human consumption, thus minimizing the animal and human exposure to this carcinogenic mycotoxin.     

Reduction of nitro phenols using nitroreductase from E. coli in the presence of NADH

The reductions of nitrophenols catalyzed by nitroreductase from E. coli in the presence of NADH were investigated in this paper. 4-Aminophenol and 4-hydroxylaminophenol were found in the reductive products of 4-nitrophenol and the maximum reductive ratio was about 83.49% when the reaction time was 70 min; 4,6-dinitro-2-pimelie kelone was found in the reductive products of 2,4-dinitrophenol and the maximum reductive ratio was about 75.28% when the reaction time was 80 min; 2,4-dinitrophenol and 4,6-dinitro-2-pimelie kelone were found in the reductive products of 2,4,6-trinitrophenol and the maximum reductive ratio was about 62.08% when the reaction time was 100 min. The similar reductive ratios of nitrophenols were obtained under aerobic and anaerobic conditions. The results indicated that nitroreductase was an oxygen-insensitive enzyme.     

奥氏体不锈钢高精度薄璧管的旋压工艺研究

本文叙述了1Cr18Ni9Ti钢高精度薄壁管的旋压工艺。该薄壁管璧厚为0.35mm,长度600mm,壁厚偏差≤0.01mm,粗糙度Rα0.63～1.25μm。通过试验找出了比较理想的旋压工艺参数,文章还讨论了影响旋压薄璧管精度的主要因素。     

Homogeneous grammars with a reduced number of non-context-free productions

A homogeneous production has its left-hand side formed by a non-empty string of identical nonterminals. A phrase-structure grammar is homogeneous if each of its productions is homogeneous. The present paper discusses the reduction of homogeneous grammars with respect to the number of non-context-free productions. More specifically, it demonstrates that for every phrase-structure grammar, there exists an equivalent homogeneous grammar that has only three non-context-free productions of the form 00→ε, 11→ε, and 22→ε.