Role of ammonium sulfate in sulfurization flotation of azurite: Inhibiting the formation of copper sulfide colloid and its mechanismOA

In this study, the role of(NH₄)₂SO₄ during the sulfurization of azurite and its response to flotation were investigated. The flotation results showed that adding(NH₄)₂SO₄ prior to sulfurization decreased the formation of colloid in flotation pulp, and the floatability of the suppressed azurite caused by excess sodium sulfide was restored. After adding(NH₄)₂SO₄ prior to sulfurization, the formation ...     

遂昌萤石矿的工艺矿物学及其浮选性能

为了高效利用浙江遂昌萤石矿资源,基于工艺矿物学对浮选性能研究的重要性,研究了矿石的主要化学成分、矿物组成及嵌布特征,并探讨了矿物的浮选行为.结果表明,遂昌矿区横坑坪矿和坑口矿两种矿石的结构类型基本一致,脉石矿物主要为石英,其次为长石、绢云母、方解石、高岭石等.两种矿石的主要区别在于,横坑坪矿样中方解石含量较高,达5.4%,且嵌布关系较为复杂.方解石与萤石的可浮性相近,直接导致横坑坪矿样的选别难度相对较大.浮选试验结果与矿石工艺矿物学研究结果一致.     

Growth units model of anion coordination-polyhedra and its application to crystal growth

A crystal will exhibit various morphologies in different growth systems. This is known as the crystallization habit. Until now, most theories of crystal growth cannot guide optimization of the process of crystal growth well, because those theories deviate from and lose sight of the effect of external circumstance upon the process of crystal growth. For this reason, Zhong proposed the growth-units model of anion coordination-polyhedra in the early 1990s[1,2] to reduce the gap between the theory…     

Insights into the influence of temperature on the adsorption behavior of sodium oleate and its response to flotation of quartz

Temperature affects the flotation of quartz in the calcium/sodium oleate(NaOL)system,while there is a lack of understanding of its potential mechanism.Therefore...     

方铅矿磨矿体系表面电化学性质及其对浮选的影响

采用电化学测试技术研究方铅矿磨矿体系中磨矿介质类型（瓷介质和铁介质）、机械力以及捕收剂对方铅矿表面电化学性质的影响。研究结果表明：瓷介质中,方铅矿表面会发生适当的氧化反应,有利于方铅矿浮选：增大方铅矿与瓷介质间的机械力,体系的还原性增强,同时削弱矿物表面的氧化反应,给浮选造成一定影响。铁介质中,一方面,由于铁与方铅矿的腐蚀电偶作用增强了体系的还原性,降低了药剂在方铅矿表面的吸附性能,另一方面,由于腐蚀电偶作I用产生的铁离子增强了方铅矿表面的亲水性,两方面的影响都不利于方铅矿的浮选;增大方铅矿与铁介质间的机械力,二者之间的腐蚀电偶作用和体系的还原性增强,同样不利于方铅矿浮选。当pH=9时,在瓷介质和铁介质磨矿体系中是否添加捕收剂,对方铅矿表面电化学性质和浮选影响不大。     

SINGLE CRYSTAL GROWTH OF Cu BASED SHAPE MEMORYALLOYANDITSTHERMODYNAMICANALYSIS

ＳＩＮＧＬＥＣＲＹＳＴＡＬＧＲＯＷＴＨＯＦＣｕＢＡＳＥＤＳＨＡＰＥＭＥＭＯＲＹＡＬＬＯＹＡＮＤＩＴＳＴＨＥＲＭＯＤＹＮＡＭＩＣＡＮＡＬＹＳＩＳＳＩＮＧＬＥＣＲＹＳＴＡＬＧＲＯＷＴＨＯＦＣｕＢＡＳＥＤＳＨＡＰＥＭＥＭＯＲＹＡＬＬＯＹＡＮＤＩＴＳＴＨＥＲ...     

二苯乙二酮苯甲酰腙的合成、晶体结构及荧光性

由二苯乙二酮和苯甲酰肼通过缩合反应,合成新的酰腙化合物：二苯乙二酮苯甲酰腙.通过X射线单晶衍射和荧光光谱对该化合物进行晶体结构的表征.研究表明,该酰腙为三斜晶系,空间群为P-1,晶胞学数据：a=0.561 0（4）nm,α=99.868（9）,°b=1.028 5（8）nm,β=98.775（8）°,c=1.565 1（12）nm,=103.503（8）.°V=0.847 5（11）nm^3,Z=2,μ=0.087 mm^-1,Dc=1.350 mg/m^3,F（000）=364,R1=0.1461[I〉2sigma（I）],wR2=0.412 3（all data）.荧光光谱表明,该化合物的荧光性能较好,可以作为一种潜在的光活性材料.     

TN型液晶焚烧产物及其反应机理

在研究TN型液晶焚烧失重特征,分析其焚烧产物的基础上,探讨了TN型液晶焚烧反应机理.结果表明,TN型液晶焚烧过程易导致单体化合物苯甲酰基C-O键、与苯环侧链甲基相连烃基之间C-C键断裂,生成大量烃基、苯甲酰基等自由基团,该自由基团随温度升高进一步发生分解反应、合成反应及过程产物燃烧反应,这些过程主要发生在410 ℃以内.指出TN型液晶焚烧产物绝大多数是芳香族有机物,易对人体健康和环境造成威胁,TN型液晶显示器不宜混同生活垃圾一起焚烧,应单独回收处理.     

砷钼钨杂多酸根—结晶紫显色反应研究及应用

研究了砷钼钨杂多酸根与结晶紫的缔合显色反应．在硫酸介质及聚乙烯醇存在下,砷钼钨杂多酸根与结晶紫形成１∶２络合物,可直接用于水相测定钨,其选择性及灵敏度均好,且可消除钼的干扰．λｍａｘ和ε′分别为５６０ｎｍ和６．１×１０４Ｌ／（ｍｏｌ·ｃｍ）．钨含量在０～２μｇ／ｍＬ符合比耳定律．     

ZnO薄膜生长及声表面波性能研究

采用传统射频磁控溅射技术,通过引入Si O2缓冲层以及调节工作气压的方法,在Si衬底上制备具有高度(1120)择优取向的Zn O薄膜.采用X射线衍射技术和原子力显微镜分析Zn O薄膜的晶体特性和择优取向.研究发现,引入Si O2缓冲层能显著减小Zn O/Si O2/Si三层结构声表面波器件的温度延迟系数(temperature coefficient of delay,TCD),当Si O2缓冲层厚度为200 nm时,Zn O薄膜同时具有(0002)和(1120)择优取向,且TCD值仅为2×10-6℃-1左右,说明器件温度稳定性佳.当工作气压降低时,Zn O(1120)择优取向增强,相应的声表面波器件的机电耦合系数(K2)也增大.在大机电耦合系数和高温度稳定性的Zn O/Si O2/Si三层结构的基础上,有望制作出高性能的Love波声表面波生物传感器.     

ZnO纳米薄膜在竹材表面的生长及防护性能

在低温溶液反应体系下,通过晶种形成和晶体生长两步法在竹材表面培育ZnO纳米结构薄膜,应用场发射环境扫描电镜(FESEM)、X射线衍射仪(XRD)和X射线能谱仪(EDAX)对薄膜形态和结构进行表征,重点研究种子液浸渍时间对纳米薄膜形态及竹材防霉和抗光变色性能的影响.研究结果表明,在生长时间一定的前提下,竹材在种子液中经过0.5 h、1 h和2 h的浸渍,其表面可形成壁厚为50～80 nm的网状结构薄膜,使竹材的防霉性能和光稳定性得到显著改良;当种子液浸渍时间增加到4 h,网状结构薄膜则被大量直径约700 nm的ZnO圆片所覆盖,虽然此时竹材的防光变色性能保持不变,但防霉性能下降,表明纳米网状结构对于充分发挥ZnO防护性能起到重要作用.     

近30年色林错湖面变化特征及其对气候变化的响应

为了探讨气候变化对高原湖色林错湖面面积变化的影响,基于1988—2020年Landsat卫星遥感影像资料,用最大似然法提取色林错水体信息,采用线性回归及M-K检验法分析色林错湖面面积及其流域内温度、降水和积雪深度等气候因子变化特征,并用皮尔逊相关分析法探讨了湖面面积与气象因子之间的相关性.结果表明:近30年色林错湖面面积增加了650.70 km²,增长速率为203.34 km²／(10 a).色林错湖面扩张存在着明显的空间差异,湖面向南、向北扩展比较明显;色林错流域年平均气温及降水量呈显著上升趋势(p<0.05),而积雪深度呈显著下降的趋势(p<0.05),其中增温速率为0.50℃／(10 a),降水量增加速率为17.32 mm／(10 a),积雪深度递减率为0.65 cm／(10 a);色林错湖面面积的变化与该流域气温的升高以及冷季积雪深度的降低具有极显著相关性(p<0.001),气温升高使得色林错上游的冰雪融水增加是色林错湖面面积增大的主要原因.     

Ground response to high horizontal stresses during longwall retreat and its implications for longwall headgate support

Roof falls in longwall headgate can occur when weak roof and high horizontal stress are present. To prevent roof falls in the headgate under high horizontal stress, it is important to understand the ground response to high horizontal stress in the longwall headgate and the requirements for supplemental roof support. In this study, a longwall headgate under high horizontal stress was instrumented to monitor stress change in the pillars, deformations in the roof, and load in the cable bolts. The conditions in the headgate were monitored for about six months as the longwall face passed by the instrumented site.The roof behavior in the headgate near the face was carefully observed during longwall retreat.Numerical modeling was performed to correlate the modeling results with underground observation and instrumentation data and to quantify the effect of high horizontal stress on roof stability in the longwall headgate. This paper discusses roof support requirements in the longwall headgate under high horizontal stress in regard to the pattern of supplemental cable bolts and the critical locations where additional supplemental support is necessary.     

形状记忆合金的动力响应特性及振动控制

通过对形状记忆合金（ＳＭＡ）材料基本性能的试验研究，提出了ＳＭＡ的相变伪弹性恢复力模型，并以此为基础研究了ＳＭＡ减振控制系统的动力响应问题．模拟结果表明这种减振控制装置对较强烈的振动有更好的抑制作用，并且控制其温度即可使系统处于最佳工作状态．     

城市地表热环境季节变化及与下垫面特征关系

为进一步揭示城市地表热环境的时空分异机制,利用遥感信息技术提取深圳市西部地区不同季节的地表温度、植被覆盖、不透水面、水分状况等下垫面特征参数,在此基础上分析地表热环境的季节变化特征及与下垫面生物物理参数的定量关系.结果表明:研究区地表热力景观的空间分布、强度随季节发生显著变化;不透水面指数、湿度指数与地表温度分别呈指数正相关、线性负相关且在不同季节表现稳定,而植被指数与地表温度呈非线性关系并随季节变化;多元线性逐步回归分析表明,不透水面对地表温度的调节作用最大、地表湿度次之、植被覆盖最小.     

Lubricating behavior of iron rhenate and its relation to matching pairs

The iron rhenate was compounded by chemical method, which may be generated during wear process of Fe-Re alloys at elevated temperature. The friction coefficient of iron rhenate has been determined by a pin-on-disc device. The results show that iron rhenate plays role of lubricating at RT-600 °C. The lubricating behavior is related to the matching pairs. The hardness of the materials of matching pairs, compatibility of iron rhenate with materials of matching pairs and surface roughness of disc affect the lubricating behavior of iron rhenate mostly. The principle of matching pairs is proposed. Project supported by the National Natural Science Foundation of China Synopsis of the first author Xiong Dangsheng. associated professor, born in 1960. Current research fields include high-temperature self-lubricating alloys and tribological properties of material.     

Improved response surface method and its application in stability reliability degree analysis of tunnel surrounding rock

An approach of limit state equation for surrounding rock was put forward based on deformation criterion.A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward. The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function(PDF) of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not iterative circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method, whose workload is only 30% of classical method and its accuracy is comparative.     

同坡曲面的方程及其在弯斜路面边坡设计和绘图中的应用

对同坡曲面的形成作了分析,给出更为一般的同坡曲面的方程,特别对于目前建筑工程中的常用弯斜路面边坡,做了较深入的研究,找出了该曲面等高线的规律,给出了此曲面的方程和等高线方程,从而将过去的近似作图改为精确作图.为弯斜路面边坡的设计和计算机绘图提供了一种新方法.     

A General Procedure for Surface Modification of Nano-alumina and Its Application to Dendrimers

A general procedure for surface modification of nano-alumina using N, N＇-dicyclohexyl- carbodiimide （DCC） mediated amidation is reported. Aliphatic and aromatic carboxylic acids reacted smoothly with nano-alumina pretreated with 3-aminopropyltriethoxysilane in the presence of DCC, giving modified aluminas having organic surfaces. The grafted aluminas have been characterized qualitatively by FT-IR or ^13C CPMAS NMR spectroscopy, and quantitatively by thermogravimetric analysis and elemental analysis. The procedure was applied to polyether dendrons bearing carboxyl groups at the focal points, giving successful grafting of dendrimers onto nano-alumina.     

方舱及装舱电子设备在道路谱随机激励下的响应预测

基于线性系统平稳随机振动理论，该文预测了多自由度大型复杂方舱结构在道路谱激励下的响应，导出了结构在一种宽带位移谱激励下动力响应的解析积分表达式，该文预测的数值结果对某电子方舱的工程设计具有重要参考价值。