Effect of Sintering Temperature and Zinc Content on Some Properties of Li-Zn Ferrites

Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, densification, microstructure and a.c. electrical conductivity have been studied. Under the effect of changing the firing temperature and Zn content, high sintered Li-Zn ferrite bodies are achieved. More fine structure bodies having high electrical resistance are obtained at high Zn content

叶面喷施锌肥对小豆产量及籽粒锌含量的影响

为促进黑龙江省小豆产业提质增效,以龙红豆4号和冀红352为试验材料,分别于2022和2023年进行硫酸锌施用浓度和施用次数效果试验。2022年,设置5个ZnSO4浓度(质量百分数为0%,0.1%,0.2%,0.3%和0.4%),在结荚期进行叶面喷施处理,研究其对小豆产量因子及籽粒锌含量的影响,并筛选出最佳施用浓度(0.3%)。2023年,在结荚初期、结荚中期、结荚初期+结荚中期,进行叶面喷施0.3%的ZnSO4筛选出最佳喷施次数。2年研究结果表明,喷施外源ZnSO4可提高小豆单株有效荚数、单株粒重和百粒重。喷施0.3%的硫酸锌最为适宜,能有效提高小豆百粒重和籽粒锌含量,分别较CK提高6.68%~9.97%和16.17%~25.33%;在结荚初期+结荚中期叶面喷施2次浓度为0.3%的外源ZnSO4可显著提高小豆籽粒锌含量,龙红豆4号和冀红352较对照分别提高33.33%和48.16%,喷施2次与喷施1次相比,显著提高了冀红352的单株产量。

内蒙古某含碳高硫锌锡矿石选矿试验研究

内蒙古某含碳高硫锌锡矿石锌品位1.02%、锡品位0.86%,硫和碳含量分别为14.02%、1.68%。矿石矿物组成较复杂,主要有用矿物为闪锌矿、锡石和黄铁矿,脉石矿物主要为石英、绿泥石和绢云母等。为确定矿石合理的开发利用工艺,采用预先脱碳—浮重联合工艺流程开展选矿试验研究。结果表明,矿石经预先脱碳、1粗1扫1精锌硫混选、1粗1扫3精锌硫分离浮选流程处理,闭路试验可得到Zn品位为45.16%、Zn回收率为71.19%的锌精矿,S品位为46.92%、S回收率81.91%的硫精矿;浮选尾矿采用摇床重选,经粗选、精选、复选和中矿再选,可获得Sn品位45.52%、Sn回收率81.99%的锡精矿,以及Sn品位3.13%、Sn回收率11.09%的锡中矿。所设计试验流程较好地解决了矿石中有机碳对浮选的不利影响,综合回收了有价矿物,可为同类矿石的开发利用提供理论借鉴。

火焰原子吸收光谱测定葡萄糖酸锌口服液中锌含量

“火焰原子吸收光谱”是本科生仪器分析实验教学中的重要实验之一。原子吸收光谱用于实际样品中某一特定元素的定量测定,具有测定准确度高、精密度高和选择性好等优点。葡萄糖酸锌口服液是生活中常见的口服补锌类非处方药,通过本科生自主实验,建立火焰原子吸收实验方法,测定葡萄糖酸锌口服液中锌含量,方法简便、易于操作。通过该自主实验,培养学生利用课堂所学理论知识解决实际问题的能力,实现“学以致用,用以促学”的育人目标。

络合滴定法测定复方乳酸依沙吖啶软膏中氧化锌的含量

目的:建立复方乳酸依沙吖啶软膏中氧化锌含量的测定方法。方法:采用络合滴定法对同一批次复方乳酸依沙吖啶软膏供试品进行氧化锌含量测定,对其专属性、线性范围、精密度、准确度实验结果进行数据分析,以判断方法的适用性。结果:本实验方法专属性良好,氧化锌在6.0~56.5 mg质量范围内线性关系良好,线性方程Y=0.245196X+0.050564(r=0.9994);氧化锌检出限为0.13 mg,定量限为0.43 mg;精密度实验氧化锌重复性实验相对标准偏差(RSD)为1.5%(n=6),氧化锌中间精密度RSD为1.3%(n=12);所有加标水平氧化锌平均回收率为100.3%(RSD=2.7%)。结论:该方法简单、快速,测定结果均符合《中华人民共和国药典》2020年版四部通则9101要求,适用于复方乳酸依沙吖啶软膏中氧化锌的含量测定。

兼顾江汉平原水稻产量和品质提高的优化施锌量研究

在大田条件下,以4个水稻品种(立香85、象牙香占、合两优927、昌两优8号)为试验材料,通过基施锌肥研究不同施锌量[0 kg/hm^(2)(CK)、7.5 kg/hm^(2)(Zn1)、15 kg/hm^(2)(Zn2)、30 kg/hm^(2)(Zn3)]下水稻产量、品质的变化,为江汉平原优质稻锌肥施用提供理论依据。结果表明,施锌可以显著提高水稻产量,且水稻产量随着施锌量的增加呈先上升后降低的趋势,总体上以Zn2处理最高,Zn1处理次之。立香85、合两优927、昌两优8号以Zn2处理产量最高;象牙香占以Zn1处理产量最高,Zn2处理次之。施锌处理产量较CK增加了8.1%~28.8%。施锌对稻米加工品质有明显的改善作用,整体以Zn1和Zn2处理下糙米率、精米率、整精米率较高。不同施锌处理下直链淀粉含量因品种而异,其中,立香85以Zn1处理最高,昌两优8号以Zn2处理最高,象牙香占和合两优927以Zn3处理最高。对于淀粉RVA谱特征值,立香85、象牙香占、昌两优8号均以Zn1处理崩解值最高;消减值表现为立香85和合两优927在CK下最低,象牙香占和昌两优8号在Zn1处理下最低。各品种粗蛋白含量随施锌量的增加呈先升高后降低的趋势,其中,立香85、合两优927均以Zn1处理粗蛋白含量最高,象牙香占和昌两优8号均以Zn2处理粗蛋白含量最高。总体上,清蛋白、球蛋白和醇溶蛋白含量均以Zn2处理最高,谷蛋白含量以Zn1处理最高。糙米、精米锌含量也随着施锌量的增加呈现先增加后降低的趋势。其中,立香85、合两优927均以Zn1处理糙米锌含量最高,分别为23.1、19.8 mg/kg;象牙香占和昌两优8号均以Zn2处理最高,分别为20.0、17.7mg/kg。各品种糙米锌含量均大于精米锌含量。综合水稻产量、品质等多方面因素来看,江汉平原施锌处理以Zn1—Zn2为优,施锌量为7.5~15 kg/hm^(2)。

蓖麻油酸锌中锌含量测定方法的研究

如今,蓖麻油酸锌作为一种高效环保的新型除臭材料而被广泛应用,其中锌含量的高低会直接影响蓖麻油酸锌的除臭效果。然而,蓖麻油酸锌中锌含量的测定还没有国家标准,相关的文献报道以及实验研究也较少。为此,开展铬黑T指示剂EDTA络合滴定法、二甲酚橙指示剂EDTA络合滴定法以及火焰原子吸收光谱法测定蓖麻油酸锌中锌含量的对比研究实验,并分析EDTA络合滴定法测定蓖麻油酸锌中锌含量的关键影响因素。研究结果表明,两种EDTA络合滴定法与火焰原子吸收光谱法的测定结果较为相近,方法的准确度及适用性都较好,但火焰原子吸收光谱法不适用于大规模生产样品的分析,两种EDTA络合滴定法操作简便快捷且经济,更能满足实际检测需求。

汉中市土壤有效锌的含量分布及影响因素分析

针对汉中市农业生产中存在施肥措施不当,致使部分地方土壤微量元素养分供给能力失衡,限制了水稻、玉米等粮食作物产量的提升等问题。本研究在汉中市11个县区共采集土壤样品6142个,采用DTPA浸提-原子吸收分光光度计测定法统计分析了土壤有效锌的含量和分布。结果表明:汉中市土壤有效锌含量主要分布在0.51~1.0 mg/kg和1.01~1.5 mg/kg这2个区间,占总量的34.80%和30.80%,而有效锌含量低于1.5 mg/kg的土壤样品占总量的78.3%,即汉中市78.3%的土壤有效锌含量处于中等水平以下,47.4%的土壤有效锌含量处于低和很低的水平。水稻、玉米产区土壤有效锌平均含量为1.11 mg/kg,其中水稻耕作区为1.15 mg/kg,玉米耕作区为1.07 mg/kg。水稻耕作区土壤有效锌含量高于玉米耕作区,略高于平均值。土壤中有效锌含量与土壤pH、土壤有机质含量及土壤有效磷含量都呈现负相关。综上所述,汉中市耕作土壤有效锌总体能够满足作物生长的需求,但在部分缺锌地区,建议加强锌肥、有机肥的施用,减少土壤缺锌对作物的影响。

高分散性活性剂SA-800在胎面胶中的应用

研究高分散性活性剂SA-800(简称SA-800)等氧化锌含量(简称等锌)或减氧化锌含量(简称减锌)替代普通氧化锌在胎面胶中的应用。结果表明:SA-800等锌替代普通氧化锌时,胎面胶的焦烧时间和正硫化时间延长,加工安全性好,其他性能基本相当,可在丁苯橡胶/顺丁橡胶/白炭黑胎面胶和天然橡胶/炭黑胎面胶中替代普通氧化锌;SA-800减锌替代普通氧化锌时,胎面胶的焦烧时间和正硫化时间与等锌替代时相比略有缩短,仍长于普通氧化锌胎面胶,其他性能变化不大,且与普通氧化锌胎面胶基本相当。使用SA-800可实现锌减量的目的。

低锌高炉灰选锌与铁炭分离可行性研究

为提高唐山某低锌高炉灰的综合利用率,达到入窑锌粉锌品位6%左右的要求,进行了旋流器分级分选+螺旋分选机分选试验。试验结果表明:①锌品位1.75%的高炉灰经1粗1精两段旋流器分级分选,最终可获得锌品位分别为5.96%、6.27%,锌回收率分别为47.10%和44.21%的锌粉。②对产率15%左右的二段旋流器底流采用螺旋分选机分离铁、炭,螺旋分选机内圈产品铁品位分别为47.76%、48.98%,可作为低品位铁产品,或并入底流1一并开展后续选铁试验;螺旋分选机中圈和外圈产品铁品位在34%左右,热量值在2500 cal/kg左右,铁品位和热量均不高,且粒度较细,处理难度大,没有再处理或作为单独产品的意义。研究确定了较理想的锌回收工艺,可作为开发利用依据。

高锌含量铅锌氧化渣直接还原试验研究

铅锌氧化渣熔融还原是得到金属铅和锌的重要步骤,但氧化渣中锌含量升高和铅含量降低会导致熔化温度增加,使得还原工艺条件发生较大变化。本文对高锌含量铅锌渣(Zn≈25%)的还原工艺条件和渣型制度进行了研究,主要考察了还原煤量、还原温度、还原时间、Fe/SiO_(2)、CaO/SiO_(2)对铅锌氧化渣中Pb、Zn、Cu回收率的影响。试验结果表明,铅锌渣Pb、Zn、Cu金属回收率随着还原煤量、还原温度、还原时间的增加而增加,但过高的煤比和还原温度不利于Pb、Cu回收率的提高;铅锌渣Pb、Zn、Cu金属回收率随着Fe/SiO_(2)和CaO/SiO_(2)的增加而增加,但Fe/SiO_(2)增加至0.78,CaO/SiO_(2)增加至0.8时,继续增加Fe/SiO_(2)和CaO/SiO_(2)将降低Pb、Zn、Cu金属回收率。试验用铅锌渣的适宜还原条件为煤比1.2~1.4、还原温度1623~1673 K、还原时间90~120 min、Fe/SiO_(2)=0.78~1.17,CaO/SiO_(2)=0.5~0.8。在上述工艺条件下,铅锌氧化渣中Pb、Zn、Cu回收率分别可达84.01%、94.51%、85.8%以上。

基于长短期记忆神经网络的反应液葡萄糖含量预测

目的建立皮尔逊相关系数(Pearson correlation coefficient,PCC)和长短期记忆(long short term memory,LSTM)神经网络的反应液葡萄糖含量预测模型用以实时预测葡萄糖酸锌生产过程中反应液葡萄糖含量。方法通过葡萄糖酸锌制备实验,结合PCC理论确定对反应液葡萄糖含量有较大影响的因素,对这些因素进行数据采集并将其作为神经网络的输入变量,采集反应液葡萄糖含量数据并进行处理,将其作为神经网络的输出变量,进而建立反向传播神经网络(backpropagation neural network,BP)和LSTM神经网络的反应液葡萄糖含量预测模型。结果通过100次模型迭代训练,对照BP反应液葡萄糖含量预测模型可以看出LSTM反应液葡萄糖含量预测模型在测试集的误差约为0.45%,误差较小,准确度较高。结论基于LSTM反应液葡萄糖含量预测模型显著提高了预测精度,相比现有检测方法更加智能高效,能够有效辅助生产进行。

某复杂铅锌矿锌精矿降碳试验研究

针对某复杂铅锌矿选矿所得锌精矿含碳量高的问题,进行了锌精矿降碳试验。采用可溶性淀粉为碳抑制剂,闭路试验获得了锌品位48.71%、含碳0.86%、锌回收率90.28%的锌精矿;与原工艺指标相比,在提高锌精矿品位及回收率的同时,碳含量降至1%以下,降碳效果显著。

Mo含量对自熔性铁基合金组织性能的影响

为提高镀铝锌板生产机组316L沉没辊的耐高温磨损–腐蚀性能,采用激光熔覆技术在316L基体表面制备Fe60涂层和4种含Mo(质量分数为2.5%,5.0%,7.5%,10.0%)的Fe60复合涂层,对不同涂层的物相、微观组织、力学性能、摩擦性能和腐蚀性能进行表征,探究Mo含量对Fe60涂层组织和性能的影响。结果表明:含Mo涂层析出硬质相Fe_(9.7)Mo_(0.3),Mo对Fe60涂层晶粒度和组织缺陷均有影响,随Mo含量的增加,涂层晶粒度和组织缺陷数均先减后增,w(Mo)=5.0%涂层晶粒度最小、组织无缺陷;与Fe60涂层相比,含Mo涂层硬度降低,而耐磨性均有提升,随Mo含量的增加,涂层耐磨性能先增后减,w(Mo)=5.0%涂层磨损失重最低;与Fe60涂层相比,含Mo涂层耐高温铝锌液腐蚀性能均有提升,随Mo含量的增加,涂层腐蚀速率下降,但Mo质量分数超过5%时,涂层腐蚀面存在局部断裂,实际耐腐蚀性能下降。

Effects of Different Nitrogen Fertilizer Levels and Native Soil Properties on Rice Grain Fe, Zn and Protein Contents

Deposition of protein and metal ions （Fe, Zn） in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron （Fe） and zinc （Zn） contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content （GPC） increased significantly （1.1% to 7.0%） under higher nitrogen fertilizer application （120 kg/hm2） whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value （pH 6.83） and higher organic matter content than the other two locations （Locations I and II）, indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 （27.62 μg/g grain Zn content and 7.80% GPC） and R1033-968-2-1 （30.05 μg/g grain Zn content and 8.47% GPC） were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.

高效液相色谱法测定复方鱼肝油氧化锌软膏中维生素A含量

目的建立测定复方氧化锌鱼肝油软膏中维生素A含量的高效液相色谱法。方法采用正己烷提取样品中的维生素A,色谱柱为Waters silica柱(250 mm×4.6 mm,5μm),流动相为正己烷-异丙醇(997∶3,V/V),流速为1.0 mL/min,检测波长为325 nm,柱温为30℃,进样量为10μL。结果维生素A醋酸酯的活性单位浓度在1.43~28.60 IU/mL范围内与峰面积线性关系良好(r=0.9999,n=5);检测限为30μg/g,定量限为100μg/g;精密度、稳定性、重复性试验结果的RSD均小于3.0%;加样回收率为95.76%,RSD为3.58%(n=6)。3批样品中维生素A的含量分别为760.34,794.62,747.67 IU/g。结论该方法操作简便、重复性好、结果准确,可用于复方氧化锌鱼肝油软膏中维生素A的含量测定。

Reduced nitrogen availability during growth improves quality in red oak lettuce leaves by minimizing nitrate content, and increasing antioxidant capacity and leaf mineral content

Overuse of N in lettuce production can lead to environmental problems caused by leaching and the accumulation of harmful nitrates in edible tissues. This study investigated the effect of applied nitrogen (N) concentrations between 40 and 2400 mg·L–1 on growth, nitrate accumulation, mineral leaf content, and antioxidant capacity in Oak Leaf lettuce cv. “Shiraz” grown under hydroponic conditions in Australia. Yield (g FW) increased with nitrogen (N) application rate up to 1200 mg·L–1, as did leaf N content, while C:N declined. Nitrogen Utilization Efficiency (NUtE) increased rapidly from 40 to 75 mg·L–1 applied N, leveling at 150 mg·L–1 with no subsequent effect of N concentrations between 400 and 2400 mg·L–1. Nitrate content rose significantly with increased N, particularly at 1200 and 2400 mg·L–1. Leaf total plant phenolic content (TPP) and antioxidant capacity (measured by ferric reducing antioxidant power—FRAP) were both maximal at 75 and 400 mg·L–1 applied N, while highest oxygen radical absorption capacity (ORAC) values were found in leaves supplied with low N (40 to 400 mg·L–1). Applied N as calcium nitrate also significantly affected leaf mineral content as B, Mg, Mn, and Zn significantly decreased with increasing N. These results indicate that N applications of 1200 mg·L–1 or higher can result in reduced antioxidant capacity and mineral content in lettuce leaves.

Impact of Different Zinc Application Methods on Yield and Yield Components of Various Wheat (<i>Triticum aestivum</i>L.) Cultivars

To evaluate the impact of different zinc application methods on yield and yield components of various wheat cultivars, a field experiment was carried out at Student’s Farm, Department of Agronomy, University of Agriculture Faisalabad, during winter 2014-2015. The experiment was laid out in RCBD (Randomized Complete Block Design) with factorial arrangement. In this experiment, all the treatments were replicated three times, using the net plot size of 1.8 m × 5.0 m. The experiment comprised of two factors. Factor A consists of two varieties: Faisalabad-2008 and Punjab-2011. While, Factor B consists of different methods of zinc application, control, zinc application in soil before planting 23 kg·ha-1, zinc foliar application, 4% ZnSO4 solution at two stages (tillering and stem elongation stage). The data regarding different parameters were collected and analyzed from the crop using standard procedures. Regarding the impact of zinc application method maximum plant height at maturity (103.6 cm), total number of tillers (564.67 m-2), spike length (10.83 cm), number of spikelets spike-1 (19.50), number of grains spike-1 (50.36), 1000-grain weight (34.16 g), biological yield (11.93 t·ha-1), grain yield (6.00 t·ha-1) and harvest index (39.25%) were recorded in treatment where zinc was applied both in the soil before planting and by foliar application on later growth stages. Similarly, grain zinc contents (33.11 mg·kg-1), grain protein contents (10.1%) and grain carbohydrate contents (64.23%) were also observed in the treatment where zinc was applied both in the soil before planting and by foliar application on later growth stages, which is better than all other treatments. In case of wheat varieties, Faisalabad-2008 performed better than Punjab-2011, with maximum method maximum total number of tillers (460.67 m-2), spike length (9.70 cm), number of grains spike-1 (48.80), 1000-grain weight (33.81 g), biological yield (10.32 t·ha-1), grain yield (5.0 t·ha-1) and harvest index (33.93%). It is concluded that sowing of wheat cultivar Faisalabad-2008 + application of zinc in soil before planting with foliar application at later stages (tillering and stem elongation stage) of wheat could give better results in terms of yield.

区域土壤锌空间分布的异质性及制约因素分析

了解区域土壤锌(Zn)元素的地球化学特征及其空间分布的区域性特点对土壤生态环境管理具有重要的指导意义。通过查阅目前相关文献的研究成果,对我国西南地区土壤Zn的含量水平、空间分布的异质性及制约因素进行了分析及归纳总结。结果表明:不同地质年代的地层及岩性组合变化是制约区域土壤Zn含量水平及空间异质性的自然因素,碳酸盐岩发育的微碱性土壤Zn含量明显高于碎屑岩发育的酸性土壤,不同地层中碳酸盐岩与碎屑岩分布的占比大小是导致区域土壤Zn空间分布异质性的主要原因。此外,矿产资源开发及加工利用是制约区域土壤Zn含量水平及空间异质性的人为因素,铅锌矿区及冶炼区土壤Zn存在明显的污染风险。区域土壤Zn元素分布存在明显的空间异质性,根据土壤Zn含量水平可划分为低锌区(1~50 mg/kg)、中锌区(50~80 mg/kg)、富锌区(80~200 mg/kg)、高锌区(>200 mg/kg);在高锌土壤区应加强土壤Zn污染的生态风险评估,富锌土壤区宜规划及发展成为富锌农产品的重要产区,而中低锌土壤区则要强化土壤Zn元素的养分管理及优化施肥技术。

土壤改良剂对富锌马铃薯品种云薯304贮藏品质的影响

以富锌马铃薯品种云薯304为试材,研究2种土壤改良剂(复合木霉菌和阿尔格)对云薯304货架期、薯片外观品质及营养品质的影响。结果表明,复合木霉菌处理可有效延长云薯304的货架期,改善并维持贮藏期间的薯片外观品质;2种土壤改良剂处理对云薯304贮藏前后营养成分含量影响不大,但贮藏103d后的锌含量较对照相比略有上升。