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Primary water and oxygen isotope composition are important tools in tracing magma source and evolution. Metamictization of zircon due to U-Th radioactive decay may introduce external secondary water to the crystal, thereby masking the primary water and oxygen isotope signature. Recently, Raman-based screening has been established to select the low-degree metamict zircons. However, such an approach may not be appropriate for ancient samples, in which nearly all zircons are metamict. It was reported that thermal annealing can potentially heal crystals and retrieve primary water content and δ18O information from metamict zircons, given the weaker hydrogen bond of secondary water than that of primary water. Heating experiments at temperatures of 200–1000 °C over a period of 2–10 h reveal that annealing can effectively recover primary water and oxygen isotopes from metamict zircons. Primary water in crystalline and metamict zircons remains intact when heated at 4 h, which represent the optimal annealing treatment condition. Hydrothermally altered zircon is an exception. It only yields the minimum estimate of its primary water contents at 600 °C over a period of >4 h, probably due to partial primary water loss during metamictization for hydrothermal zircons. Moreover, the proportion of low-δ18O (700 °C. This study therefore provides the basis for applying zircon water and δ18O proxies to geologically ancient samples.

In this study, we developed four clinopyroxene (cpx) and five orthopyroxene (opx) samples as reference materials for SIMS water content analysis.

Water, in trace amounts, can greatly alter chemical and physical properties of mantle minerals and exert primary control on Earth’s dynamics. Quantifying how water is retained and distributed in Earth’s deep interior is essential to our understanding of Earth’s origin and evolution. While directly sampling Earth’s deep interior remains challenging, the experimental technique using laser-heated diamond anvil cell (LH-DAC) is likely the only method available to synthesize and recover analog specimens throughout Earth’s lower mantle conditions. The recovered samples, however, are typically of micron sizes and require high spatial resolution to analyze their water abundance. Here we use nano-scale secondary ion mass spectrometry (NanoSIMS) to characterize water content in bridgmanite, the most abundant mineral in Earth’s lower mantle. We have established two working standards of natural orthopyroxene that are likely suitable for calibrating water concentration in bridgmanite, i.e., A119(H2O) = 99 ± 13 μg/g (1SD) and A158(H2O) = 293 ± 23 μg/g (1SD). We find that matrix effect among orthopyroxene, olivine, and glass is less than 10%, while that between orthopyroxene and clinopyroxene can be up to 20%. Using our calibration, a bridgmanite synthesized by LH-DAC at 33 ± 1 GPa and 3,690 ± 120 K is measured to contain 1,099 ± 14 μg/g water, with partition coefficient of water between bridgmanite and silicate melt ∼0.025, providing the first measurement at such condition. Applying the unique analytical capability of NanoSIMS to minute samples recovered from LH-DAC opens a new window to probe water and other volatiles in Earth’s deep mantle.

Water content and oxygen isotopes in zircon provide crucial constraints on magma source and process, yet they can be significantly modified by zircon metamictization, which causes secondary water absorption into the zircon crystal and the concomitant oxygen isotope changes. Therefore, it is imperative to develop a screening scheme to select the least-metamict zircons for the analyses. We propose a screening scheme based on our study on the Suzhou A-type granite (South China) through integrating Raman spectroscopy, water and trace element measurements, and oxygen isotope analysis. The results show that the primary water content is retained in zircon when the full-width at half maximum (FWHM) is 1007 cm−1 of ν3(SiO4) vibration band, while the primary δ18O is preserved at 1005.5 cm−1 Raman shift. Changes in trace element concentrations in Suzhou zircons are different from previous observations in metamict zircons but most likely related to magma evolution, which implies that trace elements are insensitive to metamictization. Primary δ18O in Suzhou zircons (4.5–6.0‰) fall into the mantle range, indicating a dominant mantle contribution to Suzhou granites. Primary water content was estimated at ca. 650–1400 ppm, significantly higher than those of typical I-type granite (400–736 ppm) and upper mantle-derived zircons (81–177 ppm). The high primary zircon water content was not controlled by the sub-solidus process, temperature, pressure, and cation charge balance but considered to reflect the high-water content in melts. This suggests a hydrous origin for the Suzhou A-type granite, which challenges the conventional view of anhydrous petrogenesis for A-type granites.

The neutron flux monitor is a critical part of the process of 40Ar/39Ar dating. We report a new protocol to prepare a neutron flux monitor from the sanidine contained within obsidian, a rock which has undergone rapid eruption and cooling on the surface.

The application of a 1012 Ω amplifier Faraday cup improved the secondary ion mass spectrometry analytical precision of the apatite Cl isotope by a factor of about two.

Despite their close temporal and spatial relationships, the effects of tectono-thermal events on ore formation remain obscure. To better understand this process, a comprehensive geochemical investigation was conducted on syn-tectonic pegmatite and quartz veins associated with the Devonian subduction and Permian collision of the Chinese Altai. We found that the Devonian fluids were organic alkanes-CO2-S-Ca-Mg-rich saline fluids with variable CO2/CH4 (0.09~5.03), lower F−/SO42− (0.02~0.14) and Al3+/Mg2+ (0~0.11) ratios, whereas the Permian fluids are immiscible fluids including CO2-C4H10-CO-rich oxidized gas bubbles and CH4-C3H8-C2H6-Ca-Na-K-Al-S-Cl-F-rich reduced saline fluids with lower CO2/CH4 (0~1.31, mostly

The Chinese Tianshan experienced large-scale transcurrent tectonics, synkinematic emplacement of ultramafic to felsic intrusions, and the formation of various mineral deposits during late Paleozoic accretionary orogenesis. The relationships among the spatial variation of deformation, the distribution of Permian orogenic Au and magmatic Ni-Cu sulfide deposits, and the kinematic evolution of crustal-scale shear zones, however, remain ambiguous. To address these ambiguities, the spatial variation in the degree of deformation in the Kanggur-Huangshan shear zone in the Chinese Tianshan was characterized using detailed structural measurements and zircon U-Pb and muscovite 40Ar/39Ar age data. The new structural data indicate that a prominent spatial variation exists in the style of deformation throughout the Kanggur-Huangshan shear zone; intense ductile deformation structures are dominant in the east, while brittle structures become progressively more dominant toward to the west. Zircon U-Pb and muscovite 40Ar/39Ar age data for syn- and postkinematic intrusions along the Kanggur-Huangshan shear zone indicate that dextral strike-slip shearing occurred between 279 Ma and 249 Ma. The spatial variation in the degree of deformation and exhumation along the Kanggur-Huangshan shear zone was potentially caused by regional differential uplift induced by the collision of the Tianshan and Beishan regions; this was likely responsible for the predominant occurrence of magmatic Ni-Cu sulfide deposits in the eastern portion of the Kanggur-Huangshan shear zone and orogenic Au deposits in the western portion. The identified spatio-temporal relationship between deformation and distribution of orogenic Au and magmatic Ni-Cu sulfide deposits is crucial to the future success of mineral exploration in the Central Asian orogenic belt.

To explore the response of atrazine (AT) degradation rate, soil organic matter (SOM) distribution and the relationship between them to straw mulching and nitrogen application, field experiments were conducted to study the distribution of SOM content and AT degradation rate under different straw returning modes combined with nitrogen fertilization in 2 years in Hetao Irrigation District. No (N0), low (NL), medium (NM), and high (NH) levels of N fertilization were incorporated into the soil combined with the surface coverage straw (Treatment BN0, BNL, BNM, BNH, respectively) and the deeply buried straw (Treatment SN0, SNL, SNM, SNH, respectively). The traditional cultivation was used as a control treatment (Treatment CK). The results showed that SOM content of Treatment B was accumulated in 0~20 cm soil layer. The largest SOM content of Treatments B in 0~20 cm soil layer was found in BNH treatment, with an average increase of 14.2% and 24.1% significantly when compared with those in CK and SNH (P M had the largest SOM content in the soil layer of 20~40 cm and 40~60 cm, with an average increase of 82.6% and 67.7% when compared with Treatment CK (P P > 0.05). Straw returning methods and nitrogen application level significantly affected AT digestion rate and digestion half-life, with significant differences among treatments (P M had the highest digestion rate and the shortest half-life of AT. Compared with Treatment CK, the digestion rate of Treatment SNM was increased by 5.3% on average, and the half-life was shortened by 3.9 days on average. Single regression and stepwise regression analysis of the half-life of AT degradation and SOM content in different soil layers (0~20 cm and 20~40 cm) showed that the degradation of AT was greatly affected by SOM content of 20~40 cm soil layer. Based on the comprehensive analysis, the effect of straw deep burial combined with medium nitrogen application rate (Treatment SNM) was best, which could achieve the goal of increasing SOM content and shortening the half-life of AT digestion. The research provided a technical support for straw resource utilization, alleviated AT pollution and improved farmland ecological environment in Hetao Irrigated District.

Geophysical and geochemical evidence revealed that certain amounts of water are stored in the Earth’s interior, and its distribution exhibits temporal and spatial differences. Recent studies indicate that the H2O-in-zircon has a potential to reveal magma water content. Using secondary ion mass spectrometry (SIMS), we analyzed the zircon water content and oxygen isotopes in granitoids (two-mica granite, quartz monzonite, diorite, and granodiorite) from southern Tibet. The results are used to explore the diversity of water content in crust-derived magmas, which is also supported by the LA-ICPMS zircon trace element analysis. There are low zircon water contents for two partial melting products of the ancient crust (peak at 85 and 300 ppm, respectively). Meanwhile, there are high H2O-in-zircon peaks (435 and 475 ppm, respectively) for two partial melting products of the juvenile crust. The calculated radiation damage accumulation in these zircon grains is below 3×1015 α decay events mg–1, suggesting that the zircon grains are well crystalline. There is no correlation between REE+Y and H+P, indicating that the mechanism of charge balance for water uptaking into zircon, in which the excess of REE+Y to P controls H content, is not applicable to the studied samples. The degree of magma fractionation cannot account for the zircon water content variation, because there is no co-variation between zircon Hf and H2O contents. Similarly, the degree of partial melting was unlikely to be responsible for the H2O-in-zircon distinction. We interpret that the H2O-in-zircon variation reflects the influence of melting mode (dehydration vs. water-fluxed) and water content in the crustal source. In the Late Devonian, dehydration melting of the crustal rocks was facilitated at elevated temperatures, which produced magmas with the lowest water contents. Water-fluxed melting of the ancient crust would produce relatively “drier” magma than water-fluxed melting of the juvenile crust.

The Earth is unique in the Solar System due to significant volumes of granite in the lithosphere. However, the origins of granites are still highly debated, especially sediment-derived granites, which are often treated as a geochemical end-member of the continental crust. In the Yunnan region of South China, we identify the occurrence of pure sediment-derived granite in a subduction system. The suite of strongly peraluminous granite reported herein is interpreted to represent pure metasedimentary melts based on their whole-rock elemental and Sr-Nd-B and zircon Hf-O isotopic compositions. These Late Permian–Early Triassic (ca. 254–248 Ma) granites are characterized by radiogenically enriched Sr, Nd, and Hf isotopic signatures. They show δ11B and δ18O signatures akin to those of continental shales. Geochemical modeling indicates no contributions from the mantle that can be detected. Considering the regional tectonic evolution, these granites are suggested to be formed in a subduction zone by decompression melting of rapidly exhumed back-arc sediments. We posit that decompression melting was triggered by widespread extension and thinning of the crust prompted by rollback of the subducting oceanic crust. These granites thus provide evidence that granite formation in subduction zones does not necessarily contribute to crustal growth. These subduction-related pure sediment-derived granites have different elemental ratios and contents (e.g., Al2O3/TiO2 and Yb) from the Himalayan leucogranites. Considering their source compositions (e.g., pelitic rocks), which are similar to those of the Himalayan leucogranites, these differences are likely due to their higher formation temperature and lower pressure despite a great similarity in isotopic compositions. Identification of pure sediment-derived, strongly peraluminous granites (SPGs) in subduction systems provides an important geodynamic mechanism for crustal anatexis, which can both geochemically and tectonically complement their collisional counterparts identified in the Himalayas.

In this study, we developed two new SIMS (secondary ion mass spectrometry) analytical protocols to simultaneously measure oxygen–hydrogen (O–H) isotopic compositions and water content for hydrous geological samples. These two protocols involve the measurement of two sets of secondary ion contents: (1) 1H, 2H, 16O, 18O; and (2) 16O, 16O1H, 18O, 17O1H, 16O2H. Both measurements utilize a hybrid dynamic multi-collector system of CAMECA IMS 1280-HR, which benefits from both the static multi-collector mode and peak-hopping mono-collector mode. These new methods can simultaneously measure (with high-precision) the 18O/16O ratio in static multi-collector mode without trading off its analytical precision, and 1H/16O (or 16O1H/16O) and 2H/1H (or 16O2H/16O1H) ratios in conventional peak-hopping mono-collector mode. Three glass samples (LBS7H, LBS5H and LBS6H-) with known water contents and two apatite samples (Kovdor, Durango) with known oxygen–hydrogen isotopes and water content were measured to verify the protocols' reliability. The olivine crystal San Carlos with ∼1 ppmw water content was used for background monitoring. For the apatite samples, the external precision (spot-to-spot reproducibility) for δ18O and δD is better than 0.56‰ (2SD) and 54‰ (2SD), respectively. After eliminating the outlier (beyond 3SD error), the external precision of 16O1H/16O or 1H/16O ratio improves to 10.27% (2SD). For the glass samples, the water content calibration curves, which were constructed by comparison of the known water content with the SIMS measured 16O1H/16O or 1H/16O ratios, yielded good correlations. It is noteworthy that the apatite and glass samples can have a uniform water content calibration curve for protocol 1, but not for protocol 2, indicating different matrix effects for the two protocols.

In 40Ar/39Ar dating, 39ArK generated is dependent on irradiation conditions, and the accumulation fast neutron fluence is a critical parameter for 40Ar/39Ar dating. With technological advancement, especially in the ultra-low background and multicollector technology, the boundary conditions to choose irradiation conditions have been greatly improved. Based on the detected and processed signal, the maximum boundary condition of 40Ar*/39Ar can be up to 5750, meaning that very low 39Ar signals can yield considerable analytical accuracy. In this study, one biotite sample (ZBH-25) was irradiated for 4 hours to assess the modified irradiation conditions, and the high 40Ar*/39Ar ratio up to 4100 could yield ∼1% analytical uncertainty. This reveals that the new boundary condition is useful to choose fast neutron fluence, especially for very old or low K/Ca ratio samples.

With the aim of improving soil fertility, it is of great significance to put forward optimal irrigation and nitrogen fertilizer application strategies for improving land productivity and alleviating non-point source pollution effects. To overcome this task, a 6-hidden layer neural network with a preference mechanism, namely Preference Neural network (PNN), has been developed in this study based on the field data from 2018 to 2020. PNN takes soil total nitrogen, organic matter, total salt, pH, irrigation time and target soil depth as input, and irrigation amount and nitrogen application rate (N rate) as output, and the prior preference matrix was used to adjust the learning of weight matrix of each layer. The outcomes indicated that the predictive accuracy of PNN for irrigation amount were (R2 = 0.913, MAE = 0.018, RMSE = 0.022), and for N rate were (R2 = 0.943, MAE = 0.009, RMSE = 0.011). The R2 predicted by PNN at the irrigation amount and N rate were 40.03% to more than 99% and 40.33% to more than 99% higher than those obtained using support vector regression (SVR), linear regression (LR), logistic regression (LOR) and traditional back propagation neural network (BPNN), respectively. In addition, compared with the neural network (Reverse Multilayer Perceptron, RMLP) with the same structure but no preference structure, the R2 of the predicted irrigation amount and N rate by PNN increased by 25.81% and 27.99%, respectively. The results showed that, through the irrigation of 93 to 102, 92 to 98 and 92 to 98 mm, along with nitrogen applications of 65 to 71, 64 to 73 and 72 to 81 kg/hm2 at 17, 59 and 87 days after sowing, respectively, the organic matter, total nitrogen, total salt content and pH of the soil would reach high fertility levels simultaneously.

As an important food production area in the north of China, the Hetao plain is extremely vulnerable to nitrate pollution caused by agricultural production activities and additional factors. Thus, it is of great significance for the environmental protection and rational use of groundwater to detect the current situation of groundwater nitrate pollution, temporal and spatial evolution characteristics, and main influencing factors in the Hetao irrigation district. We selected the Wualte irrigation area as the study area, and the characteristics of temporal and spatial changes in groundwater nitrate concentration and the main influencing factors in this area were explored. We used statistical analysis to analyze the nitrogen content of groundwater in the study area, and the Piper three-line diagram was used to explore the characteristics of chemical composition and evolution; furthermore, we used ion ratio and correlation analysis methods to explore the source of NO

Zircon water content is an important physicochemical parameter for many geological processes, yet its measurement by the secondary ion mass spectrometry (SIMS) technique is hampered by the lack of suitable reference materials and high water background, especially if large-geometry (LG)-SIMS is used. Here we have described a suite of newly developed reference materials for SIMS zircon water content analysis and a modified micro-analytical technique (using a CAMECA IMS 1280-HR SIMS) that can simultaneously measure the zircon water content and oxygen isotopes. A total of 20 natural zircon grains/sherds were analyzed via Fourier transform infrared spectroscopy (FTIR), among which 8 (with good water content result reproducibility) were further analyzed by SIMS. Before the SIMS analysis, FTIR analyzed sample blocks were mounted with a Sn-based alloy to minimize degassing and background water. As in routine SIMS oxygen isotope measurement, 16O− and 18O− were collected using two Faraday cups, and in addition 16O1H− was simultaneously measured using an electron multiplier. The measured 16O1H/6O ratio was converted into water content, using a calibration line established based on SIMS 16O1H−/16O− ratios vs. the FTIR water content. Both the internal and external precisions of corrected δ18O are

Metasomatism by silicate or carbonatite melts can significantly modify the mineral physical and chemical properties, and the hydrogen geochemical behavior during the interaction of olivine and melt remains unclear. In this study, olivine wate content was measured by SIMS on two peridotite xenolith suites. The water content in the silicate-metasomatized olivine increases along with the metasomatism intensity, whereas the opposite trend is present in the carbonatite-metasomatized ones. These results reflect that H enters olivine via silicate metasomatism, whereas it is extracted by carbonatite melts due to its high-water solubility. In addition, as 7Li (more hydrotropic than 6Li) have more similar geochemical behavior to H, 7Li preferentially enter olivine during silicate metasomatism, but remain in the melt during carbonatite metasomatism, resulting in distinct Li isotope behavior during the two different metasomatism. Therefore, the water content of olivine can be used to distinguish metasomatic melts, as well as to explain the δ7Li differentiation.

To explore the effects of straw mulching and reduced nitrogen fertilization on the temporal and spatial patterns of soil nitrogen, groundwater nitrogen pollution, and summer maize yield, field experiments were carried out in the Hetao irrigation district in 2017 and 2018. The experiment involved the following seven treatments:a control (CK) treatment involving conventional fertilization and traditional tillage, and conventional nitrogen applications reduced by 30% (N1), 20% (N2), and 10% (N3) coupled with either straw surface covering (B) or deep straw burial (S). The results showed that the distribution of soil nitrogen in the CK treatment varied depending on soil depth, with an overall decreasing trend. In the 0-20 cm soil layer under straw surface covering (B) treatments, soil nitrogen was superficially accumulated. NO

It is difficult to repair large skull and dural defects. We observed the therapeutic effects of anterolateral thigh flaps with vascular fascia lata for repairing large skull and dural defects.From December 2008 to June 2019, we repaired large skull and dural defects for 28 cases including 12 cases with scalp malignant tumor and 16 cases requiring removal of titanium mesh which had been once placed due to craniocerebral trauma. The scalp malignant tumor invaded full-thickness skull in 12 cases; and invaded cervical lymph nodes, dura mater or brain tissue in 3 cases. In the 12 cases with scalp malignant tumor, the scalp defects of 12 cm × 9 cm to 22 cm × 18 cm and skull defects of 9 cm × 7 cm to 15 cm × 12 cm after radical tumor resection were repaired using anterolateral thigh flaps of 14 cm × 11 cm to 23 cm × 19 cm with fascia lata of 10 cm × 8 cm to 16 cm × 12 cm. Postoperative radiotherapy and chemotherapy were also performed in the 3 cases with tumor metastasis. In the 16 cases requiring removal of titanium mesh, the skull and dural defects of 8 cm × 7 cm to 15 cm × 11 cm after removal of titanium mesh were repaired using anterolateral thigh flaps of 10 cm × 8 cm to 16 cm × 12 cm.In all cases, the transplanted anterolateral thigh flap with fascia lata survived after surgery and no vascular crisis occurred. During the followup of 8 months to 9 years, the flap appearance in the head-repaired area was fine, no external hernia of brain tissue occurred, the appearance of the femoral donor site was acceptable, and femoral muscle strength and movements were normal in all cases. The 12 cases with scalp malignant tumor had no local recurrence or distant metastasis.Repairing the skull and dural defects caused by radical surgery for scalp malignant tumor or removal of titanium mesh using anterolateral thigh flaps with vascular fascia lata, is effective. The appearance in the head-repaired area is fine without external hernia of brain tissue.

Trapped fossil fluids in mineral-hosted fluid inclusions preserve pivotal information on the evolution of paleo geological systems, particularly the hydrothermal mineralization systems. However, identification of the sources of the extracted gases during bulk analysis of fluid inclusions is challenging because multiple generations, types, and phases of fluid inclusions may exist in the same mineral. To better identify the gas sources during stepwise crushing we report an improved gas extraction model of fluid inclusions. Stepwise extracted gases from fluid inclusions in quartz and cassiterite were measured with a quadrupole mass spectrometer and compared with Raman analysis of different types of secondary (SFIs) and primary (PFIs) fluid inclusions. We found that H2O-poor and CO2-rich gases with elevated CO2/CH4 ratios, H2O and formamide-rich gases, and CH4-rich gases were extracted sequentially during stepwise crushing. Such compositional variations of the released gases suggest that the extraction of fluid inclusions starts from SFIs with high vapor-filling degrees (f) and CO2-bearing tri-phase high-f fluid inclusions, which is followed by large liquid-rich SFIs and mid-sized high-f PFIs that are rich in CO2 and formamide, and ends with small CH4-rich low-f PFIs. These findings suggest that the degassing pattern of hydrothermal minerals during stepwise crushing is mostly governed by the physicochemical characteristics of the fluid inclusions, in particular, their vapor-filling degrees, sizes, compositions (which can lead to different inner pressures and densities), and associations with micro-cracks. This updated model of gas release patterns strengthens the theoretical basis for differentiating and identifying the sources of gases extracted during stepwise crushing experiments, which is key to understanding the fluid geochronology and geochemistry of hydrothermal deposits with multi-stage hydrothermal evolution in general.

In this study, a high-precision secondary ion mass spectrometry (SIMS) zircon oxygen isotope ratio analytical protocol is described. The analysis is conducted using a Cameca IMS 1280-HR at the SIMS Laboratory of Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS). Four reference zircons (91,500, Qinghu, TEMORA 2 and Penglai) have been chosen to evaluate the reproducibility (precision) and accuracy. An identical protocol is used for the analyses, with unchanged instrumental parameters and with ion beam intensities kept as identical as possible. The Penglai zircon is used as an external reference material to calibrate the instrumental mass fractionation. The 91,500, Qinghu and TEMORA 2 zircons are used as the unknown samples, which yielded 10.15 ± 0.26‰ (2SD), 5.46 ± 0.24‰ (2SD) and 8.33 ± 0.29‰ (2SD), respectively, all consistent with the recommended values within error (2SD). A half-year long-term precision of 0.44‰ (2SD) is achieved using the Qinghu zircon as a monitoring sample for the routine measurement of zircon 18O/16O ratio, which demonstrates the reliability of this analytical protocol.

First comprehensive investigations of the Cuonadong leucogranite exposed in North Himalayan gneiss dome of southern Tibet are presented in this study. The SIMS U–Pb ages of oscillatory zircon rims scatter in a wide range from 34.1 to 16.0 Ma, and the Cuonadong leucogranite probably emplaced at 16.0 Ma. High-precision 40Ar/39Ar dating on a muscovite sample yields an essentially flat age spectrum with consistent plateau and isochron ages, indicating that the Cuonadong leucogranite cooled below 450 °C at 14 Ma. Based on the youngest zircon U–Pb age and muscovite 40Ar/39Ar age, the Cuonadong leucogranite experienced rapid cooling with a rate of 119 °C/Myr from 16 to 14 Ma. The geochronological data of this undeformed leucogranite also suggest that the ductile extension of the South Tibetan Detachment System in the eastern Himalaya ceased by ca. 14 Ma. Furthermore, the initial Sr–Nd isotopic compositions and Nd model ages demonstrate that the leucogranite was derived from metapelitic source within the Greater Himalayan Crystalline Complex. The distinct Ba depletion with high Rb/Sr ratios and negative Eu anomalies make it clear that the leucogranite melts were generated by breakdown of muscovite under fluid-absent conditions.

Secondary ion mass spectrometry (SIMS) has been applied to analyze a wide range of materials for earth science research due to its high sensitivity, high precision and capacity for in situ micro-analysis. This technique operates under ultra-high vacuum (UHV) conditions, especially for water content measurements on nominally anhydrous minerals (NAMs). However, UHV conditions are hard to achieve when using epoxy mounts, which degas readily during the vacuum processes. In this study, we developed a novel sample preparation method using a tin-based alloy instead of epoxy resin. Using a tin alloy mount coupled with an automatic liquid nitrogen refilling system, the results show that the vacuum conditions have been significantly improved from ∼1.2 × 10−8 mbar to ∼1.9 × 10−9 mbar. The background for mineral water content, measured with a CAMECA IMS 1280-HR SIMS installed at the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS), is lowered to

The presence of water has significant influence on magma properties such as the chemistry, viscosity, and crystallization temperature. Water content in the magma can be modified by magma replenishment or crystal fractionation, but technique for direct tracing of these processes are lacking. In this study, we analyzed zircon water content, oxygen isotopes, and trace element contents for a co-genetic granitic suite (one primitive biotite granite and two evolved garnet-bearing two-mica granites) from the Gangdese batholith in Tibet. The biotite granite shows a relatively narrow H2O-in-zircon range with a sharp peak in the density plot, while multiple peaks are present for the garnet-bearing two-mica granites. The wide Hf range indicates that the zircon grains have a protracted magmatic history, and the positive H2O vs. Hf correlation indicates that H2O-in-zircon faithfully recorded the water variation of the evolving magma. These results suggest that H2O-in-zircon is a good indicator to trace magma fluid evolution.

It has been proposed that the proto-South China Sea (PSCS) existed in the southeastern continental margin of the South China Block (SCB) before the opening of the present South China Sea (SCS). However, the age of initial spreading and the geodynamics of the opening of the PSCS remain enigmatic. Here we present geochronological and geochemical data for diorite and diabase samples from Well NK-1, which was drilled into the Nansha Block in the Dangerous Grounds area of the southern SCS, to investigate their petrogenesis and their association with the formation of the PSCS. The Early Jurassic diorites (ca. 177 Ma) are geochemically similar to continental arc basalt, with enrichment in Rb, Ba, Pb, and Sr, and pronounced negative Nb, Ta, and Ti anomalies. They were originated from a mantle source metasomatized by subducted-sediment-derived melts in a continental arc setting related to subduction of the Paleo-Pacific plate beneath the SCB. The Early Cretaceous diabases (ca. 124 Ma) are compositionally similar to back-arc basin basalt, with enrichment in Rb, Ba, and Pb, and negligible Nb, Ta, Ti, Zr, and Hf anomalies. The mantle source of the diabases was metasomatized by aqueous fluids derived from the subducted slab in a back-arc basin associated with subduction of the Paleo-Pacific plate. Furthermore, the diabase samples are geochemically similar to mafic rocks and ophiolite complexes previously regarded as remnants of the PSCS oceanic crust. Therefore, the Early Cretaceous diabases in the Nansha Block are interpreted as representing coeval magmatism of the nascent ocean of the PSCS, indicating that the PSCS during the Early Cretaceous was a spreading back-arc basin associated with retreat of the subducting Paleo-Pacific plate.

The gentle stepwise crushing technique permits progressive extraction of gases from large, irregular, secondary fluid inclusions (SFIs) along micro-cracks to small, regular, liquid-rich primary fluid inclusions (PFIs). Previous studies have verified this general gas release pattern in different hydrothermal minerals based on the agreements between 40Ar/39 Ar ages of the released gases from different crushing stages and the most likely corresponding geological events dated with other methods; and based on the excellent agreements between gas chemistry measured by QMS (quadrupole mass spectrometer) during stepwise crushing and the expected characteristics of SFIs and PFIs in the same samples acquired using Raman spectroscopy. In this study, we applied this QMS-based gentle stepwise crushing technique on ore and gangue minerals from the world-class Yaogangxian tungsten deposit in South China. Gases released from PFIs in cassiterite, wolframite, and quartz from ore-bearing veins show high CH 4, N2, C3H8, and low CO2, C4H10 contents, low CO2/CH4 (≪1) and high N2/Ar (327–861 for ore minerals and 60.7–943 for quartzs from ore veins) ratios, along with multiple organic gaseous species. Their compositions resemble those of gases released from PFIs in quartzs from the Yaogangxian granites which represent magmatic-hydrothermal fluids that exsolved from the granitic magma. However, compared with these exsolved magmatic-hydrothermal fluids, ore mineral PFIs have relatively high He contents which indicate contributions from non-magmatic crustal fluids. This is consistent with high Ca2+, low F− concentrations, and low K+/Na+ (0.21–0.32) ratios observed in fluids in the quartz samples, as well as their relatively low water hydrogen isotopes (δD-H2O = −102 to −59‰). These chemical characteristics, coupled with their magmatic sulfur (δ34S-molybdenite and arsenopyrite = −0.2–1.4‰), methane hydrogen (δD-CH4 = −58 to −42‰), and fluid oxygen (δ18O-H2O = 3.9–5.1‰) isotopic compositions, indicate both magmatic and non-magmatic crustal components in the mineralizing fluids. Based on these observations and the low methane carbon isotope values (δ13C-CH4) in the studied quartz samples, we propose that fluid-rock interactions between the exsolved magmatic-hydrothermal fluids and the metasedimentary wall rocks played an important role in promoting W-Sn precipitation in this ore deposit. This study demonstrates the power of combining QMS-based stepwise crushing technique with traditional geochemical techniques in investigating ore-forming processes.

Identifying whether and when the southern continental margin of the South China Sea (SCS) was part of the South China Block (SCB) is important for Mesozoic–Cenozoic paleogeographic reconstructions of Southeast Asia. In this paper, we present geochronological and geochemical data for dacites from Well NK-1 in the Nansha Block (Dangerous Grounds) of the southern SCS margin to investigate their petrogenesis and tectonic affinity. Zircon U Pb and 40Ar/39Ar datings show that these dacites formed during the Late Triassic (218–217 Ma). The dacites have high total alkali (K2O + Na2O = 7.39–8.42 wt%) and relatively low CaO contents (1.87–3.38 wt%), and show geochemical affinities with A-type granites, with high Zr saturation temperatures (806–855 °C), FeOTot/MgO ratios (5.22–7.48), Zr + Nb + Ce + Y contents (530–680 ppm) and 10,000 × Ga/Al values (2.40–2.94), and relatively low A/CNK values (0.86–1.04). The primitive magma for the dacites was likely generated by partial melting of ancient crustal materials. Late Triassic dacites in the Nansha Block and Triassic A-type granites in the SCB formed in an extensional setting at the continental margin of the SCB. This setting was probably related to the Paleo-Pacific plate subduction that restarted prior to the Early Triassic. Therefore, the southern SCS margin was part of the SCB continental margin during the early Mesozoic, which provides more detailed insights into the paleogeography of SE Asia since the Mesozoic.

To investigate regional differences in open access among China, USA and Japan, we presented different test methods in contrast distributions of open access journals in SCI-E. We analyzed quartiles in category and influence of open access journals in basic subjects (mathematics, physics, chemistry) by JCR, found top0.10% papers and highly cited papers according to baselines in ESI. The results show that Chinese scholars approved open access journals better than USA and Japan, the ratio is 6.78%; three countries have significant difference in OA overall distribution; OA articles of China increases significantly since 2008, while Japan is relatively stable growth in mathematics, fluctuating in physics and chemistry; three countries publish more than 30% in top 50% journals in the each subject; Chinese scholars issue more than 50% papers in open access journals of chemistry and mathematics; highly cited papers are mostly interdisciplinary research papers or publishing in interdisciplinary journals. Acceptances to OA journals seem likely to incline to some publisher’s country/territory. KeywordsOpen Access; regional recognition; highly cited; Kruskal-Wallis test; Wilcoxon test

Some alterations of similar spectral reflectances cannot be distinguished accurately for their lower spectral resolution when the traditional methods, such as, band ratio and principal component analysis are used to extract alteration information from Landsat ETM multi-spectral data. In this paper, the band1~band7 of MODIS whose wave lengths are among 10~500nm, together with ETM’s multi-spectral bands, whose spatial resolutions are 30m, are chosen in the execution of data assimilation. After the third order wavelet transformation, the low-frequency component of ETM data are replaced by the MODIS data subsequently, then the inverse wavelet transform is in progress. The result of data assimilation consists of not only ETM’s spatial information but also MODIS’ spectral information. At last, four bands of assimilation results are selected to process PCA transform, as a result, two types of alteration in the study area are extracted accurately according to their components.

Geometric precision correction of remote sensing image plays a more and more important role in the application of high precision remote sensing. A reference image database is built up based on PostgreSQL, an open-source relation database, and ArcSDE, a widely used spatial data engine. Compared with single reference image, the reference image database has the advantages of managing convenience, lower-cost maintenance and high retrieval efficiency. Meanwhile, the correction accuracy is boasted by Gopfert algorithm , and efficiency is improved by advanced parallel model based on parallel I/O and I/O hidden strategy. Beyond this, combined with MapServer which can rapidly display images, a geometric precision correction system of high performance with dual servers is formed, with which mass production ability is achieved.

Sleeping Beauty is a typical phenomenon of delayed recognition in scientific discovery. She was unnoticed for a long time, and suddenly found by researchers and cited a lot. This is known as waking-up Sleeping Beauty. The one who arouse the Sleeping Beauty is called prince. In order to discover the waking-up mechanism of Sleeping Beauty, we collect seven classic Sleeping Beauty's citing and cited data, and use co-citation cluster analysis method to analyze core citation circle in citation network by CITESPACE. At the same time, we take direct and indirect citations of the Sleeping Beauty into account to identify who was the true prince (he terminated the slumber of the Sleeping Beauty and made a significant contribution to the scientific development). It is a new approach to study the phenomenon of Sleeping Beauty even delayed recognition and identify waking-up mechanism.

To observe the clinical effects of repair of complicated tissue defects of several body parts with composite anterolateral femoral fascia lata perforator tissue flaps (fascial flap or fascial skin flap) with the aid of micro-surgery.From February 2008 to August 2012, complicated tissue defects in 12 patients were repaired with composite anterolateral femoral fascia lata perforator tissue flaps. Two of the 12 patients suffered from a defect of scalp, skull, and dura mater as a result of resection of a malignant tumor of the scalp; 3 patients showed a defect of skin and tendo calcaneus in the heel and lower leg; 2 patients showed a defect of skin and extensor tendon in the dorsum of hands; the other 5 patients suffered from defects of skin and extensor tendon in the foot and ankle combined with exposure of bone or internal buttress plate. The size of tissue flaps ranged from 12 cm ×6 cm to 19 cm ×18 cm. The donor sites were closed by immediate suturing or skin grafting.All 12 tissue flaps survived. Patients were followed up for 2 to 36 months. The flaps were shown to have good appearance, texture and function. Two patients with the defect of the scalp, skull and dura mater after a resection of the malignant tumor of the scalp did not have recurrence or herniation of brain tissue. The foot-raising function in 3 patients with the defect of skin and tendo calcaneus in the heel and lower leg was recovered, and according to Arner-Lindholm criteria the result was excellent in 2 cases and good in 1 case. The extension function of fingers of 2 patients with defects of skin and extensor tendon in the dorsum of hands was good according to the evaluation criteria of Chinese Medical Association Society of Hand Surgery for tendon repair of hand. The extension function of toes of 5 patients with defects of skin and extensor tendon in the foot and ankle combined with exposure of bone or internal buttress plate was recovered and improved.Transplantation of composite anterolateral femoral fascia lata perforator tissue flaps with the aid of micro-surgery is an effective method in repairing the tissue defects of skull, dura mater, and the extensor tendon of hands or feet, with restoration of the extension function.

Static chamber/gas chromatogram method was adopted to measure the methane emission flux of Zhalong Phragmites australis wetlands with different water levels in a growth season from May to October, 2009, aimed to understand the methane emission pattern in natural freshwater P. australis wetland in frigid region. During the observation period, the average methane emission flux of test wetlands ranged from -21.18 to 46.15 mg x m(-2) x h(-1), with a mean of 7.67 mg x m(-2) x h(-1). In deep water zone (average water level 100 cm) and shallow water zone (average water level 25 cm), the average methane emission flux was 5.81 and 9.52 mg x m(-2) x h(-1), with a peak in August and July, respectively, and the minimum in October. In summer (from June to July), the methane emission flux in deep water zone was significantly lower than that in shallow water zone; while in spring (May) and autumn (from August to October), a reversed trend was observed. The methane emission flux had a seasonal pattern of summerautumnspring, and a diurnal pattern of being the highest at 12:00 and 14:00 and the lowest at 0:00. Temperature and water level were the major factors affecting the methane emission flux in freshwater P. australis wetlands in frigid region.

To investigate ideal methods to repair cervical cicatricial contracture in children.The expanders were implanted subcutaneously around the cervical scar and above the latissimus. After expansion was completed, the cervical cicatricial contracture was released and the wound was covered with local expanded flaps and free expanded prefabricated thoracodorsal artery perforator flap, leaving no injury to thoracodorsal nerves and latissimus. The wound at the donor site was closed directly.From July 2007 to October 2009, 10 patients were treated. All the flaps survived completely. All the wounds were repaired totally and the deformities were corrected completely. The patients were followed up for 3-30 months. When the patients grew up, the flaps enlarged simultaneously. The flaps were not bulky and had a good color match. The scar at the donor site was inconspicuous with no functional morbidity.The fabricated expanded thoracodorsal artery perforator flaps is an ideal method for severe cervical cicatricial contracture in children.