检索结果-南通市图书馆

One-dimensional Copper（Ⅱ） Complex Constructed with Nitrate Counter-anion as Bitopic Connector

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第9期16卷 1255-1258页

作者： chun Hua GE Xiang Dong ZHANG Wei GUAN Qi tao liu Institute of Chemical Science ＆ Engineering Liaoning University Shenyang 110036 Department of Environmental Science Liaoning University Shenyang 110036

Coordination polymer {[Cu（NPPCA）3（NO3）（H20）]-NOyH20}n 1 （ NPPCA = N-（4＇- nitrophenyl）-4-pyridinecarboxamide） has been synthesized by the reaction of NPPCA with copper（H） nitrate in ethanol-water solution and characterized by X-ray diffraction. 1 crystallizes in the monoclinic space, group P21/n, a = 17.341（6）A, b = 6.744（2）A, c = 34.555（12）A, β = 100.493（6）°, V = 3974（2） A^3, Z = 4. Each copper（H） ion has a distorted octahedral coordination geometry. Nitrate anion adopts the unusual coordination mode linking two adjacent copper（H） ions to form a one-dimensional coordination polymer and these chains are further linked by noncovalent interactions.

关键词： Copper(H) complex one-dimensional coordination polymer bidentate nitrate non-covalent interaction

Annealing effect on structural and magnetic properties of Tb and Cr co-implanted AIGaN

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2012年第4期6卷 366-370页

作者： chun-Hai YIN Chao liu Dong-Yan tao Yi-Ping ZENG Key Laboratory of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Unintentionally doped AIGaN layers, which were *** with 400 keV Tb＋ ions and 200keV Cr＋ ions at doses of 1.5×1015cm-2, have been rapid thermally annealed at 800℃ and 900℃ for 5 min in flowing N2, Compared with Tb implanted AIGaN sample, the Tb and Cr co-implanted sample revesls a larger magnetic signal. In this work, the annealing effect on the structural and magnetic properties of Tb and Cr co-implanted AIGaN thin films have been studied. XRD and raman scattering results indicate that no second phase presents in thetin films and mast of the implantation induced defects can be removed by post-implantation annealing. Superconducting quantum interference device （SQUID） measurements show clear room temperature ferromagnetic behavior and an increase in the saturation magnetization as a result of annealing. The saturation magnetization of the 900℃ annealed sample is about 15 times higher than that of the 800℃ annealed sample.

关键词： diluted magnetic semiconductor (DMS). room temperature ferromagne-tism ion implantation ltl-ride thin film

Rotational properties of the odd-Z transfermium nucleus ^(255)Lr by a particle-number-conserving method in the cranked shell model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 25-32页

作者： Yu-chun Li Xiao-tao He College of Material Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model （CSM） with the paring correlations treated by the particle-number-conserving （PNC） method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia （f^（1） and ,f^（2） versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f（1） with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6（5） keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189（1） keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 （1/2-[770]） orbital at the high spin leads to band-crossings at hω = 0.20 （hω~=0.25） MeV for the 7/2-[514]ω= -1/2 （ω= ＋1/2） band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.

关键词： rotational band spin assignment band-crossing high-j orbital transfermium nuclei

Mutations in the p16 gene in DMBA-induced pancreatic intraepithelial neoplasia and pancreatic cancer in rats

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2015年第2期14卷 208-214页

作者： Zhu Zhu tao liu Fei Han Su-Dong Zhan chun-You Wang Department of Pancreatic Surgery Union HospitalHuazhong University of Science and Technology Department of General Surgery First Affiliated HospitalUniversity of South China

BACKGROUND：7,12-dimethylbenzanthracene（DMBA）-induced pancreatic intraepithelial neoplasia（PanIN）and pancreatic cancer in rats provide a classic model for uncovering the molecular mechanisms underlying pancreatic ***,this model has not been characterized genetically,and in particular,the major genetic alterations in the p16 gene are ***： Lesions of PanlN and pancreatic cancer were induced with DMBA implantation in 40 rats, and control pancreatic tissue was obtained from 10 age-matched rats without exposure to DMBA. Pancreatic tissue was harvested three months after DMBA implantation and DNA was extracted. Homozy- gous deletions and point mutations of the pl6 （exons 1 and 2） gene were detected by PCR amplification and direct sequencing. RESULTS： DMBA implantation in the 40 rats induced 26 Pan- INs and 9 carcinomas. The overall frequency of p 16 alterations in the pancreatic tissue of these rats was 42.86% （15/35）, and the changes were point mutations, not homozygous deletions. p16 mutations were present in 30.77% （8/26） of the rats with PanIN and 77.78% （7/9） of the rats with carcinoma （P〈0.05）. The increasing incidence of p16 alterations was detected in 20.00% （1/5） of PanIN-1, 28.57% （2/7） of PanIN-2 and 35.71% （5/14） of PanIN-3 lesions. CONCLUSION： Our findings indicated that p16 alteration is a common event in the carcinogenesis of this model and that the mutation pattern is analogous to that of human lesions.

关键词： homozygous deletion point mutation p16 pancreatic intraepithelial neoplasia pancreatic carcinoma

A statistical study towards high-mass BGPS clumps with the MALT90 survey

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2018年第1期18卷 31-58页

作者： Xiao-Lan liu Jin-Long Xu Chang-chun Ning Chuan-Peng Zhang Xiao-tao liu National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China NAOC-TU Joint Center for Astrophysics Lhasa 850000 China Tibet University Lhasa 850000 China Department of Finance Central China Normal University Wuhan 430079 China

In this work,we perform a statistical investigation towards 50 high-mass clumps using data from the Bolocam Galactic Plane Survey（BGPS）and Millimetre Astronomy Legacy Team 90-GHz survey（MALT90）.Eleven dense molecular lines（N2H^＋（1–0）,HNC（1–0）,HCO^＋（1–0）,HCN（1–0）,HN^（13）C（1–0）,H^（13）CO^＋（1–0）,C2H（1–0）,HC3N（10–9）,SiO（2–1）,^（13）CS（2–1）and HNCO（4（4,0）-3（0,3）））are detected.N2H^＋ and HNC are shown to be good tracers for clumps in various evolutionary stages since they are detected in all the *** detection rates of N-bearing molecules decrease as the clumps evolve,but those of O-bearing species increase with ***,the abundance ratios[N2H^＋]/[HCO^＋]and log（[HC3N]/[HCO^＋]）decline with log（[HCO^＋]）as two linear functions,*** suggests that N^＋2H^＋ and HC3N transform to HCOas the clumps *** also find that C2H is the most abundant molecule with an order of magnitude 10^（-8）.In addition,three new infall candidates,G010.214–00.324,G011.121–00.128 and G012.215–00.118（a）,are discovered to have large-scale infall motions and infall rates with an order of magnitude 10^（-3）M⊙yr^（-1）.

关键词： stars:formation ISM:abundance ISM:molecules radio lines:ISM ISM:kinematics and dynamics

Quantifying lateral penumbra advantages of collimated spot-scanning beam for intensity-modulated proton therapy

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第11期30卷 52-59页

作者： chun-Bo liu Yun-tao Song Hong-Dong liu Hai-Zhou Xue Han-Sheng Feng University of Science and Technology of China Hefei 230026China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Hefei CAS Ion Medical and Technical Devices Co. LtdHefei 230088China

Intensity-modulated proton therapy(IMPT)is becoming essential for proton therapy and is under rapid ***,for IMPT,the lateral penumbra of the spot-scanning proton beam is still an urgent issue to be ***-specific block collimators(PSBCs),which can block unnecessary doses,play a crucial role in passive scattering delivery technology but are rarely used in spot *** objective of this study is to investigate the lateral penumbra variations of intensity-modulated spot scanning with and without a *** fields with varying degrees of sharpness and at varying depths in a water phantom,the lateral penumbral widths were calculated using a Monte Carlo-based dose engine from RayStation *** results suggest that the lateral penumbral widths can be reduced by more than 30%for uniform target volumes,regardless of whether a range-shifter is used,and that the maximum dose beyond the field edges can be reduced *** results of patient cases show that the doses in organs-at-risk near the edge of the target volume decrease if a PSBC is *** study demonstrates that intensity-modulated spot scanning with a PSBC can effectively reduce the lateral penumbra and block unnecessary doses and is therefore promising for clinical applications in spot-scanning proton therapy.

关键词： Lateral penumbra Patient-specific block collimator Monte Carlo Intensity-modulated proton therapy

Optimize nitrogen fertilization location in root-growing zone to increase grain yield and nitrogen use efficiency of transplanted rice in subtropical China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2017年第9期16卷 2073-2081页

作者： WU Meng liu Ming liu Jia LI Wei-tao JIANG chun-yu LI Zhong-pei State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008P.R.China Graduate University of Chinese Academy of Sciences Beijing 100049P.R.China

The optimized nitrogen fertilization location differs in different rice-growing regions. We optimized nitrogen deep-point application in root-growing zone（NARZ） for transplanted rice in subtropical China. Field plot experiments were conducted over two years（2014–2015） in a double-rice cropping system to evaluate the effects of nitrogen（N） fertilizer location on grain yield and N use efficiency（NUE）. Four different nitrogen deep-point application methods（DN） were compared with traditional broadcast application（BN） using granular urea. The results showed that grain yield, recovery efficiency of N（REN）, agronomic efficiency of N（AEN）, and partial factor productivity of N（PFP_N） significantly increased 10.3–63.4, 13.7–56.7, 24.7–201.9 and 10.2–63.4%, respectively, in DN treatment compared to BN, respectively. We also find that DN treatments increased grain yield as well as grain N content, and thus grain quality, in comparison with conventional BN treatment. Correlation analysis indicated that significant improvement in grain yield and NUE mainly resulted from increases in productive panicle number and grain N content. In our proposed NARZ method, granular urea should be placed 0 to 5 cm around the rice seeding at a 12-cm depth druing rice transplanting. In NARZ, balanced application of N, P and K further improved grain yield and NUE over treatments with a single N deep-point application. High N uptake by the rice plant did not cause significant soil fertility depletion, demonstrating that this method could guarantee sustainable rice production.

关键词： N recovery efficiency grain yield deep-point application N application in root-growing zone

Photoproducts of tetracycline and oxytetracycline involving self-sensitized oxidation in aqueous solutions:Effects of Ca^(2+) and Mg^(2+)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第10期23卷 1634-1639页

作者： Yong Chen Hua Li Zongping Wang tao tao chun Hu School of Environmental Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Tetracyclines constitute one of the most important antibiotic families and represent a classic example of phototoxicity. The photoproducts of tetracyclines and their parent compounds have potentially adverse effects on natural ecosystem. In this study, the self-sensitized oxidation products of tetracycline （TC） and oxytetracycline （OTC） were determined and the effects of Ca2＋ and Mg2＋on self-sensitized degradation were investigated. The Ca2＋ and Mg2＋ in the natural water sample accounted for enhancement （pH 7.3） and inhibition （pH 9.0） of photodegradation of TC and OTC due to the formation of metal-ions complexes. The formation of Mg2＋ complexes was unfavorable for the photodegradation of the tetracyclines at both pH values. In contrast, the Ca2＋ complexes facilitated the attack of singlet oxygen （102） arising from self-sensitization at pH 7.3 and enhanced TC photodegradation. For the first time, self- sensitized oxidation products of TC and OTC were verified by quenching experiments and detected by LC/ESI-DAD-MS. The products had a nominal mass 14 Da higher than the parent drugs （designated M＋ 14）, which resulted from the 102 attack of the dimethylamino group on the C-4 atom of the tetracyclines. The presence of Ca2＋ and Mg2＋ also affected the generation of M＋ 14 due to the formation of metal-ions complexes with TC and OTC. The findings suggest that the metal-ion complexation has significant impact on the self- sensitized oxidation processes and the photoproducts of tetracyclines.

关键词： tetracyclines complexation self-sensitized oxidation photoproducts

Asymptotical Behaviors for Neumann Boundary Problem with Singular Data

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2019年第4期35卷 463-480页

作者： tao ZHANG chun Qin ZHOU School of Mathematical Sciences Shanghai Jiao Tong University

In this paper, we will analyze the blow-up behaviors for solutions to the Laplacian equation with exponential Neumann boundary condition. In particular, the boundary value is with a kind of singular data. We show a Brezis–Merle type concentration-compactness theorem, calculate the blow up value at the blow-up point, and give a point-wise estimate for the profile of the solution sequence at the blow-up point.

关键词： Exponential Neumann boundary condition singular data blow up analysis profile of the solution sequence