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The acquisition of low-frequency vibration signals in earthquake exploration is a crucial aspect of seismic exploration technology. Addressing the difficulty current fiber optic sensors face in monitoring low-frequency vibrations, this paper proposes an acceleration sensor based on S-type Fiber Bragg Grating (FBG). First, an FBG acceleration sensor model is established and theoretically analyzed. Then, the impact of structural parameters on the sensor's sensitivity and natural frequency is examined, employing the ANSYS finite element analysis software for static stress and modal simulation analysis. Finally, a prototype is developed, and a low-frequency vibration testing system is assembled to test the sensor's performance. The results show that the sensor has a natural frequency of 34 Hz, operates in a frequency band of 0.2-14 Hz, has a dynamic range of 63.5 dB, a lateral interference of less than 3%, a sensitivity of ∼274.45 pm/g, good linearity, and is insensitive to temperature. The findings provide a reference for the development of similar sensors and further exploration of the lower frequency limit.

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Acceleration sensors play an important role in bridges, dams, seismic monitoring, geological exploration, and more. Aiming at the problem that it is still difficult to accurately measure low-frequency vibration signals with low-frequency acceleration sensors, a high-sensitivity, wide-low-band fiber Bragg grating (FBG) acceleration sensor incorporating a rotating cantilever and springs was proposed. A sensor mechanics model was built, and its key parameters were analyzed theoretically and optimized in size. ANSYS Workbench was used for simulation analysis, and the physical sensor was developed while a low-frequency test platform was established for performance tests. The experimental results suggested that the natural frequency of the sensor was 78 Hz, the operating frequency band was 1-55 Hz, the sensitivity was 1127.2 pm/g, the transverse interference immunity was less than 5.45%, and the dynamic range was 86.45 dB. With high sensitivity, wide low frequency band, and excellent temperature compensation characteristics, the designed sensor could provide a reference for the design of like FBG acceleration sensors.

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Recently, swarm intelligence algorithms have received much attention because of their flexibility for solving complex problems in the real world. Recently, a new algorithm called the colony predation algorithm (CPA) has been proposed, taking inspiration from the predatory habits of groups in nature. However, CPA suffers from poor exploratory ability and cannot always escape solutions known as local optima. Therefore, to improve the global search capability of CPA, an improved variant (OLCPA) incorporating an orthogonal learning strategy is proposed in this paper. Then, considering the fact that the swarm intelligence algorithm can go beyond the local optimum and find the global optimum solution, a novel OLCPA-CNN model is proposed, which uses the OLCPA algorithm to tune the parameters of the convolutional neural network. To verify the performance of OLCPA, comparison experiments are designed to compare with other traditional metaheuristics and advanced algorithms on IEEE CEC 2017 benchmark functions. The experimental results show that OLCPA ranks first in performance compared to the other algorithms. Additionally, the OLCPA-CNN model achieves high accuracy rates of 97.7% and 97.8% in classifying the MIT-BIH Arrhythmia and European ST-T datasets.

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Strain monitoring is of great significance to identify the failure of key mechanical components and ensure the good operation of mechanical equipment. In terms of the common issue of the low sensitivity of fiber Bragg grating (FBG) strain sensor in strain measurement on the mechanical structure surface, this paper describes a flexible hinge strain sensor with the FBG as the sensitive element. A theoretical analysis of the sensitivity of the sensor is performed, a copper alloy material with a large elastic modulus is selected, the simulation analysis and optimization design for the structural parameters of the sensor are carried out by using ANSYS and Solidworks software, then the object of the sensor is developed according to the simulation results, and finally, the performance of the sensor is tested. The results show that the maximum deformation the sensor can measure is 0.5299 µÎµ, the sensitivity of the sensor is ∼1.8870 pm/µÎµ, which is approximately twice that of the bare FBG sensor, the linearity is greater than 99%, and the relative standard deviation of the repeatability is 0.9%. The results of the study provide a reference for developing the optical fiber strain sensor and further improving its sensitivity.

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Strain measurement has important applications in mechanical engineering, civil engineering, aerospace, earthquake monitoring, and other fields. Aiming at the problem of low sensitivity of existing fiber Bragg grating (FBG) strain sensors, a high-sensitivity FBG strain sensor of the substrate type with a sensitization structure is proposed. The sensitivity of the sensor is analyzed theoretically, the sensor is simulated by Solidworks and ANSYS software, and the structural parameters are optimized. According to the simulation results, the real sensor is developed, and the strain test system is built to test the performance of the sensor. The results show that the strain sensitivity of the sensor is 3.21p m/µÎµ, which is about 2.7 times that of the bare FBG strain sensor, which is basically in line with the theoretical value. The fitting linear correlation coefficient is 0.9999, and the repeatability error is 3.9%FS. The research results provide a reference for developing the same type of sensors and further improving the sensitivity of fiber strain sensors.

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P. (T.) anningense sp. n. and P. (T.) biloborum sp. n. are described and illustrated as male imagines from Oriental China. DNA barcodes of two new species are also presented. A key to known male imagines of the subgenus Tripodura from China is given.

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The larva and female of Polypedilum (Probolum) bullum Zhang Wang associated with morphological characteristics and DNA barcodes are described and illustrated for the first time. The female is characteristic with developed dorsomesal lobe and ventrolateral lobe both densely covered with apical setae, ventrolateral lobe partially covered by dorsomesal lobe. The larva is distinguished by the shape of mentum, pecten epipharyngis, labral SI and labral SII.

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The utility of COI DNA barcodes in species delimitation is explored as well as life stage associations of five closely related Propsilocerus species: Propsilocerus akamusi (Tokunaga, 1938), Propsilocerus paradoxus (Lundström, 1915), Propsilocerus saetheri Wang, Liu et Paasivirta, 2007, Propsilocerus sinicus Sæther et Wang, 1996, and Propsilocerus taihuensis (Wen, Zhou et Rong, 1994). Results revealed distinctly larger interspecific than intraspecific divergences and indicated a clear "barcode gap". In total, 42 COI barcode sequences including 16 newly generated DNA barcodes were applied to seven Barcode Index Numbers (BINs). A neighbor-joining (NJ) tree comprises five well-separated clusters representing five morphospecies. Comments on how to distinguish the larvae of P. akamusi and P. taihuensis are provided.

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To explore the ability of bloom-forming cyanobacterium Chrysosporum ovalisporum to utilize different kinds of phosphorus compounds in the water column, we examined the growth response of C. ovalisporum in the laboratory by taking dipotassium hydrogen phosphate as the control and set different treatments of phosphorus substrates. The results showed that C. ovalisporum could utilize sodium tripolyphosphate and terasodium pyrophosphate decahydrate, with better utilization of sodium tripolyphosphate. After 15 days, it had the highest biomass and chlorophyll a concentrations under the treatment of sodium tripolyphosphate, with a value of (426.96±47.42) mg·L-1 and (1852.34±116.60) µg·L-1, respectively. Compared with the control, there was no significant difference in biomass of C. ovalisporum under both the (2-aminoethyl)-phosphonic acid and disodium ß-glycerol phosphate pentahydrate treatments. The change characteristics of dissolved inorganic phosphate were related to the alkaline phosphatase activity, indicating that C. ovalisporum was able to utilize these two organophosphorus compounds via enzyme hydrolysis. The concentration of dissolved inorganic phosphate reached 0 mg·L-1 during the whole experiment when the C. ovalisporum were fed with glyphosate. Biomass, specific growth rate, chlorophyll a concentration and photosynthetic activity of algal cells were significantly lower than those of the control, indicating that C. ova-lisporum could not uptake phosphorus compounds in the glyphosate substrate and thus their growth being inhibited. Our results present new insights to understand the diffusion mechanism of C. ovalisporum into different aquatic ecosystems and had theoretical reference value for the prevention and control of new cyanobacterial blooms.

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DNA barcodes and morphology recognize a new non-biting midge within the genus Polypedilum (Diptera: Chironomidae). Polypedilum (Cerobregma) heberti Lin et Wang sp. n. is described and illustrated based on an adult male from Gaoligong Mountains, Yunnan, China. Key to adult males of the subgenus Cerobregma is given.

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Base scale entropy analysis (BSEA) is a nonlinear method to analyze heart rate variability (HRV) signal. However, the time consumption of BSEA is too long, and it is unknown whether the BSEA is suitable for analyzing pulse rate variability (PRV) signal. Therefore, we proposed a method named sliding window iterative base scale entropy analysis (SWIBSEA) by combining BSEA and sliding window iterative theory. The blood pressure signals of healthy young and old subjects are chosen from the authoritative international database MIT/PhysioNet/Fantasia to generate PRV signals as the experimental data. Then, the BSEA and the SWIBSEA are used to analyze the experimental data; the results show that the SWIBSEA reduces the time consumption and the buffer cache space while it gets the same entropy as BSEA. Meanwhile, the changes of base scale entropy (BSE) for healthy young and old subjects are the same as that of HRV signal. Therefore, the SWIBSEA can be used for deriving some information from long-term and short-term PRV signals in real time, which has the potential for dynamic PRV signal analysis in some portable and wearable medical devices.

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In this study, we tested the utility of the mitochondrial gene cytochrome c oxidase subunit 1 (CO1) as the barcode region to deal with taxonomical problems of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae). The 114 DNA barcodes representing 27 morphospecies are divided into 33 well separated clusters based on both Neighbor Joining and Maximum Likelihood methods. DNA barcodes revealed an 82% success rate in matching with morphospecies. The selected DNA barcode data support 37-64 operational taxonomic units (OTUs) based on the methods of Automatic Barcode Gap Discovery (ABGD) and Poisson Tree Process (PTP). Furthermore, a priori species based on consistent phenotypic variations were attested by molecular analysis, and a taxonomical misidentification of barcode sequences from GenBank was found. We could not observe a distinct barcode gap but an overlap ranged from 9-12%. Our results supported DNA barcoding as an ideal method to detect cryptic species, delimit sibling species, and associate different life stages in non-biting midges.

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The genus Hydrosmittia from China is reviewed. Two new species H. continalinea sp. n. and H. sipinata sp. n. are described and illustrated based on male imagines. Key to known male imagines of genus Hydrosmittia worldwide is provided.

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The subgenus Tripodura Townes of Polypedilum Kieffer from China including 26 species is reviewed. Eleven new species, named P. (T.) absensilobum Zhang & Wang sp. n., P. (T.) apiculusetosum Zhang & Wang sp. n., P. (T.) arcuatum Zhang & Wang sp. n., P. (T.) bilamella Zhang & Wang sp. n., P. (T.) conghuaense Zhang & Wang sp. n., P. (T.) dengae Zhang & Wang sp. n., P. (T.) mengmanense Zhang & Wang sp. n., P. (T.) napahaiense Zhang & Wang sp. n., P. (T.) parallelum Zhang & Wang sp. n., P. (T.) pollicium Zhang & Wang sp. n. and P. (T.) trapezium Zhang & Wang sp. n. are described and illustrated based on male imagines. Three species, P. (T.) quadriguttatum Kieffer, P. (T.) unifascia (Tokunaga) and P. (T.) udominutum Niitsuma are firstly recorded in China. A key to known male imagines of Chinese species and an updated world checklist of subgenus Tripodura are presented.

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In order to study the physiological response to heavy metals and organic-phosphorus pesticide toxicity of aquatic organisms, Neocaridina denticulate was used as a test organism to investigate the impact of physiological indices of N. denticulate muscle tissues when they were exposed to Cu2+ and chlorpyrifos for 5 days respectively with the test methods of semi-static toxicity. The results showed that: when exposed to different concentrations of Cu2+ and chlorpyrifos solutions, the protein concentrations in muscle tissues were significantly lower with the extension of time to varying degrees. In the lower concentration groups of Cu2+ (0.086 mg x L(-1) and 0.172 mg-L-') and the higher concentration groups of chlorpyrifos (0. 006 0 [g-L-' and 0.012 0 µg x L(-1)), the total SOD activity showed inhibitory effect; the trend of the higher concentration group of Cu2+ (0.344 mg x L(-1) and 0.688 mg x L(-1)) showed " inhibition-promotion-inhibition", however, the lower concentration groups of chlorpyrifos (0.001 5 µg x L(-1) and 0.003 0 µg x L(-1)) showed the" inhibition-promotion" changes in trends; MDA contents changed similarly, and within a certain range of concentrations, MDA contents presented a gradually rising trend with increasing Cu2+ and chlorpyrifos concentration, which indicated that Cu2+ and chlorpyrifos accelerated lipid, peroxidation in muscle tissues of N. denticulate. In addition, AChE activity in Cu2+ and chlorpyrifos solutions showed inhibitory effect, and in the solutions with higher concentration of Cu2+ and chlorpyrifos, the activity was gradually decreased with the increase of concentration, indicating that Cu2+ and chlorpyrifoscs impacted the normal physiological functions of N. denticulate, and the higher the concentration, the greater the damage effect. Based on the analysis results, we confirmed that the total SOD, MDA and AChE played significant roles as physiological indicators in evaluating toxic effect of heavy metals and organic-phosphorus pesticide on N. denticulate.

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Polypedilum (Tripodura) falcatum sp. n. and P. (T.) procerum sp. n. of the acifer species group of Polypedilum subgenus Tripodura Townes are described and illustrated as male imagines from China. The male adult of P. (T.) falcatum sp. n. is distinguished by the presence of two faint markings on wing; short and interrupted abdominal tergite bands; the sickle-like superior volsella bearing 0-2 outer setae and a tuft of short setae on its apex. The male adult of P. (T.) procerum sp. n. differs in having short abdominal tergite bands; a long, slender and apically curved superior volsella; a high fore leg ratio (2.30-2.33). A key to known male imagines of Polypedilum subgenus Tripodura from China is presented.

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The community structures of rotifers were surveyed in Lin'gang B Gang River, a new estuarial river in Shanghai, from December 2011 to November 2012. A total of 23 rotifer species were identified, of which 19 species were the indicator of environmental pollution. Rotifer species' number rose monthly from 2 to 13. A conspicuous succession of dominant species was observed from a single dominant species (Keratella cochlearis) to several species. The rotifer community structure of Lin'gang B Gang River differs with that of the outer water body (Lu Chaoyin River). Pearson analysis showed that the rotifers' density had a significant correlation with water temperature and chlorophyll-a (P <0. 05) , but had no significant correlation with salinity; the densities of dominant species (except Keratella cochlearis) presented negatively correlations with concentration of nutrients and salinity (P < 0. 05). The low species similarity index between every month demonstrated that aquatic ecosystem of Lin'gang B Gang River was in the unstable state. However, the increase of Margalef index and Shannon-Wiener index of rotifers and the decline of E/O value monthly showed the water environment of Lin'gang B Gang. River was improved.

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A new species of Polypedilum (Uresipedilum) Oyewo & Sæther, 1998, Polypedilum (Uresipedilum) minimum sp. n. is described as male. A key to adult males of the subgenus from China is presented.

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Aimed to explore the purification effect of constructed wetland on phytoplankton community structure, an investigation was conducted on the species composition, biomass, and community diversity of phytoplankton in the water body of Shijiuyang constructed drinking water source wetland of Jiaxing, Zhejiang Province of East China in winter, 2010. A total of 77 phytoplankton species were identified, belonging to 39 genera of 7 phyla. The main phylum was Bacillariophyta, with 33 species of 14 genera. The dominant species were Melosira varians, Cyclotella meneghiniana, Nitzschia sp., Chroococcus sp., Dactylococcopsis rhaphidioides, Scendesmus quadricauda, and Tribonema bombycium, among which, C. meneghiniana had the highest dominance (0.144). The phytoplankton density in winter was averagely 1.28 x 10(6) cell x L(-1), with the minimum (6.80 x 10(5) cell x L(-1)) in the water outlet, and the density of Cyanophyta in the water outlet was significantly lower than that in the water inlet (P < 0.05), only occupying 14.9% of the latter. The Shannon index of the phytoplankton community at the sampling sites ranged from 0.94 to 1.27. According to the cluster analysis and multidimensional scaling (MDS), the phytoplankton community was classified into five phytoplankton community groups, i.e., root-channels littoral community, root-channels flow community (2 styles), highly purified area community, and headwater region community. Diverse ecological environment and water flow velocity at the sampling sites were found to be the main contributors to the formation of the five phytoplankton community groups.

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