联吡啶基共价三嗪框架负载单位点钴用于光催化分解水产氧

氢能是重要的清洁能源,如何低成本获取氢能是其走向实际应用的重要挑战.利用太阳能驱动半导体光催化剂分解水制氢是解决这一挑战的理想途径之一.光催化全解水包括两个半反应,即析氢反应(HER)和析氧反应(OER).其中,光催化OER半反应涉及四个电子的转移(包括O–H键断裂和O–O键形成),其动力学速率远低于两电子转移的HER半反应,因此被认为是光催化全解水的决速步骤.欲实现高效光催化全解水,首先需解决光催化OER半反应动力学缓慢的问题,因此开发高效的OER光催化剂成为当务之急.受单原子催化剂的启发,本文设计并合成了联吡啶基共价三嗪框架(CTF-Bpy),因CTF-Bpy骨架上存在周期性的联吡啶官能团作为金属配位位点,并且有很好的结晶性以及合适的能带结构,是良好的光催化OER反应载体材料.然后通过简单的浸渍配位处理,将单位点的钴作为助催化剂引入到CTF-Bpy中,并用于光催化OER.X射线光电子能谱和X射线近边吸收光谱结果表明,钴是以单位点的Co^(2+)形式存在的.在可见光(λ≥420 nm)照射下,CTF-Bpy-Co在初始1 h内的平均析氧速率为3359μmolg^(–1)h^(–1),5 h内的平均析氧速率为1503μmolg^(–1)h^(–1),光催化性能超过大多数多孔有机聚合物基光催化剂.在420 nm单波长氙灯照射下,CTF-Bpy-Co的光催化析氧表观量子产率(AQY)为0.466%.此外,CTF-Bpy-Co可实现连续析氧40 h,总析氧量可达到180μmol.为明确单位点钴在光催化OER中所起的重要作用,采用相同钴含量的不同形式钴基粒子(游离的Co^(2+),Co,CoO,Co_(2)O_(3)和Co(OH)_(2))作为助催化剂引入CTF-Bpy骨架中进行对比.结果发现,配位的CTF-Bpy-Co表现出最好的光催化析氧效果,表明单位点钴在光催化OER中具有较大的优势.采用密度泛函理论研究了CTF-Bpy-Co的差分电荷密度,并结合上述实验结果提出了CTF-Bpy-Co光催化OER的机理:在可见光激发下,CTF-Bpy-Co光催化剂产生了光生电子和空穴,然后光生电子和空穴被分离并转移到光催化剂与水之间的界面.差分电荷密度证实了电子主要分布于三嗪位点周围,被Ag^(+)迅速捕获生成Ag纳米颗粒;空穴主要分布在Bpy-Co附近,单位点钴可以作为空穴的捕获中心,迅速将Co^(2+)氧化为更高价态的Co^(3+),并与界面上的水分子发生氧化反应产生氧气回到基态,完成整个光催化分解水反应循环.综上所述,为了解决光催化OER的瓶颈问题,本文提出了在催化剂中引入单位点金属助催化剂的策略,显著提升了光催化析氧性能.本研究也为实现更高效的无牺牲剂条件下的光催化全解水提供参考.

Failure mechanism and influencing factors of cement sheath integrity under alternating pressure

The failure of cement sheath integrity can be easily caused by alternating pressure during large-scale multistage hydraulic fracturing in shale-gas well.An elastic-plastic mechanical model of casing-cement sheath-formation(CSF)system under alternating pressure is established based on the Mohr-Coulomb criterion and thick-walled cylinder theory,and it has been solved by MATLAB programming combining global optimization algorithm with Global Search.The failure mechanism of cement sheath integrity is investigated,by which it can be seen that the formation of interface debonding is mainly related to the plastic strain accumulation,and there is a risk of interface debonding under alternating pressure,once the cement sheath enters plasticity whether in shallow or deep well sections.The matching relationship between the mechanical parameters(elastic modulus and Poisson's ratio)of cement sheath and its integrity failure under alternating pressure in whole well sections is studied,by which it has been found there is a“critical range”in the Poisson's ratio of cement sheath.When the Poisson's ratio is below the“critical range”,there is a positive correlation between the yield internal pressure of cement sheath(SYP)and its elastic modulus.However,when the Poisson's ratio is above the“critical range”,there is a negative correlation.The elastic modulus of cement sheath is closely related to its Poisson's ratio,and restricts each other.Scientific and reasonable matching between mechanical parameters of cement sheath and CSF system under different working conditions can not only reduce the cost,but also protect the cement sheath integrity.

金属粉末注射成型制备血管支架的实验动物生物相容性

通过临床动物实验评价金属注射成型(MIM)制备的新型血管支架的可行性与安全性。采用粉末注射成型技术制备血管支架,大幅提高材料利用率;研究MIM过程中碳杂质含量变化对316L不锈钢力学性能与耐腐蚀性能的影响;同时开展MIM血管支架的体外毒性测试与动物实验以评价支架的安全性。结果表明,316L不锈钢的性能对碳含量变化极为敏感,在MIM制备过程中应该对碳含量波动实施精准控制。所有MIM血管支架都成功植入狗的主动脉血管,MIM 316L不锈钢支架未出现明显毒性,能够稳定维持支架形状及结构,快速实现内皮化过程,呈长期植入通畅性。采用MIM技术制备的新型血管支架具备合适的结构、物理以及化学稳定性和生物相容性,在临床实践中具有广阔应用前景。

抹茶味花生蔓越莓牛轧糖的工艺研究

以棉花糖、奶粉、黄油为主要原料,抹茶粉、花生、蔓越莓为辅料,采用感官评定为参考指标,通过单因素试验和正交试验,确定抹茶味花生蔓越莓牛轧糖的最佳生产工艺条件。试验结果为:当棉花糖用量为100 g、黄油用量为30 g、奶粉用量为40 g、抹茶粉用量为6 g、花生用量为50 g、蔓越莓用量为10 g、熬制时间为1.5 min时,所生产的牛轧糖具有抹茶特有的淡香味,糖体甜而不腻,软硬程度适中,咀嚼性好,口感最佳。经微生物的检测其指标符合国家规定的标准。

中希比雷埃夫斯港项目运营风险及防范

比雷埃夫斯港项目被称作中国和希腊投资合作的典范,目前该项目运营仍面临内部人事、公关、组织与管理等方面的整合风险和希腊周边地缘政治、经济、法律和社会文化风险,需要中国和希腊政府及相关企业密切沟通与合作,有效防范比雷埃夫斯港项目运营风险。

微波消解-原子荧光光谱法同时测定化妆品中砷、锑、铅和汞

建立了微波消解-原子荧光光谱法同时检测化妆品中砷、锑、铅和汞4种有害元素含量的方法。经微波消解仪消解的样品溶液,在预处理加热仪上120℃赶酸后,用氢化物发生双道原子荧光光谱仪以1.0%硝酸为载流,5.0%硫脲-抗坏血酸为还原剂同时测定砷、锑、铅和汞。结果表明,砷、锑、铅和汞4种元素在相应的浓度范围内线性良好,相关系数R^2分别为0.9993,0.9984,0.9973和0.9997。4种元素的加标回收率为91.7%~101.9%。此方法具有操作简便、快速、线性范围宽、适用性强等优点。

A new tumor-associated antigen prognostic scoring system for spontaneous ruptured hepatocellular carcinoma after partial hepatectomy

Objective:Spontaneous hepatocellular carcinoma(HCC)rupture can be fatal,and hepatic resection could achieve a favorable long-term survival among all strategies of tumor rupture.However,there is no available prognostic scoring system for patients with ruptured HCC who underwent partial hepatectomy.Methods:From January 2005 to May 2015,129 patients with spontaneous HCC rupture underwent partial hepatectomy.Preoperative clinical data were collected and analyzed.Independent risk factors affecting overall survival(OS)were used to develop the new scoring system.Harrell’s C statistics,Akaike information criterion(AIC),the relative likelihood,and the log likelihood ratio were calculated to measure the homogeneity and discriminatory ability of a prognostic system.Results:In the multivariable Cox regression analysis,three factors,including tumor size,preoperativeα-fetoprotein level,and alkaline phosphatase level,were chosen for the new tumor-associated antigen(TAA)prognostic scoring system.The 1-year OS rates were 88.1%,43.2%,and 30.2%for TAA scores of 0–5 points(low-risk group),6–9 points(moderate-risk group),and 10–13points(high-risk group),respectively.The TAA scoring system had superior homogeneity and discriminatory ability(Harrell’s C statistics,0.693 vs.0.627 and 0.634;AIC,794.79 vs.817.23 and 820.16;relative likelihood,both<0.001;and log likelihood ratio,45.21 vs.22.77 and 21.84)than the Barcelona Clinic Liver Cancer staging system and the Cancer of the Liver Italian Program in predicting OS.Similar results were found while predicting disease-free survival(DFS).Conclusions:The new prognostic scoring system is simple and effective in predicting both OS and DFS of patients with spontaneous ruptured HCC.

Improved single image dehazing using dark channel prior

An improved single image dehazing method based on dark channel prior and wavelet transform is proposed. This pro-posed method employs wavelet transform and guided filter instead of the soft matting procedure to estimate and refine the depth map of haze images. Moreover, a contrast enhancement method based on just noticeable difference （JND） and quadratic function is adopted to enhance the contrast for the dehazed image, since the scene radiance is usual y not as bright as the atmospheric light, and the dehazed image looks dim. The experimental results show that the proposed approach can effectively enhance the haze ima-ge and is wel suitable for implementing on the surveil ance and obstacle detection systems.

转向个体实践取向的文化全球化与本土化研究探析

以本土"文化形式"对全球流通的"文化质料"进行灵活多样地解读与使用,是理解文化全球化与本土化并行发生、全球化时代文化多样性维续生成的重要分析维度。这一分析最终要落实到以个体行动者特别是"关键行动者"的实践为分析单位和对象。中国对外文化传播应借助人类学民族志田野研究这一有力的方法工具,加强对各国文化本土特色的了解与尊重,并借靠本土关键行动者的力量来推动中国文化的在地融入。

Short-term results in canines of novel stent-graft design for chimney technique in TEVAR

Introduction:Parallel stent-stent grafting is a major endovascular technique used to preserve the supra-aortic branches during thoracic endovascular aortic repair(TEVAR)of aortic pathologies involving the aortic arch.The short-and mid-term results of this technique are satisfactory;however,endoleak remains a major concern.Thus,here we designed a new chimney stent-graft to decrease the endoleak rate.Aim:To testify the feasibility and safety of the new chimney stent-graft system in a canine model.Material and methods:Six Labrador retrievers were used.Pre-operative data were collected and all operations were performed under general anesthesia.The main and chimney stent-grafts were implanted through the abdominal aorta and left subclavian artery approaches,respectively.Completion digital subtraction angiography(DSA)was performed to confirm the immediate outcomes.All dogs were fed separately for 6 months and sacrificed after aortic angiography.The thoracic aorta and the main and chimney stent-grafts were harvested for histopathologic examination.Results:No complications were found in follow-up DSA.All branch arteries were patent.In?ammatory responses were observed around the stent-grafts in 3 experimental animals,and slight hyperplasia was observed in the surrounding tissues compared with the normal vessels.There was no mural thrombus in the stent,endothelial cells were noted on the inner surface of the stent,and thrombus was formed in the outer skirt and gutter area.The histopathologic examinations revealed similar results to those of gross necropsy observations.Conclusions:This study demonstrated the feasibility and safety of the Longuette stent-graft and the first to report a revised stent-graft specific for chimney technique.

Magnetic nanoparticle drug targeting to patient-specific atherosclerosis: effects of magnetic field intensity and configuration

Nanoparticle-mediated drug delivery is recognized as a promising option for targeted treatment of atherosclerosis. In this paper, the Eulerian-Lagrangian technique is adopted to simulate the delivery of drug-loaded nanoparticles to patient-specific atherosclerotic plaque with the aid of an external magnetic field. Plaques and vascular walls are introduced as porous media formulated by the Darcy-Forchheimer model in this targeted transport process. The results demonstrate that the delivery efficiency of particles to atherosclerosis depends on the external magnetic field, such as configuration and intensity, in which the configuration angle of the current wire is a key factor and the double current wires have advantages over the single current wire. Meanwhile, the delivery efficiency gradually decreases as the distance between the plaque cap and the current wire increases. Further, although augmenting the current or magnetic susceptibility can generally improve the delivery efficiency of nanoparticles, this increase is not apparent when small-sized nanoparticles are employed as drug transport particles. The results obtained can potentially serve as the guideline to optimize regimens for the targeted therapy of atherosclerosis.

A coupled immersed boundary-lattice Boltzmann method and its simulation for biomimetic problems

A coupled immersed boundary-lattice Boltzmann method （IB-LBM） is introduced to solve biomimetic problems. Compared to the conventional IB-LBM, the strict satisfaction of no-slip boundary condition is implemented in the current method. Consequently, the phenomenon of flow penetration that is frequently observed in the conventional IB-LBM is fully prevented, and subsequently the force on the boundary can be calculated more accurately. This feature is of importance for the simulation of biomimetic problems. Moreover, by applying the relationship between the velocity correction and forcing term, the boundary force can be calculated easily. Several biomimetic problems are then simulated. Based on the good agreement between the current results and those in the literature, it may be concluded that the present IB-LBM has the capabilitv to handle various biomimetic oroblems.

ED7阴极电泳漆在车身电泳槽的混用

对ED6(第六代)阴极电泳漆与ED7(第七代)阴极电泳漆的混溶试验和在汽车涂装线上的混槽工作进行了论述,对混槽过程中相关性能进行了分析对比和测试,并肯定了ED7阴极电泳漆的优异性能。

Growth marks in eyestalks of Portunus trituberculatus:A development of technique and evidence of molting

The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of the swimming crab(Portunus trituberculatus).We found that dark pigmentation as a result of boiling has an influence on the observation of the eyestalk microstructure.Choosing an unboiled eyestalk,this study compared the cross section and longitudinal section,and concluded that the cross section is suitable for the observation of growth increments with 6.1%CV(coefficient of variation),and growth bands are suitable for the observation of the longitudinal section with 5.4%CV.The width of growth increments near the edge of the endocuticle is small,and the width of growth increments of the middle part of the endocuticle is large.Relationship of number of growth bands to molting time was fitted to a linear function with the slope not significantly different from 1,indicating that growth bands are formed associated with molting.Periodicity of growth increment formation was calculated as 3.7 d,however was not verified.Our results provide a new improved technique for identification of crustacean molting and growth.

Machine learning of synaptic structure with neurons to promote tumor growth

In this paper,we use machine learning techniques to form a cancer cell model that displays the growth and promotion of synaptic and electrical signals.Here,such a technique can be applied directly to the spiking neural network of cancer cell synapses.The results show that machine learning techniques for the spiked network of cancer cell synapses have the powerful function of neuron models and potential supervisors for different implementations.The changes in the neural activity of tumor microenvironment caused by synaptic and electrical signals are described.It can be used to cancer cells and tumor training processes of neural networks to reproduce complex spatiotemporal dynamics and to mechanize the association of excitatory synaptic structures which are between tumors and neurons in the brain with complex human health behaviors.

新型隧道支护体系钢架选型对比试验研究

新型隧道支护体系采用钢架、连接筋、钢筋网及喷射混凝土组合的方式作为支护手段,及时进行围岩加固,这其中型钢钢架与格栅钢架有增强支护能力,有效加固围岩的作用,但型钢和格栅喷射混凝土初期支护结构的力学性能对比,目前仍没有相关试验研究。基于此问题,按照初支二衬联拱隧道新型支护形式,设置了型钢和格栅喷射混凝土结构进行试验,除此之外,为优化型钢喷混初支结构,试验改变了纵向连接筋的连接形式,通过室内加载试验,得到结论如下:(1)采用插入式的纵向连接筋连接,更能够优化型钢喷混初支结构,提高结构的整体刚度和承载力水平,但主要影响在加载后期;(2)在受荷相同时,型钢比格栅刚度大,提升承载力的效果更好,但其与混凝土的粘结力差。

Quantitative determination of metaxalone in human plasma by LC-MS and its application in a pharmacokinetic study

A simple and rapid method using liquid chromatography–mass spectrometry(LC-MS) for the determination of metaxalone in human plasma has been developed and validated.Letrozole was used as the internal standard(IS). The plasma samples were simply treated with acetonitrile which allowed the precipitation of plasma proteins. The chromatographic separation was achieved on a Sapphire C18(2.1 mm × 150 mm, 5 μm, Newark, USA)column using the mobile phase(5 mM ammonium acetate containing 0.01% formic acid:acetonitrile(45:55, v/v)) at a flow rate of 0.3 ml/min. The selected ion monitoring(SIM) in the positive mode was used for the determination of [M + H]+m/z 222.1 and 286.1 for metaxalone and letrozole, respectively. The standard curve obtained was linear(r2≥ 0.99)over the concentration range of 30.24-5040 ng/ml. Meanwhile, no interfering peaks or matrix effect was observed. The method established was simple and successfully applied to a pharmacokinetic study of metaxalone in healthy Chinese volunteers after a single oral dose administration of 800 mg metaxalone. The main pharmacokinetic parameters of metaxalone were as follow: Cmax,(1664 ± 1208) ng/ml and(2063 ± 907) ng/ml;AUC0-36,(13925 ± 6590) ng/ml h and(18620 ± 5717) ng/ml h;t1/2,(13.6 ± 7.7) h and(20.3 ± 7.7) h for the reference and test tablets, respectively. These pharmacokinetic parameters of metaxalone in healthy Chinese volunteers were reported for the first time.

Clinical Analysis on the Effectiveness of Transvaginal Cervical Cerclage in Singleton Pregnancies and Its Predictive Factors

Objective: To evaluate the effectiveness of transvaginal cervical cerclage in singleton pregnancies with cervical incompetence, determine the predictive factors of success and failure, and then compare elective and emergency cerclage. Study Design: This was a retrospective study of 62 patients who underwent cervical cerclage in The First Hospital of Jilin University, China, between May 2015 and January 2018. Successful group was defined as those who delivered live babies and failure group who experienced abortion or stillbirth. Results: Out of 104 patients, 62 met inclusion criteria. In 62 cases, 47 (75.8%) succeeded and 15 (24.2%) failed. In successful group, 21 (44.7%) women delivered pretermly and 26 (55.3%) termly. No severe complications occurred except cervical laceration (2, 3.23%), premature rupture of membranes (13, 20.97%). In 62 cases, 40 (64.5%) have ≤2 previous second-trimester losses and 22 (35.5%) have >2 previous second-trimester losses. No significant differences were found in neonatal outcomes. Analysis revealed that higher postoperative C-reactive protein and presence of premature rupture of membranes were the strongest predictors of cerclage failure. Among 62 cases, 48 (77.4%) were allocated in elective and 14 (22.6%) in emergency cerclage. Pregnancy prolongation was significantly more (P = 0.014) in elective group with no significant differences in premature rupture of membranes, neonatal outcomes (all P > 0.05) except Apgar score at 5 min (P = 0.042). Conclusion: Achieving 75.8% live births proves that transvaginal cervical cerclage is an effective and safe technique in prolonging the gestational age, improving the obstetric outcomes in singleton pregnancies with cervical incompetence under various cerclage indications. Postoperative C-reactive protein and premature rupture of membranes are the predictive factors related to success or failure. Elective cerclage is more effective in prolonging the pregnancy compared to emergency cerclage, no significant differences are seen regarding neonatal outcomes and complications.

靠近体验与缩短距离:对人类学生命史研究方法的反思

现代西方人类学发展的一大趋向是对他者社会中个体主体体验的关注日渐增强,在本体论、认知论、方法论上对体验议题进行过颇富成效的探索。人类学生命史研究方法专注于回构特定主体在生命周期各阶段的生活经历体验,突显出有效获知他者体验的方法效度和文本价值。本文将简要回顾该方法发展史,并基于对三本经典人类学生命史民族志的评述,探讨人类学研究获知他者体验的一个关键方法论问题:如何缩短研究者和信息提供者在人际关系和体验理解上的双重距离,以激发信息提供者对个人体验的真诚讲述和达成研究者对他者体验的精确理解阐释。恰当处理这两个距离,对于最大限度发挥生命史以及其他以体验为导向的民族志研究对个人体验的真实呈现作用至关重要。

Biomarkers for early diagnosis of autism obtained through bioinformatics analysis of human blood sample

Objective:autism spectrum disorder(ASD),a serious disorder that begins early in life,con-tinues throughout the lifespan.Children with ASD who are diagnosed early are more responsive to therapeutic interventions and have less social and language impair-ment than children diagnosed later;however,current di-agnostic measures are mostly applied to children older than one year and lack the appropriate biological markers for early diagnosis of ASD.Using bioinformatic analy-sis,this study explores the molecular information mech-anism of ASD.Method:in this study,we used dataset GSE6575 from Gene Expression Omnibus(GEO)to an-alyze the mRNA expression profile of ASD,including 35 ASD samples and 12 normal control samples looking for different genes and we did enrichment analysis of those genes.We then used the STRING database to construct a protein-protein interaction(PPI)network of differential genes.Finally,Cytoscape plug-in cytoHubba was used to search for hub genes.The diagnostic value of the hub genes was verified by subject operating characteristic curves.Result:we looked for 50 different genes and did an enrichment analysis of those genes.The results of the enrichment analysis showed that these differential genes were mainly concentrated in the response to viruses,the immune regulation of inflammation and energy metabo-lism.Using Cytoscape plug-in cytoHubba,we found ten different genes.We drew ROC curves for all ten genes among which two genes,interleukin 2 receptor subunit beta(IL2Rβ)and perforin 1(PRF1),had good sensitivity and specificity for the early diagnosis of autism.The ar-eas under the ROC curves were 0.855,0.830 for IL2Rβ,PRF1.Conclusion:data analysis using the GEO data-base can provide new insights into the etiology of ASD as well as some possible biomarkers and therapeutic targets for early diagnosis and treatment of ASD.