太阳燃料：新一代绿色能源

 综述了燃料发展的历史、太阳燃料的发展起源及光解水制氢、CO₂光还原制化学品的科学研究总体进展情况与发展趋势，并结合我国人工合成太阳燃料科学研究概况，提出了发展新型高效光催化材料的合成方法学等发展建议。     

Synthesis and reaction of 16-electron Cp<Superscript>t</Superscript>Rh halfsandwich complexes containing 1,2-dichalcogenolate carborane ligands

The reactions of [Cp^tRhCi(μ-Ci)]2 (1) (Cp^t=^tBu2C5H3) with Li2E2C2B10H10 (E = S, Se) lead to the green 16-electron dichaicogenolate complexes Cp^tRh(E2C2B10H10) [E = S(2a), Se(2b)]. The 16-electron complexes 2a and 2b can take up two-electron donor ligands such as tert-butyi isonitrile and carbon monoxide to give the 18-electron dichaicogenolate derivatives Cp^t(L)(E2C2B10H10) [L = ^tBuNC, E =S(3a), Se(3b); L = CO, E = S(4a), Se(4b)]. The molecular structures of complexes 2a and 3a were determined by X-ray crystal structure analysis. The molecular structure of 16-electron complex 2a shows the pseudoaromatic system in IrSe2C2 five numbered ring.     

谈“入世”给我国会计业带来的影响

中国加入世界贸易组织将带来会计理论研究方向的拓展和会计体系的完善 ,也将促进会计准则和会计制度的调整和完善 ,同时也给中国会计业带来前所未有的机遇和挑战。     

Analysis of length distribution of short DNA fragments induced by ^7Li ions using the random-breakage model

Deoxyribonucleic acid (DNA) is an important bio-macromolecule. DNA double strand breaks (DSBs) are considered to be the most important initial damage responsible for all biological effects induced by ionizing radiation. In this paper the length distribution of DNA fragments induced by ^7Li ionizing radiation is fitted with the random breakage model. In this model, the parameter u is the average number of DSBs on every DNA molecule induced by ionizing radiation. The fitting result shows that the random breakage model cannot describe the distribution of DNA fragments in lower doses, while the random breakage model is in better accordance with the experimental data in higher doses. It is shown that the length distribution of DNA fragments has random statistical feature in higher doses. In this situation, the random breakage model looks like a model without any parameter since the u has specific physical meaning and can directly be obtained from experimental data.     

A Network-Attached Storage System Supporting Guaranteed QoS

We propose a network-attached storage system that can support guaranteed Quality of Service （QoS）, called POPNet Storage. The special policy of date access and disk scheduling is enable users to access files quickly and directly with guaranteed QoS in the POPNet Storage. The POPNet Storage implements a measurement-based admission control algorithm （PSMBAC） to determine whether to admit a new data access request stream and admit as many requests as possible while meeting the QoS guarantees to its clients. The data reconstruction algorithms in the POPNet Storage also put more emphasis on data availability and guaranteed QoS, thus it is designed to complete the data recovery as soon as possible and at the same time provide the guaranteed QoS for high-priority data access. The experiment results show that the POPNet Storage can provide more significant performance, reliability, and guaranteed QoS than conventional storage systems.     

Left-handed metamaterial and its experimental verifications

The artificial metamaterial simultaneously possessing negative permittivity and permeability has many fantastic properties, and has attracted a lot of attention in the field of physics and electromagnetism. In this paper, we fabricated this kind metamaterial and performed refraction and beam shifting experiments using triangular-shaped and parallelogram-shaped sample respectively. The experimental results demonstrate that, the metamaterial we fabricated may have negative permittivity and permeability simultaneously in a specific small frequency band.     

A continuous 3000—year precipitation record of ENSO variability during LGM from a stalagmite in Nanjing

A glacial stalagmite chronology from Nanjing has been established by the TIMS-U series dating and annual band counting methods. The annually layering sequence spanning the 3000-year period from 18179 to 14900 calendar years before the present (aBP) was analyzed for evidence of East Asian summer monsoon precipitation variability during the Last Glacial Maximum (LGM). Power spectral analysis of the sequence shows a distinct interannual (2—7 years) band of enhanced variability suggestive of El Ni駉-Southern Oscillation (ENSO) teleconnections into East China during the LGM when climatic boundary conditions were different from those of today. The lower frequency bands (4—7 years) variability becomes weaker from 18179 to 14900 aBP, sup-porting the precession forcing model. The reappearance of the ENSO band in the coldest climatic boundary conditions during the Heinrich Event 1, however, suggests the stimula-tion of the enhanced East Asia winter monsoon to the El Ni駉 events.     

图像强化去噪的一种偏微模型

给出了图像处理中加强去噪的一种方法．具体作法是在能量泛函中用模糊算子作用后的原图像与获得图像之间的距离代替原图像与获得图像之间的距离．实验结果表明，这样的处理不仅加强了去噪效果，而且保持了现有处理方法的其他优点．建立了与这一模型对应的流方程Cauchy问题的逼近问题的古典解的存在惟一性，使得这类问题的讨论完善化了．