Search

Aiming at the frost heave characteristics of long-distance and large-section underground freezing projects in cities, the double-line tunnel of Shanghai Metro Line 18 undercrossing an operation station was select as an example,a three-dimensional numerical model was established by using finite element software based on the thermal-mechanical coupling equation. Combined with the physical parameters obtained from laboratory tests, the evolution law of frost heave displacement field of the project was studied, and the influence of measures such as the staggered peak freezing and the adjustment of brine temperature on the frost heave displacement field was explored. Under the experimental conditions, the results show that: ① the deformation of the station floor caused by frost heave which mainly occurs in the active freezing period. When the double-line tunnel is frozen at the same time, the vertical displacement of the station floor at 45days of freezing reaches 77.72% of the displacement at 90 days of freezing. ② When the freezing time reaches 90 days, compared with simultaneous freezing, the displacement of the station floor reduced by 7.7% under the condtion of staggered peak freezing. The superposition effect of frost heave in the same time period is effectively avoided, and the frost heave effect is reduced to a certain extent. ③ When the freezing time reaches 90 days, compared with simultaneous freezing, the displacement of the station floor reduced by 34.2% under the condtion of adjusting the brine temperature, it shown that the expansion rate and frost heave effect of frozen soil are effectively controlled. In engineering practice, measures such as staggered freezing and adjusting brine temperature are used together to control frost heave, and the maximum vertical deformation of the station floor is 25.41 mm. The deformation law of the station floor obtained by numerical simulation is basically consistent with the measured data, which effectively guided the construction of the project.

Purposes Owing to the varietry of electrical equipment and the complex connection between them in transformer station, there are many common problems includeng relatively limited location and picture contrast of equipment, insufficient target images and markers in practical applications, and inaccurate electrical equipment image segmentation brought by the traditional way. In this paper, CNN (Convolutional Neural Network) is combined with Transformer to form a new model for segmentation of electrical equipment, and a new SE-Transfomer (Substation Equipment Transformer) network based on codec structure is proposed. Methods To obtain the local context information, the coder extracts the spatial feature map by using CNN at first. Meanwhile, the feature map is carefully modified with multi-scale feature inputs for global feature modeling. The decoder extracts global deep features using Transformer and performs stepwise up-sampling to predict the detailed segmentation map. SE-Transfomer is extensively experimented on the dataset of Liangjiazhuang Transformer Station in Shanxi province, and its longitudinal results of Dice, Recall, Specificity, and RMSE (Root Mean Square Error) are 89.31%, 90.52%, 89.62%, and 11.32, respectively. Findings The results indicate that SE-Transfomer obtains comparable or higher results than previous state-of-the-art segmentation methods on the scanning of electrical equipment in the transformer station.

The paper comprehensively summarizes the process of China's coal mine construction technology from introduction and absorption to independent development since the founding of New China more than 70 years ago, as well as the important achievements in basic research, process innovation, technological breakthrough, equipment development and achievement transformation, involving drilling and blasting method, freezing method, grouting method, drilling method, caisson method and other drilling technology as well as coal mine rock tunneling technology. At present, the mechanization and automation level of drilling and blasting equipment mainly for drilling and blasting rock has been significantly improved, and the comprehensive drilling technology for short-segment excavation of kilometer-level deep wells has been mature, and the maximum depth of vertical shaft drilling has reached 1341.6 m.The level of geological support technology for drilling and tunneling such as freezing method and grouting method has been significantly improved, gradually replacing the curtain method, sheet pile method and dewatering method and other drilling technology. The maximum frozen depth of vertical shaft is 990 m, and the maximum frozen section of inclined shaft is 681 m. The longest inclined shaft of 5875 m is built by working face grouting, and the ground pre-grouting reinforcement depth is 1355 m.Breakthroughs have been made in the technology of mechanical rock breaking and tunneling. The maximum drilling diameter of reverse drilling rig is 6 m, and the maximum drilling depth is 562 m.The maximum drilling diameter of vertical drilling rig is 10.8 m, and the maximum drilling depth is 660 m, and the application range is gradually expanded. The drilling method of vertical tunneling machine has achieved a breakthrough of zero, which has laid a foundation for intelligent drilling of coal mine vertical shaft. The operation line of the mechanized excavation method of the rock tunnel has been formed, and the average tunneling speed of the full section tunneling machine is more than 400 m/month. In summary, the innovation and development of coal in China mine construction technology and equipment in the past 70 years has significantly improved the operation environment, construction efficiency and safety level of the coal mine tunneling, realized the unmanned and fully mechanized operation of the tunneling working face, solved the problems of the tunnel construction in each stage of coal development in China, and ensured the basic construction and mining continuous construction of coal mines. At the same time, the technical equipment developed from the coal mine construction and the successful experience have been promoted and practiced in the underground engineering fields such as hydraulic power generation, municipal rail transit, mountain traffic tunnels, water diversion tunnels, and made contributions to the construction of national key projects and the development of national economy.

Objective To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. Methods After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. Results Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P

In order to explore the influence of dressing process parameters, such as dressing depth ad, axial feed speed fd and dressing speed ratio qd, on the grinding surface integrity of 18CrNiMo7-6 gear steel, orthogonal experiments were conducted for shaping dressing process using ceramic bonded chrome corundum grinding wheels with resin bonded diamond disc wheels, bronze bonded diamond disc wheels and single particle diamond pens, respectively. The cross grinding test of 18CrNiMo7-6 gear steel was carried out with a chrome corundum wheel after dressing. The results show that the surface roughness Ra of the grinding process increased with the increase of the dressing process parameters, and residual compressive stresses were more easily obtained on the grinding surface. The comprehensive evaluation of the grinding surface integrity for the three dressing tools, using a normalized dimensionless method, shows that the grinding surface integrity of the bronze-bonded diamond disc wheel dressing is better than the other two dressing methods. Furthermore, the grinding surface integrity is better when ad=4 μm, fd=100 mm/min, and qd=0.3.

In order to understand the main occupational disease hazards of coal mines in Huaibei City, from 2019 to 2020, all 16 coal mines in Huaibei City were selected by cluster random sampling to investigate the respiratory dust and noise of main posts, and the incidence of occupational diseases was investigated. The results show that the main occupational hazards in Huaibei coal mines are still dust and noise. The over standard rate of dust blowing posts is 51.88%, and the over standard rate of noise posts is 34.7%. The concentration of respirable dust exposed by coal miners is higher than that of tunnellers and auxiliary workers, and the exposure noise intensity of tunnellers is higher than that of coal miners and auxiliary workers. The occupational health examination for coal miners was carried out well, but the physical examination rate of noise exposed workers (34.49%) was low; the new pneumoconiosis patients are coal miners, tunnellers, etc. The length of exposure to dust and the onset latency of new pneumoconiosis patients in different types of work are different. The control of dust and noise hazards in coal mining and tunneling posts should be further strengthened.

[Objective] The effects of forest types on soil carbon and nitrogen contents and enzyme activity were analyzed in order to provide a scientific basis for the selection of tree species and forest management methods in the transformation of subtropical coniferous forests. [Methods] The study evaluated data from a subtropical evergreen broad-leaved forest (Castanopsis carlesii forest), an evergreen deciduous broad-leaved mixed forest (Betula fujianensis and Phoebe bournei mixed forest), and a coniferous forest (Pinus massoniana forest) at the same altitude and similar environmental conditions. [Results] ① The total soil organic carbon content in the P. massoniana forest was significantly greater than in the other two forest types, and the total soil nitrogen content was not significantly different from that in the B. fujianensis and P. bournei mixed forest. However, both carbon and nitrogen contents were significantly greater than in the C. carlesii forest. The soil nitrogen and carbon reserves of the P. massoniana forest and the B. fujianensis and P. bournei mixed forest were significantly greater than the nitrogen and carbon reserves of the C. carlesii forest. The soil soluble organic carbon contents in the P. massoniana forest and the B. fujianensis and P. bournei mixed forest were significantly greater than in the C. carlesii forest. The soil soluble organic nitrogen content in the P. massoniana forest was significantly less than in the C. carlesii forest and the B. fujianensis and P. bournei mixed forest. The soil microbial biomass carbon and nitrogen contents in the C. carlesii forest and the P. massoniana forest were significantly greater than in the B. fujianensis and P. bournei mixed forest. There were no significant differences in the soil ammonium nitrogen contents among the three forest stands. However, the soil nitrate nitrogen content in the B. fujianensis and P. bournei mixed forest was significantly greater than in the other two forest types. ② The soil urease activity in the C. carlesii forest was significantly greater than in the B. fujianensis and P. bournei mixed forest. There were significant differences in soil invertase activities among the three stands, and the differences in activity followed the order of P. massoniana forest > C. carlesii forest > B. fujianensis and P. bournei mixed forest. The soil catalase activities in the P. massoniana forest and the C. carlesii forest were significantly greater than in the B. fujianensis and P. bournei mixed forest. There was no significant difference in soil phosphatase activity among the three forest stands. Soil β-glucosidase activity in the P. massoniana forest was significantly greater than in the C. carlesii forest and the B. fujianensis and P. bournei mixed forest. RDA analysis showed that the main factors affecting the change of soil enzyme activity in the three forests were total soil carbon (explanation rate of 59.5%), total nitrogen (explanation rate of 11.0%), and nitrate nitrogen (explanation rate of 14.6%). [Conclusion] The P. massoniana forest and the B. fujianensis and P. bournei mixed forest had greater soil carbon and nitrogen storage values than observed for the C. carlesii forest under the same disturbance background. The increased soil organic matter was conducive to increase soil enzyme activity.

Objective: To investigate the value of dual-source CT dual-energy virtual plain scan in the preoperative diagnosis of extramural vascular invasion (EMVI) in rectal cancer. Methods: A total of 150 patients with rectal cancer (64 females (42.7%) and 86 males (57.3%), with an average age of (62.3±11.8) years) who were scheduled for surgical treatment in our hospital from November 2019 to December 2021 were selected for the preoperative dual-source CT dual-energy virtual plain scan;. Two senior radiologists independently analyzed preoperative imaging data (including ctEMVI status, local lymph node infiltration, and distant metastasis) to determine the existence of preoperative EMVI. With pathological results as the gold standard, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of VNC in the diagnosis of EMVI were evaluated, and the area under the receiver operating characteristic curve (ROC) was used to evaluate the diagnostic efficiency. Results: Among 150 patients with rectal cancer, 56 (37.3%) were positive for EMVI and 94 (62.7%) were negative for EMVI. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EMVI evaluation by physician 1 were 86%, 80.36%, 89.36%, 81.82%, and 88.42%, respectively, and the AUC was 0.831 (95%CI, 0.756~0.905). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of physician 2 were 88.67%, 80.36%, 93.62%, 88.24%, and 88.89%, respectively, and the AUC was 0.870 (95%CI, 0.802~0.938). The consistency of the evaluation results between physician 1 and physician 2 was high (k=0.943). Conclusion: Dual-source CT dual-energy virtual plain scan has a certain diagnostic value in the preoperative evaluation of EMVI of rectal cancer.

Based on the structure, working principle, and working conditions of conductance water cut sensor, it is revealed that the early failure of the metal electrode of the sensor is due to the comprehensive influence of well fluid erosion, electrochemical corrosion, and oil pollution during its long-term service in the downhole. A technology for electrode surface treatment is proposed using boron-doped diamond (BDD) films to improve the service performance of the modified electrode. The hot wire chemical vapor deposition method was adopted to fabricate BDD film, the boron doping concentration and deposition time were optimized, and fluorination treatment was applied to improve the wear resistance, electrochemical corrosion resistance, and oleophobic property of the BDD film comprehensively. The results showed that BDD film with boron doping concentration of 6×10-3 exhibited high wear resistance and good electrochemical corrosion resistance, and endowed the modified electrode with superior erosion resistance and corrosion resistance. The friction coefficient and wear rate of BDD modified electrode were 92% and 78% lower than those of Invar alloy, also, the low-frequency impedance modulus value of the modified electrode was higher than 1×104 Ω·cm2. The BDD film prepared with a deposition time of 8 h had a favorable micro-nano structure owing to small grain size and uniform distribution. Such morphology was conducive to enhancing the oleophobic performance of the modified electrode, and its contact angle in the simulated well fluid was high to 102°. The engineering applicability of BDD film modified electrode under simulated working conditions indicated that, the modified electrode had excellent comprehensive performances of erosion resistance, electrochemical corrosion resistance and oil adhesion resistance, and can realize the long-term stable operation of the conductance water cut sensor under harsh downhole conditions.

To improve the adverse effects of corn starch on the color presentation of paprika red in prepared meat products, the characteristics of the effects of different concentrations of corn starch, pectin and paprika red on the color of the system were studied. The uniform design was used to optimize the concentration of the three components, and the partial least squares quadratic polynomial was used for data regression analysis. The predictive model was established that taking concentration of corn starch, pectin and paprika red as independent variables, L*, a*, b*, h, ΔE and the scattering rate as dependent variable. Results showed that, the prediction model had high accuracy, the ratio of corn starch, pectin and paprika red at best color of system, was the combination of various factors: Corn starch concentration 5.37%, pectin concentration 2.90%, paprika concentration 0.27%. At this time, the total color difference and scattering rate were: L* 49.6024, a* 39.7159, b* 40.0236, h 44.6671, ΔE 10.3461, scattering rate 0.2063. The optimal color conditions were verified to be effective in improving the color of corn starch-paprika red system in prepared meat products. In this paper, the ratio of corn starch, pectin and paprika red at best color of system obtained by the prediction model could effectively improve the color of corn starch-paprika red system.

In order to explore the influence of the grinding process parameters on the surface roughness and surface layer residual stress of 18CrNiMo7–6 steel, the cylindrical longitudinal grinding experiment was carried out by using an end cylindrical grinder. With using the workpiece speed nw, grinding depth ap and longitudinal feed speed vf, the single-factor experimental research is carried out. The research results show that with the increase of nw, the surface roughness Ra of the workpiece decreases first and then increases. When nw is 120 r/min, the surface roughness Ra reaches the minimum value, and the surface residual compressive stress value is the largest at this condition, and when nw is greater than 120 r/min, the surface residual stress exists fluctuation. With the increase of ap, the surface roughness Ra of the workpiece decreases first and then increases, and the tensile stress influence on the surface layer of the workpiece increases with the increase of the grinding depth. The surface roughness Ra first decreases and then increases with the increase of vf. When vf is 210 mm/min, the surface roughness value Ra is the smallest. With the increase of vf, the residual compressive stress of the surface layer gradually decreases and gradually changes to increasing residual tensile stress.

As the main energy source in our country, coal plays an important role in the development of the national economy. In order to facilitate industrial operation, it is necessary to reduce the temperature of coal with high ash melting point. The cement with a lower melting point was selected, and three high-melting coals (Datong, Zhundong, and Changping) were added according to a certain ratio to explore the effect of the cement on the ash melting characteristics of the high-ash-melting coal. The results show that the mortar can reduce the ash melting point of the three high-melting coals, but the degree of reduction in the melting temperature of the three coal ash is not linearly related to the content of the mortar. The effect of mortar on reducing the melting temperature of three kinds of coal ash is presented: Datong> Zhundong> Changping; the lower ash melting point of mortar is mainly due to the high content of alkaline oxides in the mortar and low content of acidic oxides, which are easy to combine with oxygen. On the contrary, alkali The ion potential of the sex ions is low, which reduces the aggregation of polymers, thereby lowering the ash melting point.

To effectively solve the difficulty of the prevention of coal spontaneous combustion in a fully mechanized caving face in deep and remote mining area, the main reasons for the problems include strong air leakage and depth buried coalbed by taking the 7302 working surface of Baodian Coal Mine as an example. By analyzing the danger of coal spontaneous combustion and SF6 trace, the air leakage channel in the dangerous area of the goaf was studied. For the period of rotating mining, the measures for monitoring and controlling, glue injection, nitrogen injection, and chemical resistance are proposed; for the period of faults, the measures for isolation walls, nitrogen injection, injection of super absorbent materials, and chemical resistance are proposed; for the period of suspension and withdrawal, the measures of setting up coal stack walls, gas monitoring, glue injection, nitrogen injection are proposed. The results through analysis show that the air leakage rate of 7302 working face is about 15.87%, which ensures that the 7302 working face mining is safety.

The air leakage flow field in large area goaf is complex, and the air leakage law is not clear. Once coal spontaneous combustion occurs, it will threaten the safety of the mine. In this study, taking the large area goaf of Baodian Coal Mine in Shandong Province as an example, the dynamic changes and coupling of complex flow fields such as temperature field, gas seepage field and gas concentration field in the large area goaf are studied by means of field observation and numerical simulation. The relationship between coal spontaneous combustion and high temperature on gas migration in large area goaf is analyzed. The results show that pressure is the direct driving force to induce gas migration in large area goaf. Under the influence of thermal buoyancy, the flow direction of the gas changes, O2 around the suction area migrates and accumulates to the high pressure area at the top of the goaf in the negative pressure area at the bottom of the goaf, expanding the range of oxidation heating zone in the goaf and accelerating the spontaneous combustion of coal. By controlling the wind speed of the air leakage source in the goaf, the risk of spontaneous combustion in the goaf can be reduced, and the emission of harmful gases in the deep part of the goaf can be controlled.

A multiplex real-time polymerase chain reaction (PCR) method for simultaneous and rapid detection of components derived from sweet potato, cassava, potato, and corn was established. The g3pdhs gene of sweet potato and cassava, the UGPase gene of potato and the zSSIIb gene of corn were used as target genes to design specific primers and TaqMan probe, and the 18S rRNA gene was used as the internal reference gene. Methodological validation was performed, and the proposed method was applied to simulated samples with different mixing ratios and actual starch samples. The results showed that this method was high-throughput, sensitive and specific. No cross-reaction was found with 15 non-target sources. The detection sensitivity for template DNA was 3 × 10-3 ng/μL, and the proposed method had a good linear relationship and high amplification efficiency. The detection limit for edible starch samples was 0.1%. The results of the PCR method for 50 actual samples were consistent with those of the reference method, indicating that this method could be used for the detection of common adulterants in edible starches.

为提高虾青素的生物利用度，增加其稳定性，采用均质乳化-探头超声法制备虾青素纳米脂质载体（AST-NLC）。以粒径和包封率为指标，通过单因素试验和中心复合设计法优化AST-NLC的制备工艺，并对制备的AST-NLC进行X射线衍射（XRD）和傅里叶红外光谱（FT-IR）结构表征，以及4、25、50 ℃下的热稳定性测试。结果表明:制备AST-NLC的最佳工艺条件为甘油三硬脂酸酯与中链甘油三酯质量比1∶ 11（总质量0.99 g）、乳化剂用量（吐温-80+大豆卵磷脂，质量比1∶ 1）3.8%（以水相质量为基准）、油水比1∶ 34（体积比）、均质速度5 000 r/min、超声时间2 min、虾青素添加量2.0 mg，在此条件下制备的AST- NLC粒径为（79.30±1.21）nm，多分散系数（PDI）为0.01±0.01，包封率为（81.36±1.84）%，Zeta电位为（-18.13±2.83）mV；结构表征结果表明，AST-NLC中的虾青素是以分子的状态包裹在脂质体中；热稳定性结果显示，4 ℃更有利于AST-NLC的保存。综上，成功制备了粒径小、分散均匀且包封率较高的AST-NLC。In order to improve the bioavailability and increase the stability of astaxanthin, astaxanthin nanolipid carrier (AST-NLC) was prepared by the homogeneous emulsification-probe ultrasonic method. The preparation process of AST-NLC was optimized by single factor experiment and central composite design method with particle size and encapsulation rate as indexes, and the AST-NLC prepared was structurally characterized by X-ray diffraction (XRD) and Fourier infrared spectroscopy(FT-IR) and tested for thermal stability at 4, 25 ℃ and 50 ℃. The results showed that the optimal process conditions for preparing AST-NLC were mass ratio of glycerol tristearate to medium chain triglyceride 1∶ 11 (total mass 0.99 g), emulsifier dosage (Tween-80+soybean lecithin, mass ratio 1∶ 1)3.8%(based on water phase mass), oil-water volume ratio 1∶ 34, homogeneous speed 5 000 r/min, ultrasonic time 2 min, astaxanthin dosage 2.0 mg. Under the optimal conditions, the AST-NLC was prepared with a particle size of (79.30±1.21) nm, a polymer dispersity index(PDI) of 0.01±0.01, an encapsulation rate of (81.36±1.84)%, and Zeta potential（-18.13±2.83）mV. The structural analysis revealed that astaxanthin in AST-NLC was encapsulated in liposomes in the state of molecules. The thermal stability results showed 4 ℃ was more favorable for the preservation of AST-NLC. In conclusion, AST-NLC with small particle size, homogenous dispersion and high encapsulation rate was successfully prepared.

Efficient removal of dissolved organic matter (DOM) is an important task for wastewater treatment. However, the molecular composition of DOM and its transformation during the treatment are still unclear. In this paper, the organic components in the stream of a coal coking wastewater treatment process were studied. The wastewater was extracted by dichloromethane (CH2Cl2)，the extract was named as ‘oil phase’. Then the raffinate was extracted by solid-phase extraction, the extract was named as ‘water phase’. The ratios of total organic carbon contents (TOC) in the oil and water phase samples were generally consistent during the treatment process. The extracted DOM was characterized by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Eight class species were as assigned from the mass spectra, namely N1O1-7, N2O1-6, N1O5, N1O2-6S1, N2O3-5S1, O2-8, O2-6S1, O4-5S2. The class categories which contain multiple oxygen atoms (Ox) and both multiple oxygen and sulfur atoms (OxSy) were dominant in the oil phase. The relative abundance of each species was decreased sharply after the first aerobic biological process, which was consistent with the TOC rapid decline in the sample. O2-8 compounds existed in all wastewater samples and dominated in the final sample, indicating that these compounds were the most stubborn pollutants which were difficult to remove in all treatment processes. It is speculated that these compounds may come from some humic-acids which have complex structure and multiple oxygen atoms naturally existing in natural water. The composition of O3 class species showed two patterns among the wastewater treatment process, compounds with high double bond equivalent (DBE) were dominant in the first four processes, while a proliferation of low DBE components was observed in the last three samples. It indicated that those low DBE components were generated by the oxidation of other substances, such as O1 and O2 species. The water phase organic matter had an extremely complex molecular composition and a total of 27 different compound class species were identified in a single mass spectrum. Ox, OxS1-2 and NxOyS1-2 were the major class categories in water phase. On the whole, OxS1-2 was much easier than the other two categories to be removed during the wastewater treatment process. In the OxS1-2 class category, O4S1 had a much higher relative abundance than other species. It decreased sharply among the process, but it still accounted for a large proportion in the final process, which implied the O4S1 species had strong resistance to removal. The relative abundances of each species in NxOyS1-2 had consistent composition and transformation, and could be effectively removed after the wastewater treatment process. The composition transformation trend of O6S1 was similar to N1O6S1, those compounds with low DBE value (512) and low carbon number (1020) were dominated after the aerobic biological process section and remained in the final process. The study of DOM in coal coking wastewater treatment from the molecular level by FT-ICR MS will contribute to understand the transformation law of pollutant compounds. However, limited by the mass spectrometry, only the molecular composition information can be obtained. The molecular structure information, especially for the functional groups, is hard to be obtained. In order to research the transformations law of pollutant compounds for further, the structural information needs to be deduced combining the molecular composition, the precursor and the polarity of wastewater pollutants. Developing more efficient and advanced separation and enrichment methods is another way to research the molecular structure information. By the further work, a fully understand of the pollutant composition will be obtained, and a more effective wastewater treatment process will be developed.

A multiplex real-time polymerase chain reaction (PCR) method for simultaneous rapid detection of donkey-, horse-, pig- and duck-derived components was established. For this purpose, the Nad5, ATpase6, ATP8 and cytb were used as target genes to design specific primers and Taqman probes, and the 18S rRNA gene was used as internal reference gene. The developed method was validated and applied to detect simulated adulterated meat products, simulated processed meat products and actual donkey meat samples. This method was characterized by high-throughput, and excellent sensitivity and specificity. The system had no cross-reaction to non-target sources when the cycle threshold (Ct) value did not exceed 35.0. The sensitivity was 2 × 10-4 ng/μL of template DNA. The detection limit for raw and cooked meat was 0.001% and 0.01% of the meat content, respectively. The results of this method for 100 actual samples were consistent with those of the national standard method, indicating that the multiplex real-time PCR method can be used for the detection of commonly adulterants in meat and meat products.

Currently, micro- and nanoplastics are the most concerning pollutants, which have been confirmed to exist in every stage of drinking water treatment process. Micro- and nanoplastics in drinking water have large specific surface areas, which could adsorb inorganic matter, organic matter, and microorganisms, thereby increasing their risk to human health. The adsorption and agglomeration behavior of micro- and nanoplastics on typical pollutants is called the "colloid pump effect." Focused on the micro- and nanoplastics in drinking water, the occurrence, colloid pump effect, and toxic effect on the human body and the effect of colloid pumps on the removal of micro- and nanoplastics were summarized and described. The results revealed that micro- and nanoplastics existed widely in source water, treated water, pipe network water, and tap water. The colloid pump effect of micro- and nanoplastics promoted their agglomeration with inorganic matter, organic matter, and microorganisms, which not only intensified the toxic effect of micro- and nanoplastics but also affected the removal effect. There were different viewpoints on the effect of coagulation and sedimentation on the removal of micro- and nanoplastics, and the removal effect of sand filters was limited. The advanced treatment was an efficient process to remove micro- and nanoplastics with a particle size smaller than 5 μm. The removal rate of micro- and nanoplastics could be effectively improved by exploring the mechanism of the colloid pump effect and its initiation conditions. Finally, from the perspective of the drinking water treatment process and colloid pump effect, the control of micro- and nanoplastics in drinking water was prospected in order to provide reference for reducing the occurrence and toxicity of micro- and nanoplastics in drinking water, ensuring drinking water quality safety and human health.

As an emerging pollutant of global concern, microplastics (plastics with size<5 mm) and heavy metals are widely found in freshwater environments. Microplastics migrate easily, are difficult to degrade, and have large specific surface areas. They can enrich a variety of pollutants such as heavy metals and greatly increase their potential harm to the environment and ecology. Firstly, the special environmental behavior of microplastics carrying heavy metals and migrating together in freshwater environments was defined as the "Trojan-horse effect." Then, the Trojan-horse effect and its mechanism of microplastics and heavy metals in the freshwater environment were summarized and expounded from four aspects:the source and distribution of microplastics in the freshwater environment, the enrichment effect of microplastics on heavy metals, the impact of microplastics and the heavy metal Trojan-horse effect on its migration behavior, and the biological impact of microplastics and the heavy metal Trojan-horse effect. The results showed that, as a wide range of non-point source pollutants, microplastics widely existed in freshwater environments. In freshwater environments, the adsorption degree of single metals was different in different environments. It was mainly affected by microplastics, metals, and environmental factors. There was competitive adsorption in the presence of multiple metal ions. The Trojan-horse effect of microplastics and heavy metals could also affect their co-transport behavior. The Trojan-horse effect of microplastics and heavy metals in the freshwater environment frequently exacerbated their toxicity to aquatic organisms. This study provides references for comprehensively understanding the Trojan-horse effect and its mechanism in microplastics and heavy metals in the freshwater environment, which could effectively reduce the ecological risk and impact on human health of microplastics and heavy metals in the freshwater environment.