弧形齿万向联接轴附加弯矩计算技术的开发

针对大交叉角异轴传动构件——弧形齿万向联接轴,在工作时存在附加弯矩而导致弧形齿磨损加剧的情况,对弧形齿万向联接轴进行了齿间载荷分配的计算,进而对联接轴附加弯矩进行计算,阐述了计算方法和具体过程。对工程中分析弧形齿联接轴及其相应轴段所受弯矩的影响具有重要参考价值。     

Influence of addition of ammonium and different amino acid concentrations on nitrogen metabolism in spontaneous must fermentation

The effect of the addition of different amino acid concentrations in must on yeast nitrogen metabolism during alcoholic fermentation was studied. To do this, fermentations of Mazuelo must, poor in nitrogen compounds, were carried out. Ammonium and different concentrations of amino acids (0, 45, 120, 250 and 450 mg/l) were added to the must. Addition of 45, 120 and 250 mg/l of proteic amino acids to the must increased the rate of fermentation. Proline was mainly consumed in fermentations with smaller amounts of amino nitrogen and, at the same time, this amino acid showed the highest residual concentration in the final wines. The consumption of other proteic amino acids was directly proportional to their concentration in the musts, with the exception of leucine and isoleucine that were synthesized. However, a difference in the percentages of the amino acids consumed by the yeasts was observed. The percentages of aspartic acid, alanine and arginine consumed were higher in the fermentations supplemented with amino acids than in the fermentation where only ammonium was added. The percentages of tyrosine and phenylalanine consumed gradually increased with increase of their initial concentration.     

Some results on addition/subtraction chains

Let ?(n) (respectively $\text{?}$(n)) be the length of the shortest addition chain respectively addition/subtraction chain for n. We shall present several results on $\text{?}$(n). In particular, we determine $\text{?}$(n) for all n satisfying $\text{s}\text{(}\text{n}\text{) ? 3}$ and show $\text{?}\text{log n}\text{? + 2 ?}\text{?}\text{(}\text{n}\text{)}$ for all n satisfying $\text{s}\text{(}\text{n}\text{) ? 3}$, where $\text{s}\text{(}\text{n}\text{)}$ is the extended sum of digits of n. These results are based on analogous results for ?(n) and on the following two inequalities: |n| ? 2^d?1F_f+3 < 2^k?b and $\text{f + b}\text{?}\text{log}\text{s}\text{(n)}$ for a chain of length k = d + f + b with d doublings, f short steps, and b back steps for n. Moreover, we show that the difference $\text{?(}\text{n}\text{)?}\text{?}\text{(}\text{n}\text{)}$ (respectively $\text{?}\text{(}\text{n}\text{)??}\text{log n}\text{?}$) can be made arbbitrarily large. In addition, we prove that $\text{?}\text{(}\text{m}\text{) ?}\text{?}\text{(?}\text{m}\text{) ?}\text{?}\text{(}\text{m}\text{) + 1}\text{for m}\text{> 0}$ and characterize the case $\text{?}\text{(?}\text{m}\text{) =}\text{?}\text{(}\text{m}\text{)}$. Finally, we determine $\text{?}{}_{\mathrm{<mtext>k</mtext>}}\text{(}\text{n}{}_1\text{,…,}\text{n}{}_{\mathrm{k}}\text{)}$, the k-dimensional generalization of $\text{?}$, with the help of $\text{?}\text{(}\text{n}{}_1\text{,…,}\text{n}{}_{\mathrm{k}}\text{)}$, the k-element generalization of $\text{?}$.     

Theoretical solutions of stopping power in cylindrical many-electron systems

Using several kinds of mathematical formulae of the modified Bessel function, and taking into account the uncertainty principle at mathematically singular point for inelastic interactions between a projectile and electron, we develop the theory of stopping power for cylindrical many-electron systems. Addition theorem, the formula of Wronskian and integral formulae of the modified Bessel function perform important roles in solving complex integral equation of stopping power discussed here. For a cylindrical free electron gas, we derive the theoretical solution of stopping power analytically. We also show the equipartion rule of contributions due to surface plasmon mode to stopping power for random systems.     

对多层住宅加装电梯时结构加固技术的探讨

随着我国经济的飞速发展,人民生活水平的不断提高,人们对住宅的人性化需求也越来越高。在城市用地越来越小的当下,改造既有结构建筑,满足人们的现代化生活成了当务之急。随着城市的老龄化,大量居住于多层住宅的老人出行成了城市生活的一大问题,本论文举例分析了多层住宅改造及加装电梯的重要性,探讨了建筑结构在加装电梯时改造的技术。     

乙硫氮作捕收剂时有机调整剂加药顺序对典型硫化矿物浮选的影响

研究了乙硫氮作为捕收剂时有机大分子调整剂糊精、腐殖酸钠、阳离子瓜尔胶和DP115(改性聚丙烯酰胺有机大分子)不同加药顺序对典型硫化矿物黄铜矿、方铅矿、闪锌矿和黄铁矿浮选行为的影响。单矿物浮选试验结果表明,有机大分子调整剂与捕收剂乙硫氮的加药顺序对硫化矿物浮选的影响不同。与调整剂先加相比,乙硫氮先加时,糊精对黄铜矿、方铅矿和闪锌矿浮选的抑制作用更强;腐殖酸钠对黄铜矿和方铅矿浮选的抑制作用不同程度增强,腐殖酸钠用量较低时对闪锌矿浮选的抑制作用减弱,而用量较高时则强烈抑制闪锌矿;阳离子瓜尔胶对黄铜矿和方铅矿浮选的抑制作用减弱,对闪锌矿浮选的抑制作用略强;DP115对黄铜矿浮选的抑制作用减弱,DP115用量低时对方铅矿浮选的抑制作用相当而对闪锌矿浮选的抑制作用减弱,用量较高时对方铅矿浮选的抑制作用更强而对闪锌矿浮选的抑制作用相当;糊精、腐殖酸钠、阳离子瓜尔胶和DP115对黄铁矿浮选的影响很小。研究结果可为部分硫化矿通过改变有机大分子调整剂与捕收剂的加药顺序提高矿物浮选分离的选择性和效率提供借鉴。     

线路转移法制造印制电路板

印制电路板的发展已有半个多世纪,如果没有印制电路板,今天的电子信息产品,不知是个什么样子.但印制电路板生产的经典工艺就是腐蚀覆铜层压板,这就是"减法",它存在不少缺点.虽然一直有人想用另一种方法来取代它,也就是"加法",但也一直不理想.近年,笔者试验成功了一种不同于以往"加法"的新型"加法",这就是"线路转移法"并对其进行了全面的介绍.     

稀土添加剂在上引铸造无氧铜杆工艺中的应用

简述了稀土添加剂在上引铸造无氧铜杆中的工艺试验,讨论了稀土添加剂在上引无氧铜杆中的作用及其应用效果。     

保健食品安全风险点研究

目的掌握市售保健食品的安全风险点,为监管提供技术支撑。方法对2014-2015年国家和省、市相关部门市场抽样的保健食品按照产品质量标准检验,对易非法添加的5类保健食品和假冒保健食品按照国家相关补充检验方法对非法添加物质进行检测,对可能存在食品安全的因素进行风险监测、检验与评估。结果1041批保健食品中不合格61批,合格率为94.1%。在不合格的保健食品中,功效成分/标志性成分不合格频次为36.1%,是保健食品不合格的首要因素。总黄酮、总皂苷、粗多糖、氨基酸总量和蛋白质不合格机率较高;理化指标不合格是保健食品不合格的第二大原因,不合格频次为24.6%,其中水分、灰分、铅等参数不合格的情况较常见,非法添加的不合格率为21.3%;假冒保健食品非法添加形势严峻,在101批额外检品中,检出非法添加83批,非法添加率高达82.2%,主要添加西地那非、西布曲明等。结论湖南省保健食品抽检合格率较高,风险点主要为非法添加和保健食品原材料控制不严,标准研究能力有待提升,对假冒保健食品和非法添加的打击力度有待进一步加强,法规有待进一步完善。