在20世纪的前50年,神经解剖学的研究主要是基于科学家对采用传统技术固定的尸体脑所做的观察。根据这些研究所绘制的立体图谱已经成为广泛应用的工具书。对神经外科学、神经放射学、神经科学和神经解剖学的研究和应用具有重要参考价值...在20世纪的前50年,神经解剖学的研究主要是基于科学家对采用传统技术固定的尸体脑所做的观察。根据这些研究所绘制的立体图谱已经成为广泛应用的工具书。对神经外科学、神经放射学、神经科学和神经解剖学的研究和应用具有重要参考价值和不可替代的作用。尤其是Talairach和Schaltenbra编辑的图谱是最具权威性的,也是迄今应用最广泛的图谱。近年来随着神经影像技术的引进,特别是核磁共振(nuclear magnetic nesonance),结合计算机图象处理所取得的令人震惊的进展,使我们能够接近在病人脑内直接进行更准确和高度精细的神经解剖学定位。展开更多
The biological characteristics of crustacean spermatozoa is important for the artificial reproduction and genetic breeding. With reference to the latest studies and related materials, this paper reviewed the research ...The biological characteristics of crustacean spermatozoa is important for the artificial reproduction and genetic breeding. With reference to the latest studies and related materials, this paper reviewed the research progress in the biological characteristics of crustacean spermatozoa, such as morphological structure of sperm, spermatogenesis, sperm viability, preservation in vitro and acrosome reaction et al. The prospects of the research field have also been anticipated.展开更多
α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decrease...α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.展开更多
Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects,so it is important to conduct vibration research on the shells and find it’s a simpler correspo...Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects,so it is important to conduct vibration research on the shells and find it’s a simpler corresponding compact calculation method. Utilising the input and transfer point mobility of a thin plate structure, a theoretical expression of the cylindrical shell’s bending vibration responsewas deduced and numerical simulations were done to simplify the theoretical expression within an acceptable error margin, greatly reducing the amount of computations. Furthermore, whole vibration response distributions of the cylindrical shell were analyzed. It was found thathe vibration energy propagates in helical form under mono-frequency excitation, while under bandwidth frequency excitation, it attenuates around in term of fluctuation.The axial attenuation rate of the vibration energy is larger than the circumferential attenuation rate.展开更多
The synergistic effect of high voltage discharge non‐thermal plasma(NTP)and photocatalysts on contaminant removal has repeatedly confirmed by plenty of researches.Most previous plasma‐photocatalyst synergistic syste...The synergistic effect of high voltage discharge non‐thermal plasma(NTP)and photocatalysts on contaminant removal has repeatedly confirmed by plenty of researches.Most previous plasma‐photocatalyst synergistic systems focused on the utilization of the ultraviolet light but ignored the visible light generated by high voltage discharge.Graphitic carbon nitride(g‐C3N4),a metal‐free semiconductor that exhibits high chemical stability,can utilize both the ultraviolet and visible light from high voltage discharge.However,the synergistic system of NTP and g‐C3N4 has been researched little.In this paper,the effect of NTP generated by dielectric barrier discharge(DBD)on g‐C3N4 is studied by comparing the photocatalytic activities,the surface physical structure and the surface chemical characteristics of pristine and plasma treated g‐C3N4.Experimental results indicate that the DBD plasma can change the physical structure and the chemical characteristics and to further affect the photocatalytic activity of g‐C3N4.The effect of NTP on g‐C3N4 is associated with the discharge intensity and the discharge time.For a long time scale,the effect of NTP on g‐C3N4 photocatalysts presents a periodic change trend.展开更多
The active site amount of photocatalysts,being the key factors in photocatalytic reactions,directly affects the photocatalytic performance of the photocatalyst.Pristine graphitic carbon nitride(g‐C_(3)N_(4))exhibits ...The active site amount of photocatalysts,being the key factors in photocatalytic reactions,directly affects the photocatalytic performance of the photocatalyst.Pristine graphitic carbon nitride(g‐C_(3)N_(4))exhibits moderate photocatalytic activity due to insufficient active sites.In this study,cyano‐modified porous g‐C_(3)N_(4)nanosheets(MCN‐0.5)were synthesized through molecular self‐assembly and alkali‐assisted strategies.The cyano group acted as the active site of the photocatalytic reaction,because the good electron‐withdrawing property of the cyano group promoted carrier separation.Benefiting from the effect of the active sites,MCN‐0.5 exhibited significantly enhanced photocatalytic activity for CO2 reduction under visible light irradiation.Notably,the photocatalytic activity of MCN‐0.5 was significantly reduced when the cyano groups were removed by hydrochloric acid(HCl)treatment,further verifying the role of cyano groups as active sites.The photoreduction of Pt nanoparticles provided an intuitive indication that the introduction of cyano groups provided more active sites for the photocatalytic reaction.Furthermore,the controlled experiments showed that g‐C_(3)N_(4)grafted with cyano groups using melamine as the precursor exhibited enhanced photocatalytic activity,which proved the versatility of the strategy for enhancing the activity of g‐C_(3)N_(4)via cyano group modification.In situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations were used to investigate the mechanism of enhanced photocatalytic activity for CO2 reduction by cyano‐modified g‐C_(3)N_(4).This work provides a promising route for promoting efficient solar energy conversion by designing active sites in photocatalysts.展开更多
The title compound (C20H30N4O6, Mr = 422.48) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with cell parameters: a = 8.330...The title compound (C20H30N4O6, Mr = 422.48) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with cell parameters: a = 8.330(2), b = 8.468(2), c = 16.017(3) ? ?= 97.30(3), ?= 92.33(3), ?= 103.94(3)? V = 1084.7(4) ?, Dc = 1.294 g/cm3, Z = 2, F(000) = 452 and ?= 0.096 mm-1. The structure was refined to R = 0.0483 for 3732 observed reflections with I > 2s(I) and wR = 0.1335 for 4828 unique reflections. The hydantoin rings are planar and the two ring planes of one molecule are paralleled to each other.展开更多
As one of the first and most original creations of literary postmodernism, published in the year 1961, Catch-22's (1961) position in American literature remains secure. Yet its ending has been held as unconvincing ...As one of the first and most original creations of literary postmodernism, published in the year 1961, Catch-22's (1961) position in American literature remains secure. Yet its ending has been held as unconvincing ever since its publication. Taking the overall structure, tone, and the theme of the novel into consideration, this paper aims to prove the credibility of this controversial part. It consists of five sections apart from an introduction and a conclusion. Section One provides general information on the life and works of Joseph Heller. Section Two traces the impact of existentialism and the generation of black humor to clarify the literary position of Catch-22. Section Three brings out the disputative opinions on the ending part. Sections Four and Five, try to prove Yossarian's final desertion a natural and convincing ending from different perspectives: Section Four analyses how Yossarian gains an entropic vision of the cosmos; section Five studies his existential vision of physical life and searches for the immediate factors that propel Yossarian's desertion. Section five also explains the ending's change in tone and structure. The conclusion summarizes the paper and points out the social significance of the novel.展开更多
Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)] I and bis-[oxo-bis(-ferrocenoyl- propionyloxy di-n-propyltin)] II were synthesized and their crystal structures have been determined by X-ray diffraction analysis. The...Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)] I and bis-[oxo-bis(-ferrocenoyl- propionyloxy di-n-propyltin)] II were synthesized and their crystal structures have been determined by X-ray diffraction analysis. The compound I2C6H6 ([(FcC6H4COOSnPr2)2O]22C6H6 or C92H108Fe4O10Sn42C6H6, Mr = 2384.16) is of triclinic, space group P?with a = 12.826(4), b = 13.099(5), c = 17.539(5) ? = 78.229(5), ?= 71.852(5), = 62.746(5)? V = 2483(1) ?, Z = 1, Dc = 1.490 g/cm3, = 0.71073 ? (MoK? =1.611 mm-1 and F(000) = 1128. The structure was refined to R = 0.0491 and wR = 0.1053 for 4690 unique reflections with I > 2(I). The compound IIC6H6 ([(FcCOCH2CH2COOSnPr2)2O]2C6H6 or C80H108Fe4O14Sn4C6H6, Mr = 2115.93) is of triclinic, space group P?with a = 11.260(4), b = 14.126(5), c = 15.961(6) ? = 91.400(6), = 110.654(6), = 104.931(6), V = 2277(1) 3, Z = 1, Dc = 1.510 g/cm3, = 0.71073 ? (MoK? = 1.750 mm-1 and F(000) = 1046. The structure was refined to R = 0.0466 and wR = 0.1138 for 5061 unique reflections with I > 2(I). The two compounds have the similar structures: both are dimers containing centrosymmetric Sn2O2 cores. But there are some differences in the ligating modes between the carboxylate groups and the Sn atoms.展开更多
Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of t...Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.展开更多
Atomically precise gold cluster catalysts have emerged as a new frontier in catalysis science,owing to their unexpected catalytic properties.In this work,we explore the evolution of the catalytic activity of clusters ...Atomically precise gold cluster catalysts have emerged as a new frontier in catalysis science,owing to their unexpected catalytic properties.In this work,we explore the evolution of the catalytic activity of clusters formed by the structural fusion of icosahedral Au13 units,namely Au25(SR)18,Au38(SR)24,and Au25(PPh3)10(SC2H4Ph)5Cl2,in the oxidation of pyrrolidine toγ-butyrolactam.We demonstrate that the structural fusion of icosahedral Au13 units,forming vertex-fused(vf),face-fused(ff),and body-fused(bf)clusters,can induce a decrease in the catalytic activity in the following order:Aubf>Auff>Auvf.The structural fusion of icosahedral Au13 units in the clusters does not distinguish the adsorption modes of pyrrolidine over the three clusters from each other,but modulates the chemical adsorption capacity and electronic properties of the three clusters,which is likely to be the key reason for the observed changes in catalytic reactivity.Our results are expected to be extendable to study and design atomically defined catalysts with elaborate structural patterns,in order to produce desired products.展开更多
Along with the rich material life, the change of the diet structure, people's shape also began to change.With performance m females is the body fat's increasing, the shape is not beautiful, therefore, body sculpting...Along with the rich material life, the change of the diet structure, people's shape also began to change.With performance m females is the body fat's increasing, the shape is not beautiful, therefore, body sculpting underwear has become the first choice for women to pursue beauty.To the requirement of sculpting body underwear is also becoming higher and higher for women.Comfortable and fashion is the sign of measuring a sculpting body underwear quality. This paper introduces the development history of sculpting body underwear, sculpting body underwear comfort evaluation index.And from the three aspects of the human body, clothing, environment do research to sculpting body underwear about the influence factors of wearing comfort.lt provides the certain reference value for consumers to purchase the sculpting body underwear and for enterprise to product sculpting body underwear.展开更多
A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characteriza...A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.展开更多
OBJECTIVE:To determine the effects of Bushenhuoxue formula(BHF) on interleukin-1 beta(IL-1β),transforming growth factor beta 1(TGF-β1),discoidin domain receptor 2(DDR2) and matrix metalloproteinase-1(MMP-1) levels i...OBJECTIVE:To determine the effects of Bushenhuoxue formula(BHF) on interleukin-1 beta(IL-1β),transforming growth factor beta 1(TGF-β1),discoidin domain receptor 2(DDR2) and matrix metalloproteinase-1(MMP-1) levels in a rat model of osteoarthritis(OA).METHODS:Sprague-Dawley rats were used to establish an OA model and subjected to various treatments over 6 weeks.Rats were treated with BHF,glucosamine sulfate(G5),or starch as a control.Serum levels of IL-1β and MMP-1 and joint fluid levels of IL-1 β were determined by means of ELISAs.We used immunohistochemistry to determine DDR2 levels in knee cartilage.Gene expression levels of MMP-1 in joint synovial tissue were assessed using reverse transcription polymerase chain reaction assays.RESULTS:Serum IL-1β levels were unchanged throughout the study.Levels of IL-1β in joint fluid and MMP-1 in sera from the BHF- and GS-treated groups were significantly reduced.DDR2 levels in knee cartilage were also significantly reduced in the BHF group.Expression of the MMP-1 gene was significantly reduced by BHF treatment.CONCLUSION:BHF might be beneficial in the inhibition and alleviation of local inflammatory responses and cartilage degeneration in OA.展开更多
A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n-nH20) has been synthesized and characterized by elemental analysis, IR and electronic spectra s...A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n-nH20) has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measure- ment, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallo- graphic data: a -- 12.4537(4)/~, b = 9.3897(5) A, c = 30.1264(10) A, and Z = 8. In the crystal structure, the octahedral coordi- nated copper(II) ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu'"Cu separation of 6.1719/~, along with phen ligands attached to both sides of the chain altematively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evalua- tion of the cytotoxic activity of the copper(II) complex against HCT-8 (colorectal carcinoma), A549 (pulmonary carcinoma), HeLa (cervical cancer), HepG2 (hepatocarcinoma), BGC-823 (gastric carcinoma), and MCF-7 (breast adenocarcinoma) cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.展开更多
Five new binuclear lanthanide compounds [Ln(2,4-DClBA)3phen]2(Ln = Pr(1), Eu(2), Tb(3), Ho(4) and Er(5); 2,4-DClBA = 2,4-dichlorobenzoate; phen = 1,10-phenanthroline) have been synthesized and structurally characteriz...Five new binuclear lanthanide compounds [Ln(2,4-DClBA)3phen]2(Ln = Pr(1), Eu(2), Tb(3), Ho(4) and Er(5); 2,4-DClBA = 2,4-dichlorobenzoate; phen = 1,10-phenanthroline) have been synthesized and structurally characterized by X-ray crystallography. And all of them were carefully investigated by elemental analysis, molar conductance, IR, UV and TG/DSC-FTIR technology. Single-crystal X-ray diffraction studies revealed that compounds 1–5 were binuclear molecules with an inversion center and the Ln3+ ions contained two kinds of coordination environment that was a distorted monocapped square-antiprism in the compounds 1–2, and a distorted square-antiprism geometry in the compounds 3–5. The 3D surface graphs for the FTIR spectra of gaseous products for the compounds 1–5 were recorded using simultaneous TG/DSC-FTIR technique which is intended to further analysis of the thermal decomposition processes. Hence the gaseous products were identified by the solved single IR spectra obtained at different temperatures from the 3D surface graphs. Furthermore, the Eu(Ш) and Tb(Ш) ternary compounds exhibited intense luminescence under the radiation of UV light. And the results for antimicrobial test show that these compounds exhibit good bacteriostatic activity against Staphylococcus aureus, and better antimicrobial activity against Escherichia coli and Candida albicans.展开更多
文摘在20世纪的前50年,神经解剖学的研究主要是基于科学家对采用传统技术固定的尸体脑所做的观察。根据这些研究所绘制的立体图谱已经成为广泛应用的工具书。对神经外科学、神经放射学、神经科学和神经解剖学的研究和应用具有重要参考价值和不可替代的作用。尤其是Talairach和Schaltenbra编辑的图谱是最具权威性的,也是迄今应用最广泛的图谱。近年来随着神经影像技术的引进,特别是核磁共振(nuclear magnetic nesonance),结合计算机图象处理所取得的令人震惊的进展,使我们能够接近在病人脑内直接进行更准确和高度精细的神经解剖学定位。
基金supported by the Jiangsu Province Science and Technology Development Project (Grant No. BN2010026)
文摘The biological characteristics of crustacean spermatozoa is important for the artificial reproduction and genetic breeding. With reference to the latest studies and related materials, this paper reviewed the research progress in the biological characteristics of crustacean spermatozoa, such as morphological structure of sperm, spermatogenesis, sperm viability, preservation in vitro and acrosome reaction et al. The prospects of the research field have also been anticipated.
基金supported by the National Natural Science Foundation of China(51502221)~~
文摘α‐,β‐,δ‐,andγ‐MnO2nanocrystals are successfully prepared.We then evaluated the NH3selective catalytic reduction(SCR)performance of the MnO2catalysts with different phases.The NOx conversion efficiency decreased in the order:γ‐MnO2>α‐MnO2>δ‐MnO2>β‐MnO2.The NOx conversion with the use ofγ‐MnO2andα‐MnO2catalysts reached90%in the temperature range of140–200°C,while that based onβ‐MnO2reached only40%at200°C.Theγ‐MnO2andα‐MnO2nanowire crystal morphologies enabled good dispersion of the catalysts and resulted in a relatively high specific surface area.We found thatγ‐MnO2andα‐MnO2possessed stronger reducing abilities and more and stronger acidic sites than the other catalysts.In addition,more chemisorbed oxygen existed on the surface of theγ‐MnO2andα‐MnO2catalysts.Theγ‐MnO2andα‐MnO2catalysts showed excellent performance in the low‐temperature SCR of NO to N2with NH3.
文摘Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects,so it is important to conduct vibration research on the shells and find it’s a simpler corresponding compact calculation method. Utilising the input and transfer point mobility of a thin plate structure, a theoretical expression of the cylindrical shell’s bending vibration responsewas deduced and numerical simulations were done to simplify the theoretical expression within an acceptable error margin, greatly reducing the amount of computations. Furthermore, whole vibration response distributions of the cylindrical shell were analyzed. It was found thathe vibration energy propagates in helical form under mono-frequency excitation, while under bandwidth frequency excitation, it attenuates around in term of fluctuation.The axial attenuation rate of the vibration energy is larger than the circumferential attenuation rate.
文摘The synergistic effect of high voltage discharge non‐thermal plasma(NTP)and photocatalysts on contaminant removal has repeatedly confirmed by plenty of researches.Most previous plasma‐photocatalyst synergistic systems focused on the utilization of the ultraviolet light but ignored the visible light generated by high voltage discharge.Graphitic carbon nitride(g‐C3N4),a metal‐free semiconductor that exhibits high chemical stability,can utilize both the ultraviolet and visible light from high voltage discharge.However,the synergistic system of NTP and g‐C3N4 has been researched little.In this paper,the effect of NTP generated by dielectric barrier discharge(DBD)on g‐C3N4 is studied by comparing the photocatalytic activities,the surface physical structure and the surface chemical characteristics of pristine and plasma treated g‐C3N4.Experimental results indicate that the DBD plasma can change the physical structure and the chemical characteristics and to further affect the photocatalytic activity of g‐C3N4.The effect of NTP on g‐C3N4 is associated with the discharge intensity and the discharge time.For a long time scale,the effect of NTP on g‐C3N4 photocatalysts presents a periodic change trend.
文摘The active site amount of photocatalysts,being the key factors in photocatalytic reactions,directly affects the photocatalytic performance of the photocatalyst.Pristine graphitic carbon nitride(g‐C_(3)N_(4))exhibits moderate photocatalytic activity due to insufficient active sites.In this study,cyano‐modified porous g‐C_(3)N_(4)nanosheets(MCN‐0.5)were synthesized through molecular self‐assembly and alkali‐assisted strategies.The cyano group acted as the active site of the photocatalytic reaction,because the good electron‐withdrawing property of the cyano group promoted carrier separation.Benefiting from the effect of the active sites,MCN‐0.5 exhibited significantly enhanced photocatalytic activity for CO2 reduction under visible light irradiation.Notably,the photocatalytic activity of MCN‐0.5 was significantly reduced when the cyano groups were removed by hydrochloric acid(HCl)treatment,further verifying the role of cyano groups as active sites.The photoreduction of Pt nanoparticles provided an intuitive indication that the introduction of cyano groups provided more active sites for the photocatalytic reaction.Furthermore,the controlled experiments showed that g‐C_(3)N_(4)grafted with cyano groups using melamine as the precursor exhibited enhanced photocatalytic activity,which proved the versatility of the strategy for enhancing the activity of g‐C_(3)N_(4)via cyano group modification.In situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculations were used to investigate the mechanism of enhanced photocatalytic activity for CO2 reduction by cyano‐modified g‐C_(3)N_(4).This work provides a promising route for promoting efficient solar energy conversion by designing active sites in photocatalysts.
基金This project was supported by the National Natural Science Foundation of China (No 39870983)
文摘The title compound (C20H30N4O6, Mr = 422.48) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallizes in the triclinic system, space group P with cell parameters: a = 8.330(2), b = 8.468(2), c = 16.017(3) ? ?= 97.30(3), ?= 92.33(3), ?= 103.94(3)? V = 1084.7(4) ?, Dc = 1.294 g/cm3, Z = 2, F(000) = 452 and ?= 0.096 mm-1. The structure was refined to R = 0.0483 for 3732 observed reflections with I > 2s(I) and wR = 0.1335 for 4828 unique reflections. The hydantoin rings are planar and the two ring planes of one molecule are paralleled to each other.
文摘As one of the first and most original creations of literary postmodernism, published in the year 1961, Catch-22's (1961) position in American literature remains secure. Yet its ending has been held as unconvincing ever since its publication. Taking the overall structure, tone, and the theme of the novel into consideration, this paper aims to prove the credibility of this controversial part. It consists of five sections apart from an introduction and a conclusion. Section One provides general information on the life and works of Joseph Heller. Section Two traces the impact of existentialism and the generation of black humor to clarify the literary position of Catch-22. Section Three brings out the disputative opinions on the ending part. Sections Four and Five, try to prove Yossarian's final desertion a natural and convincing ending from different perspectives: Section Four analyses how Yossarian gains an entropic vision of the cosmos; section Five studies his existential vision of physical life and searches for the immediate factors that propel Yossarian's desertion. Section five also explains the ending's change in tone and structure. The conclusion summarizes the paper and points out the social significance of the novel.
文摘Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)] I and bis-[oxo-bis(-ferrocenoyl- propionyloxy di-n-propyltin)] II were synthesized and their crystal structures have been determined by X-ray diffraction analysis. The compound I2C6H6 ([(FcC6H4COOSnPr2)2O]22C6H6 or C92H108Fe4O10Sn42C6H6, Mr = 2384.16) is of triclinic, space group P?with a = 12.826(4), b = 13.099(5), c = 17.539(5) ? = 78.229(5), ?= 71.852(5), = 62.746(5)? V = 2483(1) ?, Z = 1, Dc = 1.490 g/cm3, = 0.71073 ? (MoK? =1.611 mm-1 and F(000) = 1128. The structure was refined to R = 0.0491 and wR = 0.1053 for 4690 unique reflections with I > 2(I). The compound IIC6H6 ([(FcCOCH2CH2COOSnPr2)2O]2C6H6 or C80H108Fe4O14Sn4C6H6, Mr = 2115.93) is of triclinic, space group P?with a = 11.260(4), b = 14.126(5), c = 15.961(6) ? = 91.400(6), = 110.654(6), = 104.931(6), V = 2277(1) 3, Z = 1, Dc = 1.510 g/cm3, = 0.71073 ? (MoK? = 1.750 mm-1 and F(000) = 1046. The structure was refined to R = 0.0466 and wR = 0.1138 for 5061 unique reflections with I > 2(I). The two compounds have the similar structures: both are dimers containing centrosymmetric Sn2O2 cores. But there are some differences in the ligating modes between the carboxylate groups and the Sn atoms.
基金Project(10804101) supported by the National Natural Science Foundation of ChinaProject(2007CB815102) supported by the National Basic Research Program of ChinaProject(2007B08007) supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Silver nano-particles with average diameter of about 60 nm were compacted in a high-strength mold under different pressures at 523 K to produce nano-structured Ag solid materials. The structure and characteristic of the nano-structured Ag solid materials (NSS-Ag) were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectrometer. The NSS-Ag could be used as highly efficient surface-enhanced Raman scattering (SERS) active substrates. The common probe molecules Rhodamine 6G (R6G, 1×10-10 mol/L) were used to test the SERS activity on these substrates at very low concentrations. It is found that the SERS enhancement ability is dependent on the density of NSS-Ag. When the relative density of NSS-Ag is 83.87%, the materials reveal great SERS signal.
文摘Atomically precise gold cluster catalysts have emerged as a new frontier in catalysis science,owing to their unexpected catalytic properties.In this work,we explore the evolution of the catalytic activity of clusters formed by the structural fusion of icosahedral Au13 units,namely Au25(SR)18,Au38(SR)24,and Au25(PPh3)10(SC2H4Ph)5Cl2,in the oxidation of pyrrolidine toγ-butyrolactam.We demonstrate that the structural fusion of icosahedral Au13 units,forming vertex-fused(vf),face-fused(ff),and body-fused(bf)clusters,can induce a decrease in the catalytic activity in the following order:Aubf>Auff>Auvf.The structural fusion of icosahedral Au13 units in the clusters does not distinguish the adsorption modes of pyrrolidine over the three clusters from each other,but modulates the chemical adsorption capacity and electronic properties of the three clusters,which is likely to be the key reason for the observed changes in catalytic reactivity.Our results are expected to be extendable to study and design atomically defined catalysts with elaborate structural patterns,in order to produce desired products.
文摘Along with the rich material life, the change of the diet structure, people's shape also began to change.With performance m females is the body fat's increasing, the shape is not beautiful, therefore, body sculpting underwear has become the first choice for women to pursue beauty.To the requirement of sculpting body underwear is also becoming higher and higher for women.Comfortable and fashion is the sign of measuring a sculpting body underwear quality. This paper introduces the development history of sculpting body underwear, sculpting body underwear comfort evaluation index.And from the three aspects of the human body, clothing, environment do research to sculpting body underwear about the influence factors of wearing comfort.lt provides the certain reference value for consumers to purchase the sculpting body underwear and for enterprise to product sculpting body underwear.
基金This work was financially supported by the Ministry of Science and Technology of China (Grants 2012CB215500 and 2013CB933100) and the National Natural Science Foundation of China (Grants 21103178 and 21033009).
文摘A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.
基金Supported by the Shandong Provincial Department of Education(Mechanism of Bushenhuoxue Formula Protecting Chondrocytes of Osteoarthritis,No.J07YD08)the Shandong Provincial Administration of Traditional Chinese Medicine(Relationship between Bushenhuoxue Formula and the Osteoarthritis Signaling Molecule DDR2,No.2007-027)
文摘OBJECTIVE:To determine the effects of Bushenhuoxue formula(BHF) on interleukin-1 beta(IL-1β),transforming growth factor beta 1(TGF-β1),discoidin domain receptor 2(DDR2) and matrix metalloproteinase-1(MMP-1) levels in a rat model of osteoarthritis(OA).METHODS:Sprague-Dawley rats were used to establish an OA model and subjected to various treatments over 6 weeks.Rats were treated with BHF,glucosamine sulfate(G5),or starch as a control.Serum levels of IL-1β and MMP-1 and joint fluid levels of IL-1 β were determined by means of ELISAs.We used immunohistochemistry to determine DDR2 levels in knee cartilage.Gene expression levels of MMP-1 in joint synovial tissue were assessed using reverse transcription polymerase chain reaction assays.RESULTS:Serum IL-1β levels were unchanged throughout the study.Levels of IL-1β in joint fluid and MMP-1 in sera from the BHF- and GS-treated groups were significantly reduced.DDR2 levels in knee cartilage were also significantly reduced in the BHF group.Expression of the MMP-1 gene was significantly reduced by BHF treatment.CONCLUSION:BHF might be beneficial in the inhibition and alleviation of local inflammatory responses and cartilage degeneration in OA.
基金supported by the Doctoral Fund of Ministry of Education of China (20110001110054)
文摘A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n-nH20) has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measure- ment, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallo- graphic data: a -- 12.4537(4)/~, b = 9.3897(5) A, c = 30.1264(10) A, and Z = 8. In the crystal structure, the octahedral coordi- nated copper(II) ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu'"Cu separation of 6.1719/~, along with phen ligands attached to both sides of the chain altematively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evalua- tion of the cytotoxic activity of the copper(II) complex against HCT-8 (colorectal carcinoma), A549 (pulmonary carcinoma), HeLa (cervical cancer), HepG2 (hepatocarcinoma), BGC-823 (gastric carcinoma), and MCF-7 (breast adenocarcinoma) cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.
基金supported by the National Natural Science Foundation of China(21073053,21141002,20773034)the Natural Science Foundation of Hebei Province(B2012205022)
文摘Five new binuclear lanthanide compounds [Ln(2,4-DClBA)3phen]2(Ln = Pr(1), Eu(2), Tb(3), Ho(4) and Er(5); 2,4-DClBA = 2,4-dichlorobenzoate; phen = 1,10-phenanthroline) have been synthesized and structurally characterized by X-ray crystallography. And all of them were carefully investigated by elemental analysis, molar conductance, IR, UV and TG/DSC-FTIR technology. Single-crystal X-ray diffraction studies revealed that compounds 1–5 were binuclear molecules with an inversion center and the Ln3+ ions contained two kinds of coordination environment that was a distorted monocapped square-antiprism in the compounds 1–2, and a distorted square-antiprism geometry in the compounds 3–5. The 3D surface graphs for the FTIR spectra of gaseous products for the compounds 1–5 were recorded using simultaneous TG/DSC-FTIR technique which is intended to further analysis of the thermal decomposition processes. Hence the gaseous products were identified by the solved single IR spectra obtained at different temperatures from the 3D surface graphs. Furthermore, the Eu(Ш) and Tb(Ш) ternary compounds exhibited intense luminescence under the radiation of UV light. And the results for antimicrobial test show that these compounds exhibit good bacteriostatic activity against Staphylococcus aureus, and better antimicrobial activity against Escherichia coli and Candida albicans.