Study on precipitation of struvite and struvite-K crystal in goats during onset of urolithiasis

To learn more about the biomineralization process of struvite in ruminants, a seldom noticeable crystal, struvite-K, was investigated in six goats in which urolithiasis was induced by feeding a cottonseed meal and rice straw diet supplemented with MgO. The compositions of crystals and calculi were studied by chemical qualitative analysis and X-ray energy dispersive spectrometry (EDS). The activity product (AP) and relative supersaturation (RSS) of magnesium ammonium phosphate (MAP) and potassium magnesium phosphate (MKP) were calculated to compare the difference of crystals formed in this process. The results showed that calculi consisted of MAP with a little MKP. Crystals in the urine consisted of MAP and MKP before stone formation, but crystals in urine after stone formation mainly consisted of MKP. The AP and RSS of MAP and MKP significantly decreased after stone formation. It was concluded that MAP and MKP may coexist in the crystals of urine before struvite calculi formation but MKP did not precipitate to struvite calculi and was separated out as crystal sedimentation of urine. The changes of crystallization of MAP and MKP contributed partially to the supersaturation status of MAP and MKP during struvite stone formation.     

磷酸胍盐的合成

用碳酸胍和磷酸在水溶液中反应,控制溶液的pH值,可分别获得磷酸一胍和磷酸二胍。经胍含量测定,含N量和含P量分析及红外光谱测定,得知所制得产品纯度较高。     

Relationship Between pH Value of the Water and Release Silt Bottom of Nitrogen & Phosphate in the Three Gorges

By experimental study of release characteristics bottom silt of total nitrogen (TN) & total phosphate (TP) in the Three Gorges, the influence and cause of pH value to Three Gorges bottom silt TN & TP release are analyzed. pH values is between 3.98 to 11.05 the release capacity of TN & TP reaches maximal in 3 days and pH values is between 11.05 to 11.94 the release capacity of TN reaches maximal in the 3 days. While pH value between 11.05 to 11.94, the release capacity of TP reaches maximal in 1 days; If pH value is lowered, the maximal release capacity of TN is enhanced: The maximal release capacity of TP basically has no changes on the condition of pH values between 3.98 and 10.07, but its maximal release capacity rises extremely obvious if pH value is between 10.07 to 11.05. At the same time, the existence of latent danger of the Three Gorges bottom silt TN & TP to water quality is explained, and the basis of eutrophication treatment in the aspects control of N & P nutrients for theThree Gorges is supplied.     

Study on Adsorption of Suspended Sediments to Phosphate in the Three Gorges Reservoir Area

Suspended sediments play an important role in the transformation process of pollutants in rivers.The adsorption characteristic of suspended sediments in Three Gorges Reservoir Area to phosphate was studied in this paper.Based on the indoor adsorption balancing experiment and kinetic modeling experiment,the main factors for adsorption process of sediments(particle size of sediment,initial concentration etc.) were discussed.The major results of the experiment were as follows:(1) Three kinds of suspended sediments with different particle sizes were used for the study of adsorption characteristic with different sediment concentration.The amount of phosphate adsorption increased with the increase of the sediment concentration and sediment particle size.(2) With the help of Langmuir isotherm theory,the related parameters in kinetic model were estimated,the experiment results indicated that the adsorption isotherm of phosphate in Three Gorges Reservoir Area fitted with the fifth type of Langmuir adsorption isotherm,the maximum amount of phosphate adsorption would emerge when the phosphate concentration was relatively high,but it would move down when the phosphate concentration increased afterwards.(3) Phosphate adsorption increased with the increase of initial phosphate concentration,the average time for adsorption balance was 2-4 hours.     

Effects of papaverine on carbachol- and high K+-induced contraction in the bovine abomasum

The effects of papaverine on carbachol (CCh) -and high K⁺- induced contraction in the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM) -and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin or sodium nitroprusside inhibited CCh-induced contractions in a concentration-dependent manner in association with increases in the cAMP or cGMP contents, whereas papaverine increased cGMP contents only at 30 µM. Changes in the extracellular Ca²⁺ from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high K⁺-depolarized muscles, but papaverine-induced relaxation did not change. Futhermore, papaverine (30 µM) and NaCN (300 µM) decreased the creatine phosphate contents. These results suggest that the relaxing effects of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy metabolism.     

绿洲区滴灌条件下施磷对紫花苜蓿生产性能及品质的影响

为提高滴灌条件下紫花苜蓿的生产性能及营养品质,对北疆绿洲区滴灌条件下两个品种紫花苜蓿开展施磷的研究。设置一次性施180 kg／hm2磷肥（L1）、一次性施360 kg／hm2磷肥（H 1）、分次施180 kg／hm2磷肥（L2）、分次施360 kg／hm2磷肥（H2）及不施肥（CK）5个处理,通过对其生产性能和营养品质进行测定。结果表明,不同施磷模式对新牧2号第1茬干草产量、生长速度、叶茎比及第3茬株高有显著影响（P ＜0．05）,对三得利第3茬干草产量、生长速度有显著影响（P ＜0．05）,对其余各生产性能相关指标均无显著影响（P ＞0．05）。不同施磷模式对新牧2号各茬次粗蛋白、粗纤维及第1茬粗灰分有显著影响（P ＜0．05）,对三得利第1,3茬粗灰分有显著影响（P ＜0．05）,对其余各营养品质相关指标均无显著影响（P ＞0．05）。采取模糊相似优先比分析法综合生产性能及品质的各项指标,得到新牧2号和三得利的最佳施磷模式,按优劣排序为 H 1＞L1＞H2＞L2＞CK。     

玉米施用氮磷化肥的后效研究

通过两年盆栽和4年的定位试验,研究了氮磷化肥施用后的残留后效。结果表明,合理施用氮磷化肥具有明显的后效,不但促进了翌年玉米植株的营养生长并提高了单产,而且增加了土壤速效氮和速效磷的含量,培肥了地力。