Feasibility of central loop TEM method for prospecting multilayer water-fi lled goaf

With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic （TEM） method is favorable for prospecting conductive layers because of the coupling relationship between its field structure and formation. However, the shielding effect of conductive overburden would not only require a longer observation time when prospecting the same depth but also weaken the anomalous response of underlying layers. Through direct time domain numerical simulation and horizontal layered earth forward modeling, this paper estimates the length of observation time required to prospect the target, and the distinguishable criterion of multilayer water-filled goal is presented with observation error according to the effect of noise on observation data. The observed emf curves from Dazigou Coal Mine, Shanxi Province can distinguish multilayer water-filled goaf. In quantitative inversion interpretation of observed curves, using electric logging data as initial parameters restrains the equivalence caused by coal formation thin layers. The deduced three-layer and two-layer water-filled goals are confirmed by the drilling hole. The result suggests that when observation time is long enough and with the anomalous situation of underlying layers being greater than the observation error, the use of the central loop TEM method to orosoect a multilaver water-filled goaf is feasible.

IMPROVEMENT OF THE PERFORMANCE OF THE DISPENSER CATHODE WITH Re AS A MIDDLE LAYER

A new type of dispenser cathode with dual-layer (Os-W/Re) is developed. The cathode coated with Os-W/Re shows better emission performance than the cathode coated with Os-W alloy. X-ray Photoelectron Spectroscopy (XPS) spectra demonstrate that ternary alloy coating (Os-W-Re) formed on the surface of the cathode with dual-layer (Os-W/Re) after full activation is the major reason why it has better emission than the cathode with Os-W alloy. The surface of each variety of the cathode is characterized with Scanning Electron Microscope (SEM) before and after activation: the emitting surface of the cathode with Os-W alloy after ageing appeared non-adherence (flaking) in localized areas, which is one of the reasons for non-uniform emission. However, the surface of the cathode with dual-layer (Os-W/Re) does not present film peeling under the same conditions. Thus it ensures better emission uniformity and functional reliability for the dispenser cathode.

Fossil woods from the Upper Cretaceous to Paleocene of Heilongjang(Amur)River area of China and Russia

Fossil woods were collected from the Upper Cretaceous to Paleocene beds distributed around Heilong- jang （Amur） River area of China and Russia. A total of 43 specimens were collected from Baishantou, Long- gushan, and Yong＇ancun in Jiayin, China, and 85 specimens from Zeya-Bureya Basin lying southeast of Blagoveshchensk in Russia. Selected specimens were sectioned and studied anatomically. The source deposits of almost all identifiable specimens belong to the Upper Cretaceous （Campanian） Taipinglinchang Formation and the Paleocene Wuyun Formation in China, and the Paleocene Upper Tsagayan Formation in Russia. Al- though the results obtained are still far from complete, the taxonomic composition of the fossil woods show marked stratigraphic differences between the two horizons beyond the K/T boundary in China. There is also a strong similarity in wood flora between the Wuyun Formation of China and the Upper Tsagayan Formation of Russia. All identified specimens from the Taipinglinchang Formation are Xenoxylon latiporosum, This is one of the stratigraphically younger records of Xenoxylon, which is a conifer morphogenus of uncertain affinity most common in the Triassic to Early Cretaceous. Only one specimen with possible derivation from either the Wuyun or the Maastriehtian Furao Formation in China was identified as Taxodioxylon sp. The Wuyun Formation yielded both conifers and dicotyledonous woods. The conifers include Taxodioxylon sequoianum of the Taxodiaceae, and Protopiceoxylon amurense, which is attributable to the extant genera Keteleeria or Nothotsuga of the Pinaeeac, both are at present endemic to China. At least two morphotypes of dicotyledonous woods were recognized, with one identified as el. Hamamelidoxylon , and the other diffuse porous wood is characterized by numerous heterogeneous rays. From the Zeya-Buleya Basin of Russia, Taxodioxylon sequoianum and cf. Hamamelidoxylon sp. were identified from the Upper Tsagayan Formation. The similarity of wood composition in both Wuyun and Upper Tsagayan Formations support lithological as well as biostratigraphic correlations proposed for the two formations.

Route and Rethink of China＇s Directly Applicable Law

Directly Applicable Law is an important achievement theory of private international law in the late nineteen fifties, widely used by states. The people＇ s Republic of China foreign civil legal relationship applicable law established the frame of our country＇ s Directly Applicable Law in the legislative level. In practice, there exists some shortcomings in the use of the rules and theory of Directly Applicable Law. In this paper, the author defines the rules from the micro level to order picture from macro level as the starting point, discussed the perfect approach of Directly Applicable Law from the dimension of the interpretation, system, evolution route ,and rethought our current legislative situation.

Micromorphological Features of Diagnostic Horizons in Several soils in Southwest China: Implication for Soil Taxonomic Classification

The comparative studies on micromorphological features in diagnostic horizons of Stagnic Anthrosols, Ustic Ferrosols and Ustic Vertosols in southwestern China were conducted to underpin the rationale for Chinese Soil Taxonomy. The following findings were explored: (1) Stagnic Anthrosols had the specific micromorphological features, e.g., the humic formation in anthrostagnic epipedon, the platy structures in plow subhorizon, the secondary formation of ferromanganese and the weakly optical-orientation clay domains in hydragric horizon, etc.: (2) The groundmasses of ferric horizon in Ustic Ferrosols appeared in hue of 2.5YR or redder, and had pellicular grain structure; (3) Ustic Vertosols had a crust horizon (Acr), and crack structure dominated in Acr and angular blocky structure in disturbed horizon; (4) Because of the distinct differences in micromorphological features among these three soils, the specific micromorphological features might be employed as diagnostic horizons to differentiate soils while the quantifiable micromorphological features might potentially be selected as diagnostic indices for Chinese soil taxonomic classification.

L3-Edge Jump and Shift on White-Line of Pd Interlayer for Trilaminar Neutron Production Target under H2^＋ Irradiation

Interlayer Pd for the Li/Pd/Cu neutron target for BNCT （boron neutron capture therapy） was characterized after 0.1-5 keV H2^＋ irradiation by XAFS （X-ray absorption fine structure） technique, and following conclusions were derived： （1） from the XAFS observation of white line of Pd, remarkable Pd L3 edge jump was found in 1.1-3 times higher than before irradiation in low irradiation fluence; （2） this fact indicates increase of hole density in Pd 4d-band, whereas, no change was observed for XASF spectra of Ag sample under the same irradiation conditions; （3） remarkable Pd L3 edge shift of 0.12-0.66 eV was also found with increase of H2＋ irradiation energy in low fluence, and drastically decreased after peak in high irradiation energy and fluence; （4） implanted protons deposited in Pd as negative under the balance of electron population enhanced by proton irradiation and charge transfer.

Progressive collapse resisting capacity of reinforced concrete load bearing wall structures

Reinforced concrete(RC) load bearing wall is widely used in high-rise and mid-rise buildings. Due to the number of walls in plan and reduction in lateral force portion, this system is not only stronger against earthquakes, but also more economical. The effect of progressive collapse caused by removal of load bearing elements, in various positions in plan and stories of the RC load bearing wall system was evaluated by nonlinear dynamic and static analyses. For this purpose, three-dimensional model of 10-story structure was selected. The analysis results indicated stability, strength and stiffness of the RC load-bearing wall system against progressive collapse. It was observed that the most critical condition for removal of load bearing walls was the instantaneous removal of the surrounding walls located at the corners of the building where the sections of the load bearing elements were changed. In this case, the maximum vertical displacement was limited to 6.3 mm and the structure failed after applying the load of 10 times the axial load bored by removed elements. Comparison between the results of the nonlinear dynamic and static analyses demonstrated that the "load factor" parameter was a reasonable criterion to evaluate the progressive collapse potential of the structure.

Super-aligned films of sub-1 nm Bi_(2)O_(3)-polyoxometalate nanowires as interlayers in lithiumsulfur batteries

Sub-1 nm nanowires(SNWs) can not only be processed like polymers due to their polymer-analogue properties but also show multifunctions owing to their well-manipulated compositions and structures. Rationally designed and engineered multicomponent heterostructure SNWs can further enhance their multifunction performance while it is very challenging to achieve such SNWs at sub-nanoscale.Herein, we synthesized Bi_(2)O_(3)-polyoxometalate heterostructure SNWs(PMB SNWs), and fabricated super-aligned PMB SNWs films(S-PMB SNWs films), which can serve as interlayers to efficiently suppress lithium polysulfide(LPS)shuttling, intrinsically promote the redox kinetics of the LPS conversion and substantially protect the Li anode. The lithium-sulfur(Li-S) battery with the S-PMB SNWs film as the interlayer showcases an ultralow capacity decay rate with 0.013% per cycle over 850 cycles. This study demonstrates the potential of heterostructure SNWs to improve the performance of Li-S batteries.

A potential stratotype for the regional lowermost stage of the continental Paleocene in China

Phanerozoic chronostratigraphic units can only be defined through their lower boundary stratotypes.The lowermost stage of the Paleocene of China,which mainly consists of terrestrial deposits,can only be defined through its lower boundary stratotype,i.e.the continental Cretaceous/Paleogene boundary stratotype.There is no section yet found which contains continuous terrestrial deposits and biostratigraphic records of the Cretaceous-Paleogene transition in Nanxiong,Guangdong and Jiayin,Heilongjiang,there is no evidence for establishing the continental stratotype of the Cretaceous/Paleogene boundary in either area.Therefore,both the"Shanghuan stage"and"Furaoan stage"are not good candidates for the lowermost stage of the Paleocene of China.From the viewpoint of charophytes,the outcrop section of the Dangyang,Hubei Province(Central China)contains the most continuous,abundant and diverse terrestrial biostratigraphic records of the Cretaceous-Paleogene transition,in particular the early Paleocene,known so far in the world.The biostratigraphic records of ostracods in the transition are also continuous,rich,and diverse.The Dangyang outcrop section is the only section known so far in China that is a possible candidate for a continental stratotype of the Cretaceous/Paleogene boundary in China and the section is the only potential section identified to date for establishing the regional lowermost stage of the Paleocene,Paleogene and Cenozoic in China or stratotype section for the stage.

Global structure and seasonal variations of the migrating 6-h tide observed by SABER/TIMED

Ten years of SABER/TIMED temperature data are used to analyze the global structure and seasonal variations of the migrating 6-h tide from the stratosphere to the lower thermosphere. The amplitudes of the migrating 6-h tide increase with altitudes. In the stratosphere, the migrating 6-h tide peaks around 35°N/S. The climatologically annual mean of the migrating 6-h tide clearly shows the manifestation of the(4, 6) Hough mode between 70 and 90 km that peaks at the equator and near 35°N/S. Above 90 km, the 6-h tide shows more than one Hough mode with the(4, 6) mode being the dominant one. The migrating 6-h tide is stronger in the southern hemisphere. Annual, semiannual, 4-, and 3-month oscillations are the four dominant seasonal variations of the tidal amplitude. In the stratosphere and stratopause, the spring enhancement of the 6-h tide at middle latitudes is the most conspicuous feature. From the mesosphere to the lower thermosphere, the tidal amplitude at low latitudes is gradually in the scale of that at middle latitudes and exhibits different temporal variations at different altitudes and latitudes. Both ozone heating in the stratosphere and the background atmosphere probably affect the generation and the seasonal variations of the migrating 6-h tide. In addition, the non-linear interaction between different tidal harmonics is another possible mechanism.