河南省两大土类不同肥料配方一次性施肥对玉米产量和经济效益的影响

在砂浆黑土区和潮土区对玉米分别进行田间试验，目的在于筛选出适合当地的复合肥配方，减少肥料用量，增加经济效益。2种不同土壤试验结果表明：4个处理中，以缓释肥（25-10—10）处理产量最高，分别为7954kg／hm2和8365kg／hm2，其利润也最高，分别为13373元／hm2和14154元／hm2；缓释肥（25—10—10）处理比CK（不施肥）处理分别增产3498kg／hm2和3491kg／hm2，利润分别增加4907元／hm2和48937L／hm2，均优于其他2个施肥处理，而且在氮肥施用量上比其他施肥处理降低10．7％。     

一个极小不可满足公式子集的构造

对于极小不可满足公式和它的子类的研究是近年来兴起的一个热门方向。极小不可满足公式通过分裂得到的公式保持了极小不可满足性,它的子类的某些性质对于建立在分裂上的归纳证明是很有用的。找到了一个能递归构造的极小不可满足公式的子类MAX+,并证明这种递归构造方法具有可靠性和完备性,最后给出了一个构造实例。     

Sphingoid bases in infant formulas

Sphingolipids are a group of lipids present in all eukaryotic cells. They consist of a long-chain sphingoid base that is amide-bound to a fatty acid and a polar group on C-1 sphingosine. Sphingosine is the most widespread base in mammals. The goal of this study is to determine the concentrations of free and total sphingosine and sphinganine in infant formulas and human milk. Following the extraction of sphingolipids, base and acidic hydrolysis was preformed. Sphinganine and sphingosine were determined by means of high-performance liquid chromatography. The results of this research illustrate the differences between the concentrations of sphingoid bases in infant formulas and human milk. On the basis of the obtained results, it can be concluded that despite all efforts made to produce infant formulas as similar to human milk as possible, in terms of their structure and the amount of their constituents, there are differences that could be biologically significant and thus need to be further researched.     

阀门承压件最小壁厚计算式的分析与应用

介绍了阀门承压件最小壁厚设计准则和强度理论,推导出阀门承压件最小壁厚计算公式。     

逐步图解法淹没式堰流公式推流的使用范围

堰闸水文站出现淹没式堰流时可以使用逐步图解法定线推流,但小水位差时用自记水位推流,计算流量的误差可能很大。通过对淹没式堰流计算流量的不确定度的分析计算,得到水位差的百分不确定度XΔz,根据计算流量的不确定度要求,推算得到满足计算流量不确定度要求的水位差的范围:对于开宽大于2.0 m、下游水头大于0.5 m的堰闸站出现淹没式堰流时,只有水位差大于0.14 m时,才能使用自记水位推流。     

肠内免疫营养联合重组人生长激素对严重烧伤病人营养状况和细胞免疫的影响

目的研究肠内免疫营养（enteral immune nutrilion,EIN）联合重组人生长激素（recobinant human growthhormone,rhGH）对重度烧伤病人营养状况、细胞免疫及肝肾功能的影响。方法 22例严重烧伤病人按随机数字表法分为2组,即肠内营养（enteral nutrilion,EN）＋rhGH组和EIN＋rhGH组,每组11例。EN＋rhGH组病人给予常规EN液能全力,同时肌内注射生长激素,连续2周;EIN＋rhGH组则提供EIN液（强化精氨酸EN液）,其余同EN＋rhGH组。观察治疗前和治疗2周后营养蛋白、T淋巴细胞亚群及肝肾功能的变化。结果①EN＋rhGH组病人治疗2周后有效提高了总蛋白、球蛋白、前白蛋白水平（P〈0.05）,EIN＋rhGH组病人治疗后除提高了以上蛋白水平外,还明显提高了转铁蛋白水平（P〈0.05）,但2组间比较差异无统计学意义（P〉0.05）。②EN＋rhGH组病人CD3＋、CD8＋水平升高,而CD4＋、CD4＋/CD8＋则下降;EIN＋rhGH组CD3＋水平提高,但CD4＋、CD8＋、CD4＋/CD8＋变化不大。2组比较差异无统计学意义（P〉0.05）。③EN＋rhGH组病人谷丙转氨酶较治疗前有所升高（P〈0.05）,但仍在正常值范围;EIN＋rhGH组治疗前后谷丙转氨酶变化不大（P〉0.05）。2组谷草转氨酶、尿素氮、肌酐组内比较或组间比较差异均无统计学意义（均P〉0.05）。结论 EN或EIN联合rhGH均可改善严重烧伤病人的营养状态,且未明显加重肝肾功能负担,但EIN联合rhGH相比EN联合rhGH,更有利于维持烧伤病人的免疫平衡。     

电容补偿后的电动机软起动电网压降计算

在电网短路容量相对于电动机的起动容量偏小时,可以并接补偿电容减小电网的起动网压降。补偿电容的接入,增加了电网起动网压降的计算难度。推导了基于单位方向矢量和相关电力器件容量的简明计算起动网压降的公式,并演示了计算结果。导出公式的适用范围并不仅仅限于电动机起动。     

Release of β-casomorphins 5 and 7 during simulated gastro-intestinal digestion of bovine β-casein variants and milk-based infant formulas

The release of β-casomorphin-5 (BCM5) and β-casomorphin-7 (BCM7) was investigated during simulated gastro-intestinal digestion (SGID) of bovine β-casein variants (n = 3), commercial milk-based infant formulas (n = 6) and experimental infant formulas (n = 3). SGID included pepsin digestion at pH 2.0, 3.0 and 4.0 and further hydrolysis with Corolase PP™. β-Casein (β-CN) variants were extracted from raw milks coming from cows of Holstein-Friesian and Jersey breeds. Genomic DNA was isolated from milk and the β-CN genotype was determined by a PCR-based method. Phenotype at protein level was determined by capillary zone electrophoresis in order to ascertain the level of gene expression. Recognition and quantification of BCMs involved HPLC coupled to tandem MS. Regardless of the pH, BCM7 generated from variants A1 and B of β-CN (5–176 mmol/mol casein) the highest amount being released during SGID of form B. As expected, the peptide was not released from variant A2 at any steps of SGID. BCM5 was not formed in hydrolysates irrespective of either the genetic variant or the pH value during SGID. Variants A1, A2 and B of β-CN were present in all the commercial infant formulae (IFs) submitted to SGID. Accordingly, 16–297 nmol BCM7 were released from 800 ml IF, i.e. the daily recommended intake for infant. Industrial indirect-UHT treatments (156 °C × 6–9 s) did not modify release of BCM7 and, during SGID, comparable peptide amounts formed in raw formulation and final heat-treated IFs.     

Lod generalized trapezoidal formula schemes for parabolic differential equations in two space dimensions

We describe locally one-dimensional (LOD) time integration schemes for parabolic differential equations in two space dimensions, based on the generalized trapezoidal formulas (GTF(α)). We describe the schemes for the diffusion equation with Dirichlet and Neumann boundary conditions, for nonlinear reaction-diffusion equations, and for the convection-diffusion equation in two space dimensions. The obtained schemes are second order in time and unconditionally stable for all α ∈ [0, 1]. Numerical experiments are given to illustrate the obtained schemes and to compare their performance with the better known LOD Crank-Nicolson scheme. While the LOD Crank-Nicolson scheme can give unwanted oscillations in the computed solution, our present LOD-GTF(α) schemes provide both stable and accurate approximations for the true solution.     

Generalized trapezoidal formulas for parabolic equations

We investigate the application of the one-parameter family of generalized trapezoidal formulas (GTFs) introduced in Chawla et al. [2] for the time-integration of parabolic equations. The resulting GTF finite-difference schemes (GTF-FDS) are, in general, second order in both time and space and unconditionally stable. Interestingly, there exists a method of the family which is third order in time. Unlike the popular Crank -Nicolson scheme, our present GTF-FDS can cope with discontinuities in the boundary conditions and the initial conditions. We consider extensions of the GTF-FDS for equations with derivative boundary conditions and to a nonlinear problem. Numerical experiments demonstrate the superiority of the present GTF-FDS, especially for the case of problems with discontinuities in the boundary and the initial conditions.