This study examines hourly precipitation data from 128 national meteorological observation stations within the Sichuan Basin (SB) spanning 2002 to 2021, focusing on warm-season (May to September) hourly extreme precipitation (HEP) and its events (HEPEs). Significant spatial variability is observed across the SB regarding thresholds, amount, intensity, and frequency of warm-season HEP. HEP predominantly occurs from mid-July to early August, with a higher probability of peak events in the afternoon during these months. HEPEs starting from midnight to early morning tend to have prolonged durations, whereas, in the afternoon, prompt-duration HEPEs lasting within 3 h are more prevalent. Around the basin, the northwest and northeast regions experience HEPEs with higher precipitation amounts but fewer occurrences. The northwestern region encounters shorter-duration HEPEs with greater rainfall intensity, while the northeastern region records a higher frequency of moderate or weak HEPEs lasting ≥ 13 h. Comparatively, the southwestern basin exhibits a higher frequency of nocturnal HEP events characterized by relatively lower rainfall intensity. The eastern Sichuan parallel ridge-valley area in the southeastern basin demonstrates more frequent HEP occurrences with lower rainfall intensities. Additionally, mountainous regions of the southeastern SB and the southern branch of the eastern Sichuan parallel ridge-valley exhibit lower HEPE amounts but greater numbers of events, primarily characterized by prompt-duration events in the afternoon. These findings unveil the diverse spatiotemporal patterns of warm-season HEP and HEPEs within the SB, highlighting the regional variability across different geographical zones. This study provides insights for managing vital resources and timely natural disaster evacuation.

Frequent rainstorms caused by climate change are causing significant stresses and impacts on karst zones and even global hydrological systems. However, few reports have focused on rainstorm sediment events (RSE) based on long series, high-frequency signals in karst small watersheds. Present study assessed the process characteristics of RSE and analyzed the response of specific sediment yield (SSY) to environmental variables using random forest and correlation coefficients. Management strategies are then provided based on revised index of sediment connectivity (RIC) visualizations, sediment dynamics and landscape patterns, and modeling solutions for SSY are explored through the innovative use of multiple models. The results showed that the sediment process showed high variability (CV > 0.36), and the same index had obvious watershed differences. Landscape pattern and RIC show highly significant correlation with mean or maximum suspended sediment concentration (p<0.01, |r|>0.235). Early rainfall depth was the dominant factor affecting SSY (Contribution = 48.15 %). The hysteresis loop and RIC infer that the sediment of Mahuangtian and Maolike mainly comes from downstream farmland and riverbeds, while Yangjichong comes from remote hillsides. The watershed landscape is centralized and simplified. In the future, patches of shrubs or herbaceous plants should be added around the cultivated land and at the bottom of the sparse forest to increase the sediment collection capacity. The backpropagation neural network (BPNN) is optimal for modeling SSY, particularly for running the variables preferred by the generalized additive model (GAM). This study provides insight into understanding RSE in karst small watersheds. It will help the region to cope with future extreme climate change and develop sediment management models that are consistent with regional realities.

Soil moisture restricts the ecological restoration in karst, but studies on soil moisture storage (SMS) in karst are lacking. Thus, this study analyzed the characteristics of SMS in the karst area of China (K) and revealed the relationships of SMS with its influencing factors. The main results are as follows: (1) Average SMS in K is higher than that in the non-karst area (N). However, when SMS is below the thresholds 12 mm (0–7 cm) and 563.6 mm (0–289 cm), SMS in K is lower than that in N. (2) SMS in K experienced a decreasing trend in 1979–2017. (3) SMSs of K and N increase with precipitation class, but the SMS in K is more sensitive to precipitation. (4) SMSs of Agriculture and Forest landcovers in K significantly reduced in 1979–2017. Overall, the SMSs in K are high, but the soil water is easily lost due to serious soil erosion.

有效教学（effective teaching）的理念源于20世纪上半叶西方的教学科学化运动，在美国实用主义哲学和行为主义心理学影响的教学效能核定运动后，引起了世界各国教育学者的关注。20世纪以前在西方教育理论中占主导地位的教学观是“教学是艺术”。但随着20世纪以来科学思潮的影响，以及心理学特别是行为科学的发展，人们意识到，教学也是科学。即教学不仅有科学的基础，而且还可以用科学的方法来研究。于是，人们开始关注教学的哲学、心理学、社会学的理论基础，以及如何用观察、实验等科学的方法来研究教学问题。有效教学就是在这一背景下提出来的。

Spatialization of soil formation rate (SFR) is always a difficult problem in soil genesis. In this study, the dissolution rate in karst areas of China during the period 1983–2015 was estimated on the basis of geospatial analysis techniques and detection of variation via the law of chemical thermodynamics in conjunction with long-term serial ecohydrology data. SFR at different lithological backgrounds was calculated on the basis of the content of acid-insoluble substances. Results showed that the spatial dissolution rate of carbonate rock ranges between 0 and 106 mm/ka, averaged at 22.51 mm/ka, and the SFR ranges between 10 and 134.93 t km−2 yr−1, averaged at 18.59 t km−2 yr−1. The dissolution rate and SFR exhibit a slight increasing trend with 0.04 mm/ka and 0.003 t km−2 yr−1, respectively. The risk for soil erosion was reevaluated on the basis of the SFR results, and the area with erosion risk and the ecologically safe area were corrected. Results indicated that the area with erosion risk is four times higher than the ecologically safe area. This study will hopefully instigate and facilitate the application and popularization of geospatial analysis technology to the research field of rock weathering and soil formation.

在全球气候变暖背景下,气温变化具有显著的地域差异,认识区域气温变化特征,对于生态安全和可持续发展是非常重要的.本文基于CRU、MODIS遥感数据以及气象站观测数据,使用累积距平、一元线性回归、5a滑动平均、线性倾向率、R/S分析等方法,揭示了贵州高原气温的时空演变特征及对生态安全的影响.结果表明:(1)在空间上,贵州高原气温时空演变历史过程具有地域差异性和季节性,总体呈南高北低的空间分布格局,春季和冬季气温空间分布特征比较相似,夏季与春季、冬季特征近似相反,秋季空间分布不明显,主要受到海拔和纬度的影响;(2)1901以来,气温呈现出以-0.31℃/century的速率波动下降趋势,且以秋季为主;(3)1951年以来,气温呈现出以0.71℃/century的速率波动上升趋势,且以秋季为主;(4)2000年以来,气温呈现出以-5.43℃/century的速率波动下降趋势,且以冬季为主,具有一定的年际性和季节性.综上所述,贵州高原气温呈现下降趋势,且主要受到海拔和纬度的双重影响.本研究结果为研究区合理利用气候资源、区域产业结构调整、生态环境保护工程等提供决策支撑.

碳酸盐岩风化吸收的大气CO2主要以HCO3-形式连续地经由河流从大陆输送到海洋,成为陆地生态系统的重要碳汇.目前主要河流流域的碳酸盐岩风化碳汇估算存在不确定性,分布格局尚不清晰.基于GEMS-GLORI全球河流数据库提供的全球10万km2以上主要河流流域多年平均监测数据,利用水化学径流法估算出全球主要河流流域碳酸盐岩对CO2的吸收速率为0.43±0.15 Pg CO2 yr-1,平均CO2吸收通量为7.93±2.8 t km-2 yr-1.CO2吸收通量在不同气候带下差异显著,热带和暖温带CO2年吸收速率占全球主要河流流域年吸收速率的62.95％.冷温带CO2年吸收速率占全球主要河流流域的33.05％,仅次于热带地区.本文划分出全球CO2吸收通量的9个关键带,关键带的交汇处CO2吸收通量较高.喀斯特出露流域碳酸盐岩对CO2吸收通量的均值为8.50 t km-2 yr-1,约为非喀斯特流域的3倍.全球喀斯特出露流域碳酸盐岩风化碳汇在全球碳循环、水循环及碳收支平衡估算研究方面占据重要地位.

Evaluating the coupling effects of climate variability and ecological restoration on carbonate rock weathering⁃ related carbon sink ( CS) is an important objective in current research on carbon cycle and climate change in karst ecosystems. In this study, we estimated the flux of CS (CSF) in the typical karst valley of Southwest China from 1992 to 2017 based on the thermodynamic dissolution model for carbonate rock. We extended our research by using the Lindeman⁃ Merenda⁃Gold model to quantify the relative contribution rates of climate change and ecological restoration factors to CSF. We obtained the following results: 1) annual average temperature and precipitation of the valley were both increasing continuously at rates of 0.06°C per year and 12 mm per year, respectively, and after 2000, these rates of increase slowed down. The annual evapotranspiration increased before 2000, and decreased after that. 2) The increase rate of fractional vegetation cover (FVC) in the valley was 0.004 per year, and the proportion of increased area reached 95.07%, which indicated significant ecological restoration in the valley. 3) The annual average CSF in the valley was 9.42 t C km a with an increasing trend during the study period showing an average increase rate of 0.2 t C km a, and the proportion of the area with increased CSF was 89.28%. 4) CSF in the valley was affected by climatic factors (precipitation, evapotranspiration, temperature) and ecological restoration factors (FVC); among these factors, precipitation, temperature, and FVC had a positive impact on CSF, whereas, evapotranspiration exerted a negative impact on CSF. The relative contribution rate of precipitation in the valley was the maximum among that of all factors, with a magnitude of 70.36%. 5) We revealed the coupling influence mechanism of climate change and ecological restoration on rock weathering process.

以中国南方喀斯特槽谷区为研究对象,基于改进的喀斯特地区土壤侵蚀算法,定量分析了槽谷区土壤侵蚀时空演变特征,并利用CA-Markov模型对土壤侵蚀状况的未来情景进行预测。结果表明:（1）喀斯特槽谷区2000—2015年土壤侵蚀总量由61.86×10~7 t/a减少至2.97×10~7 t/a,区域年平均侵蚀模数由21.61 t hm -2 a -1 降低至1.04 t hm -2 a -1 ,轻度及轻度以下侵蚀等级的面积增加了76.13×10~5 hm~2,重度及重度以上侵蚀面积减少了46.90×10~5 hm~2,侵蚀状况明显减轻;（2）不同地貌类型之间的土壤侵蚀状况存在一定差异,平原地区侵蚀模数最小,盆地地区侵蚀模数最大,达到平原地区侵蚀模数的近4倍;（3） 2000—2015年间,槽谷区轻度及轻度以上侵蚀等级都逐渐向微度侵蚀等级转移,土壤侵蚀等级由高等级向低等级转移率达到了98%以上,总体呈现出好转的趋势;（4）基于CA-Markov模型模拟槽谷区2020年土壤侵蚀等级的未来演变趋势,其总体Kappa系数达到了0.9788,一致性最佳;（5）到2020年,槽谷区土壤侵蚀等级基本为微度和轻度侵蚀,土壤侵蚀状况将进一步改善。本研究的结果可为喀斯特槽谷区当前土壤侵蚀治理成效的评价以及未来的防治提供理论和数据方面的参考。

Anaerobic oxidation of methane and sulfate reduction was studied in the pore waters of four cores at two stations of the middle Okinawa Trough. Pore water vertical distributions of sulfate, methane, sulfide, total alkalinity, ammonium, and phosphate were determined in this study. Our results show strong linear sulfate concentration gradients of 6.83 mmol/L m?1 in Core A and 5.96 mmol/L m?1 in Core C, which were collected from two stations. Concurrent variations of methane, total alkalinity and hydrogen sulfide all exhibit steep increases with depth at both cores, which indicate active methane seep activities around two stations. Pore water ammonium and phosphate concentrations reveal minor influences of organic matter degradation on sulfate reduction at two stations. Sulfate methane interface(SMI) was extrapolated from linear sulfate profiles in methane seep cores. Shallower SMI depths(A: 4.9 mbsf; C: 5.4 mbsf) indicate strong methane fluxes and active anaerobic oxidation of methane in the underlying sediments.

为实现大型回转体空间异面直线角度的自动精确测量,以激光模组为光源,以精密位置测试传感器象限探测器为敏感探测器件,以精密电控转台、多维调节结构为辅助装置,构建了测量系统.通过调节,保证激光出射光路与回转体轴线平行及电控转台轴心与回转体轴线重合.采用公共基准将异面角度映射到同一平面,两象限探测器分别安装于空间异面待测点,其坐标原点与待测点重合.电动转台控制激光光束先后扫描象限探测器坐标原点,光电转换并调理后获得起、止位置信号.最后,通过数据采集和处理,获得空间异面直线角度.在自然照明条件下,对空间角为5°的标准大型回转体进行了自动和手动两种模式的重复实验.实验结果表明,系统在自动模式下的绝对误差均值△为0.005 5°,满足了实际工程对大型回转体空间异面角度的精度需求.

As a typical land cover class of Qinghai-Tibetan Plateau,glacier is widely distributed in alpine terrain.However,field measurement is impossible in those areas because of complex terrain and adverse weather.At first,on the basis of analyzing the glacier image features such as the spectrum and shape,object spatial relations based on context and environment distribution including terrain and climate,this study combined and developed the existing features description algorithm of object-oriented method.Secondly,we build a series of combined extraction models for glacier information using high resolution remote sensing images and DEM data.At last,based on object-oriented method and combined extraction models,the paper tested the glacier landform extraction in the study area under the Western Mapping Project in Qinghai-Tibetan Plateau.Results indicate that the multi-feature combination model is feasible.The researches introduce a new remote sensing auto-extraction approach of glacier information where it is hardly to make field measurement.Moreover,the paper develops some new ideas for researches on glacier ablation monitoring and climatic change.

SiC/cordierite composite porous ceramics were prepared by a reactive process, in which clay, talc and alumina were mixed with SiC powder and graphite was used as the pore former. The mixture was heated in air so that graphite was burned out and SiC particles were bonded by reaction-derived cordierite. The sintering temperature was chosen as 1360°C according to DTA and XRD studies. The volume fraction of graphite had a strong influence on porosity and strength. A three-point bending strength of 54.6MPa was achieved at a porosity of 27.6%, while the strength of 9.3MPa was corresponding to a porosity of 59.6%. Moreover, as-prepared composite porous ceramics exhibited excellent resistance to cyclic thermal shock.

The monodispersed PbS nanoparticles which are modified by sodium dodecyl benzene sulfonal (DBS) were prepared by microemulsion method. The transient optical properties were studied by femtosecond pump-probe method. Compared with the PbS stabilized by PVA, we found that the surface chemical environment has a very important effect on the transient optical properties. The corresponding mechanism was discussed.