Agricultural Insurance in China

The system of agricultural insurance is a key sector of the state economy and the development of agricultural sector in general. As we may see now China is one of the leading agricultural countries showing good indicators of agricultural products export. By the aid of this insurance program farmers have become secure and make a significant contribution to the development of rural economy and, as a result, economy of the whole country. This article is aimed at the history of agricultural insurance market, its success and failures, its establishment as a separate mechanism since 2007, though the agricultural insurance goes back to 1980s. The article analyzes the structure of agricultural insurance systems, focuses on the sustainable development of the agricultural sector after the introduction of the new insurance campaign of 2007

Global Analysis of Data on the Proton Structure Function g1 and Extraction of its Moments

Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)**2. We compute for the first time low-order moments of g1 and study their evolution from small to large values of Q2. The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = sigmaL / sigmaT from Jefferson Lab, as well as a new model for the transverse asymmetry A2 in the resonance region. The contributions of both leading and higher twists are extracted, taking into account effects from radiative corrections beyond the next-to-leading order by means of soft-gluon resummation techniques. The leading twist is determined with remarkably good accuracy and is compared with the predictions obtained using various polarized parton distribution sets available in the literature. The contribution of higher twists to the g1 moments is found to be significantly larger than in the case of the unpolarized structure function F2.Comment: 18 pages, 13 figures, to appear in Phys. Rev.

Hemochromatosis - modern condition of the problem

The iron overload syndrome can be associated with various acquired states and hereditary factors. Hereditary hemochromatosis is the most common genetic disorder. Without therapeutic intervention the disease can lead to the development of life-threatening complications such as cirrhosis, hepatocellular carcinoma. The article presents data on pathogenesis, diagnosis and treatment of hereditary hemochromatosis. Own clinical observation is given

Measurement of the Nucleon Structure Function F2 in the Nuclear Medium and Evaluation of its Moments

We report on the measurement of inclusive electron scattering off a carbon target performed with CLAS at Jefferson Laboratory. A combination of three different beam energies 1.161, 2.261 and 4.461 GeV allowed us to reach an invariant mass of the final-state hadronic system W~2.4 GeV with four-momentum transfers Q2 ranging from 0.2 to 5 GeV2. These data, together with previous measurements of the inclusive electron scattering off proton and deuteron, which cover a similar continuous two-dimensional region of Q2 and Bjorken variable x, permit the study of nuclear modifications of the nucleon structure. By using these, as well as other world data, we evaluated the F2 structure function and its moments. Using an OPE-based twist expansion, we studied the Q2-evolution of the moments, obtaining a separation of the leading-twist and the total higher-twist terms. The carbon-to-deuteron ratio of the leading-twist contributions to the F2 moments exhibits the well known EMC effect, compatible with that discovered previously in x-space. The total higher-twist term in the carbon nucleus appears, although with large systematic uncertainites, to be smaller with respect to the deuteron case for n<7, suggesting partial parton deconfinement in nuclear matter. We speculate that the spatial extension of the nucleon is changed when it is immersed in the nuclear medium.Comment: 37 pages, 15 figure

The HPS electromagnetic calorimeter

The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called “heavy photon.” Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable as a narrow peak in the invariant mass spectrum of such pairs, or, depending on its lifetime, by a decay downstream of the production target. The HPS experiment is installed in Hall-B of Jefferson Lab. This article presents the design and performance of one of the two detectors of the experiment, the electromagnetic calorimeter, during the runs performed in 2015–2016. The calorimeter's main purpose is to provide a fast trigger and reduce the copious background from electromagnetic processes through matching with a tracking detector. The detector is a homogeneous calorimeter, made of 442 lead-tungstate (PbWO4) scintillating crystals, each read out by an avalanche photodiode coupled to a custom trans-impedance amplifier

The Jlab Upgrade - Studies of the Nucleon with CLAS12

An overview is presented on the program to study the nucleon structure at the 12 GeV JLab upgrade using the CLAS12 detector. The focus is on deeply virtual exclusive processes to access the generalized parton distributions, semni-inclusive processes to study transverse momentum dependent distribution functions, and inclusive spin structure functions and resonance transition form factors at high Q^2 and with high precision.Comment: 7 pages, 12 figures, NSTAR 2007 conference, Bonn, September 5-8, 200

КОМПЛЕКСНАЯ 3-МЕРНАЯ ГЕОЛОГО-ГЕОФИЗИЧЕСКАЯ МОДЕЛЬ КОРЫ НА ЮГО-ВОСТОКЕ ФЕННОСКАНДИНАВСКОГО ЩИТА: ПРИРОДА ПЛОТНОСТНОЙ РАССЛОЕННОСТИ КОРЫ И КОРОМАНТИЙНОЙ ГРАНИЦЫ

The complex geophysical 3D model of the Earth's crust and the upper mantle is created for the Archaean Karelian Craton and the Late Palaeoproterozoic accretionary Svecofennian Orogen of the southeastern Fennoscandian Shield with the use of methods of complex inversion of geophysical data based on stochastic description of interrelations of physical properties of the medium (density, P-wave velocity, and heat generation). To develop the model, we use results of deep seismic studies, gravity and surficial heat flow data on the studied region. Numerical solutions of 3D problems are obtained in the spherical setting with an allowance for the Earth's surface topography. The geophysical model is correlated with the regional geological data on the surface and results of seismic CMP studies along 4B, FIRE-1 and FIRE-3-3A profiles. Based on results of complex geophysical simulation and geological interpretation of the 3D model, the following conclusions are drawn. (1) The nearly horizontal density layering of the continental crust is superimposed on the previously formed geological structure; rock differentiation by density is decreasing with depth; the density layering is controlled by the recent and near-recent state of the crust, but can be disturbed by the latest deformations. (2) Temperature variations at the Moho are partially determined by local variations of heat generation in the mantle, which, in turn, are related to local features of its origin and transformation. (3) The concept of the lower continental crust being a reflectivity zone and the concept of the lower continental crust being a layer of high density and velocity are not equivalent: the lower crust is the deepest, high-density element of near-horizontal layering, whereas the seismic image of the reflectivity zone is primarily related to transformation of the crust as a result of magmatic under- and intraplating under conditions of extension and mantle-plume activity. (4) At certain combinations of crustal thickness and temperature at the level of Moho discontinuity, the crust in a platform region can be transformed into eclogites. In this case, the crust–mantle boundary is determined by quantitative proportions of the rocks that underwent eclogitization or escaped this process and by corresponding density and velocity values. (5) High compaction of rocks in the crust under lithostatic loading cannot be explained by «simple» concepts of metamorphism and/or rock compaction, which are based on laboratory studies of rock samples and mathematical simulations; this is an evidence of the existence of additional, quite strong mechanisms providing for reversible changes of the rocks.Трехмерная комплексная геофизическая модель земной коры и верхней части мантии архейского Карельского кратона и позднепалеопротерозойского Свекофеннского аккреционного орогена на юго-востоке Фенноскандинавского щита получена с использованием методов комплексной инверсии геофизических данных, основанных на стохастическом описании взаимосвязей физических свойств среды: плотности, скорости продольных волн и теплогенерации пород. Для построения модели использованы результаты глубинных сейсмических исследований, данные о гравитационном поле и поверхностном тепловом потоке изучаемого региона. Численные схемы решения трехмерных задач реализованы в сферической постановке с учетом реального рельефа Земли. Методика достаточно универсальна и перспективна при исследовании строения коры и литосферы крупных регионов. Геофизическая модель сопоставлена с региональными поверхностными геологическими данными и результатами сейсмических исследований МОГТ по профилям 4В, FIRE-1 и FIRE-3-3A. По результатам комплексного геофизического моделирования и геологической интерпретации особенностей полученной объемной модели показано: (1) субгоризонтальная плотностная расслоенность континентальной коры накладывается на ранее сформированную геологическую структуру, плотностная дифференциация пород с глубиной уменьшается; особенности плотностной расслоенности в преобладающей степени определяются современным и относительно недавним состоянием коры, но могут быть нарушены в результате наиболее поздних деформаций; (2) температурные вариации на разделе Мохо частично определяются «локальными» изменениями теплогенерации мантии, которые обусловлены особенностями ее формирования и преобразования; (3) представления о нижней коре континентов как о «зоне рефлективити» и как о слое значительно повышенной плотности и скорости не являются эквивалентными: нижняя кора – это наиболее глубинный и наиболее высокоплотный элемент субгоризонтальной плотностной расслоенности, в свою очередь, сейсмический образ «зоны рефлективити» преимущественно связан с процессами преобразования коры в результате магматического андерплейтинга и интерплейтинга в обстановках рифтогенного растяжения и мантийно-плюмовой активности; (4) при определенных сочетаниях мощности коры и температурного режима на уровне раздела Мохо породы коры платформенных областей могут быть преобразованы в эклогиты – в этом случае граница коры и мантии определяется количественными соотношениями пород, подвергшихся и не подвергшихся эклогитизации, и соответствующими значениями плотностных и скоростных характеристик; (5) высокий уровень уплотнения пород в коре под воздейстием литостатической нагрузки невозможно объяснить на уровне «простых» представлений о метаморфизме и/или об уплотнении и компакции пород, базирующихся на лабораторных исследованиях образцов и расчетных моделях, что свидетельствует о существовании дополнительных и весьма мощных механизмов, которые обеспечивают обратимые изменения горных пород.