含钴三元硫化物常压硫酸浸出钴的动力学研究

开展含钴三元硫化物常压硫酸浸出的实验研究。考察搅拌速度、浸出温度、硫酸浓度和粒度对钴浸出率的影响,并分析从含钴三元硫化物中浸出钴的动力学。结果表明,在最佳条件下,钴和铁被选择性浸出,且浸出率均大于99%,而钼和铜则富集于浸出渣。通过对实验数据的分析可知,钴的浸出符合由固体产物层产生的收缩核模型,且浸出过程受内扩散控制。浸出反应的活化能为49.86k J/mol,硫酸浓度和粒度的反应级数分别为0.57和-1.4。

同心圆式反应器中精确调控和连续制备β-四钼酸铵

采用同心圆式反应器制备β-四钼酸铵,研究制备过程中Mo离子聚合形态和微观结构受溶液酸度影响的变化规律。结果表明,将溶液的pH值控制在2.5以下可以得到四钼酸铵晶体;采用NH_(3)·H_(2)O将溶液pH值调回至3.0有利于细粒钼酸铵结晶的溶解,并促进七钼酸铵向四钼酸铵结晶的转变;降低(NH_(4))_(4)Mo_(4)O_(12)(O_(2))2·2H_(2)O晶体与结晶母液的接触时间有利于获得β-(NH_(4))_(2)Mo_(4)O_(13)结晶。基于钼的聚合机理,设计多个格区的同心圆反应器,实现钼酸铵结晶的分区域调控。通过调控硝酸、氨水和含晶种的母液在各格区中加入的位置和时机,可制备出优质的β-(NH_(4))_(2)Mo_(4)O_(13)结晶。

MicroRNA-150水平与原发性肝癌手术预后的关系

目的分析血清microRNA-150(miR-150)水平与原发性肝癌(PHC)手术预后的关系。方法选取2016年1月—2018年1月在成都市第一人民医院接受手术治疗的PHC患者80例作为PHC组。另选取同期该院健康体检者80例作为对照组。采用qRT-PCR检测血清miR-150水平,以miR-150相对表达量0.42作为分界值,将PHC组分为高表达组和低表达组,分别有48例和32例。分析miR-150水平与PHC患者临床特征及预后的关系。结果PHC组术前血清miR-150相对表达量较对照组低(P<0.05),术后血清miR-150相对表达量较术前高(P<0.05)。高表达组与低表达组患者不同组织分化程度、不同TNM分期、是否伴有肝硬化及是否伴有转移比例比较,差异有统计学意义(P<0.05)。高表达组与低表达组患者不同性别、不同年龄、不同肿瘤直径、是否伴有肝硬化复发、是否伴有乙型肝炎、不同AFP水平、是否伴有门脉癌栓比较,差异无统计学意义(P>0.05)。低表达组3年累积生存率较高表达组低(P<0.05)。多因素Cox回归模型分析结果显示,miR-150低表达[HR^(^)=3.065(95%CI:1.196,4.978),P<0.05]、肿瘤直径≥5 cm[HR^(^)=2.046(95%CI:0.429,3.062),P<0.05]、TNM分期Ⅲ期和Ⅳ期[HR^(^)=1.902(95%CI:1.003,3.257),P<0.05]、肝硬化[HR^(^)=0.395(95%CI:0.225,0.763),P<0.05]、转移[HR^(^)=0.446(95%CI:0.198,0.857),P<0.05]、AFP≥25 ng/ml[HR^(^)=0.489(95%CI:0.206,0.983),P<0.05]及伴有门脉癌栓[HR^(^)=0.465(95%CI:0.227,0.863),P<0.05]是影响PHC患者3年生存率的独立因素。结论miR-150在PHC患者中低表达,与患者预后、组织分化程度、TNM分期等密切相关,有望成为评估PHC患者预后的新型分子标志物。

远视性屈光参差性弱视儿童治疗前后黄斑区视网膜厚度的临床研究

目的:探讨远视性屈光参差性弱视儿童治疗前后黄斑各分区视网膜厚度、注视性质、最佳矫正视力(BCVA)、眼轴、等效球镜度数随着治疗时间延长发生的变化。方法:前瞻性纵向对照研究试验。选取2018-08/2019-08于我院确诊前未进行过弱视治疗的4~8岁单眼弱视的远视性屈光参差患儿共计40例(中心注视20例,旁中心20例),治疗前,治疗后6、12mo均行阿托品散瞳验光、眼底黄斑注视性质、眼轴、OCT视网膜厚度检查。用统计学分析远视性弱视眼的黄斑区视网膜厚度是否随治疗发生变化以及产生影响的相关因素,不同注视性质间是否存在差异。结果:治疗前,治疗后6、12mo中心注视组和旁中心注视组的中心凹视网膜厚度、内环鼻侧视网膜厚度均有差异(P<0.01),黄斑区其余视网膜厚度均无差异(P>0.05);随着治疗时间延长中心注视组和旁中心注视组的中心凹视网膜厚度、内环鼻侧视网膜厚度变薄(均P<0.05)。相同测量时间中心注视组的中心凹和内环鼻侧视网膜厚度比旁中心注视组薄(均P<0.05),黄斑区其余视网膜厚度无差异(均P>0.05)。治疗前后弱视眼的眼轴、BCVA、等效球镜度数有差异(均P<0.01);随着治疗时间延长眼轴长度增加,BCVA升高,等效球镜度数降低。远视性弱视眼黄斑各分区视网膜厚度厚于对侧正常眼,眼轴长度小于对侧正常眼(均P<0.01)。弱视眼与对侧正常眼治疗前后眼轴长度变化有差异(P<0.05),弱视眼眼轴短于对侧正常眼眼轴,随着治疗时间的延长弱视眼与对侧正常眼眼轴长度都变长。结论:中高度的弱视眼黄斑区视网膜各分区厚度均大于对侧正常眼,眼轴小于对侧正常眼。治疗后随着最佳矫正视力的提高,中心注视、旁中心注视组黄斑区中心凹和内环鼻侧的视网膜厚度均变薄。

Research and development trends of hydrometallurgy:An overview based on Hydrometallurgy literature from 1975 to 2019

Modern hydrometallurgy has been developing for more than 100 years and the related articles keep piling up.Based on a bibliometric analysis of the articles in Hydrometallurgy,the most authoritative journal in the field of hydrometallurgy,we try to catch the research and development trends from a global perspective.Firstly,keywords burstness shows that rare earth,recycling,lithium,ionic liquid,and thorium are the hotspots in recent years,and the economic and technological reasons behind them were discussed in depth.Secondly,the proportion of biohydrometallurgy grows fast from 5%to 13%and the related articles are almost all about bioleaching.There are some new directions such as direct preparation of materials in hydrometallurgical processes and ion-imprinted techniques.Thirdly,the advanced instrument analysis methods such as XAFS(X-ray absorption fine structure),gene sequencing,and micro-CT promote the deep understanding of hydrometallurgy mechanism.Finally,the cooperation network and contribution of the main institutes were mapped.

隐匿性近视相关因素的研究进展

隐匿性近视是指在儿童正常年龄段视力范围之内,眼轴长度超出相应年龄段正常范围,角膜曲率低于正常值范围,二者缺一不可所形成的一种特殊类型的近视。由于隐匿性近视儿童的视力在正常范围内,近视筛查中极易被忽视,在未及时进行近视防控的情况下,隐匿性近视极易发展成显性近视,不仅视觉发育受到严重影响,视功能也将产生不可逆的改变。研究发现,隐匿性近视眼轴长度、角膜曲率、视网膜、脉络膜等不同于普通近视,可通过这些指标的变化辅助诊断,观察其发展进程。本文旨在总结国内外关于隐匿性近视儿童眼轴长度、角膜曲率、黄斑区视网膜厚度、黄斑区脉络膜厚度等相关因素的研究进展,以期为相关临床研究提供参考依据。

Removal of tungsten from molybdate solution by Fe-Mn binary oxide adsorbent

Considering the different geochemical enrichment behaviors of W and Mo,Fe?Mn binary oxide(FMBO),ferric hydroxide(Fe(OH)3)and manganese dioxide(MnO2)were studied to separate W from molybdate solution,respectively.The experimental results demonstrated that Fe?Mn binary oxide(FMBO)was the most suitable adsorbent for the separation.Under a wide pH(6.9?11.3)region,more than80%W removal efficiency and less than3%Mo loss could be obtained.In addition,the Fe?Mn binary oxide adsorbent can be regenerated by treating with3mol/L NaOH,and the W adsorption efficiency was retained after five adsorption?desorption?regeneration cycles.All these indicate that the Fe?Mn binary oxides have the potential for the separation of W from molybdate solution.

Nonalcoholic fatty liver disease shows significant sex dimorphism

Nonalcoholic fatty liver disease(NAFLD),which has been renamed metabolic dysfunction-associated fatty liver disease,is a growing global medical problem.The incidence of NAFLD and its associated end-stage liver disease is increasing each year,and many research advancements have been achieved to date.This review focuses on the current knowledge of the sex differences in NAFLD and does not elaborate on areas without differences.Studies have revealed significant sex differences in the prevalence,influencing factors,pathophysiology,complications and therapies of NAFLD.Men have a higher incidence than women.Compared with women,men exhibit increased visceral fat deposition,are more susceptible to leptin resistance,lack estrogen receptors,and tend to synthesize fatty acids into fat storage.Male patients will experience more severe hepatic fibrosis and a higher incidence of liver cancer.However,once NAFLD occurs,women show a faster progression of liver fibrosis,higher levels of liver cell damage and inflammation and are less likely to undergo liver transplantation than men.In general,men have more risk factors and more severe pathophysiological reactions than women,whereas the development of NAFLD is faster in women,and the treatments for women are more limited than those for men.Thus,whether sex differences should be considered in the individualized prevention and treatment of NAFLD in the future is worth considering.

Effectiveness of drug interventions in nonalcoholic fatty liver disease:A network meta-analysis

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is a major chronic liver disorder worldwide,and there is no established treatment for this disease.We conducted a network meta-analysis(NMA)to compare existing treatments,which include four classes of antidiabetic drugs,and examined the optimum treatments for NAFLD.AIM To compare the effectiveness of different treatments for NAFLD.METHODS An NMA was conducted using Stata 14.0(Corporation LLC,College Station,United States)and R(X643.6.3 version)in this study.Eligible randomized controlled trials(RCTs)were searched in the PubMed,Cochrane Library,Embase,Medline and Web of Science databases from database inception to April 2021.Two researchers independently screened the available studies in strict accordance with inclusion and exclusion criteria.The Cochrane Risk of Bias tool was used to evaluate the risk of bias of the included studies.The variables with and without dimensional differences were calculated as the standardized mean difference and weighted mean difference,respectively.An inconsistency model and“nodesplitting”technique were used to test for inconsistency.Funnel plots were used to evaluate publication bias.RESULTS Twenty-two eligible RCTs involving 1377 participants were eventually included in our analysis.Data were pooled using a random-effects model.Our NMA results revealed that glucagon-like peptide-1 receptor agonists(GLP-1RAs)were the most effective treatment,yielding improvements in hepatic fat content(HFC),alanine aminotransferase(ALT),aspartate aminotransferase(AST),serumγ-glutamyl transferase(GGT)and body weight[surface under the cumulative ranking curve(SUCRA)=99.6%,92.6%,82.8%,92.3%and 99.6%,respectively],while thiazolidinediones(TZDs)were the best intervention for reducing the NAFLD activity score(NAS;SUCRA=98.9%).In addition,moderate performance was observed for the sodium glucose cotransporter-2 inhibitors groups(SUCRA=25.1%,66.2%,63.5%,58.2%and 71.9%for HFC,ALT,AST,GGT and body weight,respectively).However,metformin performed poorly according to most indicators(SUCRA=54.5%,0.3%,19.5%,33.7%,57.7%and 44.3%for HFC,NAS,ALT,AST,GGT and body weight,respectively).CONCLUSION GLP-1RAs may be the optimum choice for most patients with NAFLD.However,TZDs are considered the most effective therapies in NAFLD patients with histological disease activity.

Gate tunable Rashba spin-orbit coupling at CaZrO_(3)/SrTiO_(3)heterointerface

High mobility quasi two-dimensional electron gas(2DEG)found at the CaZrO_(3)/SrTiO_(3) nonpolar heterointerface is attractive and provides a platform for the development of functional devices and nanoelectronics.Here we report that the carrier density and mobility at low temperature can be tuned by gate voltage at the CaZrO_(3)/SrTiO_(3) interface.Furthermore,the magnitude of Rashba spin-orbit interaction can be modulated and increases with the gate voltage.Remarkably,the diffusion constant and the spin-orbit relaxation time can be strongly tuned by gate voltage.The diffusion constant increases by a factor of~19.98 and the relaxation time is reduced by a factor of over three orders of magnitude while the gate voltage is swept from-50 V to 100 V.These findings not only lay a foundation for further understanding the underlying mechanism of Rashba spin-orbit coupling,but also have great significance in developing various oxide functional devices.

Maturity-onset diabetes of the young type 9 or latent autoimmune diabetes in adults:A case report and review of literature

BACKGROUND Maturity-onset diabetes of the young(MODY)is a monogenic genetic disease often clinically misdiagnosed as type 1 or type 2 diabetes.MODY type 9(MODY9)is a rare subtype caused by mutations in the PAX4 gene.Currently,there are limited reports on PAX4-MODY,and its clinical characteristics and treatments are still unclear.In this report,we described a Chinese patient with high autoimmune antibodies,hyperglycemia and a site mutation in the PAX4 gene.CASE SUMMARY A 42-year-old obese woman suffered diabetes ketoacidosis after consuming substantial amounts of beverages.She had never had diabetes before,and no one in her family had it.However,her autoantibody tested positive,and she managed her blood glucose within the normal range for 6 mo through lifestyle interventions.Later,her blood glucose gradually increased.Next-generation sequencing and Sanger sequencing were performed on her family.The results revealed that she and her mother had a heterozygous mutation in the PAX4 gene(c.314G>A,p.R105H),but her daughter did not.The patient is currently taking liraglutide(1.8 mg/d),and her blood glucose levels are under control.Previous cases were retrieved from PubMed to investigate the relationship between PAX4 gene mutations and diabetes.CONCLUSION We reported the first case of a PAX4 gene heterozygous mutation site(c.314G>A,p.R105H),which does not appear pathogenic to MODY9 but may facilitate the progression of latent autoimmune diabetes in adults.

Anomalous Metallic State Driven by Magnetic Field at the LaAlO_(3)/KTaO_(3)(111)Interface

The origin of the quantum superconductor to metal transition at zero temperature in two-dimensional superconductors is still an open problem,which has caused intensely discussion.Here,we report the observation of a quantum superconductor-to-metal transition in La Al O_(3)/KTa O_(3)(111)interface,driven by magnetic field.When a small magnetic field perpendicular to the film plane is applied,the residual saturated resistance is observed,indicating the emergence of an anomalous metallic state associated with a failed superconductor.The dependence of saturated resistance on magnetic field at low temperature indicates that the observed metal state is a Bose metal state.From our findings,magnetic field regulating La Al O_(3)/KTa O_(3)(111)interface emerges as a platform to scrutinize the details of the anomalous metallic state in a controllable way.

Pichia pastoris composition expressed aerolysin mutant of Aeromonas veronii as an oral vaccine evaluated in zebrafish(Danio rerio)

Vaccines are one of the most practical means to stop the spreading of Aeromonas veronii in aquaculture.In this study,virulence factor aerolysin mutant NTaer which has lost its hemolytic activity was used as a target antigen.Pichia pastoris constitutive secretory expression NTaer(GS115-NTaer)was used as a potential safe oral vaccine to evaluate its effectiveness on zebrafish immunity.The result shows that vaccination of GS115-NTaer for four weeks did not affect the growth performance of the host,while eliciting an effective immune protective response.Compared with the control group,the GS115-NTaer could significantly up-regulate the relative expression level of the intestinal tight junction protein 1α(TJP1α)gene,and significantly increased the contents of lysozyme(LYZ),complement C3 and C4 in the gut,indicating that the innate immune response of the fish was activated.The relative gene expression levels of macrophage-expressed gene 1(MPEG1)and T cell receptor(TCR-α)in the gut,and MPEG1,CD4,CD8,TCR-α,GATA3,and T-bet in the spleen were all increased significantly,indicating that the cellular immune response of the fish was activated.Furthermore,the contents of serum IgM and intestinal mucosa IgZ antibodies were significantly increased,which showed that humoral immunity was also activated.Moreover,inoculation with GS115-NTaer significantly changed the structure of gut microbiota.In particular,the relative ratio of(Firmicutes+Fusobacteriota+Bacteroidota)/Proteobacteria was significantly higher than that of the control and GS115 groups.Lastly,the vaccinated fish were challenged with A.veronii,and the relative percent survival of GS115 and the GS115-NTear groups was 14.28%and 33.43%.This improvement of immunity was not only due to the specific immune response but also attributed to the improvement of innate immunity and the gut microbiota which was demonstrated by the germ-free zebrafish model.Collectively,this study provides information on the effectiveness of GS115-NTear as an oral vaccine for the green prevention and control of A.veronii infection in fish aquaculture.

Microstructure recognition of steels by machine learning based on visual attention mechanism

U-Net has achieved good performance with the small-scale datasets through skip connections to merge the features of the low-level layers and high-level layers and has been widely utilized in biomedical image segmentation as well as recent microstructure image segregation of the materials.Three representative visual attention mechanism modules,named as squeeze-and-excitation networks,convolutional block attention module,and extended calibration algorithm,were intro-duced into the traditional U-Net architecture to further improve the prediction accuracy.It is found that compared with the original U-Net architecture,the evaluation index of the improved U-Net architecture has been significantly improved for the microstructure segmentation of the steels with the ferrite/martensite composite microstructure and pearlite/ferrite composite microstructure and the complex martensite/austenite island/bainite microstructure,which demonstrates the advantages of the utilization of the visual attention mechanism in the microstructure segregation.The reasons for the accuracy improvement were discussed based on the feature maps analysis.

Helicene-type β-isoindigo-based boron-dipyrromethene analogs with strong near-infrared chiroptical activity

Near-infrared(NIR)chiroptical response has been less explored because it is chal-lenging to achieve both chirality and NIR absorption/emission.Herein,we describe the design of heterohelicene-typeβ-isoindigo-based boron-dipyrromethene(BOD-IPY)analogs(β-IBs),which shift the absorption peak to 800 nm and produce significant Cotton effects(127.8 M-1 cm-1)and absorbance dissymmetry factors(|gabs|3.5=×10-3).The luminescence dissymmetry factor(glum)and circu-larly polarized luminescence(CPL)brightness(BCPL)of up to 1.24×10-3 and 1.78 M-1 cm-1 were realized beyond 800 nm.Theseβ-IBs are thefirst examples of helicene-type compounds with the highest gabs in the NIR region and CPL beyond 800 nm.Theoretical calculations demonstrate that the strong chiroptical activities are triggered by their large transition magnetic dipole moments.This study not only provides a new approach to the synthesis of a larger variety of unprecedented helicene-type BODIPY analogs but also demonstrates excellent NIR chiroptical properties.

Short-term effects of cupping and scraping therapy for chronic nonspecific low-back pain:A prospective,multicenter randomized trial

Background As one of the most common musculoskeletal ailments,chronic nonspecific low-back pain(CNLBP)causes persistent disability and substantial medical expenses.Epidemiological evidence shows that the incidence rate of CNLBP in young and middle-aged people who are demanded rapidly recovery and social contribution is rising.Recent guidelines indicate a reduced role for medicines in the management of CNLBP.Objective The present study investigates the short-term effects of cupping and scraping therapy using a medicated balm,compared to nonsteroidal anti-inflammatory drug(NSAID)with a capsaicin plaster,in the treatment of CNLBP.Design,setting,participants and interventions We designed a prospective multicenter randomized clinical trial enrolling patients from January 1,2022 to December 31,2022.A total of 156 patients with CNLBP were randomized into two parallel groups.Diclofenac sodium-sustained release tablets were administered orally to participants in the control group for one week while a capsaicin plaster was applied externally.Patients in the test group were treated with cupping and scraping using a medical device and medicated balm.Main outcome measures Primary outcome was pain recorded using the visual analogue scale(VAS).Two secondary outcomes were recorded using the Japanese Orthopedic Association low-back pain scale(JOA)and the traditional Chinese medicine(TCM)syndrome integral scale(TCMS)as assessment tools.Results Between baseline and postintervention,all changes in outcome metric scales were statistically significant(P<0.001).Compared to the control group,patients in the test group had a significantly greater treatment effect in all outcome variables,as indicated by lower VAS and TCMS scores and higher JOA scores,after the one-week intervention period(P<0.001).Further,according to the findings of multivariate linear regression analysis,the participants’pain(VAS score)was related to their marital status,age,smoking habits and body mass index.No adverse reactions were reported for any participants in this trial.Conclusion The effectiveness of TCM combined with the new physiotherapy tool is superior to that of NSAID combined with topical plasters,regarding to pain intensity,TCM symptoms and quality of life.The TCM plus physiotherapy also showed more stable and long-lasting therapeutic effects.

Laparoscopic liver resection utilizing the ventral avascular area of the inferior vena cava:A retrospective cohort study

BACKGROUND Laparoscopic liver resection(LLR)can be challenging due to the difficulty of establishing a retrohepatic tunnel under laparoscopy.Dissecting the third hepatic hilum before parenchymal transection often leads to significant liver mobilization,tumor compression,and bleeding from the short hepatic veins(SHVs).This study introduces a novel technique utilizing the ventral avascular area of the inferior vena cava(IVC),allowing SHVs to be addressed after parenchymal transection,thereby reducing surgical complexity and improving outcomes in in situ LLR.AIM To introduce and evaluate a novel LLR technique using the ventral avascular area of the IVC and compare its short-term outcomes with conventional methods.METHODS The clinical cohort data of patients with pathologically confirmed hepatocellular carcinoma or intrahepatic cholangiocarcinoma who underwent conventional LLR and novel LLR between July 2021 and July 2023 at the First Affiliated Hospital of Chongqing Medical University were retrospectively analyzed.In novel LLR,we initially separated the caudate lobe from the IVC using dissecting forceps along the ventral avascular area of the IVC.Then,we transected the parenchyma of the left and right caudate lobes from the caudal side to the cephalic side using the avascular area as a marker.Subsequently,we addressed the SHVs and finally dissected the root of the right hepatic vein or left hepatic vein.The short-term postoperative outcomes and oncological results of the two approaches were evaluated and compared.RESULTS A total of 256 patients were included,with 150(58.59%)undergoing conventional LLR and 106(41.41%)undergoing novel LLR.The novel technique resulted in significantly larger tumor resections(6.47±2.96 cm vs 4.01±2.33 cm,P<0.001),shorter operative times(199.57±60.37 minutes vs 262.33±83.90 minutes,P<0.001),less intraoperative blood loss(206.92±37.09 mL vs 363.34±131.27 mL,P<0.001),and greater resection volume(345.11±31.40 mL vs 264.38±31.98 mL,P<0.001)compared to conventional LLR.CONCLUSION This novel technique enhances liver resection outcomes by reducing intraoperative complications such as bleeding and tumor compression.It facilitates a safer,in situ removal of complex liver tumors,even in challenging anatomical locations.Compared to conventional methods,this technique offers significant advantages,including reduced operative time,blood loss,and improved overall surgical efficiency.

Unraveling the therapeutic potential of Calculus Bovis in liver cancer:A novel step for targeted cancer treatment

Hepatocellular carcinoma is one of the leading causes of cancer-related deaths globally,and effective treatments are urgently needed.The present study aimed to investigate the inhibitory effect of Calculus Bovis(CB)on liver cancer and the underlying mechanisms.CB inhibited M2 tumor-associated macrophage polarization and modulated the Wnt/β-catenin signaling pathway,thereby suppressing the proliferation of liver cancer cells.The inhibitory effect on liver cancer growth was confirmed by both in vivo and in vitro experiments(detailed by Huang et al).The present study provides a theoretical basis for the application of CB for the treatment of liver cancer,providing new avenues for liver cancer treatment.

Lighting up nonbenzenoid acepleiadylene with ultra-narrowband emission through aromaticity modulation

Nonbenzenoid polycyclic arenes have attracted great attention because of their unique topological structures and appealing properties;however,they are generally considered as poor luminescent materials due to the ring puckering behavior of the nonhexagons.Acepleiadylene(APD),a nonbenzenoid isomer of pyrene,has been demonstrated as an excellent building block for optoelectronic applications,but its poor photoluminescence quantum yield(PLQY)has hampered its application in luminescent materials.Considering that the ring puckering character can be suppressed by increasing the rigidity of the nonhexagon rings,herein,we propose a novel strategy for enhancing the aromaticity of the nonhexagons to improve the PLQYs of APD derivatives.Electron-withdrawing cyano groups are introduced on the five-membered ring of APD to enhance the chargeseparated character and thus the aromaticity of the nonhexagons,endowing the cyano-substituted APDs(CNAPD and 2CNAPD)with better rigidity.Therefore,the cyano substitution successfully suppresses the nonradiative energy dissipation caused by the ring puckering,improving the PLQY from 2.4%for APD to 14%for CNAPD,and to 63%for 2CNAPD.In addition,the enhanced rigidity also suppresses the vibration sideband of the photoluminescence spectra,leading to an ultra-narrowband emission from 2CNAPD with a full-width at half-maximum(FWHM)of 13 nm(47 me V),which is a new record in organic molecules.These results demonstrate that APD derivatives have great potential in highly efficient luminescent materials with high color purity via the aromaticity regulation strategy,which provides a novel concept for designing nonbenzenoid luminescent materials.

Efficient recovery of tungsten from scheelite concentrates using a sulfur-phosphorus mixed acid leaching system

In recent years,a new process for leaching scheelite concentrates with sulfur-phosphorus mixed acid has been successfully industrialized.This process suffers from the elimination of the retarding effect of calcium sulfate,the selective extraction of tungsten from the H_(3)PW_(12)O_(40)-H_(2)SO_(4)-H_(3)PO_(4)mixture solution,and the removal of introduced phosphorus.Therefore,in this paper,we investigated the inhibition measures of a calcium sulfate-blocking membrane,the selective extraction of tungsten by ion exchange,and the removal of phosphorus by the magnesium ammonium salt method.The results showed that the addition of calcium sulfate whisker seeds and a higher H_(3)PO_(4)concentration inhibited spontaneous diffuse nucleation,promoted crystal growth,and avoided the formation of a dense blocking film.About 98 wt.%of the scheelite concentrate was digested by H_(2)SO_(4)-H_(3)PO_(4).The selective adsorption of PW_(12)O_(40)^(3-)was realized using D301 resin,and the extraction efficiency of tungsten exceeded 99.9%.After desorption with ammonia water,PW_(12)O_(40)^(3-)was depolymerized into WO_(4)^(2-)and PO_(4)^(3-).99.9 wt.%of phosphorus was removed in the form of MgNH_(4)PO_(4)by the magnesium ammonium salt method,and the residual phosphorus concentration in the solution was lower than 10 mg·L^(-1).After purification,the highest-grade ammonium paratungstate product was prepared by evaporative crystallization.