The Active Sites of the Reference Phase of SmVO_4 as Catalyst for Propane Oxidative Dehydrogenation

The active sites of samarium orthovanadate(SmVO 4) were studied by means of ESR, NO TPD and temperature programmed 18 O 2 isotope exchange(TPIE) methods. The results of ESR and NO TPD confirm the presence of V 4+ in the catalyst. The TPIE revealed that the 18 O 2 isotope exchange was carried out through a single exchange procedure. The V 4+ species associated with oxygen vacancies are the sites for O 2 activation.

二维Nb2SiTe4基化合物稳定性、电子结构和光学性质的第一性原理研究

基于第一性原理计算,确定了3种稳定未被报道的Nb2SiTe4基化合物(A2BX4:Nb2SiSe4,Nb2SnTe4和Ta2GeTe4),研究了其电子结构,光学性质以及应力工程对其电子结构的调控.计算结果表明上述3种化合物具有类似Nb2SiTe4的窄带隙值、强的光吸收性能以及显著的光学各向异性,可用于光电器件之中.其晶格常数范围为6.04Å≤a≤6.81Å,7.74Å≤b≤8.15Å.Ta2GeTe4的晶格参数与Nb2SiTe4几乎相同,带隙值减小了0.15 eV,可应用于远红外光探测.应力工程表明外加双轴拉伸应力可减小A2BX4体系带隙值.外加双轴压缩应力时,A2BX4体系价带顶轨道可出现反转(Nb2SiTe4,Nb2GeTe4和Ta2GeTe4),由B位阳离子占据态d轨道主导转变为B位阳离子占据态d轨道与X位阴离子满p轨道共同主导,导致带隙值变化趋势异常.我们预测该价带顶轨道的反转可有效降低空穴有效质量,促进载流子的迁移,有助于器件性能的提升.

Single-Atom Pd–N_(3)Sites on Carbon-Defi cient g-C_(3)N_(4)for Photocatalytic H_(2)Evolution

Photocatalytic hydrogen evolution is an attractive fi eld for future environment-friendly energy.However,fast recombination of photogenerated charges severely inhibits hydrogen effi ciency.Single-atom cocatalysts such as Pt have emerged as an eff ective method to enhance the photocatalytic activity by introduction of active sites and boosting charge separation with low-coordination environment.Herein,we demonstrated a new strategy to develop a highly active Pd single atom in carbondefi cient g-C_(3)N_(4)with a unique coordination.The single-atom Pd–N_(3)sites constructed by oil bath heating and photoreduction process were confi rmed by HADDF-STEM and XPS measurements.Introduction of single-atom Pd greatly improved the separation and transportation of charge carriers,leading to a longer lifespan for consequent reactions.The obtained singleatom Pd loaded on the carbon-defi cient g-C_(3)N_(4)showed excellent photocatalytic activity in hydrogen production with about 24 and 4 times higher activity than that of g-C_(3)N_(4)and nano-sized Pd on the same support,respectively.This work provides a new insight on the design of single-atom catalyst.

A facile sulfur-assisted method to synthesize porous alveolate Fe/g-C3N4 catalysts with ultra-small cluster and atomically dispersed Fe sites

Heterogeneous catalysts with ultra-small clusters and atomically dispersed(USCAD)active sites have gained increasing attention in recent years.However,developing USCAD catalysts with high-density metal sites anchored in porous nanomaterials is still challenging.Here,through the template-free S-assisted pyrolysis of low-cost Fe-salts with melamine(MA),porous alveolate Fe/g-C3N4 catalysts with high-density(Fe loading up to 17.7 wt%)and increased USCAD Fe sites were synthesized.The presence of a certain amount of S species in the Fe-salts/MA system plays an important role in the formation of USCAD S-Fe-salt/CN catalysts;the S species act as a"sacrificial carrier"to increase the dispersion of Fe species through Fe-S coordination and generate porous alveolate structure by escaping in the form of SO2 during pyrolysis.The S-Fe-salt/CN catalysts exhibit greatly promoted activity and reusability for degrading various organic pollutants in advanced oxidation processes compared to the corresponding Fe-salt/CN catalysts,due to the promoted accessibility of USCAD Fe sites by the porous alveolate structure.This S-assisted method exhibits good feasibility in a large variety of S species(thiourea,S powder,and NH4SCN)and Fe salts,providing a new avenue for the low-cost and large-scale synthesis of high-density USCAD metal/g-C3N4 catalysts.

A Universal Principle to Accurately Synthesize Atomically Dispersed Metal–N_4 Sites for CO_2 Electroreduction

Atomically dispersed metal-nitrogen sites-anchored carbon materials have been developed as effective catalysts for CO2 electroreduction(CO2 ER),but they still suffer from the imprecisely control of type and coordination number of N atoms bonded with central metal.Herein,we develop a family of single metal atom bonded by N atoms anchored on carbons(SAs-M-N-C,M=Fe,Co,Ni,Cu)for CO2 ER,which composed of accurate pyrrole-type M-N4 structures with isolated metal atom coordinated by four pyrrolic N atoms.Benefitting from atomically coordinated environment and specific selectivity of M-N4 centers,SAs-Ni-N-C exhibits superior CO2 ER performance with onset potential of-0.3 V,CO Faradaic efficiency(F.E.) of 98.5%at-0.7 V,along with low Tafel slope of 115 mV dec-1 and superior stability of 50 h,exceeding all the previously reported M-N-C electrocatalysts for CO2-to-CO conversion.Experimental results manifest that the different intrinsic activities of M-N4 structures in SAs-M-N-C result in the corresponding sequence of Ni> Fe> Cu> Co for CO2 ER performance.An integrated Zn-CO2 battery with Zn foil and SAs-Ni-N-C is constructed to simultaneously achieve CO2-to-CO conversion and electric energy output,which delivers a peak power density of 1.4 mW cm-2 and maximum CO F.E.of 93.3%.

Numerical Simulation for Remediation Planning for 1,4-Dioxane-Contaminated Groundwater at Kuwana Illegal Dumping Site in Japan Based on the Concept of Verified Follow Up

At Kuwana illegal dumping site in Japan, where hazardous waste was illegally dumped, groundwater was severely contaminated by Volatile Organic Compounds (VOCs). Groundwater was already remedied by conducting Pump-and-Treat (P&T) after containment of all the waste by vertical slurry walls from 2002 to 2007. However, 1,4-dioxane was detected in both waste and groundwater outside of slurry walls after it was newly added into Japan environmental standards in late 2009, which suggested that the walls did not contain 1,4-dioxane completely. Our previous study developed a model to predict the 1,4-dioxane distribution in groundwater after the previous remediation at the site. In this study, numerical simulation was applied for remediation planning at the site based on the concept of Verified Follow Up (VF-UP) that had been proposed as a new approach to complete remediation effectively with consideration of future risks. The amount of waste to be removed and pumping plans were discussed by numerical simulation to achieve the remedial objective in which 1,4-dioxane in groundwater outside of walls is remedied within 10 years and 1,4-dioxane spreading throughout the walls is prevented in the case where a portion of waste is remained. Firstly, the amount of waste to be removed considering pumping plans for P&T was determined by scenario analysis. As a result, at least two-third of waste should be removed by combining with P&T. However, if the waste is remained, future risks of 1,4-dioxane spreading through the slurry walls may occur. Our simulation suggested that groundwater within the remaining waste must be pumped up at least 20 m3/d for containment of 1,4-dioxane within the remaining waste. In conclusion, our numerical simulation determined the amount of waste to be removed and the pumping plans for P&T to achieve the remedial objective effectively considering future risks based on the concept of VF-UP.

SYNTHESIS AND STRUCTURE OF A LINEAR TRIVANADIUM COMPOUND(Ph_4P)[V_3(OC_6H_4S-o)_6]-SIMULATION OF THE VANADIUM SITE OF ALTERNATIVE NITROGENASE

Compound(Ph_4P)[V_3MP_6](MPH_2=o-HOC_6H_4SH)was obtained by reaction of VCl_3 and Na_2MP in ethanol in the presence of Ph_4PBr.It is triclinic and crystallizes in space group P1,fw=1237.3,a=14.127(4), b=14.342(4),c=15.878(4);α=65.08(2),β=73.09(2),T=78.68(2)°;V=2781.3~3, Z=2,d_c=1.48 g/cm^3.Final R factor is 0.063.The three vanadium atoms are linearly arranged and bridged by the oxygen atoms and terminally chelated by the thiolato-atoms of the six MP^2-ligands in pseudo-S_6 symmetry.

Expression of hepatocyte nuclear factor 4 alpha,wingless-related integration site,andβ-catenin in clinical gastric cancer

BACKGROUND Gastric cancer(GC)is the second most common cause of cancer-related deaths worldwide.Hepatocyte nuclear factor 4 alpha(HNF4α)that belongs to the nuclear hormone receptor superfamily,is overexpressed in GC tissues,and might be involved in the development of GC by regulating its downstream winglessrelated integration site(WNT)/β-catenin signaling.AIM To clarify the expression of HNF4α/WNT5a/β-catenin signaling proteins in clinical GC tissues.METHODS We immunohistochemically stained pathological blocks of GC and matched paracancerous tissues.The intensity of HNF4α,WNT5a andβ-catenin staining in the tumor cells was determined according to cell rates and staining intensity.The correlations between GC and HNF4α,WNT5a,andβ-catenin expression using chisquare and paired chi-square tests.Relationships between double-positive HNF4αand WNT5a expression and types of gastric tumor tissues were assessed using regression analysis.Correlations between HNF4αand WNT5a expression at the RNA level in GC tissues found in the TCGA database were analyzed using Pearson correlation coefficients.RESULTS We found more abundant HNF4αand WNT5a proteins in GC,especially in mucinous adenocarcinoma and mixed GC than in adjacent tissues(P<0.001).Low and high levels of cytoplasmicβ-catenin respectively expressed in GC and adjacent tissues(P<0.001)were not significantly associated with pathological parameters.CONCLUSION The expressions of HNF4αand WNT5a could serve as early diagnostic biomarkers for GC.

Accurate design of spatially separated double active site in Bi_(4)NbO_(8)Cl single crystal to promote Z-Scheme photocatalytic overall water splitting

The efficiency of photocatalytic overall water splitting was mainly limited by the slow reaction kinetics of water oxidation.How to design effective surface active site to overcome the slow water oxidation reaction was a major challenge.Here,we propose a strategy to accelerate surface water oxidation through the fabrication spatially separated double active sites.FeCoPi/Bi_(4)NbO_(8)Cl-OVs photocatalyst with spatially separated double active site was prepared by hydrogen reduction photoanode deposition method.Due to the high matching of the spatial loading positions of FeCoPi and OVs with the photogenerated charge distribution of Bi_(4)NbO_(8)Cl and corresponding reaction mechanisms of substrate,the FeCoPi and OVs on the(001)and(010)crystal planes of Bi_(4)NbO_(8)Cl photocatalyst provided surface active site for water oxidation reaction and electron shuttle reaction(Fe^(3+)/Fe^(2+)),respectively.Under visible light irradiation,the evolution O_(2)rate of FeCoPi/Bi_(4)NbO_(8)Cl OVs was 16.8μmol h^(-1),as 32.9 times as Bi_(4)NbO_(8)Cl.Furthermore,a hydrogen evolution co-catalyst PtRu@Cr_(2)O_(3)was prepared by sequential photodeposition method.Due to the introduction of Ru,the Schottky barrier between PbTiO_(3)and Pt was effectively reduced,which promoted the transfer of photogenerated electrons to PtRu@Cr_(2)O_(3)thermodynamically,the evolution H_(2)rate on PtRu@Cr_(2)O_(3)/PbTiO_(3)increased to 664.8 times.On based of the synchronous enhancement of the water oxidation performance on FeCoPi/Bi_(4)NbO_(8)Cl-OVs and water reduction performance on PtRu@Cr_(2)O_(3)/PbTiO_(3),a novel Z-Scheme photocatalytic overall water splitting system(FeCoPi/Bi_(4)NbO_(8)Cl-OVs)mediated by Fe^(3+)/Fe^(2+)had successfully constructed.Under visible light irradiation,the evolution rates of H_(2)and O_(2)were 2.5 and 1.3μmol h^(-1),respectively.This work can provide some reference for the design of active site and the controllable synthesis of OVs spatial position.On the other hand,the hydrogen evolution co catalyst(PtRu@Cr_(2)O_(3))and the co catalyst FeCoPi for oxygen evolution contributed to the construction of an overall water splitting system.

产教融合视角下数控技术专业“3-3-4-4”现场工程师培养模式创新与实施

随着制造业发展,数控技术日益重要。基于数控技术地位和人才需求,提出“3-3-4-4”现场工程师培养模式:三岗融合(智能数控、机械、安全工程师)、三大基础(院校、产业园区、政府产教联合体)、四类课程(安全、素养、技能、创新拓展)、四类面向(在校生、企业员工、待业者、海外培训人员)。该模式体现产教融合和实践导向,就课程设置、实践环节、教学团队建设等提出策略,培养适应现代制造业需求的高素质数控技术人才。

HMB-4型液压弹簧操作机构频繁打压故障的现场检修

HMB-4型液压弹簧操作机构因其结构紧凑、可靠性高、传动效率高等优点,逐渐得到广泛应用,但与其他型号的液压操作机构相比,现场检修经验缺乏。以国网浙江省电力公司嘉兴供电公司一起HMB-4型液压弹簧操作机构频繁打压故障的现场消缺为例,通过对频繁打压故障原因的分析,以现场实际检修经验为依据,总结该型号操作机构频繁打压故障的现场检修策略,为今后现场检修提供依据。

AVP_（4－8）结合点在大鼠海马内的分布和AVP_（4－8）对其受体发育的影响：放射自显影研究

本文利用放射自显影方法结合神经毒对海马神经元的选择性损毁观察ＡＶＰ（４－８）结合点在大鼠海马内的分布和定位；利用外源性ＡＶＰ（４－８）对新生大鼠的处理，观察海马ＡＶＰ（４－８）结合点的发育调节。在成年大鼠海马内，ＡＶＰ（４－８）结合点集中分布在整个海马的锥体细胞层和齿回的颗粒细胞层。秋水仙碱处理后，齿回颗粒细胞层消失，齿回区的ＡＶＰ（４－８）结合点也消失。红藻氨酸（Ｋａｉｎｉｃａｃｉｄ）处理后海马ＣＡ３－ＣＡ４的锥体细胞层消失，该区的ＡＶＰ（４－８）结合点也消失。新生大鼠海马锥体细胞层的ＡＶＰ（４－８）结合点在出生后第６天开始出现，齿回颗粒细胞层的ＡＶＰ（４－８）结合点在出生后第７天开始出现。然而，新生大鼠每天经外源性ＡＶＰ（４－８）处理，海马锥体细胞层和齿回颗粒细胞层的结合点均在出生后第５天已变得十分稠密。本文就大鼠海马ＡＶＰ（４－８）结合点的特异性分布和ＡＶＰ（４－８）处理促进海马ＡＶＰ（４－８）结合点的发育与成年后大鼠学习能力的提高的相互关系作了讨论。

登革4型病毒Ban18原株及其减毒株的分子特征研究

目的从分子水平上探讨登革4型病毒Ban18-30减毒株的毒力相关位点和减毒机制。方法Ban18原株及Ban18-30减毒株在Vero细胞中培养增殖,收集病毒液,经RNA抽提后RT-PCR扩增C、prM、E、NS1和3′、5′端核苷酸片段并测序,比较分析结果,研究两株病毒的分子特征。结果RT-PCR成功扩增出目的片段,对两株病毒部分基因测定序列后进行对比分析,两株病毒间在C111位和E155位各有1个氨基酸残基发生变化,在3′UTR的219位发生核苷酸改变。结论从分子水平证明两株病毒确为DEN-4型病毒,某些基因位点的变化与Ban18-30株病毒毒力减弱有关,其中E155位的突变可能关系最大。

4年制临床医学检验专业教学模式的探讨

医学检验是一门涉及多个学科的临床应用性学科。笔者以目前医学检验专业从5年制转入4年制为切入点,通过分析多年在临床本科生教学工作中所遇到的问题,提出教学应以学为主、教为辅,探讨临床检验专业教学新模式。东莞东华医院检验科根据自身经验与教学理论和实践缺一不可发展的宗旨,主动变革,探索采用临床现场教学为主与各种教学方式并存的教学方案培养新一代医学检验专业检验人才。

负载型硫酸铁对烯烃齐聚催化作用的研究 Ⅲ.Fe_2(SO_4)_3/γ-Al_2O_3的表征

用ＸＲＤ方法对Ｆｅ２（ＳＯ４）３／γ－Ａｌ２Ｏ３催化剂进行了表征，发现在Ｆｅ担载量不大于７ｗ％时，Ｆｅ２（ＳＯ４）３单层分散在γ－Ａｌ２Ｏ３的表面上。ＩＲ检测结果表明，在该催化剂表面上Ｌ酸中心与Ｂ酸中心共存，Ｌ酸量与Ｂ酸量的比例随焙烧温度的升高而增大。

基于MRI确定Cierny-Mader 4期慢性骨髓炎截骨范围的临床研究

目的确定一种适用于Cierny-Mader 4期慢性骨髓炎患者的最佳截骨标准。方法选取山东中医药大学附属医院骨科自2014年1月至2016年3月期间收治的Cierny-Mader 4期慢性骨髓炎患者70例进行回顾性分析研究,其中以X线为向导者30例,以MRI为向导者40例。所有患者均在影像学资料向导下进行彻底病灶清除后外固定架固定治疗。术后应用敏感抗生素,定期随访,检测静脉血C反应蛋白(CRP)、血沉(ESR)、血常规(白细胞WBC、中性粒细胞绝对值NEUT#、中性粒细胞百分比NEUT%)以及肌力(MTT评定表)、肌张力(肌张力评定量表)、关节活动度(中立位0°法)、协调和平衡能力(简易平衡评定法)、骨性愈合时间等指标,观察骨髓炎复发率,并依据Enneking评分标准评估患者的肢体功能恢复情况。结果所有病例均得到随访,平均随访(12.2±3.2)月,以X线为向导的Cierny-Mader 4期慢性骨髓炎患者复发率为16.7%,明显高于以MRI为向导的患者复发率(7.5%),且以MRI为向导的肢体功能恢复情况(优良率87.5%)明显优于以X线为向导者(优良率66.7%),两组数据差异有统计学意义(P<0.05)。结论以MRI为向导确定Cierny-Mader 4期慢性骨髓炎的病灶范围,并据此分别向远近端扩大0.5 cm进行截骨的方法具有治疗复发率低、肢体功能恢复良好的优点,是Cierny-Mader 4期慢性骨髓炎的最佳病灶清除标准。

双参数流式细胞术检测Molt-4和Jurkat细胞膜受体途径凋亡的始动位点

目的：建立稳定的膜受体途径的细胞凋亡模型，探讨Cyclin／DNA双参数流式细胞术检测膜受体途径细胞凋亡的周期特异性的方法。方法：用典型的受体途径诱导剂TNF-α分别处理Molt-4、Jurkat以及健康人外周血淋巴细胞；应用膜联蛋白V（AnnexinV）／碘化丙啶（PI）、API和Cyclin／DNA双参数流式细胞术等方法检测细胞凋亡。结果：AnnexinV／PI法检测早期凋亡细胞，早期凋亡率控制在8％～18％的周期特异性凋亡模型最典型；API法显示膜受体介导的细胞凋亡主要发生在细胞周期的G，期。Cyclin／DNA双参数流式细胞术显示受体途径的细胞周期特异性细胞凋亡的始动位点为G．早期。结论：应用AnnexinV／PI和API法能为建立稳定而典型的受体途径周期特异性细胞凋亡模型提供技术支撑；Cyclin／DNA双参数流式细胞术能够精确显示受体途径的细胞周期特异性细胞凋亡的始动位点。

SiCl_4、PPh_3促进的TiCl_4/Ni(acac)_2复合催化剂的乙烯聚合研究

制备了SiCl4、PPh3促进的MgCl2 -SiO2 -ZnCl2 为载体 ,TiCl4/Ni(acac) 2 为主催化剂的A、B型乙烯聚合高效催化剂。研究了SiCl4、PPh3对乙烯气相聚合的影响 ,发现SiCl4能大幅度提高催化效率 ,PPh3使催化效率出现峰值。用DSC、IR、1 3CNMR对聚合产物进行结构性能的分析和表征。结果表明 ,TiCl4/Ni(acac) 2 组成的复合催化剂较单一Ti系催化剂的聚合产物熔点、结晶度、密度、相对分子质量明显降低。添加PPh3的B型催化剂获得了支化度为 3～ 5的支化聚乙烯 ,表明B型催化剂具有一定的低聚和原位共聚功能。

从HCV蛋白一级结构预测其C,E,NS5区的CD_4^+ T细胞抗原位点

我们根据ＣＤ４＋Ｔ细胞识别抗原位点的物理化学和生物学特征，设计了一个具有查找两亲性螺旋状结构（ａｍｐｈｉｐａｔｈｉｃｈｅｌｉｘｓｔｒｕｃｔｕｒｅ）肽段功能的计算机程序。用该程序对ＨＣＶ－１型病毒Ｃ、Ｅ（Ｅ１、Ｅ２／ＮＳ１）、ＮＳ５蛋白一级结构进行分析，发现这些蛋白区存在ＣＤ４＋Ｔ细胞识别位点。此结果支持了ＣＤ４＋Ｔ细胞对ＨＣＶＣ，Ｅ，ＮＳ５区可发生增殖反应的结论。提示该程序可作为一种预测ＣＤ４＋Ｔ细胞识别ＨＣＶ抗原位点的方法。

定点突变重组ING4腺病毒基因转染系统的载体构建及鉴定

目的重组构建hING4(人ING4)氨基酸序列。方法运用定点突变技术,在鼠ING4的基础上,设计两对突变引物P1、P2和P3、P4及全长ING4上下游引物P5、P6,通过四轮PCR,将mING4基因序列进行人源化改造,获得了编码hING4氨基酸的基因序列。将获得酶切目的基因片段,连接到转移载体pAdTrack-CMV上,形成重组转移载体pAdTrack-CMV-ING4。重组转移载体经PmeI酶切后与pAdEasy-1腺病毒载体在BJ5183大肠杆菌中同源重组,得到重组腺病毒载体pAdeasy-1-pAdTrack-CMV-ING4,经PacI酶切后脂质体转染QBI-293A包装细胞,获得重组腺病毒Ad-ING4。结果测序和RT-PCR结果表明hING4基因构建成功。结论hING4基因重组腺病毒载体构建成功。