Establishment of a system for screening and identification of novel bactericide targets in the plant pathogenic bacterium Xanthomonas oryzae pv. oryzae using Tn-seq and SPR

Xanthomonas spp. cause severe bacterial diseases. However, effective strategies for prevention and management of these diseases are scarce. Thus, it is necessary to improve the efficiency of control of diseases caused by Xanthomonas. In this study, Xanthomonas oryzae pv. oryzae(Xoo), which causes rice bacterial leaf blight, has been studied as a representative. A transposon insertion library of Xoo, comprising approximately 200,000 individual insertion mutants, was generated. Transposon sequencing data indicated that the mariner C9 transposase mapped at 35.7–36.4% of all potential insertion sites, revealing 491 essential genes required for the growth of Xoo in rich media. The results show that, compared to the functions of essential genes of other bacteria, the functions of some essential genes of Xoo are unknown, 25 genes might be dangerous for the Xanthomonas group, and 3 are specific to Xanthomonas. High-priority candidates for developing broad-spectrum, Xanthomonas-specific, and environment-friendly bactericides were identified in this study. In addition, this study revealed the possible targets of dioctyldiethylenetriamine using surface plasmon resonance(SPR) in combination with high performance liquid chromatography–mass spectrometry(HPLC–MS). The study also provided references for the research of some certain bactericides with unknown anti-bacterial mode of action. In conclusion, this study urged a better understanding of Xanthomonas,provided meaningful data for the management of bacterial leaf blight, and disclosed selected targets of a novel bactericide.

An Analysis of Supply Chain Environment in Great Wall Motor Based on Life-Cycle Assessment

Great Wall Motor(GWM),a leading automotive manufacturer,places a strong emphasis on environmental sustainability and social responsibility.The company focuses on comprehensively evaluating and enhancing its supply chain to align with these objectives.This evaluation spans the entire product life cycle,encompassing design,manufacturing,packaging,distribution,usage,and recycling and disposal processes.Key areas of focus include optimizing raw material selection,improving product recyclability,reducing energy consumption and waste emissions,and minimizing carbon emissions during transportation.Through these endeavors,GWM not only enhances its environmental performance by reducing carbon emissions and resource consumption but also bolsters its brand image and competitiveness in the market.GWM’s dedication to environmental innovation and technological leadership serves as a driving force behind sustainable development and social responsibility within the industry.

Single-cell analyses reveal cannabidiol rewires tumor microenvironment via inhibiting alternative activation of macrophage and synergizes with anti-PD-1 in colon cancer

Colorectal tumors often create an immunosuppressive microenvironment that prevents them from responding to immunotherapy.Cannabidiol(CBD)is a non-psychoactive natural active ingredient from the cannabis plant that has various pharmacological effects,including neuroprotective,antiemetic,anti-inflammatory,and antineoplastic activities.This study aimed to elucidate the specific anticancer mechanism of CBD by single-cell RNA sequencing(scRNA-seq)and single-cell ATAC sequencing(scATAC-seq)technologies.Here,we report that CBD inhibits colorectal cancer progression by modulating the suppressive tumor microenvironment(TME).Our single-cell transcriptome and ATAC sequencing results showed that CBD suppressed M2-like macrophages and promoted M1-like macrophages in tumors both in strength and quantity.Furthermore,CBD significantly enhanced the interaction between M1-like macrophages and tumor cells and restored the intrinsic anti-tumor properties of macrophages,thereby preventing tumor progression.Mechanistically,CBD altered the metabolic pattern of macrophages and related anti-tumor signaling pathways.We found that CBD inhibited the alternative activation of macrophages and shifted the metabolic process from oxidative phosphorylation and fatty acid oxidation to glycolysis by inhibiting the phosphatidylinositol 3-kinase-protein kinase B signaling pathway and related downstream target genes.Furthermore,CBD-mediated macrophage plasticity enhanced the response to anti-programmed cell death protein-1(PD-1)immunotherapy in xenografted mice.Taken together,we provide new insights into the anti-tumor effects of CBD.

铋基材料光催化还原水中六价铬的研究进展

光催化还原是处理水溶液体系中六价铬(Cr(VI))的一种新方法.层状铋(Bi)基材料具有增强的光捕获能力和可调的带隙能量,被认为是一种光催化还原去除Cr(VI)的有效材料.本文从修饰策略(如异质结、缺陷工程和掺杂)和工艺变量(如溶液p H和添加剂的类型/数量)等方面,对用于光催化还原处理Cr(VI)的铋基材料的改进机制进行深入总结.此外,采用工业上用作关键指标的优值系数(FoM),对各种铋基材料的性能进行评估.结果发现,平均粒径为5-10 nm,具有shuriken形状的BiVO_(4)具有最高的FoM值(3.45×10^(-5) molg^(-1)Wh^(-1)),且其光催化还原性能最好.同时,与其他非铋基催化剂相比,BiVO_(4)的光催化还原Cr(VI)性能也具有很好的优势.但是,目前铋基催化剂成本较高,且光催化还原过程能耗较大,距离大规模实际应用还有一定的距离.未来,为实现铋基催化剂光催化还原处理含Cr(VI)废水的大规模应用,应大幅度降低催化剂的生产成本,并提高催化剂光子吸收效率从而进一步提高能源利用率.

Electrochemical synthesis of FeN_(x) doped carbon quantum dots for sensitive detection of Cu^(2+) ion

A novel strategy was developed to fabricate FeNx-doped carbon quantum dots(Fe-N-CQDs)to detect Cu^(2+) ions selectively as a fluorescence probe.The Fe-N-CQDs were synthesized by an efficient electrolysis of a carbon cloth electrode,which was coated with monoatomic ironanchored nitrogen-doped carbon(Fe-N-C).The obtained Fe-N-CQDs emitted blue fluorescence and possessed a quantum yield(QY)of 7.5%.An extremely wide linear relationship between the Cu^(2+) concentration and the fluorescence intensity was obtained in the range from 100 nmol L^(-1) to 1000 nmol L^(-1)(R^(2)=0.997),and the detection limit was calculated as 59 nmol L^(-1).Moreover,the Fe-N-CQDs demonstrated wide range pH compatibility between 2 and 13 due to the coordination between pyridine nitrogen and Fe^(3+),which dramatically reduced the affection of the protonation and deprotonation process between H^(+) and Fe-N-CQDs.It is notable that the Fe-N-CQDs exhibited a rapid response in Cu^(2+) detection,where stable quenching can be completed in 7 s.The mechanism of excellent selective detection of Cu^(2+) was revealed by energy level simulation that the LUMO level of Fe-N-CQDs(-4.37 eV)was close to the redox potential of Cu^(2+),thus facilitating the electron transport from Fe-N-CQDs to Cu^(2+).

Optically pumped wavelength-tunable lasing from a GaN beam cavity with an integrated Joule heater pivoted on Si

Dynamically tunable laser sources are highly promising for realizing visionary concepts of integrated photonic circuits and other applications. In this paper, a Ga N-based laser with an integrated PN junction heater on Si is fabricated.The photoluminescence properties of the Ga N beam cavity are controlled by temperature, and the Joule heater provides electrically driven regulation of temperature. These two features of the cavity make it possible to realize convenient tuning of the lasing properties. The multi-functional Ga N beam cavity achieves optically pumped lasing with a single mode near 362.4 nm with a high Q-factor of 1394. The temperature of this device increases by 0–5℃ under the Joule heating effect. Then, electrical control of the lasing mode is demonstrated. The lasing resonant peak shows a continuous redshift of about 0.5 nm and the device also exhibits dynamic switching of its lasing mode. The lasing modulation can be ascribed to temperature-induced reduction of the bandgap. Our work may be of benefit for external optical modulation in future chip-based optoelectronic devices.

Canonical transient receptor potential channel 1 aggravates myocardial ischemia-and-reperfusion injury by upregulating reactive oxygen species

The canonical transient receptor potential channel(TRPC)proteins form Ca^(2+)-permeable cation channels that are involved in various heart diseases.However,the roles of specific TRPC proteins in myocardial ischemia/reperfusion(I/R)injury remain poorly understood.We observed that TRPC1 and TRPC6 were highly expressed in the area at risk(AAR)in a coronary artery ligation induced I/R model.Trpc1/mice exhibited improved cardiac function,lower serum Troponin T and serum creatine kinase level,smaller infarct volume,less fibrotic scars,and fewer apoptotic cells after myocardial-I/R than wild-type or Trpc6/mice.Cardiomyocyte-specific knockdown of Trpc1 using adeno-associated virus 9 mitigated myocardial I/R injury.Furthermore,Trpc1 deficiency protected adult mouse ventricular myocytes(AMVMs)and HL-1 cells from death during hypoxia/reoxygenation(H/R)injury.RNA-sequencing-based transcriptome analysis revealed differential expression of genes related to reactive oxygen species(ROS)generation in Trpc1/cardiomyocytes.Among these genes,oxoglutarate dehydrogenase-like(Ogdhl)was markedly downregulated.Moreover,Trpc1 deficiency impaired the calcineurin(CaN)/nuclear factorkappa B(NF-kB)signaling pathway in AMVMs.Suppression of this pathway inhibited Ogdhl upregulation and ROS generation in HL-1 cells under H/R conditions.Chromatin immunoprecipitation assays confirmed NF-kB binding to the Ogdhl promoter.The cardioprotective effect of Trpc1 deficiency was canceled out by overexpression of NF-kB and Ogdhl in cardiomyocytes.In conclusion,our findings reveal that TRPC1 is upregulated in the AAR following myocardial I/R,leading to increased Ca^(2+) influx into associated cardiomyocytes.Subsequently,this upregulates Ogdhl expression through the CaN/NF-kB signaling pathway,ultimately exacerbating ROS production and aggravating myocardial I/R injury.

Tanshinone IIA protects intestinal epithelial cells from ferroptosis through the upregulation of GPX4 and SLC7A11

Background:Inflammatory bowel disease(IBD)is a chronic inflammatory disease of the gastrointestinal tract.The destruction of the intestinal epithelial barrier is one of the major pathological processes in IBD pathology.Growing evidence indicated that epithelial cell ferroptosis is linked to IBD and is considered a target process.Methods:RAS-selective lethal 3(RSL3)was used to induce ferroptosis in intestinal epithelial cell line No.6(IEC-6)cells,and cell ferroptosis and the effects of tanshinone IIA(Tan IIA)were determined by cell counting kit-8(CCK-8),reactive oxygen species(ROS)staining,Giemsa staining and transmission electron microscope(TEM).The cell viability of natural product library compounds was determined by CCK-8.The expression of ferroptosis-related genes were detected by real-time quantitative polymerase chain reaction(RT-qPCR)and western blot.Results:Treatment of IEC-6 cells results in the accumulation of ROS and typical morphological characteristics of ferroptosis.RSL3 treatment caused rapid cellular cytotoxicity which could be reversed by ferrostatin-1(Fer-1)in IEC-6 cells.Natural product library screening revealed that Tan IIA is a potent inhibitor of IEC-6 cell ferroptosis.Tan IIA could significantly protect the RSL3-induced ferroptosis of IEC-6 cells.Furthermore,the ferroptosis suppressors,glutathione peroxidase 4(GPX4),solute carrier family 7 member 11(SLC7A11),and miR-17-92 were found to be early response genes in RSL3-treated cells.Treatment of IEC-6 cells with Tan IIA resulted in upregulation of GPX4,SLC7A11,and miR-17-92.Conclusion:Our study demonstrated that Tan IIA protects IEC-6 cells from ferroptosis through the upregulation of GPX4,SLC7A11,and miR-17-92.The findings might provide a theoretical grounding for the future application of Tan IIA to treat or prevent IBD.

The extracellular secretion of miR-1825 wrapped by exosomes increases CLEC5A expression:A potential oncogenic mechanism in ovarian cancer

Background:Ovarian cancer(OC)is a leading cause of gynecological cancer-linked deaths worldwide.Exosomal miR-1825 and its target gene C-type lectin domain family 5 member A(CLEC5A)are associated with tumorigenesis in cancers that was further probed.Methods:Exosomal miR-1825 expression in exosomes and its impact on overall survival(OS)prediction were determined using Gene Expression Omnibus(GEO)and The Cancer Genome Atlas(TCGA)data.Target genes of miR-1825 were searched in five prediction databases and prognostically significant differentially expressed genes were identified.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were carried out.The ability of CLEC5A to predict OS was evaluated using univariate and multivariate Cox regression analyses and Kaplan-Meier curves.The CLEC5A expression pattern in OC was validated using immunohistochemistry.The CIBERSORT algorithm was used to compare the immune cell landscape,and the results were validated in a GEO cohort.Finally,the predicted half maximal inhibitory concentration(IC50)values for five commonly used chemotherapy agents were also compared.Results:MiR-1825 level was higher in exosomes derived from OC cells and served as a tumor suppressor.The CLEC5A gene was found to be a target of miR-1825,the upregulation of which was correlated with a poor prognosis.M2 macrophage infiltration was significantly enhanced in the CLEC5A high expression group,while T follicular helper cell infiltration was reduced in it.While the predicted IC50 for cisplatin and doxorubicin was higher in the CLEC5A high expression group,that of docetaxel,gemcitabine,and paclitaxel was lower.Conclusion:MiR-1825,a promising OC biomarker,may promote OC progression by increasing CLEC5A expression via exosome-mediated efflux from tumor cells.

The antioxidant trolox inhibits aging and enhances prostaglandin E-2 secretion in mesenchymal stem cells

Mesenchymal stem cells(MSCs)have been widely used in regenerative medicine and clinical therapy due to their capabilities of proliferation,differentiation,and immune regulation.However,during in vitro expansion,MSCs are prone to aging,which largely limits their application.Prostaglandin E-2(PGE-2)is a key effector secreted by MSCs to exert immunomodulatory effects.By screening the compound library for PGE-2 secretion,the antioxidant trolox was verified as a stimulator of MSCs to secrete PGE-2.The effect of antioxidant trolox on biological characteristics of MSCS,including aging,proliferation,and gene expression,was examined.The results demonstrated that trolox can resist aging,promote proliferation,and enhance PGE-2 secretion of MSCs without affecting their surface marker expression.Furthermore,trolox treatment up-regulates miR-17-92 clusters in MSCs and may contribute to its anti-aging effects.Thus,trolox addition might be beneficial for MSCs expansion and their application.

芦竹修复收获物热解过程中重金属的稳定性（英文）

芦竹修复收获物的热解过程会造成重金属的二次污染,本文作者研究外加物料Al_2O_3、CaCO_3、FeCl_3和NaOH的添加对热解过程中重金属稳定性的影响。结果表明,当芦竹粉在外加5%Al_2O_3、250°C下热解2 h,37%As和97%Cd固定在芦竹生物炭中;在外加5%CaCO_3、400°C下热解1 h,59%Pb固定在芦竹生物炭中。在芦竹热解最优条件下通过BCR法分析可知,Cd主要以残渣态存在,Pb和As主要以可氧化态存在。由XRD分析可知,As主要存在于Ca_2As_2O_7中,Cd主要存在于Cd(Al Cl4)2、CdPbO_3或CdSO_3中,Pb主要存在于Pb_3O_2SO_4中。

Traffic Sign Recognition Based on CNN and Twin Support Vector Machine Hybrid Model

With the progress of deep learning research, convolutional neural networks have become the most important method in feature extraction. How to effectively classify and recognize the extracted features will directly affect the performance of the entire network. Traditional processing methods include classification models such as fully connected network models and support vector machines. In order to solve the problem that the traditional convolutional neural network is prone to over-fitting for the classification of small samples, a CNN-TWSVM hybrid model was proposed by fusing the twin support vector machine (TWSVM) with higher computational efficiency as the CNN classifier, and it was applied to the traffic sign recognition task. In order to improve the generalization ability of the model, the wavelet kernel function is introduced to deal with the nonlinear classification task. The method uses the network initialized from the ImageNet dataset to fine-tune the specific domain and intercept the inner layer of the network to extract the high abstract features of the traffic sign image. Finally, the TWSVM based on wavelet kernel function is used to identify the traffic signs, so as to effectively solve the over-fitting problem of traffic signs classification. On GTSRB and BELGIUMTS datasets, the validity and generalization ability of the improved model is verified by comparing with different kernel functions and different SVM classifiers.

骨纤维结构不良恶变的病例对照研究

目的:分析骨纤维结构不良(fibrous dysplasia,FD)恶变的生物学行为,探讨恶变诊断的危险因素。方法:回顾性分析北京积水潭医院2006年3月至2017年3月收拾的FD 394例,病理学证实恶变7例为研究组。根据恶变病例的年龄、部位等流行病学资料,按照1:2配对分析同期FD 14例为对照组。对比临床特点、疼痛VAS评分、病灶大小、影像学特征、血液生化指标、随访肿瘤学结果及功能评分进行统计学分析。结果:FD恶变7例,其中男性3例,女性4例。平均随访时间为175(3～396)个月,恶变后平均随访时间为26(3～51)个月。平均和中位年龄分别为45.6岁和47(24～60)岁,其中股骨6例,胫骨1例。2例为单发病灶,5例为全身多发纤维结构不良,2例为初次手术,5例为复发后确诊,恶变距初次手术间隔平均时间为207(37～377)个月。研究组的疼痛(visual analogue scale/score,VAS)评分较对照组显著增高(Z=-3.317,P=0.001),且研究组术后VAS较术前明显改善(Z=-2.384,P=0.017)。研究组较对照组术前碱性磷酸酶(alkline phosphatase,AKP)对比明显增高(Z=-2.314,P=0.021),术前乳酸脱氢酶(lac-tate dehydrogenase,LDH)(Z=-1.269,P=0.205)两组比较均无显著性差异。研究组术后AKP较术前明显下降(Z=-2.366,P=0.018),术后LDH较术前下降(Z=-2.028,P=0.043)。CT扫描发现研究组增强后CT值明显高于对照组增强后CT值(Z=-3.659,P<0.001)。单因素分析表明术前VAS评分、AKP值、皮质破坏、软组织包块和CT增强值5项因素在判断FD恶变具有临床意义。恶变病理分别为骨肉瘤4例,低级别梭形细胞肉瘤2例,未分化多形性肉瘤1例,3例患者接受辅助化疗,2例出现肺转移,1例死亡。术后功能MSTS评分,对照组平均95.0%±3.9%,功能优于研究组86.0%±10.9%(F=5.689,P=0.029)。结论:FD恶变罕见,术前VAS评分、AKP值、皮质破坏、是否存在软组织包块以及CT增强值有助于临床判断是否恶变;广泛外科边界切除为主要治疗方法。

球形石墨增强银-石墨复合材料的摩擦学行为

采用粉末冶金技术分别制备球形石墨(SG)和鳞片石墨(FG)增强的银-石墨复合材料。并用销-盘式摩擦磨损仪在大气环境和3.0N的载荷下研究石墨形貌对银-石墨复合材料(Ag-SG和Ag-FG)摩擦学行为的影响。结果显示,Ag-FG的最低磨损率为3.5×10^-5mm^3/(N·m),而Ag-SG的最低磨损率比Ag-FG低一个数量级,为1.6×10^-6mm^3/(N·m)。Ag-SG和Ag-FG显著不同的摩擦学行为与亚表面裂纹的形成有关。在摩擦过程中,片状石墨的边缘容易发生应力集中,导致Ag-FG亚表面产生裂纹和严重的剥层磨损。然而,在Ag-SG中,球形石墨能有效抑制裂纹的萌生和扩展,从而使银-石墨复合材料具有优异的耐磨性能。

基于UG的混凝土运输车搅拌叶片参数化设计

为提高混凝土运输车的出料性能和搅拌性能,结合搅拌叶片的对数螺旋线参数方程,对Unigraphics NX软件中的UG-OPEN-GRIP模块进行二次开发编程得到搅拌叶片对数螺旋曲线参数化设计。在对螺旋曲线进行光顺性检查后,建立各截面的辅助面并生成叶片曲面。利用尺寸驱动技术,可以方便地对叶片截形进行再修改。

高效液相色谱法检测发酵液中四氢嘧啶及羟基四氢嘧啶

为实现发酵液样品中四氢嘧啶和羟基四氢嘧啶的分离检测,使用高效液相色谱(HPLC)技术建立一种测定中度嗜盐菌发酵液中四氢嘧啶及羟基四氢嘧啶含量的方法。使用乙醇抽提法提取样品,采用Vertex^(TM) NH_(2)(4.6×250 mm,5μm)液相色谱柱对中度嗜盐菌发酵液中四氢嘧啶及四氢嘧啶进行了分析,选用紫外(UV)检测器,对比不同检测条件。通过色谱条件优化,选定了70%乙腈作为流动相,柱温30℃,检测波长210 nm,流速0.8 mL/min。发酵液样品中四氢嘧啶和羟基四氢嘧啶在各自范围内线性关系良好,两种样品的平均回收率在99.2%~102%,精密度偏差在1%~2%范围内,检出限为1.5μg/mL,定量限为5μg/mL,分离度为1.70。该方法检测范围大,具有较好的重复性、分离度及稳定性,适用于发酵液中四氢嘧啶及羟基四氢嘧啶的分离检测。

CTRP9对心血管保护作用的研究进展

补体1q肿瘤坏死因子相关蛋白(CTRP)9是CTRP蛋白家族重要成员,与脂联素高度同源,结构相似。近几年发现CTRP9在动脉粥样硬化、缺血性心脏病(IHD)等心血管疾病中作用广泛。除了经典的调节糖脂代谢、调节内皮功能外,最近的研究显示外源性补充CTRP9能够对缺血心肌发挥保护作用,而且CTRP9在心脏局部特异性高表达,可能是一种重要的心脏因子,参与调节心肌局部微环境,发挥心肌保护作用,本文将就CTRP9在心血管保护方面的研究进展进行综述。

弥漫大B细胞淋巴瘤中血清铁蛋白的临床意义

目的探讨弥漫大B细胞淋巴瘤(DLBCL)中血清铁蛋白(SF)的临床意义。方法回顾性分析2015年7月1日至2017年7月1日郑州大学第一附属医院初治且病例资料完整的50例DLBCL患者的病例资料,用多重线性回归方法分析临床指标对SF的影响,由ROC曲线获得SF临界值。通过χ~2检验分析SF临界值在临床分期、预后分级及治疗前后中比值的差异。结果临床分期是SF的影响因素,通过ROC曲线求得SF的临界值为424 ng/ml。Ann Arbor分期研究显示:Ⅲ~Ⅳ期中SF>424 ng/ml的患者比例为56.25%,高于Ⅰ~Ⅱ期的11.11%,差异有统计学意义(χ~2=9.780,P<0.05);通过国际预后指数(IPI)所进行的预后分级研究显示:高中危组和高危组中SF>424 ng/ml的患者比例为54.84%,高于低危组和低中危组的15.79%,差异有统计学意义(χ~2=7.484,P<0.05)。初治效果比较:SF≤424 ng/ml患者的缓解率为80.00%,高于SF>424 ng/ml患者的30.00%,差异有统计学意义(χ~2=12.500,P<0.05)。结论 SF的临界值424 ng/ml在DLBCL的临床分期、预后分级及治疗效果预测中具有重要意义。

Structure and function of the contactin-associated protein family in myelinated axons and their relationship with nerve diseases

The contactin-associated protein （Caspr） family participates in nerve excitation and conduction, and neurotransmitter release in myelinated axons. We analyzed the structures and functions of the Caspr family- CNTNAP1 （Casprl）, CNTNAP2 （Caspr2）, CNTNAP3 （Caspr3）, CNTNAP4 （Caspr4） and CNTNAP5 （Caspr5）, Casprl-5 is not only involved in the formation of myelinated axons, but also participates in maintaining the stability of adjacent connections. Casprl participates in the formation, differentiation, and proliferation of neurons and astrocytes, and in motor control and cognitive function. We also analyzed the relationship between the Caspr family and neurodegenerative diseases, multiple sclerosis, and autoimmune encephalitis. However, the effects of Caspr on disease course and prognosis remain poorly understood. The effects of Caspr on disease diagnosis and treatment need further investigation.

石墨相氮化碳可见光下活化过一硫酸盐氧化降解光惰性邻苯二甲酸二甲酯的机理研究（英文）

近几年过一硫酸盐(PMS)活化技术备受关注,其中利用太阳能活化PMS具有可持续和环保的优势,但PMS本身不吸收可见光.因此,本文提出利用具有可见光响应的石墨相氮化碳(g-C3N4)激发产生光电子进而活化PMS.首先利用三聚氰胺前驱体通过热缩聚法制备g-C3N4,通过X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、紫外-可见光漫反射(UV-Vis)、荧光光谱(PL)、透射电镜(TEM)、N2吸附脱附测试(BET)、电化学等一系列方法对g-C3N4进行表征,研究其表面性质及光学性能.结果显示, g-C3N4具有典型的片层结构和可见光活性,禁带宽度为2.7 e V.本文选取光惰性的内分泌干扰物邻苯二甲酸二甲酯(DMP)为目标污染物,系统地研究了其降解动力学和降解机理.研究发现,在短波紫外光(254和300nm)照射下,直接光解和·OH参与的反应机理能实现DMP的光降解,而在可见光照射下g-C3N4介导的光催化过程不能使DMP分解;但当添加PMS时,体系主导自由基由·O2–转化为SO4·–和·OH,从而实现DMP的有效降解和矿化.研究还发现,高浓度的PMS和高剂量的g-C3N4均可以提高PMS的活化量和相应的DMP降解效率,但提高催化剂剂量的方式能更充分的利用PMS.尽管高浓度的DMP阻碍了PMS和光催化剂g-C3N4的有效接触,但可以提高PMS的利用率.当p H低于零电荷点(5.4)时, DMP的降解效率较高.此外,使用两种淬灭剂(乙醇和叔丁醇)与DMP进行竞争性实验,结合电子自旋共振检测,表明SO4·–和·OH都是体系主要的自由基.此外,还对g-C3N4的可持续性能进行考察,四次循环实验结果显示,该催化剂具有良好的可重复利用性.对DMP降解进行总有机碳测定,发现降低了19%.最后,利用液相色谱质谱联用对DMP降解产物进行定性定量分析,发现DMP主要通过SO4·–和·OH对苯环的攻击以及脂肪族链的氧化断键这两种途径进行降解.综上可见,利用可见光激发g-C3N4产生的光电子能有效活化PMS降解顽固型有机污染物,可为实现太阳能活化PMS技术提供有力的技术参考.