Wyniki wyszukiwania

1

Rapid startup of simultaneous nitrogen and phosphorus removal (SNPR) process and the bacterial community dynamics in a GSBR

100%

Xin X., Wang Z.

Polish Journal of Environmental Studies

|

2019

|

tom 28

|

nr 4

This study inoculated aerobic granular sludge (AGS) in a sequencing batch reactor (SBR) treatment for low carbon nitrogen (COD/N) ratio wastewater, and gradually reduced the DO concentration in order to achieve the rapid startup of the simultaneous nitrogen and phosphorous removal (SNPR) process. Meanwhile, the microbial community dynamics at different DO levels were analyzed by high-throughput sequencing. The removal efficiencies of total nitrogen (TN) and phosphorus (TP) were significantly affected as different dissolved oxygen (DO) concentrations (2.0,1.2 and 0.8 mg/L) in stages I, II and III, respectively. When DO concentration was reduced to 0.8mg/L (stage III), the SNPR process was successfully implemented and the removal efficiencies of TN and TP were up to 77.30% and 85.78%, respectively. A total of 40,983 effective 16S rRNA gene sequences were generated from four samples (1-4) that widely represented microbial community diversity. The dominant phyla transformed from Candidate_division_TM7 (the relative abundance of 68.08%) and proteobacteria (25.78%) to Firmicutes (47.57%) and proteobacteria (41.49%) when DO concentration was decreased from 2.0 mg/L (stage I) to 0.8 mg/L(stage III). Moreover, Kluyvera, Peptostreptococcaceae_incertae_ sedis, Clostridium_sensu_strict_1, Trichococcus, Denitratisoma, Clostridium_sensu_stricto_13 and Raoultell were the most abundant genus in the SNPR process. Among these communities, Clostridium_ sensu_strict_1, Clostridium_sensu_stricto_13 and Denitratisoma were considered the main organisms responsible for simultaneous nitrogen and phosphorus removal.

2

NAC (NAM/ATAF/CUC) transcription factors in different stresses and their signaling pathway

100%

Wang Z., Dane F.

Acta Physiologiae Plantarum

|

2013

|

tom 35

|

nr 05

Plants have evolved several molecular mechanisms to cope with biotic and abiotic stresses. Successful adaptation to stress is regulated through the activation or repression of the effects of transcription factors on specific target genes. The NAC (NAM, ATAF and CUC) transcription factors (TFs), which constitute one of the largest plant-specific transcription factor family, have been reported to be involved in plant development, biotic and abiotic stress regulation. Thus NAC TFs might be promising candidates for improving plants’ stress tolerance. Ongoing research on this transcription factor family has greatly broadened our knowledge in terms of its structure, functions, interaction with phytohormones, evolution and usage. This review focuses on the current status of NACs as regulators of stress.

3

Tracking animal-mediated seedling establishment from dispersed acorns with the aid of the attached cotyledons

100%

Yi X., Wang Z.

Acta Theriologica

|

2015

|

tom 60

|

nr 2

Various methods have been used to track seed dispersal of large-seeded species; however, the influence of different seed tracking methods on ecological outcomes of seed dispersal by animals is not well evaluated. Acorn removal by food hoarding animals and the following seedling establishment of Mongolian oak (Quercus mongolica) were investigated in Xiaoxing’anling Mountain, Heilongjiang, northeastern China, by using four different marking methods: plastic tagging, nail insertion, hole drilling, and isotope labeling. The acorn removal speed differed among marking methods, with plastic-tagged acorns being removed more slowly than those marked with nails, holes, and isotope. By checking the attached cotyledons and performing isotope analyses, more seedlings were found to establish from nailed acorns and isotope-soaked acorns than from drilled acorns and plastic-tagged acorns. Plastic-tagged acorns were transported closer than those marked with nails, holes, and isotope. Moreover, seedlings were often found clustered in caches containing acorns marked with plastic tags. Low level of cotyledon predation by animals makes it possible to directly identify focal seedlings of white oaks based on the attached cotyledons. Considering cotyledon predation by animals, coupling minor modification of cotyledons with isotope labeling appears to be an easy way to explore the actual pattern of seed dispersal of large-seeded trees, e.g., oaks.

4

Seasonal variations in thermogenesis and energy requirements of plateau pikas Ochotona curzoniae and root voles Microtus oeconomus

100%

Wang D., Wang Z.

Acta Theriologica

|

1996

|

tom 41

|

nr 3

The seasonal patterns of nonshivering thermogeneis (NST), resting metabolic rate (RMR) at 15"C and 25"C in plateau pikas Ochotona curzoniae {Hodgson, 1858) and root voles Microtus oeconomus (Pallas, 1776), from the Qinghai-Tibetan plateau, were determined and thermal conductance was calculated. NST tended to increase during cold season for both species. No significant seasonal variations in NST were found in pikas {mean maximum in winter: 3.46 ± 0.19 ml Oa/g-h; minimum in spring: 3.07 + 0,16 ml Ou/g-h). Voles increased NST significantly as the ambient temperature decreased, from the lowest, mean 8.00 ± 0.42 ml Oa/g-h, in summer to the peak in winter, mean 11.29 i 0.44 ml Os/g* h. RJV1R and thermal conductance were lower in winter than those in summer for both species (mean in summer at 25'C: 4.96 + 0.35 ml 02/g-h and 0.509 ± 0.027 ml Oa/g-h-"C for voles and 2.11 ± 0,09 ml Os/g-h and 0.179 ± 0.003 ml Oa/g-h-'C for pikas, respectivly; mean in winter at 25°C: 4.22 ± 0.26 mlOa/g*h and 0.379 ± 0.012 mlCVg-h-'C for voles and 1.55 ± 0.06 ml Oa/g-h and 0.123 ± 0.003 ml Oa/g-h'"C for pikas, respectively). Voles lost body weights in winter whereas pikas kept their body weights. This suggests that alpine small mammals, which have high levels of metabolism and thermal conductance, mainly depend on increasing thermogenic capacities and insulation, decreasing energy expenditure per individual, augmented by behavoral adjustments to cope with cold temperatres of winter.

5

Using an attapulgite-activated carbon composite ceramisite biofilter to remove dibutyl phthalate from source water

85%

Wang Z., Wang Z., Chen L., Lin Z., Liu Y., Liu Y.

Polish Journal of Environmental Studies

|

2018

|

tom 27

|

nr 2

This study developed an attapulgite-activated carbon composite ceramisite (AACCC) biofilter for removing trace-level dibutyl phthalate (DBP) from micro-polluted drinking source water. Total pore area and average pore diameter of AACCC were estimated to be 112.2 m²/g and 19.8 nm, respectively, while the AACCC showed considerable adsorptive capacity due to its mesoporous structure, i.e., it would be used as an ideal filtration media. Although AACCC could adsorb DBP, biological AACCC covered by different types of microorganisms appeared to be more effective in removing DBP from source water. At a filtration velocity of 2 m/h during two influent concentrations (20 μg/L and 50 μg/L), the DBP removals in AACCC biofilter were higher than the AACCC filter, being 1.2 μg/L and 1.9 μg/L. The pseudo-first-order kinetic model can serve as a good method for estimating removal performance of DBP using an AACCC biofilter. This clearly demonstrated the potential of the AACCC biofilter as a cost-effective and high-efficiency process for removing trace-level DBP from drinking source water.

6

Numerical analysis on the influence of the twisted blade on the aerodynamic performance of turbine

81%

Jin J., Wang Z., Cao L.

Polish Maritime Research

|

2016

|

tom 23

|

nr Special Issue S1

With the gradual increase of the thermal power unit capacity, the inlet steam parameters and flow of the turbine also increase gradually, which causes considerable secondary flow loss. Therefore, studying the causes and distribution of secondary flow loss within the level is of great significance to effectively improve the stage internal efficiency of turbine. Take high-pressure stage moving blade of a turbine as the research object, and adopt the k-ωSST model, the SIMPLEC algorithm to numerically simulate the formation and development process of leakage vortex between the tip clearance of the positive bending twisted blade and its effect on the secondary flow of cascade passage. Results show that relative to the conventional twisted blade, the scope of influence of leakage vortex which the steam flow formed near the suction surface of positive bending twisted blade and the disturbance to passage mainstream become smaller, and the increase of tip clearance has weakened the „C” type pressure gradient of suction surface of the positive bending twisted blade, increased the thickness of the boundary layer at both ends of blades and the loss of the blade end

7

Selection of aquatic plants for phytoremediation of heavy metal in electroplate wastewater

81%

Sun H., Wang Z., Gao P., Liu P.

Acta Physiologiae Plantarum

|

2013

|

tom 35

|

nr 02

The remediation of heavy metal-contaminated sites using plants is a promising alternative to current methodologies. In this study, small-scale wetlands were constructed to search for new plant species that are suitable and hold potential for phytoremediation of heavy metalcontaminated wastewater originating from an electroplating plant. Ten macrophyte species [Phragmites australis (Cav.) Trin., Typha orientalis Presl, Lythrum salicaria Linn., Arundo donax Linn. var. versicolor Stokes, Typha minima Funk, Juncus effusus L., Pontederia cordata L., Cyperus alternifolius Linn. subsp. flabelliformis (Rottb.) Ku¨kenth., Acorus calamus Linn., and Iris pseudacorus Linn.] were investigated and compared for their shapes, biomass, roots, and ability to accumulate heavy metals. Acorus calamus Linn., T. orientalis Presl, P. australis (Cav.) Trin., T. minima Funk, and L. salicaria Linn. exhibited the highest levels of metal tolerance, whereas P. cordata L., I. pseudacorus Linn., and C. alternifolius Linn. subsp. flabelliformis (Rottb.) Ku¨kenth. had the lowest. Some plants accumulated higher concentrations of metals in the tissues compared with other species such as T. minima Funk, P. australis (Cav.) Trin., L. salicaria Linn., A. donax Linn. var. versicolor Stokes, P. cordata L., and A. calamus Linn., whereas T. orientalis Presl and C. alternifolius Linn. subsp. flabelliformis (Rottb.) Ku¨kenth. had poor capacity to accumulate heavy metals. The results showed that, of the 10 species, P. australis (Cav.) Trin., A. calamus Linn., T. minima Funk, and L. salicaria Linn. are the most suitable and promising plant materials for phytoremediation of heavy metal-contaminated wastewater.

8

Studying the urban heat island using a local climate zone scheme

81%

Wang Z., Xing W., Huang Y., Xie T.

Polish Journal of Environmental Studies

|

2016

|

tom 25

|

nr 6

With rapid urbanization and the rise of climate change awareness, policy makers and urban planners are seeking methods and schemes that consider the urban heat island (UHI) effect. In order to investigateto what extent a homogeneous urban fabric leads to a specific thermal pattern, a local climate zone (LCZ) scheme was utilized and classification has been applied in the urban areas of Chongqing. Urban indicators were calculated to match LCZ types of measurement points. Using a mobile measurement approach, we analyzed screen-height air temperature distribution inside local climate zones in both spring and summer. An apparent seasonal difference inside LCZs was found, with air temperature amplitude about 0.8ºC in spring and 0.9ºC in summer. The average air temperature difference in LCZ 1 was 2.9ºC between the two seasons, while in LCZ H this difference was as high as 3.5ºC. The reasons why LCZ H had relatively high air temperature were explained and further investigation of UHI using LCZ scheme was proposed.

9

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

81%

Du S., Hu X., Yang Y., Wang Z.

Dendrobiology

|

2022

|

tom 88

17

Analysis and experiments on sea load and fastened mechanics on pipe clamps

81%

Wang Z., Zhang B., Wang T.

Polish Maritime Research

|

2017

|

tom 24

|

nr Special Issue S2

When an offshore oil field completed and put into production, new subsea pipelines and the new cable need to be established. Cable protection pipe clamp is used to fix cable protection pipe on the jacket. In order to avoid the problem of traditional steel structure clamp splice, counterpoint, fastening difficulty when installed cable protection pipe under water, reduce the risk and workload of under water, This paper develop a new type of portable connecting riser clamp –“backpack clamp” which solve the riser cable protection pipe difficult underwater installation problem. The main structure of backpack clamp used three valves type structure. The load characteristic of a clamping device was determined by the Morison equation which was a classical theory. Clamp device underwater mechanics analysis model was established. The minimum tension pre-tightening force was determined. The results show that the strength of the base meets the requirements after strength analysis with finite element analysis method, stability and strength experiments, which means the clamp based on resin matrix composite is feasible

18

Analysis and experiments of embedded gripping mechanism used in large-scale tools holding up pile foundation in ocean

81%

Wang Z., Zhang B., Wang T.

Polish Maritime Research

|

2019

|

tom 26

|

nr 3

With the rapid development of the marine economy and continuous improvement of the industry, the scale of the offshore engineering is increasing. This raises interest in studying, theoretically and experimentally, gripping and bearing mechanisms for large-scale holding and lifting tools used in foundation pile installations. In this paper, the embedded gripping mechanism is studied based on the theory of elastic-plastic mechanics. The embedded and bearing performance of the tooth is simulated and the influence factors are studied. In addition, the device used in the simplified embedded experiment on the tooth of the embedded block is designed. The relationship between embedded depth, load, and tooth profile angle is identified and validated. Meanwhile, the embedded performance of linear and ring type teeth is compared experimentally in order to select the suitable type of tooth for various situations. This comparison makes the basis for designing an upending gripper for the marine pile foundation, which can realize the operation of holding the pile to prevent its falling

19

Stream networks and knickpoints in the Sanjiangyuan Region

81%

Wang Z., Yu G.-A., Brierley G., Liu L.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

|

2010

|

tom 42

|

nr 1

79-91

The source area of the Lancang (Mekong), Yangtze and Yellow rivers is named in Chinese Sanjiangyuan (source of three rivers). Geographical characteristics of these rivers, and various rivers at the margin of the Qinghai- Tibetan Plateau (Jialing, Minjiang, Dadu, Yalong and Jinsha) are summarized from fi eld investigations along with digital elevation model (DEM) analyses and satellite images. Uplift of the Qinghai-Tibetan Plateau has resulted in an asymmetrical distribution of tributaries for stream networks at the margins of the plateau. Almost all tributaries join the trunk stream from the northwest. Three types of drainage network are evident: plume, nervation and dendritic. In general, plume networks have a large number of first order streams. Nervation networks have a main stream and parallel tributaries. Dentritic networks are characrterized by continuous bifurcation and have a branch-like appearance. Most stream networks in the Sanjiangyuan region are of the nervation type. Several large knickpoints are evident along the longitudinal profi les of the Yellow and Yangtze Rivers. Channel aggradation immediately upstream of these knickpoints marks a transition in river processes from vertical bed evolution (i.e. incision) to horizontal channel adjustment (and associated braided and anabranching channels).

20

Hydrodynamic load and parametric design of grouted clamp used on offshore jacket

81%

Zhang B., Wang Z., Wang T.

Polish Maritime Research

|

2018

|

tom 25

|

nr Special Issue S3

The reliability and safety of offshore platform are an important research aspect in marine engineering. The jacket platform is mainly used for oil development and submarine drilling, and the long-term work in the marine environment will be subjected to different loads, which will lead to the damage of the structure part of the offshore platform. It affects the structural strength of the platform. For the repair of jacket damage, grouted reinforcement technology is adopted, which has the advantages of simple underwater installation and low cost. The reinforcement technology of the grout hoop has been applied to the engineering projects abroad, but the stress and serialization design of the hoop in the marine environment need further study. This paper will combine the ocean current and wave force to carry out the research of underwater work and prevent loosening, and put forward the parametric design method for the specific size of the hoop. Two types of experimental models are designed: short bolt form clamp and long bolt form clamp. The mechanical experiment of the long bolt clamp is carried out, and the relationship between the slipping force and the bolt preload is analyzed, so as to verify the theoretical analysis

Ograniczanie wyników

Rapid startup of simultaneous nitrogen and phosphorus removal (SNPR) process and the bacterial community dynamics in a GSBR