Encapsulated sodium supplementation of 4 weeks does not alter salt taste preferences in a controlled low sodium and low potassium diet

Preference for saltiness is learned by oral exposure to salt taste; however, some data suggest a role for bodily sodium and potassium levels on salt taste preferences as well. The objective was to investigate whether encapsulated sodium and potassium supplementation lead to altered salt taste responses among adults with high blood pressure on a low sodium and low potassium diet. Twenty-six participants with untreated upper-range prehypertension or stage 1 hypertension were on a fully controlled low sodium and low potassium diet (both targeted at 2 g/day) for 13 weeks. Participants received capsules with sodium (3 g/d), potassium (3 g/d), or placebo, for 4 weeks each, in randomized order in a double blind crossover design. Sensory evaluation was done before and after each supplementation period and involved ratings of pleasantness and intensity in different salt (NaCl) concentrations in food and water, desire-to-eat salty food, and detection threshold for NaCl. Neither sodium supplementation nor potassium supplementation led to alterations in salt taste responses in food and water, and did not affect detection threshold (P = 0.59). There was no clear role for sodium or potassium supplementation on desire-to-eat salty food. In addition, we did not find effects of reduced oral exposure to salt over weeks, through the sodium-reduced diet, on salt taste preferences, in contrast to earlier studies. In conclusion, the results of this study suggest preference for saltiness is independent of changes in bodily sodium or potassium levels.     

玉米生产施用锰渣混配肥的肥效试验

电解金属锰渣含有丰富的矿物质营养元素,将其处理加工成锰渣混配肥,在农作物生产中应用能促进作物的生长和提高产量,是可以开发的新型肥料资源.     

氰酸钾合成研究进展

综述了氰酸钾的合成方法,并对各种方法进行了评价,其中液固相反应法具有原料易得,操作简便,产物纯度较高、易与溶剂分离、经济性好等特点,适用于工业化生产。     

云南磷肥工业副产氟资源综合利用途径初探

根据云南磷肥工业发展情况 ,提出对磷肥工业副产氟资源综合利用的设想 ,并介绍目前国内已有的一些氟资源综合利用的工艺技术     

无机复合微量元素肥料（FTE）的合成及其应用效果研究

重点研究了无机复合微肥（简称ＦＥＴ）的合成条件及生成规律，并详细探讨了组成、工艺对ＦＴＥ微肥的主要技术指标——枸溶性的影响。同时，介绍了粮、棉、果、菜等各类农作物施用ＦＴＥ后取得的显著效果，为ＦＥＴ在作物上大面积推广应用提供了理论和实践依据。     

云南省磷肥工业产品结构的现状及发展建议

分析了国内外磷肥工业产品的市场形势及发展趋势，同时对云南省磷肥产品的发展提出建议。     

硫酸钙氨法制取硫酸钾新工艺的实验研究

利用K2 +2 ,Ca2 +/ /SO2 -4 ,Cl2 -2 ,NH3—H2 O混合体系相图作为工艺指导 ,进行硫酸钙制取硫酸钾工艺的相图研究和分析 ,确定实验优选因素及水平并进行正交实验 ,根据实验结果进行极差分析 ,得出新的结论。合适的工艺条件为 :氨浓度为 40 % ,配料比n( 2KCl) :n(CaSO4 ·2H2 O)为 1:1,反应温度为 5℃ ,反应时间为 1h。     

合成氨催化剂的生产和技术

介绍了世界合成氨催化剂发展历程、新开发的合成氨催化剂种类 ,同时评述了我国化肥催化剂研发和生产近况 ,对我国化肥催化剂性能进行了评价。     

Photochemical reduction of molecular weight and number of double bonds in natural rubber film

Natural rubber (NR) can be degraded depending on various factors such as heat, mechanical force, chemical reaction, and light. Light is a very interesting factor because it can cause the NR to degrade under low temperature and pressure. The photo-degradation of NR films was carried out to investigate the effects of the light and the temperature on the reduction of the weight-average molecular weight (Mw) and the double bonds in the NR films. The NR films, with and without catalysts, titanium dioxide (TiO₂), and potassium persulfate (K₂S₂O₈), were exposed to light from a mercury light bulb at 7,000 and 36,000 lux, and at the temperature of 25 °C and 80 °C for 192 hrs. After exposure, the Mw of the NR films was analyzed by gel permeation chromatography (GPC). Changes in the Mw were used to construct a kinetic model for the process, (1/Mw)=(1/Mw₀)+(kt/2M₀) where k is the rate constant, and M₀ is the Mw of the monomer unit. The linear relationship between 1/Mw and time suggested pseudo first-order processes with random scission. The Mw distribution information from the GPC was used to calculate the number of double bonds in the NR films. The trend of the double bonds reduction curves was quite similar to the result obtained from the calculation from the FTIR spectra. This indicated that this calculation method might possibly be another alternative way to obtain the number of double bonds in the NR.