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The Cambrian pre-salt dolomite sequence in the Tarim Basin is a target zone of great strategic significance for hydrocarbon exploration in the basin. Using the results of the interpretation of 3D seismic data from Lunnan and 2D seismic data covering the whole basin, and based on a synthesis of outcrop data, drilling data, well logs, core data, and thin-section data, and the findings from previous studies, this paper studies the characteristics of the facies of the Middle–Lower Cambrian in the platform area in the Tarim Basin, the formation and evolution of platform margins, and the sedimentary characteristics, lithofacies, and paleogeographic characteristics of the Middle–Lower Cambrian series. Based on the types of lithofacies and the seismic facies analysis, the sedimentary facies of the Middle–Lower Cambrian strata can be classified into the five types. From bottom to top, the Middle–Lower Cambrian have experienced several development stages, including the deposition of continental shelf sediments of the Yuertusi Formation, gently sloping non-rimmed platform margin sediments of the Xiaoerbulake Formation, weakly rimmed platform margin sediments of the Wusongger and Shayilike formations, and strongly rimmed platform margin sediments of the Awatage Formation. In each stage, the platform margin shifted further east relative to its location in the previous stage. Based on these results and previous studies, the lithofacies and paleogeography maps of the Middle–Lower Cambrian in the Tarim Basin are modified, and the implications for hydrocarbon exploration in this area are discussed. [ABSTRACT FROM AUTHOR]

Subduction of the Paleo-Pacific Plate plays a key role in the Early Jurassic magmatism evolution in the Yanbian area, Northeast China. In this paper, zircon U–Pb ages, whole-rock geochemical, and Sr–Nd–Hf isotopic compositions are presented. The Early Jurassic gabbros, diorite enclaves, granodiorites, and granites ages range from 183 to 189 Ma. They are characterized by enrichment in large-ion lithophile elements and depletion in high-field strength elements. The gabbros are classified as low- and medium-K tholeiitic, granodiorites and granites are high-K calc-alkaline I-type, and diorite enclaves are calc-alkaline transitional series. The gabbros have zircon εHf(t) values of 6.81–9.89, whole-rock 87Sr/86Sr(i) = 0.7043–0.7044, and εNd(t) from 2.72 to 2.80. The diorite enclaves have zircons with εHf(t) values of 8.26–12.80, whole-rock 87Sr/86Sr(i) = 0.7051, and εNd(t) from 0.96 to 1.09. The granodiorites and granites have zircon εHf(t) values of 7.59–12.87, whole-rock 87Sr/86Sr(i) = 0.7042–0.7066, and εNd(t) from 2.33 to 2.61. These data indicate that gabbroic magmas were derived from partial melting of a depleted mantle wedge metasomatized by subduction-related fluids. The basaltic magma underplated and heated the juvenile crust, whereas the granodiorites and granites might be the product of fractional crystallization of a mixture of basaltic and felsic magmas or derived from partial melting of the juvenile lower crust. Our data constrain the petrogenesis of these Early Jurassic intrusive rocks which are attributed to subduction of the Paleo-Pacific Plate beneath Eurasia continent in northeastern China. [ABSTRACT FROM AUTHOR]

With the application of machine learning rapidly gaining popularity in computer science and other fields, neural network techniques have successfully simulated the performance of in-service pavements as they are efficient in predicting and solving nonlinear relationships and in dealing with uncertain large-area pavement problems. In this paper, we address the problem of the optimal timing of preventive maintenance of asphalt pavements to accurately predict the condition index (pavement condition index, PCI) of highway asphalt pavements and develop a highly accurate, long-period, multifactor prediction model with the suitability of preventive maintenance at its core. The prediction model is called differential evolution particle swarm optimization back propagation (DEPSO-BP) neural network, and the input dimension of the prediction model is determined by gray correlation analysis (GCA), and DEPSO is used to improve the search efficiency of BP neural network and the asphalt pavement usage performance with parameter continuity prediction model. Finally, the Qinglan Highway (G22) PCI of Gansu Province, China, is selected for example validation, and the prediction results are compared with those of the four models. The results show that the multifactor prediction model based on DEPSO-BP neural network has good generalization ability. This model is important for improving the economic efficiency of road maintenance, and can be used in the long-cycle process to provide model reference and scientific basis for the subsequent road maintenance budget application and decision-making scheme. [ABSTRACT FROM AUTHOR]

Transfer between the metro (underground railway system) and buses is standard in many cities, and the simultaneous arrival of these two modes can provide passengers with a smoother transfer experience. However, previous synchronous transfer studies rarely consider different public transport modes simultaneously. This paper presents an optimization model that maximizes the number of metro and bus network synchronizations considering the connection level. An improved algorithm that combines simulated annealing (SA) and artificial bee colony (ABC) is proposed. The best nectar source position in history is combined with the SA operation. The ABC and simulated annealing and improved artificial bee colony (SA–IABC) algorithms are used to solve the model using the Nanmendou metro station and the bus stations within 1.2 km around it in Fuzhou City, China. The results show that ABC and improved SA–IABC algorithms increase the synchronization times of the metro and bus network by 17% and 24% on average, respectively, without expanding the departure frequency. [ABSTRACT FROM AUTHOR]

Polygonatum cyrtonema Hua is a traditional Chinese herb medicine, and it is widely distributed in China. The intrageneric taxonomy and phylogenetic relationships within Polygonatum have long been controversial due to their morphological similarity and lacking special DNA barcodes. In this paper, the complete chloroplast genome is a relatively conserved quadripartite structure including a large single copy region of 84 711 bp, a small single copy region of 18 210 bp, and a pair of inverted repeats region of 26 142 bp. A total of 342 simple sequence repeats were identified, and most of them were found to be composed of A/T, including 126 mono-nucleotides and 179 di-nucleotides. Nucleotide diversity was analyzed and eight highly variable regions (psbl∼trnT-CGU, atpF∼atpH, trnT-GGU∼psbD, psaJ∼rps20, trnL-UAG∼ndhD, ndhG∼ndhl, ndhA, and rpl32∼ccsA) were identified as potential molecular markers. Phylogenetic analysis based on the whole chloroplast genome showed that P. cyrtonema, within the family Asparagaceae, is closely related to Polygonatum sibiricum and Polygonatum kingianum. The sequence matK, trnT-GGU & ccsA, and ndhG∼ndhA were identified as three DNA barcodes. The assembly and comparative analysis of P. cyrtonema complete chloroplast genome will provide essential molecular information about the evolution and molecular biology for further study. [ABSTRACT FROM AUTHOR]

Forest products trade has a critical role to play in both global economic development and environmental protection. Based on the trade data of global forest products, raw forest products, and processed forest products from 2000 to 2020, this paper constructed a trade network and analyzed its pattern by using indicators such as density, average distance, out-strength, and in-strength. The results show that from 2000 to 2020, the global trade network of forest products has been increasingly connected. Compared with the trade of raw material forest products, the trade network of processed forest products is more closely connected and its transport efficiency is higher. Countries with high GDP such as USA, China, and Germany are leading trading countries in forest products. Countries with abundant forest resources are the major exporters of raw forest products, while labor- and capital-abundant countries are major exporters of processed forest products. Countries with abundant labor and capital and high GDP are the main importers of raw forest products. [ABSTRACT FROM AUTHOR]

Construction of tunnels using a shield in very soft soil may result in serious shield alignment problems and ground settlement. This paper presents a detailed field instrumentation program that was conducted for the construction of the Suzhou Metro Tunnel-Line S1 in China. The characteristics of the shield kinematics in ultra-soft soil and ground responses were examined, and the mechanisms of ground movements and pore water pressure corresponding to shield motions and construction parameters were interpreted and discussed. In addition, a calculation method for ground loss corrected by shield posture was established, based on which a corresponding volume of the grout required was recommended. The results indicated that the shield typically tunnels in very soft soil with increasing inclination mode characterized by a rising tail owing to the floating segment and with a changing inclination mode characterized by a sudden downward movement and subsequent steering of the shield upon encountering hard soil. Consequently, with the uplifting of the shield tail, it was found that the ground heaves and settles with a change in the shield posture. Moreover, a large longitudinal uneven deformation of the lining was found to occur in most of the above situations, while the pore water pressure was minimally affected by the shield posture. [ABSTRACT FROM AUTHOR]

Appropriate constitutive models and reliable excavation and support sequences are believed to be the major concern in using finite element (FE) analysis to simulate shield tunnel excavation. This paper presents systematic two-dimensional (2D) and three-dimensional (3D) FE analyses employing a number of constitutive models accounting for initial soil anisotropy and non-coaxial plasticity, as evidenced within site investigations from the Tsinghuayuan Tunnel of the Jing-Zhang high-speed railway in China. The aim is to assess the effects of both the initial soil anisotropy and non-coaxiality on longitudinal and transverse tunneling-induced surface settlements. It is shown that the excavation procedures combined with the degree of cross-anisotropy are key towards the accurate prediction of maximum vertical displacements from tunneling, matching field data. Knowledge of the initial soil strength anisotropy can further improve the shape prediction of the transverse tunneling-induced surface settlement troughs. When considering n = 0.6 and β = 0° in simulations, the transverse surface settlement trough obtained is almost coincident with monitored field data. Initial stiffness anisotropy used in the prediction of shield tunnel-induced surface settlements in sandy pebble soils does improve realism of results significantly. The maximum longitudinal settlement predicted by considering cross-anisotropy is larger than that predicted by its isotropic counterpart. [ABSTRACT FROM AUTHOR]

Work zones which are usually referred to as traffic bottlenecks or critical points may lead to reductions in both operational performance and safety. Researchers have conducted extensive studies on speed characteristics in freeway work zones. However, most of these studies are based on simulation data or are travel direction-based rather than lane-based. By utilizing the video recording capability of drones, this paper aims to provide methodologies and the workflow in exploring the vehicular speed characteristics in freeway work zones with considerations for lane and location deviations. A four-to-three lane work zone on Huhang Expressway between Downtown Shanghai and Songjiang in China was selected for data collection. Then free flow speed variation pattern is analyzed, a speed prediction model is proposed, and the speed–flow relationship is investigated on each lane at nine virtual sections along the work zone. It is found that the merging area affects the speeds mainly in the segment from 200 m upstream of the taper to the start of the activity area, which is the most important risk area in the work zone, and the speed characteristics depend on vehicle types (trucks versus automobiles) as well as lane locations. It is also showed that drones are valuable and effective tools for data collection for vehicular speed characteristics analysis in freeway work zones and it is easy to extract the information needed. [ABSTRACT FROM AUTHOR]

In addition to core, logging, and other previous research results, this paper determines the fault development and tectonic evolution process of the Baxian sag with the Paleogene rift stage based on 3D seismic data. The Paleogene tectonic evolution of the sag can be divided into three episodes and six evolution stages, and three types of faults are identified: intensely active normal, active normal, and weakly active normal. One first-order sequence, three second-order sequences, and fourteen third-order sequences of the Paleogene Baxian sag were created, and fifteen sequence boundaries were recognised. According to the rifting background and sedimentary facies development characteristics of each episode, five combination types of the depositional system associations were identified, including alluvial fan-fluvial and braided-delta-lacustrine in an early rifting episode, delta-lacustrine and nearshore subaqueous fan-lacustrine in the middle rifting episode, and fluvial-flood plain in the late rifting episode. Six response models of filling and the evolution process in Paleogene Baxian sag were concluded. The multi-episodes tectonic cycles of faulted lake basins resulted in complex paleogeomorphology and variable provenance supply, forming abundant sequence structure patterns and different filling and evolution processes of faulted lake basins. The stable rifting stage is favourable to form and preserve high-quality source rock, and develop various sedimentary facies and sandbody types, which is a potential area for exploration of a lithologic stratigraphic oil and gas reservoir. [ABSTRACT FROM AUTHOR]

Geodynamic evolution in the late Paleozoic is significant for understanding the final amalgamation of the Central Asian Orogenic Belt (CAOB). No consensus has yet been reached regarding the late Paleozoic geodynamic evolution of the northern Great Xing'an Range (GXR) in northeastern China, the eastern CAOB. Furthermore, late Paleozoic syenogranite–diabase dyke association is present in the Xiaokele area in northern GXR. It provides an important opportunity to understand the nature of magmatism and the geodynamic evolution during this period. This paper presents new zircon U–Pb ages, zircon Hf isotopic compositions, and geochemical data of whole rocks for Xiaokele syenogranite and diabase. Zircon U–Pb dating suggests that the Xiaokele syenogranite (292.5 ± 0.9 Ma) and diabase (298.3 ± 1.5 Ma) were emplaced during the early Permian. The Xiaokele syenogranites have high SiO2 contents, low MgO contents, and enriched zircon εHf(t) values, suggesting that their primary magma was generated by the partial melting of the juvenile crustal material. The Xiaokele diabases have low SiO2 contents, high MgO contents, are enriched in large-ion lithophile elements, depleted in high-field-strength elements, and exhibit enriched zircon εHf(t) values. They derived from a lithospheric mantle source that had previously been metasomatized by slab-derived fluids. Combined with previous research results, we believe that the continent–continent collision between the Xing'an and Songliao blocks occurred during the late early Carboniferous – early late Carboniferous (330–310 Ma), and the two blocks were transformed into a post-collisional extensional setting during the latest Carboniferous – early Permian. [ABSTRACT FROM AUTHOR]

Limited by the low-frequency data acquisition, vehicle global positioning system (GPS) data are difficult to implement in the area of microtraffic simulation. Based on the functional design of mobile phone positioning technology, mobile phones can be used to acquire bus GPS data every second. In this paper, an analytical model is proposed to determine the parameters of signal coordination for bus priority along an arterial based on GPS data of mobile phones. First, bus priority evaluation indicators are established using bus GPS data, which are acquired by mobile phones. Second, the signal timing parameters of the arterial road are optimized, and a preliminary timing plan is developed by evaluating small changes in the plan. Finally, the corresponding final plan is developed using VISSIM micro simulation software. The feasibility of the analytical model is verified by simulating an actual arterial in Fuzhou city, China. [ABSTRACT FROM AUTHOR]

Light emitting diode (LED) traffic signs have been deployed on many urban roadways recently. However, a lack of uniform engineering criteria for the luminance level of LED traffic signs in China brought up consequences such as inaccurate recognition of signs for drivers as well as potential traffic accidents. This paper explores the possible luminance range of LED traffic signs through full-scale field static experiments. Visual recognition distance, character height, character stroke, sign background color, sign dimension, and sign complexity degree are taken into account. The visual recognition luminance value required for drivers are recorded. Experiment results reveal that: for character symbol, the background color of the board and character strokes have no significant effect on driver's visual recognition performance; for graphic symbol, the higher of graphic complex degree, the higher luminance value required for driver to recognize. This study summarizes the luminance thresholds of different kinds of LED signs for different roadway classes. The findings of this study would provide reference for future design of LED traffic signs. [ABSTRACT FROM AUTHOR]

Increasing exploration interest in oil and gas hosted by early Cambrian strata has focused research efforts on early Cambrian sandstones. The origin of phosphorus and the paleoenvironment of phosphorus-bearing sandstones from the Xinji Formation are discussed in this paper. X-ray diffraction, optical microscopy, grain size analysis, total organic carbon, and the concentrations of major, trace, and rare earth elements (REEs) are analyzed in this work. The sandstones are mostly sublitharenite with calcareous cement. The content of the sandstone samples is quartz (39.8%–73.9%), with illite (7.9%–27.6%) and calcite (4.5%–29%). The mineral particles of sandstone samples are mainly well sorted with a fine particle size, suggesting strong paleohydrodynamic force. The value of SiO2 is 37.69%–78.19%, followed by Al2O3 (6.11%–13.67%). Compared with upper continental crust, the boron in the sandstone samples is relatively enriched, whereas Sc, Sr, and Ba are relatively depleted. The ΣREE content is 124.46–323.99 ppm. Phosphorus is of biogenic origin and enriched by upwelling current. The source of the Xinji Formation sandstone samples was mainly a mixture of sedimentary rock, granite, and alkali basalt, with the provenance of terrestrial clastic materials. The sandstone was deposited under oxic conditions and a warm and humid paleoclimate with saline to brackish features on a passive continental margin. Phosphorus occurring in sandstones is sensitive to paleoclimate and can be used as an indicator to judge paleoclimate, as it is more enriched in warm and humid weather. [ABSTRACT FROM AUTHOR]

A change in sea level (or lake level) causes a change in accommodation space and sediment compensation, which then controls the formation and evolution of sequences. A multidisciplinary approach based on the integration of clay minerals, major and trace elements, paleosalinity, and three-dimensional seismic data were applied to interpret the stratigraphic sequence of the Dongying Formation in the Liaoxi low uplift. The sequence surface indicates that multistage tectonic action, paleoclimate, paleosalinity, and lake level change jointly controlled the sequence stratigraphy. The illite and illite–smectite mixed layers indicate an arid to semi-arid climate, whereas kaolinite implies humid conditions. Based on this principle, it is clear that the stratigraphic sequence is closely related to paleoclimate. Interpretation of the continental or marine character of the sediments via paleosalinity is increasingly based on the concentration of some trace elements. Hence, the sequence surface can be better evaluated through paleosalinity data. Based on the Sr/Ba and boron content, paleosalinity was evaluated and the sequence boundary was identified. Analysis of the concentration of major and trace elements was used to identify the lithology of the sedimentary region and further discern the stratigraphic sequence. These sequences are composed of lowstand, transgressive, and highstand system tracts. The work herein aimed to understand the reasons for the changes in sequences under the paleoclimate. In addition, major and trace elements, studied together with paleosalinity and clay mineral content, result in the determination of implications for sequence stratigraphy in many other basins. This paper can provide a novel method for comprehensively discerning a sequence surface. [ABSTRACT FROM AUTHOR]

The Zhanbuzhale region, in the Eastern Kunlun Orogen of northwestern China, is characterized by large volumes of Phanerozoic granitoid rocks and is an ideal region for investigating the tectonic evolution of the Paleo-Tethys system. However, the exact timing of the final closure of the Paleo-Tethys Ocean and initial continental collision remains controversial because of a lack of precise geochronological and detailed geochemical data. In this paper, we report new zircon U–Pb ages and mineralogical, petrographic, and geochemical data for samples of Middle Triassic granodiorite and alkali feldspar granite from the Zhanbuzhale region. The zircon U–Pb ages indicate that the granodiorite and alkali feldspar granite formed at 239 and 236 Ma, respectively. The granodiorites are high-K calc-alkaline, metaluminous, high Sr content, high Sr/Y ratios, low Y content, and show adakite-like affinities. The alkali feldspar granites display high SiO2, extremely low MgO, and low Zr+Nb+Ce+Y contents as well as low Fe2O3t/MgO ratios, showing metaluminous to peraluminous and high-K calc-alkaline features. Geochemical and petrological characteristics of the alkali feldspar granites suggest that they are highly fractionated I-type granites. The granodiorites and alkali feldspar granites have zircon εHf(t) values ranging from –2.26 to –0.18, and from –2.17 to +2.18, respectively. Together with regional geological data, we propose that the Triassic (approximately 239–236 Ma) granitoids were generated during the later stages of northward subduction of the Paleo-Tethys oceanic plate, and that the initial stage of collision between the East Kunlun and the Bayan Har–Songpan Ganzi terrane occurred at approximately 236–227 Ma. [ABSTRACT FROM AUTHOR]

A case study of a double-cell, large-span prefabricated reinforced concrete box culvert with a total length of 52 m, a width of 46.8 m, and a height of 9.3 m, which passes beneath the Beijing - Hong Kong -Macau highway, is presented. The culvert is embedded in silty sand and silty clay at a depth of 1.2 m. To ensure the safety and normal operation of the highway, hydraulic jacking with the protection of a pipe roof was adopted for this project. This paper introduces the construction scheme in detail. A three-dimensional numerical simulation of the responses of the highway under which a wide box culvert jacking passes was conducted. The monitoring results on the highway as well as the actual construction process and problems encountered were analyzed. The different development characteristics or trends for the settlement and horizontal displacement of a highway surface are presented. In addition, this paper discusses the reasons for the large deformation of the highway surface as well as proposes reasonable suggestions. [ABSTRACT FROM AUTHOR]

Constructing a bored pile produces a disturbed zone of soil adjacent to the pile, referred to as a “mudcake.” The physical properties of the mudcake are different from those of the surrounding soil. This paper reports research on bored piles in silt, clay, and sandy silt layers in Hangzhou, China. Laboratory tests were performed on samples of in situ soil, mudcake, and mudcake mixed with cement grout. The test results showed that mudcakes have a higher water content, higher void ratio, higher compressibility, lower friction, and lower shear strength than in situ soils. They also showed that mudcake properties could be improved by the addition of cement grout. Mudcakes form a weak, thin layer between a pile and a borehole wall, which can lead to a decrease in bearing capacity and an increase in settlement of the pile. Grouting improves the characteristics of mudcakes remarkably, thereby increasing the bearing capacity of piles, which is demonstrated by the case history in this paper. [ABSTRACT FROM AUTHOR]

Beijing is located in a semiarid region, and water shortage is a common problem in the city. Along with the rapid increase in water demand, due to fast socioeconomic development and an increase in population, a shortage of water resources and a deterioration of the water environment have become obstacles to sustainable socioeconomic development in Beijing. In the long run, sustainable water resources management, water conservation, and completion of the south to north water diversion project will solve the problem. This paper introduces the water resources situation in Beijing; analyzes future water demand; and discusses the actions of water saving, nontraditional water resources exploitation, wetland construction, and water environment protection. The paper also explains the importance of the south to north water diversion project and the general layout of the water supply strategy, water distribution system, and methods to efficiently use the diverted water in Beijing. [ABSTRACT FROM AUTHOR]

This paper aims to be a cursory relative comparison between applications of custom-designed constructed wetland systems for specific water resources protection in Canada and northern China. Comparing constructed wetlands can be difficult and at times misleading; they are custom built to deal with specific target wastewater at specific locations and differ not only in physical shape and dimension, but in vegetation cover, hydraulic retention time, and pollutant loading rates. Treatment efficiencies defined by the Canadian and northern Chinese experience vary considerably. Experience in both countries shows that the majority of effluent values are generally better than those required by discharge standards in Canada and China. Examples provided from both countries demonstrated that plants can play a role in constructed wetland systems and make a difference in treatment efficiency. A review of the available case studies on cold weather treatment in both countries indicates that this technology is feasible in Canada and northern China, although further monitoring data are needed to optimize wetland design and ensure that the effluent quality standards are consistently met. Constructed wetland systems in both countries have an apparent advantage in construction costs, and the costs for treatment and operation and maintenance of these systems are much lower than those of conventional wastewater treatment plants. Land requirements for constructed wetlands present one of the factors most limiting their broader use, especially in China, where land resources are scarce and population density is high. [ABSTRACT FROM AUTHOR]

The United States (US) Lacey Act 2008 amendment (LAA) is a timber legality regulation that requires US importers to monitor and minimize the risk of illegally harvested wood products within their supply chains. This paper empirically examines the effect of the LAA on Chinese companies' export costs to the US. The study uses 138 responses from two surveys in Shanghai, China, in 2013, i.e., 5 years after the LAA was implemented. Given the high proportion of zero export increase indicated by the Chinese companies, a zero-inflated ordered probit model was used to model Chinese companies' export cost increases to the US. The research results demonstrate that pre-LAA raw material sourcing patterns are primary indicators of the respondents' export cost increase to the US as a result of the LAA. From the results, it can be inferred that log and lumber importers from suspect regions are taking additional measures, by changing their procurement practices, to ensure the legality of their raw material, which is adding to their cost structure. The results also indicate that smaller companies, given their flexibility with raw material procurement, were less likely to experience a post-LAA cost increase relative to their larger counterparts. [ABSTRACT FROM AUTHOR]

It was not until the 1980s that China's policy makers became aware of the detrimental impacts on urban health from soil pollution as a result of industrial waste emissions. For the past three decades, the Chinese government has strived to prevent and control industrial pollution. Setting appropriate environmental policies is the key to mitigating the legacy of industrial waste emissions accumulated for three decades. In this paper, we review the development process by outlining the evolution of the policies and the resulting legal infrastructure in terms of acts, regulations, ordinances, and standards. Deficiencies of the existing policies are identified. In the early stages, environmental policies were fragmented, consisting of single-purpose laws that are narrowly focused. With time, these policies gradually evolved to become better integrated and comprehensive management plans. However, the laws emphasize contaminated site restoration instead of preventing soil pollution. The legal framework shows that the policies that are in place often lack clear mandates because the authorizations are piggybacked on environmental acts and regulations that do not directly address issues of soil pollution. Furthermore, implementation plans are impractical due to outdated soil quality standards, unclear soil cleanup goals, unenforceable liability and supervision mechanisms, limited funding, lack of transparency and public outreach, and the unreliable financial and technical capabilities of the remediation industries. [ABSTRACT FROM AUTHOR]

P2Y12, a member of the G-protein-coupled receptors, is associated with abnormal platelet aggregation, a condition that contributes to thrombus formation. As receptor antagonists are effective solutions for anti-thrombus, the P2Y12 receptor is a popular drug target. After the recent resolution of the P2Y12 receptor's crystal structure, pharmacophore modeling and docking were combined to discover potential natural antagonists. Various approaches were used for the validation of the pharmacophore models and the optimization of docking algorithms. Hypo18, which was generated by 24 known antagonists, was determined to be the best hypothesis and is comprised of one ring aromatic, one hydrogen bond acceptor, one exclude volume, and three hydrophobic features. Hypo18 was thus utilized to screen TCMD (version 2009) to identify any potential active compounds, which then resulted in a hit list of 121 compounds with drug-likeness analysis. In addition, docking was used to refine the pharmacophore-based screening results as a cross-linking method. Then, the top 20 compounds with high docking scores were reserved. This paper provides a reliable source for discovering natural P2Y12 receptor antagonists from traditional Chinese herbs. [ABSTRACT FROM AUTHOR]

Southern China has a humid climate and often receives rainfalls that are of high intensity and (or) long duration. This paper investigates the performance of an inclined three-layer cover with capillary barrier effect (CCBE) comprising silt, sand, and gravel, for usage under humid climatic conditions. Physical modeling tests were carried out to observe the response of the three-layer CCBE system to a continuous heavy rainfall of about 70 mm/h. The layered cover model, housed in a 2 m long and 1 m wide instrumented box, is made up of 0.2 m thick silt, 0.1 m thick sand, and 0.1 m thick gravel, and the inclination of the model is 1V:3H. The movement of wetting front, changes in soil suction, and the primary components of water balance were measured during the operation of the physical models. The experimental data was used to calibrate the hydraulic parameters of the numerical model using the unsaturated flow software, SVFlux. Numerical modeling was subsequently carried out on a 60 m long inclined CCBE system to investigate the effective length of lateral diversion under prolonged rainfall. The main findings of the experimental and numerical studies are as follows: ( i) the physical model tests showed that the response of the three-layer CCBE system to a heavy rainfall of 70 mm/h was different from the previous observations on experiments where the rainfall was less than 1.6 mm/h; ( ii) correlation between the physical modeling and the numerical modeling indicated anisotropic behavior with respect to the hydraulic conductivity in the unsaturated sand layer; ( iii) the long inclined, three-layer CCBE system (i.e., 0.6 m thick silt, 0.2 m thick sand, and 0.2 m thick gravel) had an effective length of lateral diversion over 10 m for 30 days of prolonged rainfall (i.e., 1080 mm in total). [ABSTRACT FROM AUTHOR]

The 12 May 2008 Wenchuan earthquake in China triggered numerous landslides. Loose landslide materials can easily evolve into deadly debris flows during wet seasons. During the period from 2008 to 2011, three separate large-scale debris flows occurred in the Pubugou Ravine near the epicentre of the earthquake that were among the largest repeated debris flows ever reported. Approximately 1.76 × 106 m3 of sediment was deposited during these three events. This paper aims to ( i) analyze the movements of solid materials during the repeated debris flows, ( ii) discuss the evolution of the initiation mechanisms of these debris flows, and ( iii) evaluate the changing depositional morphology of the debris flow fans and examine the particle sizes of the debris flow materials. To achieve the above research objectives, timely field investigations were undertaken in the past 5 years after each of these debris flow events. Satellite images were used to delineate the boundaries of the initiation areas, the transportation channels, and the deposition zones of these debris flows. With the occurrence of the repeated debris flows, the hill slope deposits gradually evolved into channel deposits and the solid materials in the channels moved toward the gully mouth. Hence, channelized flows gradually became dominant. The debris fan materials of the repeated debris flows became coarser and coarser over time. The three debris flows were all characterized by coarse boulder fronts. [ABSTRACT FROM AUTHOR]

Reflective cracking distresses frequently occur on the hot mix asphalt (HMA) overlay due to the movements of the underlying Portland cement concrete (PCC). Rubblization was proven in North America to be an effective approach among slab fracturing technologies for solving the premature reflective cracking problem. This paper presents the procedure of applying the rubblization technology in HMA overlay design in a research effort in China to develop the Chinese standard. In the study, the validity of rubblization was analyzed by a trench survey and sieve tests; the layer moduli of the composite subgrade and rubblized concrete slab were determined using FWD and plate bearing tests and a conversion chart; the thickness design for the HMA overlay over the rubblized PCC pavement was conducted using a Chinese version mechanistic-empirical design process; and finally the in-service monitoring over the pavements built using the developed procedure was conducted to test the validity of the procedure. [ABSTRACT FROM AUTHOR]

Slope instability processes occur widely on the underwater slopes of the Yellow River delta during storms. Roughly circular depressions on the upper delta front in water depths of 4 to 8 m have been detected by acoustic surveying and their processes were observed in the laboratory. This paper analyzes the properties of geomorphic and acoustic profiles of the upper delta front and compares the engineering geologic properties of samples from the disturbed and undisturbed areas. The results indicate that the weak superficial mass could oscillate with waves and the oscillation weakened the surrounding soil under the cyclic loading. The stratum was disturbed or even destroyed with depth, the area of the slide mass enlarged gradually, and finally a collapse depression formed. [ABSTRACT FROM AUTHOR]

Understory light is essential to the establishment and growth of understory plants and varies temporally and spatially within gaps. The previously defined gap light index (GLI) is a good model for assessing understory light levels, but it is time-consuming to determine gap coordinates, which are crucial to GLI, for numerous points within a gap. This paper introduces the geometric calculation (GeoCalc) of gap coordinates. GeoCalc quickly obtains gap coordinates for any specified point within a canopy gap and takes into account the tridimensional profile of the gap and the slope and aspect of the ground. The GeoCalc-based GLI was validated by the GLI derived from hemispherical photographs taken at 93 sampling points within seven natural gaps. Our results demonstrate that GeoCalc-based GLI was strongly positively correlated and not significantly differed from the GLI derived from hemispherical photographs. Next, to analyze gap light regimes and the effects of gap size, canopy height, and topography, three natural gaps of various size were selected and simulated as nine gaps with 1 and 1.5 times canopy height or on the opposite slope. Finally, we have summarized characteristics of GeoCalc-based GLI and its application. [ABSTRACT FROM AUTHOR]

By integrating the vehicle tracking system, discrete-event simulation algorithm, and evolutionary optimization algorithm, we developed HKCONSIM-Realtime, a decision-support platform created specifically for handling ready-mixed concrete operations. This platform is capable of (1) tracking the positions of concrete trucks and monitoring the motion and status of concrete deliveries in real time, (2) transforming the tracking records into data that provide updated input to simulation, and (3) optimizing the operations and logistics of concrete production based on simulation of the production system using the most current data. This paper presents an overview of the design and development of (1) the hardware and software modules, (2) the data flow and processing throughout the system, and (3) the role of the system in providing interactive, effective support for the human operator to attain cost efficiency. Case studies are given to demonstrate the functionality and application of the prototype system. [ABSTRACT FROM AUTHOR]

Landslide 1 is located on the right bank of the downstream side of the dam for Hongjiadu Hydropower Station in Guizhou Province, China. In view of its close proximity to important workings, the stability of the slide is of great concern. Ground investigation showed that the slide is potentially unstable and has two sliding directions. Reinforcement mainly by piles was proposed as the stabilization measure, but two key questions were raised during the design of the piles. (1) How could the stability of the slope be evaluated, as there are two major sliding directions? (2) How could the shear strength parameters of the slip band be determined, as it contains a significant proportion of coarse particles? In this paper, we demonstrate how these issues can be addressed by the strength-reduction technique. First, the strength parameters of the slip band are back-analyzed by assuming a factor of safety of unity. Second, the major sliding directions are determined by carrying out finite difference analyses. Third, two proposed stabilization schemes are evaluated and compared to demonstrate the versatility of the technique. The present study has demonstrated that the strength-reduction technique is a powerful tool for analyzing such problems. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative technology—grouted jetted precast concrete piling—that increases the efficiency of piling operations in coastal regions. The technology includes the following steps: (i) casting concrete piles factory-designed especially for jetting and grouting; (ii) jetting to drive the concrete piles with a crane on a floating ship or platform into soil; and (iii) grouting to enhance the sheet pile connections and to increase the pile bearing capacity. This technology was applied to a number of piling construction projects at the mouth of the Yellow River Delta in China, and this experience demonstrated that it is a robust, fast track, cost-effective, and environmentally friendly piling method. [ABSTRACT FROM AUTHOR]

This paper illustrates the importance of river ice accumulations in changing river channel geometry based on field investigations carried out at the Hequ gauging station on the Yellow River in China. A relationship is established between riverbed deformation and ice accumulation. [ABSTRACT FROM AUTHOR]

This paper investigates the failure of three gravity walls due to the 1999 Chi-Chi earthquake. Characteristics of the damaged walls were carefully recorded and backfill materials behind the damaged walls were collected and tested in the laboratory. Both the simplified analysis based on the Mononobe–Okabe method and the simplified dynamic analysis based on the Richards–Elms method were adopted. For the first case, the sliding of concrete wall blocks along the construction joint was observed. It was found that, during the earthquake, the frictional resistance at the untreated construction joint was not sufficient to resist the dynamic lateral thrust. For the second case, the retaining wall settled significantly and tilted about its toe. Seismic analysis of the wall indicated that, under the same horizontal acceleration, the factor of safety against bearing capacity failure was lower than that against overturning and sliding. A stability check against bearing capacity failure for the retaining wall should never be neglected. For the third case, the retaining wall built on top of the Che-Lung-Pu fault was severely damaged by the fault rupture. During the earthquake, the vertical displacement of the hanging wall uplifted the backfill, causing the wall to overturn. Horizontal displacement of the hanging wall caused the wall to slide and the soil in front of the toe to heave. [ABSTRACT FROM AUTHOR]

The recent discovery of the early dromaeosaurid Sinornithosaurus millenii Xu et al. 1999 is especially important for our understanding of maniraptoran evolution, particularly of avian origins. This paper presents a thorough description of the skull of this species, revises the diagnosis based on cranial features, and discusses similarities to those of other dromaeosaurids and Archaeopteryx. Distinctive cranial characteristics of S. millenii include the presence of a deep excavation on the posteroventral margin of the premaxilla, a diastema between the premaxillary and maxillary teeth, a number of pits and ridges on the anterolateral surface of the antorbital fossa, long posterolateral process of the parietal that are sharply posteriorly directed, the column-like margin of the pterygoid process of the quadrate, the bifurcated posterior end of the dentary, and a distinctive groove posterior to the anterior carina on the lingual surface of the premaxillary tooth crowns. The present study on the skull of S. millenii provides new information on the poorly known cranial anatomy of dromaeosaurid dinosaurs, revealing that dromaeosaurids share more similarities with Archaeopteryx than previously thought. It also provides evidence suggesting that early dromaeosaurids are more bird-like than the later, more derived ones, thus contradicting claims that more bird-like dinosaurs appeared later in fossil record than the earliest birds.La découverte récente du dromæosauridé précoce Sinornithosaurus millenii Xu et al., 1999, est spécialement importante pour notre compréhension de l'évolution des rapaces, surtout ceux d'origine aviaire. Cet article présente une étude complète du crâne de cette espèce, révise le diagnostic crânien et discute de ses similitudes avec ceux d'autres dromæosauridés et d'Archaeopteryx. Les caractéristiques crâniennes distinctives de S. millenii comprennent la présence d'une excavation profonde sur la bordure postéroventrale du prémaxillaire, un diasthème entre les dents prémaxillaires et maxillaires, un certain nombre de creux et de bosses sur la surface antérolatérale de la fosse antorbitale et un long processus postérolatéral du pariétal qui sont nettement dirigés vers l'arrière, une bordure de style colonne du processus ptérygoïde de l'os carré, une extrémité postérieure bifurquée du dentaire et un sillon distinctif en arrière de la carène antérieure sur la surface médiale des couronnes des dents prémaxillaires. La présente étude sur le crâne de S. millenii fournit de nouvelles informations sur l'anatomie crânienne peu connue des dinosaures dromæosauridés, révélant que les dromæosauridés partagent plus de points en communs avec Archaeopteryx qu'on ne le croyait antérieurement. Cette étude fournit également des évidences voulant que les formes précoces des dromæosauridés ressemblent plus à des oiseaux que les formes plus tardives et plus dérivées, contredisant ainsi les allégations que des dinosaures ressemblant plus à des oiseaux sont apparus plus tard dans les gisements fossilifères que les oiseaux les plus précoces.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The reclamation for the new airport at Chek Lap Kok in Hong Kong included the placement of a substantial volume of sand fill by various hydraulic placement techniques, which resulted in a wide range of as-placed densities of the sand fill. This paper described the use of cone penetration tests (CPT) on the evaluation of the possible ranges of density achievable by various hydraulic placement methods adopted in the construction of the new airport. The results of the CPT indicated that the placement technique is one of the most important factors in controlling the as-placed density of hydraulically placed sand fill. There is a marked contrast in cone tip resistance (and the associated relative density) profiles for the sand fills formed by subaerial and subaqueous placement methods, in which the cone tip resistance of the sand fill formed by subaerial placement is substantially higher than that of the sand fill formed by subaequeous placement. The results confirm that dense sand fill cannot be formed by subaqueous placement methods. The weakest zone is generally located just beneath the water level where fill is placed by subaqueous discharge.Key words: sand, hydraulic fill, cone penetration test, calibration chamber test, in situ density.Le remblayage pour le nouvel aéroport à Chek Lap Kok de Hong Kong comprend la mise en place d'un volume substantiel de remblai de sable par différentes techniques de mise en place hydraulique, qui ont résulté en une large plage de densités en place du remblai de sable. Cet article décrit l'utilisation de l'essai de pénétration au cône (CPT) pour l'évaluation des plages possibles de densité qui peuvent être obtenues par différentes méthodes de mises an place hydrauliques adoptées pour la construction du nouvel aéroport. Les résultat de CPT indiquent que la technique de mise en place est un des facteurs les plus importants pour le contrôle de la densité en place de sable remblayé par méthode hydraulique. Il y a un contraste marqué entre les profils de résistance à la pointe (et la densité relative correspondante) pour les remblais de sable mis en place par des méthodes subaériennes ou sous l'eau, le premier étant appréciablement plus élevé. Les résultats confirment qu'un remblai de sable dense ne peut pas être obtenu par des méthode de mise en place sous l'eau. La zone la plus faible est en général localisée juste sous le niveau d'eau, là où la déposition du matériau de remblayage se fait par décharge sous-l'eau.Mots clés : sable, remblai hydraulique, essai de pénétration au cône, essai en chambre de calibrage, densité in situ.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

This paper models consolidation of the foundation soils under a test embankment at the new Chek Lap Kok International Airport in Hong Kong. The modelling used a simplified finite element method and material parameters derived from results in the original site investigation report. Various features that need to be considered in applying the simplified method are illustrated through this case study. Good predictions of settlement results are obtained. Relatively large discrepancies in pore-water pressure predictions suggest that the nonlinear nature of hydraulic conductivity needs to be taken into account when large compressions are likely to occur. Geological conditions are shown to be a key factor in successful modelling of consolidation behaviour.Key words: consolidation, pore-water pressure, case modelling, finite element method, vertical drains, settlement.Cet article modélise la consolidation des sols de fondation sous un remblai d'essai au nouvel aéroport international Chek Lap Kok de Hong Kong. La modélisation a utilisé une méthode simplifiée d'éléments finis et des paramètres du matériau dérivés des résultats du rapport de l'investigation originale du site. Diverses caractéristiques qui doivent être considérées dans l'application de la méthode simplifiée sont illustrées dans cette étude de cas. De bonnes prédictions des résultats de tassement ont été obtenues. Des divergences relativement importantes dans les prédictions des pressions interstitielles portent à penser que la nature non linéaire de la conductivité hydraulique doit être prise en compte lorsque des compressions importantes peuvent vraisemblablement se produire. On montre que les conditions géologiques sont un facteur clé pour modéliser avec succès le comportement en consolidation.Mots clés : consolidation, pression interstitielle, modélisation de cas, méthode d'éléments finis, drains verticaux, tassement.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]