ECOTOXICOLOGY
·
2014
·Vol. 24
·期 1
·19-28
·
IF 2.5
Zhang Dawen,Liao Qiegen,Zhang Li,Wang Donggen,Luo Linguang,Chen Yuwei,Zhong Jiayou,Liu Jutao
Occurrence and spatial distributions of microcystins (MCs; MC-RR, -YR, -LR, -LA, -LF, -LW) in Poyang Lake were studied during the period from July 6 to July 18, 2012, by using ultra-high-performance liquid chromatography–electrospray ionization tandem triple quadrupole/mass spectrometry (UPLC-MS/MS). MC-RR was the most dominant variant (94.70 and 84.73 % for intracellular (cellular MCs) and extracellular (dissolved MCs) MCs, respectively) in Poyang Lake, followed by MC-LR (4.65 and 13.17 %, respectively), MC-YR (0.8 and 2.63 %, respectively), and MC-LA (0.02 and 0.00 %), while MC-LW and MC-LF were not detected. Total MCs concentrations (intracellular +extracellular MCs) ranged between 0.0036 and 7.97 μg/L, with an average of 0.79 μg/L, and only two sampling stations with the total MCs concentrations exceeded the drinking water guideline level of 1 μg/L for MC-LR proposed by World Health Organization. The overall spatial pattern of intracellular and extracellular MCs in Poyang Lake demonstrates decreasing trends from east to west, and the south part higher than the north part. Intracellular MCs content was negatively correlated with total nitrogen (r = −0.34, p < 0.01) and NO 3 (r = −0.35, p < 0.01), while no significant correlation was found between intracellular MCs concentration and total phosphorus, NH 4 , and NO 2 ( p > 0.05), suggesting that NO 3 might be a regulating factor for MCs production in Poyang Lake. In addition, intracellular MCs concentrations were positively correlated with wind speed, Microcystis and Cyanobacteria biomass (r = 0.34–0.51, p < 0.05), indicating that wind speed plays an important role in the spatial distributions of MCs, and NO 3 , toxic cyanobacteria (mainly Microcystis ), and wind speed seem to be the important forcing factors driving MCs spatial distributions in Poyang Lake.
研究领域:
环境科学
·
水生生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2017
·
IF 5.099
Changkun Xie,Liyan Kan,Jiankang Guo,Sijia Jin,Zhigang Li,Dan Chen,Xin Li,Shengquan Che
Particulate matter (PM) is one of the most serious environmental problems, exacerbating respiratory and vascular illnesses. Plants have the ability to reduce non-point source PM pollution through retention on leaves and branches. Studies of the dynamic processes of PM retention by plants and the mechanisms influencing this process will help to improve the efficiency of urban greening for PM reduction. We examined dynamic processes of PM retention and the major factors influencing PM retention by six trees with different branch structure characteristics in wind tunnel experiments at three different wind speeds . The results showed that the changes of PM numbers retained by plant leaves over time were complex dynamic processes for which maximum values could exceed minimum values by over 10 times. The average value of PM measured in multiple periods and situations can be considered a reliable indicator of the ability of the plant to retain PM. The dynamic processes were similar for PM 10 and PM 2.5 . They could be clustered into three groups simulated by continually-rising, inverse U-shaped, and U-shaped polynomial functions, respectively. The processes were the synthetic effect of characteristics such as species, wind speed, period of exposure and their interactions. Continually-rising functions always explained PM retention in species with extremely complex branch structure. Inverse U-shaped processes explained PM retention in species with relatively simple branch structure and gentle wind. The U-shaped processes mainly explained PM retention at high wind speeds and in species with a relatively simple crown. These results indicate that using plants with complex crowns in urban greening and decreasing wind speed in plant communities increases the chance of continually-rising or inverse U-shaped relationships, which have a positive effect in reducing PM pollution.
研究领域:
环境科学
·
植物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Sciences-Basel
·
2021
·Vol. 11
·期 16
·7258
·
IF 2.679
Qi Liu,Shengde Chen,Guobin Wang,Yubin Lan
Background: Unmanned Aerial Vehicles (UAVs) applied to agricultural plant protection is widely used, and the field of operation is expanding due to their high efficiency and pesticide application reduction. However, the work on pesticide drift lags behind the development of the UAV spraying device. Methods: We compared the spray drift potential at four liquid pressures of 2, 3, 4, and 5 bar ejected from the hydraulic nozzles mounted on a UAV test platform exposed to different wind speeds of 2, 4, and 6 m/s produced by a wind tunnel. The combination of the wind tunnel and the UAV test platform was used to obtain strict test conditions. The droplet size distribution under spray drift pressures was measured by a laser diffraction instrument. Results: Increasing the pressure leads to smaller droplet volume diameters and produced fine droplets of less than 100 µm. The deposition in the drift area was elevated at most of the sampling locations by setting higher pressure and faster wind speed. The deposition ratios were all higher than the flow ratios under three wind speeds after the adjustment of pressures. For most samples within a short drift distance (2–8 m), the drift with the rotor motor off was more than an order of magnitude higher than that with the rotor motor on at a pressure of 3 bar. Conclusions: In this study, the wind speed and liquid pressure all had a significant effect on the UAV spray drift, and the rotor wind significantly inhibited a large number of droplets from drifting further.Keywords:unmanned aerial vehicle;liquid pressure;drift deposition;wind speed;rotor wind field;droplet size
研究领域:
农业工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
URBAN FORESTRY & URBAN GREENING
·
2022
·
IF 5.766
Changkun Xie,Jiankang Guo,Lubing Yan,Ruiyuan Jiang,Anze Liang,Shengquan Che
Exploring the relationships between plant morphological structures and PM 2.5 (particulate matter < 2.5 µm in diameter) retention on leaf surfaces and determining the key factors will help to screen tree species with high-efficiency PM reduction and improve the air purification function of green spaces. PM 2.5 retention experiments were conducted in a wind tunnel using 1800 branches from 30 species with different morphological structures under wind speeds of 1, 3.5, and 8 m/s. Eight comprehensive variables (PC1–PC8) of plant morphological structure were extracted by principal component analysis , and their relationships with PM 2.5 retention and the main influencing factors were explored by stepwise regression models. Under all of the wind speeds, the totality characteristic (PC1) (composite variable of factors including volume and total surface area) and surface area/weight density (PC2) of plant branches and leaves were the two most significant influencing factors, and they had negative effects. In addition to the aforementioned two common key factors, the leaf size (PC5) and surface roughness (PC7) were the two key positive factors at wind speeds of 1 and 3.5 m/s, while the number of branches and leaves (PC3 and PC4, respectively) were the two key positive factors at a wind speed of 8 m/s. Generally speaking, with the increase of wind speed, the effect of leaf morphological characteristics on PM 2.5 retention decreased, while the crown structure characteristics became more significant. Compared with leaf morphological characteristics, the crown morphological structure variables had greater variability and a greater impact on PM 2.5 retention. Crown morphological structure should be given more importance in screening high-efficiency PM retention tree species.
研究领域:
生态学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Xinyun Shen,Xiaoxiong Wang,Mengge Yu,Hao Wang,Fengyuan Xu,Qian Zhang
Self-powered sensors are an important application development direction of nanogenerators. The development of fully self-powered systems that do not rely on traditional energy systems such as mains power or batteries is of great value to the future design of the loT. Such system design is not an easy task due to the detailed calculation of multiple units’ energy consumption combined with smart design of minimizing the total consumption of the full system design. By converting energy such as wind energy into electrical energy and designing an indication system that simultaneously utilizes this energy, we completed a fully self-powered sensing system to transduce the wind strength of a high-speed rail. The self-powered sensor part of the system utilizes the modulus design of the pleated elastomer and at the same time achieves wind pressure-LED indication. The circuit is simplified by dropping the traditional control chips, decreasing the energy consumption, and increasing the system reliability. This crumple sensor system has a faster activation speed than that of other wind cup sensors and can sense the wind force when a train passes to protect the canopy structure. This system presents ideas for future designs of fully self-powered systems.
研究领域:
材料科学
·
能源技术
·
物联网
✓ 已验证
产品关联
DOI
高影响因子
Flexible and Printed Electronics
·
2024
·Vol. 9
·期 3
·035003
·
IF 2.8
Wentao Dong,Bo Huang,Kaiqi Sheng,Xiao Cheng
Flexible self-powered sensors have been extensively applied to the Internet of Things, structural health monitoring (SHM), and intelligent transportation. It would be more demanding for the power supply to these sensors during the long-term maintenance of the rail transit system. The wind pressure/velocity generated by high-speed trains poses a substantial threat to safety of human, and new sensors without an external power supply should be developed to monitor wind pressure/velocity in the trackside. Flexible self-powered wind triboelectric nanogenerator (W-TENG) sensor with a single-electrode mode based on conductive hydrogel is designed to wind pressure/velocity monitoring without power supply by harvesting wind energy. It is devoted the relationship between the output voltage of the sensors and the wind pressure/velocity driven by high-speed trains. Material selection and structural design methods are adopted to enhance the energy harvesting efficiency and sensing accuracy of self-powered W-TENG sensors. Open-circuit current of 2.8 μA and open-circuit voltage of 12 V are achieved, and the output voltage signal has the linear relationship with trackside wind pressure/velocity. Field tests are implemented to evaluate the performance of self-powered W-TENG sensors in wind pressure/velocity measurement caused by moving trains, providing an idea to SHM application in intelligent transmit systems.
研究领域:
材料科学
·
能源技术
·
传感技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2023
·Vol. 52
·期 11
·7124-7131
·
IF 2.1
Wang Minmin,Zhao Wenwu,Shi Xu,Sun Tongming,Ju Jianfeng,Tang Yanfeng
In recent years, self-power sensing systems based on triboelectric nanogenerators (TENGs) have been extensively studied. However, pure polymer friction materials are not satisfactory in terms of their triboelectric properties and cannot meet the needs of high-performance TENGs. We have improved the performance of a polymer electrode-based TENG by increasing the specific surface area of the material as well as the dielectric constant of the triboelectric layer. Benefitting from the enhanced dielectric constant engineering and high surface area engineering, the BaTiO 3 @CMC-based TENG exhibits excellent output performance which is 3 times higher than that of a pure CMC-based TENG. As expected, the obtained self-powered TENG can be used to monitor the wind speed with a high sensitivity of 1.97 V/(m s −1 ). In addition, the obtained sensor system can accurately map the contact position and touch trajectory of the object when assembling the TENG with a 4 × 4 array on an acrylic substrate. This work will provide basic insights into improving the performance of TENGs and widen their applications in the field of sensing.
研究领域:
材料科学
·
传感器技术
·
能源转换技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Zhuo Chen,Yang Zhang,Bin Zhu,Yigen Wu,Xiaohui Du,Liwei Lin,Dezhi Wu
Tactile pressure sensing over a wide operation range (>1 MPa) is challenging for a variety of applications in fields such as aviation, oceanography, and biomedicine. Recently, innovative strategies have been utilized to improve the performances of tactile sensors using specially designed structures, dielectric layers, and electrodes. Here, a hierarchical structural design based on ionic gel films has been utilized to build iontronic pressure sensors with ultrahigh sensitivities and broad operation ranges. Sculptured patterns made by a controlled CO2 laser scanning process have been produced on polyimide films to achieve two kinds of protrusion structures for high specific surface areas and strength to withstand high pressure. The iontronic sensor has been constructed by adding two screen-printed electrodes of high surface areas to achieve an ultrahigh sensitivity of 2593 kPa–1 and a wide pressure range from 0 Pa to 3.36 MPa. The prototype device also has a fast response and recovery time of 26 and 13 ms, respectively, and an excellent mechanical durability in the endurance test of over 2700 repeated loading and unloading cycles under a pressure of 1 MPa. Several application examples have been demonstrated, including the detection of physiological signals on human volunteers, the feedback control of intelligent robots, the grasping operation of underwater soft grippers, and the environmental wind-speed monitoring. As such, this work demonstrates a versatile and economical methodology to produce high-performance flexible sensors for various potential applications.
研究领域:
材料科学
·
传感器技术
·
生物医学工程
·
机器人技术
·
环境监测
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）