Influence of Wind Deviation Angle on n-Hexane Evaporation Loss of Internal Floating-Roof Tanks

With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a representative of light oil,the effects of the WDAs(wind deviation angles)on airflow distribution,the wind speed,the n-hexane vapor concentration,and the evaporation loss rate in the IFRT were investigated,and the mass transfer of the vapor-air was analyzed.The results are shown as follows:when the WDA is 0°,the vapor concentration in the gas space above the floating deck is the lowest;when the WDA is 22.5°,the oil evaporation loss rate is the largest;when the WDA is 45°,the vapor concentration is the highest,but the evaporation loss rate is the smallest.It is recommended to arrange the vent to the wind direction with an angle of 45°to reduce the evaporation loss and protect the atmospheric environment.

Roles of Isospin in Evaporation Residue Cross Section as a Probe of Nuclear Dissipation

The influence of isospin on the excess of evaporation residue cross section over its standard statistical-model value for nuclei ^194pb, ^200Pb, and ^206pb is studied via a Langevin equation coupled with a statistical decay model. The magnitude of this excess for a low-isospin fissioning nucleus is shown to be larger and its dependence on the nuclear viscosity coefficient to be stronger than those of a high-isospin fissioning nucleus. These results suggest that to obtain a more accurate information of viscosity coefficient inside the saddle point by measuring evaporation residue cross sections, we had better choose those compound systems with small isospin.

Effects of N/Z on Spin Distribution of Evaporation Residue Cross Section as a Probe of Nuclear Dissipation

The spin distribution of the evaporation residue cross section of nuclei ^194pb, ^200Pb, ^206Pb, and ^200 Os are calculated via a Langevin equation coupled with a statistical decay model. It is shown that with increasing the neutronto-proton ratio （N/Z） of the system, the sensitivity of the significantly. Moreover, for ^200Os this spin distribution is no spin distribution to the nuclear dissipation is decreased longer sensitive to the nuclear dissipation. These results suggest that to obtain a more accurate pre-saddle viscosity coefficient through the measurement of the evaporation residue spin distribution, it is best to yield those compound systems with low N/Z.

Industrialization Process of Pesticide Residue Grade n-Hexane

This project is funded by the China government to develop the industrialization process of pesticide residue grade n-hexane, in which the industrial n-Hexane is used as crude purified by decoloration, distillation and filtration process. The products are validated by National Research Center for Environmental Analysis and Measurement (CNEAC), National Research Center for Geoanalysis, Chinese Academy of Inspection and Quarantine (CAIQ), Chinese Academy of Agricultural Sciences (CAAS) and other government originations for polychlorinated biphenyls, organochlorine pesticide or chiral pesticides analysis and further confirmed that it’s competitive to all others imported n-Hexane currently occupied in China. This patented technique will meet pesticide residue grade n-Hexane market in China and seek for cooperation globally.

Systematic study of the synthesis of heavy and superheavy nuclei in 48Ca-induced fusion-evaporation reactions

We systematically studied the evaporation residue cross sections of ^(48)Ca-induced reactions on lanthanide and actinide target nuclei under the Dinuclear System(DNS)model framework to check the reliability and applicability of the model.To produce new proton-rich Fl and Lv isotopes through hot fusion reactions in the superheavy element region with Z≥104,we utilized the reactions ^(48)Ca+^(236,238,239) Pu and ^(48)Ca+^(242,243,244,250) Cm.However,owing to the detection limit of available equipment(0.1 pb),only 283Fl and 287−289Lv,which have the maximum evaporation residue cross section values of 0.149,0.130,9.522,and 0.309 pb,respectively,can be produced.Furthermore,to produce neutron-deficient isotopes of actinides near the proton drip line with Z=93−100,we attempted to generate the new isotopes(224−227Pu,228−232,237Cm)using the reactions ^(48)Ca+180,182,183 W and ^(48)Ca+^(184,186,187,192) Os.The maximum evaporation residue cross section values are 0.07,0.06,0.26,and 0.30 nb for the former set of reactions,and 1.96 pb,5.73 pb,12.16 pb,19.39 pb,54.79 pb,and 6.45 nb for the latter,respectively.These results are expected to provide new information for the future synthesis of unknown neutron-deficient isotopes.

Development on the Technique of Total Recovery of Benzoic Acid Residue

Benzoic acid residue is solid waste produced from the production of benzoic acid by oxidizing toluene.Because it contained important chemical raw materials such as benzoic acid,benzyl benzoate and fluorenone,it is necessary to recover them from the residue.In this work the technique featured with high efficiency evaporation and vacuum distillation was developed to obtain total recovery and utilization of the benzoic acid residue.By controlling the operation temperature at 260℃ and the pressure of 16kPa in the rising and falling film evaporators,heavy components separated efficiently from the residue can be polymerized and the light components consisting of 63% of the residue entered into a benzoic acid vacuum distillation column.Keeping the temperature of polymerization at(280±10)℃,coumarone resin was produced after adjusting the softening point according to the market requirements.Vacuum distillation was operated under the following conditions:top temperature at 186℃,top pressure of 16kPa,bottom temperature at 240-250℃,reflux ratio being 3︰1.Benzoic acid of 98% purity was distilled out from the column as a side stream and the bottom product was crude benzyl benzoate.By the developed technique,the benzoic acid residue was splitted into three products,benzoic acid,crude benzyl benzoate and coumarone resin without any surplus waste.

Influence of angular momentum on evaporation residue cross section as a probe of nuclear dissipation

By calculating the excess of the evaporation residue cross sections of the ^200Pb nucleus over that predicted by the standard statistical model as a function of nuclear viscosity coefficient using a Langevin equation combined with a statistical decay model, it is found that high angular momentum not only amplifies the dissipation effects on the excess of the evaporation residue cross sections, but also considerably increases the sensitivity of this excess to the nuclear viscosity coefficient. These results suggest that on the experimental side, to accurately obtain the information of nuclear dissipation inside the saddle point by measuring the evaporation residue cross section, it had better populate those compound systems with high spins.

Spin distribution of evaporation residue cross section within a stochastic approach

The Langevin equation including particle emission was used to reproduce the recently measured spin distribution of evaporation residue cross sections in the reaction ^16O＋^184W at beam energies of 84, 92, 100, 108, 116 and 120 MeV. By comparing the theoretical calculations with the experimental data, the validity of the stochastic approach to dissipative fission is verified. Moreover, a pre-saddle nuclear viscosity coefficient of 5×10^21 s^-1 is extracted.

Evaporation residue cross sections of superheavy nuclei based on optimized nuclear data

This study proposes an optimized method for estimating atomic nucleus masses by combining the finiterangedroplet model (FRDM) with the support vector machine algorithm. The optimization process significantly improvesthe accuracy of the FRDM by reducing the root mean square error from 0.606 to 0.253 MeV. The optimizedmass data obtained from this method are then used to calculate the evaporation residue cross-sections (ERCSs) forfusion-evaporation reactions, employing the di-nuclear system model. The experimental results for the 48Ca+238U reactionare relatively well reproduced using these optimized mass data. Additionally, the study investigates the impactof mass uncertainties on fusion and survival probabilities. By considering the mass uncertainties, the ERCSs fornew elements 119 and 120 are predicted based on the obtained optimized mass data.

Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

氟化钠提纯工艺研究

经过处理后的氟化钠原料中含有较多的硅酸钠杂质。为了去除其中的杂质,提高氟化钠的纯度,获得更高的工业价值。利用溶出硅胶与蒸发结晶操作过程相结合,设计了溶出硅胶-蒸发结晶提纯氟化钠工艺,提高了氟化钠的纯度,降低了硅的含量,并且改善了氟化钠产品的外观。在溶出硅胶实验中,考察了硫酸用量比、温度、时间、搅拌速率对脱硅过程的影响,并进行了正交试验。结果表明,在溶出硅胶实验中,综合效果最好的脱硅条件为硫酸的用量比(硫酸与氟化钠原料的质量比)为0.04、反应温度为25℃、反应时间为30 min、搅拌速率为300 r/min。在蒸发结晶实验中,当蒸发时间为60 min时,蒸发结晶提纯氟化钠的综合效果最好。在最佳的实验条件下,能得到纯度>98%,二氧化硅质量分数<0.5%的氟化钠产品。研究表明,硫酸与硅酸钠反应能溶出硅胶,再过滤分离能达到除硅的效果,而通过蒸发结晶,能进一步提高氟化钠的纯度。该研究可为提纯氟化钠、回收氟硅资源提供新思路。

Cr-induced fusion reactions to synthesize superheavy elements

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 range.The cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior experiments.The estimated cross sections from this analysis are consistent with the findings of prior studies.From the current study,the predicted cross section was found to be 42fb at 236 MeV for ^(53)Cr+^(243)Am,23.2 fb at 236 MeV for ^(54)Cr+^(247)Cm,95.6 fb at 240 MeV for ^(53)Cr+248Bk,and 1.33 fb at 242 MeV for ^(53)Cr+250Cf.Consequently,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.

残留地膜对粉壤土水盐氮运移与再分布的影响

为探究残留地膜(以下简称“残膜”)对土壤水盐氮运移与再分布的影响,设置了不同残膜含量(0,100,200,400 kg/hm2)室内一维垂直土柱入渗-蒸发试验,测定了水分再分布过程中土壤湿润锋和各土层土壤质量含水率、电导率、硝态氮及铵态氮等指标.结果表明:残膜改变了土壤的入渗性能,当土壤中残膜量低于200 kg/hm2时,土壤湿润锋运移距离与累积入渗量均有增加;当残膜量高于400 kg/hm2时,土壤湿润锋运移距离与累积入渗量比处理CK分别减少3.59%和4.07%;随残膜含量增加,水分对盐分的淋洗效果降低,对氮肥的淋洗效果增加;残膜阻碍了盐分与硝态氮的向上运移,对铵态氮向上运移随铵态氮质量比减小由阻碍作用转变为促进作用;当残膜量高于400 kg/hm2时,土壤水分与盐分CV值比处理CK分别增加10.15%和6.51%;随残膜含量增加,硝态氮质量比CV值显著减小,不同处理土壤相同土层铵态氮质量比CV值差异较大,土壤剖面内铵态氮的变异程度无明显差异;蒸发结束时,残膜对水分蒸发的促进作用随残膜含量增加转变为阻碍作用.该研究可探明残膜污染土壤水盐氮运移与再分布规律,为含残膜农田制定合理的灌溉制度提供理论依据.

电热蚊香液用芯棒性能研究

目的 通过对碳芯棒、木粉芯棒、木粉掺杂芯棒及纤维芯棒的性能对比测试,判断其优劣,为选择电热蚊香液用芯棒提供方法和依据。方法 根据行标QB/T 5278—2018规定感官、毛细渗透时间和抗折力性能测试方法,国标GB/T 18418—2017挥发速度测试方法,国标GB 24330—2020有效成分测试方法,国标GB13917.6—2009方箱法,国标GB13917.10—2009模拟现场法进行测试。结果 纤维芯棒的生产工艺、感官、毛细渗透时间、抗折力、挥发速度、挥发速度的一致性都优于碳芯棒、木粉芯棒、木粉掺杂芯棒,但有效成分残留较多,生物效果不佳。结论 纤维芯棒从生产工艺取得突破,理化指标优异,但其有效成分残留较多,生物效果欠佳,还需进一步研究。

蒸发光散射检测器高效液相色谱法同时测定猪肉中4种氨基糖苷类抗生素

建立蒸发光散射检测器高效液相色谱法(HPLC-ELSD)测定猪肉中妥布霉素、安普霉素、卡那霉素、新霉素4种氨基糖苷类抗生素残留。在固液比1∶10下,采取磷酸盐缓冲液(pH值为7.0)提取猪肉样品中残留的氨基糖苷类抗生素,通过SupelMIP^(TM) SPE-Aminoglycosides分子印记固相萃取柱净化,利用HPLC-ELSD法检测提取液中4种目标物的含量。4种氨基糖苷类抗生素的质量浓度为0.1~10μg/mL范围内与对应的色谱峰面积线性关系良好,相关系数分别为0.992~0.999 4。4种目标物的平均回收率为87.2%~97.3%,测定结果的相对标准偏差为5.25%~8.68%(n=6)。该方法操作简便,灵敏度高,结果准确,满足猪肉中妥布霉素、安普霉素、卡那霉素和新霉素的残留检测要求。

古龙酸母液混制肥和草席覆盖措施对新疆旱区牧草生长和土壤养分含量的影响

古龙酸母液(RAE)是工业上通过二步发酵法生产维生素C过程中产生的废液,胶质芽胞杆菌(Bacillus mucilaginosus)是解钾细菌,二者在改善土壤质量、提升土壤肥力和促进植物生长方面具有重要意义。使用RAE与胶质芽胞杆菌的混合液作为古龙酸母液混制肥(RB),设RB施加量为0%(CK)、0.5%、1.0%的3个处理,并设置草席覆盖和未覆盖处理,开展田间小区试验,对紫花苜蓿(Medicago sativa)和披碱草(Elymus dahuricus)的生长、生理指标、土壤养分指标及相关关系进行分析。结果表明,相同覆盖处理下,RB总体上显著提高了牧草的生长和生理指标,表现为1.0%>0.5%>CK,在1.0%RB处理下,紫花苜蓿的地上生物量平均提高了112%,披碱草平均提高了80.1%。相同RB施加量处理,覆盖处理的牧草总体上发芽率、发芽势、株高、地上生物量和根系发育显著高于未覆盖处理,紫花苜蓿和披碱草发芽率平均提高164%和194%,地上生物量平均提高64.3%和24.9%。相同覆盖处理下,土壤有机碳和速效养分含量均随RB处理有效提高,1.0%RB将土壤有机碳和速效钾分别显著提高了33.1%和105%。相同RB施加量下,覆盖处理能提高土壤的有机碳含量,平均提高了2.75%。双因素方差分析表明RB和草席覆盖措施对牧草的生长、生理指标和土壤养分含量具有显著的交互影响。冗余分析和Pearson相关性分析表明影响牧草生长生理指标的环境因子主要为有机碳、铵态氮、有效磷、速效钾,建议采用1.0%RB与草席覆盖联用来改良新疆旱区土壤促进牧草生长。研究结果为古龙酸母液、胶质芽胞杆菌资源化利用和新疆旱区土地资源开发提供了科学依据。

内蒙古某矿山开采主要污染物治理与环境保护研究

内蒙古某大型铀矿床采用CO_(2)+O_(2)地浸开采技术,以CO_(2)+O_(2)作为溶浸剂配制溶浸液,与矿层中的铀络合生成离子,在井场浸出和浸出液水冶处理过程中产生废井液和工艺废水污染物。在治理污染物的过程中,通过固井、地表固化和回收方式对废井液进行处理;对树脂转型废水进行反渗透处理,将反渗透浓水、树脂反冲废水等排至蒸发池蒸发。研究结果显示,废井液放射性较低,U天然平均浓度为38 mg/L,226Ra活度浓度平均为79 Bq/L。树脂转型水反渗透处理后U天然浓度<0.05 mg/L,226Ra活度浓度<1.1 Bq/L。蒸发池残渣中U天然平均比活度为426.90 Bq/L,226Ra平均比活度696.67 Bq/kg。通过对污染物进行治理,固井、地表固化均符合环保要求,工艺废水和蒸发池残渣符合相关标准要求,为该类型矿山污染物治理提供了方法和思路。通过采用本文方法可以达到污染物治理的目的,保护当地生态环境,产生积极的企业效益和社会效益,为企业高质量发展提供保障。

硅衬底温度对电子束蒸发钛薄膜性能的影响

采用电子束蒸发法在硅衬底表面制备Ti薄膜。采用台阶仪、原子力显微镜、反射率测试仪、四探针电阻测试仪和应力测试仪分析了在不同衬底温度下所得Ti薄膜的厚度、表面粗糙度、镜面反射率、方块电阻和残余应力。结果表明,随着衬底温度从25℃升高到200℃,Ti薄膜的厚度、方块电阻和残余应力逐渐降低;表面粗糙度先减小后增大,镜面反射率则先升高后降低。

中试减压蒸馏装置切割俄罗斯原油试验研究

俄罗斯原油性质上为轻质原油,API值为34.5,属于中间基原油,其中馏分段大于520℃的组分为20.84%。首次采用中试单级减压蒸馏装置,通过对刮膜蒸发器和残渣系统等技术改造,获取的减压渣油馏分中≥525℃的组分含量高于75%,达到预期目标,可以为延长石油集团碳氢技术研究中心悬浮床加氢裂化装置提供合格原料。

蒸盐调理剂对煤化工高盐废水蒸发尾液减量的研究分析

为实现煤化工废水的减量和资源回收利用,需对处理后废水进行膜浓缩和蒸发处理,以达到高盐废水的减量或零排放,但煤化工高盐废水因高COD、高硬度等原因,在蒸发过程中无法实现完全蒸发,一般会产生一定量的残留尾液无法继续蒸发浓缩,需作为危废委外处置。本研究采用自配的蒸盐调理剂,对蒸发尾液加药调理和过滤,可以提高蒸发尾液的蒸发效率,实现高盐废水蒸发尾液的继续减量。