摘要：Three well-dated Sabina Przewalskii ring-width chronologies from Dulan, china, have been used to reconstruct annual precipitation (from prior July to current June) variations on the northeast Tibetan Plateau since 850 AD. The reconstructions account of the instrumentally recorded precipitation variance are: 54.7% for the period of 1385-2000AD; 50.5% for 1099-1384AD and 45.7% for 850-1098AD. On the millenary scale, the precipitation variation over this region displays “W” shape, which has three peaks and two valleys. The precipitation is low during 1571-1879 AD, and high during 1880-2000 AD. 1900-2000 AD is the century with the highest precipitation over the northeast Tibetan Plateau in the last 1000 years, and 1962-2000 is the period with the highest pre- cipitation, and the highest variability of precipitation as well in the last 1000 years. The reconstructed series also reveals that the variability of annual precipitation is large when the precipitation is more, and contrarily, variability is small when the precipitation is low. With the temperature increasing obvi- ously in the 20th century, the precipitation in the study region significantly increased too, the variability of precipitation became larger, and drought and flooding occurred more frequently. The yearly tree-ring width (high frequency signal) series in this region reflects the local annually precipitation variation. However, the series with 40-year moving average (low frequency signal) cor- responds to the Northern Hemisphere temperature variations on the decadal to centurial scale. It correlates significantly with seven temperature curves of the Northern Hemisphere in the different time spans. For example, the correlation coefficients with the most temperature curves are around 0.9 during the period of 1852-1982 AD. In general, the temperature and the precipitation change syn- chronously in the Dulan region. It means that low temperature corresponds to low precipitation, andvice versa. This relations

摘要：Assessment of the nitrogen （N） balance and its long-term trend is necessary for management practices because of the negative environmental effects caused by an imbalance of reactive N in grassland ecosystems. In this study, we designed a module for the IAP-N （Improving Anthropogenic Practices of managing reactive Nitrogen） model to enable it to assess the N budget of regional grasslands. The module was developed to quantify the individual components of the N inputs and outputs for grassland ecosystems using livestock and human populations, grassland area, and fossil-energy consumption data as the model inputs. In this paper, the estimation approaches for individual components of N budget, data acquisition, and parameter selection are described in detail. The model was applied to assess the N budget of Inner Mongolia in 2006 at the county scale. The simulation results show that the most important pathway of N outputs from the grassland was livestock intake. The N output from livestock intake was especially large in the middle of Inner Mongolia. Biological fixation, atmospheric deposition, and livestock excreta deposition were comparably important for the N inputs into the grassland. The N budget for Inner Mongolia grassland in 2006 was -1.7×10 8 ±0.6×10 8 kg. The case study for Inner Mongolia shows that the new grassland module for the IAP-N model can capture the characteristics of the N budget in a semiarid grassland.

摘要：This article introduces the design and performance of the data acquisition system used in an omnidi- rectional gamma-ray positioning system, along with a new method used in this system to obtain the position of radiation sources in a large field. This data acquisition system has various built-in interfaces collecting, in real time, information from the radiation detector, the video camera and the GPS positioning module. Experiments show that the data acquisition system is capable of carrying out the proposed quantitative analysis to derive the position of radioactive sources, which also satisfies the requirements of high stability and reliability.

摘要：Recent studies have demonstrated that the membrane-proximal external region （MPER） of human immunodeficiency virus 1 （HIV-1） glycoprotein 41 contains a series of epitopes for human monoclonal antibodies, including 2F5, Zl3el, 4El0, and 10E8, which were isolated from HIV-l-infected individuals and show broad neutralizing activities. This suggests that MPER is a good target for the development of effective HIV-1 vaccines. However, many studies have shown that it is difficult to induce antibodies with similar broad neutralizing activities using MPER-based peptide antigens. Here, we report that 10E8-1ike neu- tralizing antibodies with effective anti-HIV-1 activity were readily induced using a precisely designed conformational immu- nogenic peptide containing the 10E8-specific epitope. This immunogenic peptide （designated T10HE） contains a 15-mer MPER-derived 10E8-specific epitope fused to T-helper-cell epitopes from tetanus toxin （tt）, which showed a significantly sta- bilized a-helix structure after a series of modifications, including substitution with an （S）-c^-（2＇-pentenyl） alanine containing an olefin-bearing tether and ruthenium-catalyzed olefin metathesis, compared with the unmodified T10E peptide. The stabilized （x-helix structure of T10HE did not affect its capacity to bind the 10E8 antibody, as evaluated with an enzyme linked immuno- sorbent assay （ELISA） and surface plasmon resonance binding assay （SPR assay）. The efficacies of the T10HE and T10E epitope vaccines were evaluated after a standard vaccination procedure in which the experimental mice were primed with ei- ther the T10HE or T10E immunogen and boosted with HIV-1 JRFL pseudoviruses. Higher titers of 10E8-1ike antibodies were induced by T10HE than that by T10E. More importantly, the antibodies induced by T10HE showed enhanced antiviral potency against HIV-1 strains with both X4 and R5 tropism and a greater degree of broad neutralizing activity than the antibodies in- duced by T10E. These results indic

摘要：The Lunar-based Ultraviolet Telescope （LUT） is a funded lunar-based ultraviolet telescope dedicated to continuously monitor- ing variable stars for as long as dozens of days and performing low Galactic latitude sky surveys. The slow and smooth spin of the Moon makes its step by step pointing strategy possible. A flat mirror mounted on a gimbal mount is configured to enlarge the sky coverage of the LUT. A Ritehey-Chretien telescope with a Nasmyth focus configuration is adopted to reduce the total length of the system. A UV enhanced back illuminated AIMO CCD 47-20 chip together with the low noise electric design will minimize the instrumental influence on the system. The preliminary proposal for astrometric calibration and photometric cali- bration are also presented.

摘要：The structure, function and working principle of JLUIV-3, which is a new typeof auto-mated guided vehicle (AGV) with computer vision, is described. The white stripe line withcertain width is used as inductive mark for JLUIV-3 automated navigation. JULIV-3 can automaticallyrecognize the Arabic numeral codes which mark the multi-branch paths and multi-operation buffers,and autonomously select the correct path for destination. Compared with the traditional AGV, it hasmuch more navigation flexibility and less cost, and provides higher-level intelligence. Theidentification method of navigation path by using neural network and the optimal control method ofthe AGV are introduced in detail.

摘要：Three acceptor-donor-acceptor （A-D-A） small molecules DCAODTBDT, DRDTBDT and DTBDTBDT using dithieno[2,3-d：2＇,3＇-d＇]benzo[1,2-b：4,5-b＇]dithiophene as the central building block, octyl cyanoacetate, 3-octylrhodanine and thiobarbituric acid as the end groups were designed and synthesized as donor materials in solution-processed photovoltaic cells （OPVs）. The impacts of these different electron withdrawing end groups on the photophysical properties, energy levels, charge carrier mobility, morphologies of blend films, and their photovoltaic properties have been systematically investigated. OPVs device based on DRDTBDT gave the best power conversion efficiency （PCE） of 8.34%, which was significantly higher than that based on DCAODTBDT （4.83%） or DTBDTBDT （3.39%）. These results indicate that rather dedicated and balanced consideration of absorption, energy levels, morphology, mobility, etc. for the design of small-molecule-based OPVs （SM-OPVs） and systematic investigations are highly needed to achieve high performance for SM-OPVs.

摘要：A new type of pit supporting structure, which was tested and verified using the sensor monitoring technology, was presented. The new supporting structure is assembled by prefabricated steel structural units. The adjacent steel structural units are jointed with fasteners, and each steel structural unit has a certain radian and is welded by two steel tubes and one piece of steel disc. In order to test and verify the reliability of the new supporting structure, the field tests are designed. The main monitoring programs include the hoop stress of supporting structure, lateral earth pressure, and soil deformation. The monitoring data of the field tests show that the new supporting structure is convenient, reliable and safe.

摘要：The PandaX-Ⅲ experiment will search for neutrinoless double beta decay of 136Xe with high pressure gaseous time projection chambers at the china Jin-Ping underground Laboratory. The tracking feature of gaseous detectors helps suppress the background level, resulting in the improvement of the detection sensitivity. We study a method based on the convolutional neural networks to discriminate double beta decay signals against the background from high energy gammas generated by 214Bi and 2^208 T1 decays based on detailed Monte Carlo simulation. Using the 2-dimensional projections of recorded tracks on two planes, the method successfully suppresses the background level by a factor larger than 100 with a high signal efficiency. An improvement of 62% on the efficiency ratio of Еs/√Еb is achieved in comparison with the baseline in the PandaX-Ⅲ conceptual design report.

摘要：Road horizontal alignment contains three elements: straight line,circular arc,and *** AutoCAD,clothoid can only be fitted by polyline or spline,and the graphics which are separated from the road data are independent of each ***,it is necessary to develop a new curve for road horizontal ***,the differential approximation and series integration methods for clothoid were ***,the geometric formulae for road line which contain the three elements were derived as a ***,the advantages and feasibility of customizing a road line class,which was derived from the curve base class,were analyzed based on ObjectARX(AutoCAD Runtime eXtension) ***,the data structure and operations for the road line class were *** experimental results show that the road line can integrate the road elements,graphics and data to implement the graphics-oriented design,which can be widely used in road alignment design.