Multi-objective optimisation model of a low-cost path to peaking carbon dioxide emissions and carbon neutrality in China.

A low-cost path system for achieving carbon neutrality in China was modelled using multi-objective programming by integrating industrial production, electric power, heating, transportation, and forest carbon sequestration. We aimed to minimise the total system cost, CO2 emissions, and air pollutants. The constraints included China's targets of peaking CO2 emissions before 2030; achieving carbon neutrality before 2060; ensuring industry, power, heating, and transportation supplies; promoting green energy; and implementing emission control. The model accounted for industries with high coal consumption, such as steel and chemical industries. Various power sources were considered, including coal-fired, nuclear, wind, and solar energy. Forest carbon sink and carbon capture and storage technologies were employed to achieve the emission reduction goals. The model, which was validated using available research data, offered cost-effective path schemes and exhibited high validity. Our findings emphasise the importance of structural adjustments and emission control, with electric power, heating, and transportation sectors showing higher feasibility and providing greater contributions to achieving carbon neutrality than other industries. Conversely, industrial transformation in sectors such as iron and steel, chemical, and construction materials had low feasibility and limited contribution. The modelling outcomes provide valuable insights for developing low-cost, carbon emission-targeted transportation structures in China's complex system. The results presented here demonstrate the global applicability of this method in contributing to plans aimed at meeting key carbon reduction targets.

Complex resistivity spectrum of pollutant soils with low-concentration heavy metals.

Soil contamination by heavy metals occurs globally, with varying degrees of severity, especially in agricultural fields. Investigating the frequency response characteristics of different types of heavy metal pollutants through induced polarization can provide valuable evidence for surveys based on this method. Soil specimens with varying low concentrations of copper (Cu), chromium (Cr), cadmium (Cd), and lead (Pb) heavy metals were prepared for this study, and parameters including complex resistivity, amplitude-frequency, and resistivity phase were measured. Our findings reveal the following trends: Complex resistivity decreases as heavy metal concentrations increase, demonstrating significant shifts within lower concentration ranges but presenting limitations for assessing pollution in high-concentration areas. Conversely, amplitude-frequency increases with higher heavy metal concentrations, displaying excellent performance in high-concentration scenarios. The differences in complex resistivity and amplitude-frequency among different types of heavy metal pollutants are distinct. In contrast, the absolute phase decreases with rising heavy metal concentrations. The resistivity phase spectra for various heavy metal pollutants exhibit unique patterns. For example, copper-contaminated soil exhibits phase peaks in the frequency range of 8-32 Hz, whereas chromium-contaminated soil shows phase peaks at 16-64 Hz. Cadmium-contaminated soil displays phase peaks ranging from 0.25 Hz to 2 Hz, while lead-contaminated soil exhibits phase peaks within the 0.5 Hz-4 Hz range. Leveraging the frequency range corresponding to phase peaks as an identification method for heavy metal pollution types proves effective. The frequency response characteristics of induced polarization vary significantly among different types and concentrations of heavy metal pollutants, providing important foundations for the application of induced polarization method in the field of heavy metal pollution detection.

Triple-function Hydrated Eutectic Electrolyte for Enhanced Aqueous Zinc Batteries.

Aqueous rechargeable zinc-ion batteries (ARZBs) are impeded by the mutual problems of unstable cathode, electrolyte parasitic reactions, and dendritic growth of zinc (Zn) anode. Herein, a triple-functional strategy by introducing the tetramethylene sulfone (TMS) to form a hydrated eutectic electrolyte is reported to ameliorate these issues. The activity of H2 O is inhibited by reconstructing hydrogen bonds due to the strong interaction between TMS and H2 O. Meanwhile, the preferentially adsorbed TMS on the Zn surface increases the thickness of double electric layer (EDL) structure, which provides a shielding buffer layer to suppress dendrite growth. Interestingly, TMS modulates the primary solvation shell of Zn2+ ultimately to achieve a novel solvent co-intercalation ((Zn-TMS)2+ ) mechanism, and the intercalated TMS works as a "pillar" that provides more zincophilic sites and stabilizes the structure of cathode (NH4 V4 O10 , (NVO)). Consequently, the Zn||NVO battery exhibits a remarkably high specific capacity of 515.6 mAh g-1 at a low current density of 0.2 A g-1 for over 40 days. This multi-functional electrolytes and solvent co-intercalation mechanism will significantly propel the practical development of aqueous batteries.

Biocompatible zinc battery with programmable electro-cross-linked electrolyte.

Aqueous zinc batteries (ZBs) attract increasing attention for potential applications in modern wearable and implantable devices due to their safety and stability. However, challenges associated with biosafety designs and the intrinsic electrochemistry of ZBs emerge when moving to practice, especially for biomedical devices. Here, we propose a green and programmable electro-cross-linking strategy to in situ prepare a multi-layer hierarchical Zn-alginate polymer electrolyte (Zn-Alg) via the superionic binds between the carboxylate groups and Zn2+. Consequently, the Zn-Alg electrolyte provides high reversibility of 99.65% Coulombic efficiency (CE), >500 h of long-time stability and high biocompatibility (no damage to gastric and duodenal mucosa) in the body. A wire-shaped Zn/Zn-Alg/α-MnO2 full battery affords 95% capacity retention after 100 cycles at 1 A g-1 and good flexibility. The new strategy has three prominent advantages over the conventional methods: (i) the cross-linking process for the synthesis of electrolytes avoids the introduction of any chemical reagents or initiators; (ii) a highly reversible Zn battery is easily provided from a micrometer to large scales through automatic programmable functions; and (iii) high biocompatibility is capable of implanted and bio-integrated devices to ensure body safety.

Exopolysaccharide-producing bacteria enhanced Pb immobilization and influenced the microbiome composition in rhizosphere soil of pakchoi (Brassica chinensis L.).

Lead (Pb) contamination of planting soils is increasingly serious, leading to harmful effects on soil microflora and food safety. Exopolysaccharides (EPSs) are carbohydrate polymers produced and secreted by microorganisms, which are efficient biosorbent materials and has been widely used in wastewater treatment to remove heavy metals. However, the effects and underlying mechanism of EPS-producing marine bacteria on soil metal immobilization, plant growth and health remain unclear. The potential of Pseudoalteromonas agarivorans Hao 2018, a high EPS-producing marine bacterium, to produce EPS in soil filtrate, immobilize Pb, and inhibit its uptake by pakchoi (Brassica chinensis L.) was studied in this work. The effects of strain Hao 2018 on the biomass, quality, and rhizospheric soil bacterial community of pakchoi in Pb-contaminated soil were further investigated. The results showed that Hao 2018 reduced the Pb concentration in soil filtrate (16%-75%), and its EPS production increased in the presence of Pb2+. When compared to the control, Hao 2018 remarkably enhanced pakchoi biomass (10.3%-14.3%), decreased Pb content in edible tissues (14.5%-39.2%) and roots (41.3%-41.9%), and reduced the available Pb content (34.8%-38.1%) in the Pb-contaminated soil. Inoculation with Hao 2018 raised the pH of the soil, the activity of several enzymes (alkaline phosphatase, urease, and dehydrogenase), the nitrogen content (NH4 +-N and NO3 --N), and the pakchoi quality (Vc and soluble protein content), while also raising the relative abundance of bacteria that promote plant growth and immobilize metals, such as Streptomyces and Sphingomonas. In conclusion, Hao 2018 reduced the available Pb in soil and pakchoi Pb absorption by increasing the pH and activity of multiple enzymes and regulating microbiome composition in rhizospheric soil.

Measurement of Tourism-Related CO2 Emission and the Factors Influencing Low-Carbon Behavior of Tourists: Evidence from Protected Areas in China.

In the fight against climate change, future policy directions in the transition toward a green travel- and tourism-based economy include improving tourism-derived CO2 emission levels and guiding individual low-carbon behavior. In China, people tend to engage in outdoor adventure travel and cultural tourism in natural areas. However, limited information is available on the empirical evaluation of energy use and the CO2 emissions associated with tourism in protected areas. The present study used a life cycle assessment to explore energy use and CO2 emissions due to tourism and identify the factors driving low-carbon behavior. To these ends, survey data for the protected areas of the Qinling Mountains from 2014 to 2019 were used. The results showed that energy use and CO2 emissions in various tourism sectors steadily increased from 2014 to 2019, primarily because of an increase in transportation activity. This study used data derived from the calculation of CO2 emissions per tourist per trip to identify the various factors jointly contributing to the low-carbon behavior of tourists. These included a low-carbon attitude, low-carbon knowledge, environmental education, and policy reward. The broader implications of this study are that several emission reduction policy options are available to address the challenges inherent in sustainable tourism development and that these policies may be selected according to specific conditions. The low-carbon transformation of recreational facilities at travel destinations, policy rewards, and environmental education can regulate tourist behavior, holding the key to sustainable tourism development in protected areas.

Zincophilic Electrode Interphase with Appended Proton Reservoir Ability Stabilizes Zn Metal Anodes.

The rampant dendrites and hydrogen evolution reaction (HER) resulting from the turbulent interfacial evolution at the anode/electrolyte are the main culprits of short lifespan and low Coulombic efficiency of Zn metal batteries. In this work, a versatile protective coating with excellent zincophilic and amphoteric features is constructed on the surface of Zn metal (ZP@Zn) as dendrite-free anodes. This kind of protective coating possesses the advantages of reversible proton storage and rapid desolvation kinetics, thereby mitigating the HER and facilitating homogeneous nucleation concomitantly. Furthermore, the space charge polarization effect promotes charge redistribution to achieve uniform Zn deposition. Accordingly, the ZP@Zn symmetric cell manifests excellent reversibility at an ultrahigh cumulative plating capacity of 4700 mAh cm-2 and stable cycling at 80 % depth of discharge (DOD). The ZP@Zn//V6 O13 pouch cell also reveals superior cycling stability with a high capacity of 326.6 mAh g-1 .

Tuning Zn2+ coordination tunnel by hierarchical gel electrolyte for dendrite-free zinc anode.

Aqueous zinc-ion batteries (ZIBs) are perceived as one of the most upcoming grid-scale storage systems. However, the issues of electrode dissolution, dendrite formation, and corrosion in traditional liquid electrolytes have plagued its progress. In this work, Zn dendrite growth and side reactions are effectively suppressed by a highly-confined tannic acid (TA) modified sodium alginate (SA) composite gel electrolyte (TA-SA). The ion-confinement effect is enhanced by divalent zinc ions coordinated with carboxyl groups and chelated with phenolic hydroxyl groups, thus guiding and regulating Zn deposition to achieve steady zinc plating/stripping behavior. As a consequence, the Zn/TA-SA/NH4V4O10 full cells deliver a high specific capacity of 238.6 mAh g-1 and maintain 94.51% over 900 cycles at 2 A g-1. Notably, after resting over 5 d, the capacity can be stabilized with a capacity retention of 97.25% after 200 cycles at 2 A g-1. This highly-confined and hydrogen bond-strengthened gel electrolyte may provide an effective strategy for the future development of quasi-solid-state metal batteries.

A smelting-rolling strategy for ZnIn bulk phase alloy anodes.

Reversibility and stability are considered as the key indicators for Zn metal anodes in aqueous Zn-ion batteries, yet they are severely hindered by uncontrolled Zn stripping/plating and side reactions. Herein, we fabricate a bulk phase ZnIn alloy anode containing trace indium by a typical smelting-rolling process. A uniformly dispersed bulk phase of the whole Zn anode is constructed rather than only a protective layer on the surface. The Zn deposition can be regarded as instantaneous nucleation due to the adsorption of the evenly dispersed indium, and formation of the exclusion zone for further nucleation can be prevented at the same time. Owing to the bulk phase structure of ZnIn alloy, the indium not only plays a crucial role in Zn deposition, but also improves the Zn stripping. Consequently, the as-designed ZnIn alloy anode can sustain stable Zn stripping/plating for over 2500 h at 4.4 mA cm-2 with nearly 6 times smaller voltage hysteresis than that of pure Zn. Moreover, it enables a substantially stable ZnIn//NH4V4O10 battery with 96.44% capacity retention after 1000 cycles at 5 A g-1. This method of regulating the Zn nucleation by preparing a Zn-based alloy provides a potential solution to the critical problem of Zn dendrite growth and by-product generation fundamentally.

Spontaneous Construction of Nucleophilic Carbonyl-Containing Interphase toward Ultrastable Zinc-Metal Anodes.

Multifunctional interfacial engineering on the Zn anode to conquer dendrite growth, hydrogen evolution, and the sluggish kinetics associated with Zn deposition is highly desirable for boosting the commercialization of aqueous zinc-ion batteries. Herein, a spontaneous construction of carbonyl-containing layer on a Zn anode (Zn@ZCO) is rationally designed as an ion redistributor and functional protective interphase. It has strong zincphilicity and dendrite suppression ability due to the significant interaction of the highly electronegative and highly nucleophilic carbonyl oxygen, favoring ion transport and homogenizing Zn deposition effectively. On the other side, the hydrogen bond formed by the proton acceptor of oxygen atom in ZCO regulates the Zn-ion desolvation process at the interfaces, thus bounding water activity and then mitigating water-induced parasitic reactions. Consequently, the Zn@ZCO anode exhibits an extended cycling lifespan of 5000 h (>208 days) with a dendrite-free surface and negligible by-products. More encouragingly, the effectiveness is also convincing in NH4 V4 O10 -based full-cells with excellent rate performance and cyclic stability. The stabilized Zn anode enabled by the strategy of spontaneous construction of functional solid electrolyte interphase brings forward a facile and instructive approach toward high-performance zinc-storage systems.

Integrated 'all-in-one' strategy to stabilize zinc anodes for high-performance zinc-ion batteries.

Many optimization strategies have been employed to stabilize zinc anodes of zinc-ion batteries (ZIBs). Although these commonly used strategies can improve anode performance, they simultaneously induce specific issues. In this study, through the combination of structural design, interface modification, and electrolyte optimization, an 'all-in-one' (AIO) electrode was developed. Compared to the three-dimensional (3D) anode in routine liquid electrolytes, the new AIO electrode can greatly suppress gas evolution and the occurrence of side reactions induced by active water molecules, while retaining the merits of a 3D anode. Moreover, the integrated AIO strategy achieves a sufficient electrode/electrolyte interface contact area, so that the electrode can promote electron/ion transfer, and ensure a fast and complete redox reaction. As a result, it achieves excellent shelving-restoring ability (60 hours, four times) and 1200 cycles of long-term stability without apparent polarization. When paired with two common cathode materials used in ZIBs (α-MnO2 and NH4V4O10), full batteries with the AIO electrode demonstrate high capacity and good stability. The strategy of the 'all-in-one' architectural design is enlightened to solve the issues of zinc anodes in advanced Zn-based batteries.

Synergetic stability enhancement with magnesium and calcium ion substitution for Ni/Mn-based P2-type sodium-ion battery cathodes.

The conventional P2-type cathode material Na0.67Ni0.33Mn0.67O2 suffers from an irreversible P2-O2 phase transition and serious capacity fading during cycling. Here, we successfully carry out magnesium and calcium ion doping into the transition-metal layers (TM layers) and the alkali-metal layers (AM layers), respectively, of Na0.67Ni0.33Mn0.67O2. Both Mg and Ca doping can reduce O-type stacking in the high-voltage region, leading to enhanced cycling endurance, however, this is associated with a decrease in capacity. The results of density functional theory (DFT) studies reveal that the introduction of Mg2+ and Ca2+ make high-voltage reactions (oxygen redox and Ni4+/Ni3+ redox reactions) less accessible. Thanks to the synergetic effect of co-doping with Mg2+ and Ca2+ ions, the adverse effects on high-voltage reactions involving Ni-O bonding are limited, and the structural stability is further enhanced. The finally obtained P2-type Na0.62Ca0.025Ni0.28Mg0.05Mn0.67O2 exhibits a satisfactory initial energy density of 468.2 W h kg-1 and good capacity retention of 83% after 100 cycles at 50 mA g-1 within the voltage range of 2.2-4.35 V. This work deepens our understanding of the specific effects of Mg2+ and Ca2+ dopants and provides a stability-enhancing strategy utilizing abundant alkaline earth elements.

ZnSe Modified Zinc Metal Anodes: Toward Enhanced Zincophilicity and Ionic Diffusion.

Zinc metal is an ideal candidate for aqueous rechargeable batteries due to its high theoretical capacity and natural abundance. However, its commercialization is inevitably challenged by several critical factors such as dendrite growth and parasitic side-reactions, leading to low coulombic efficiency and a limited lifespan. Herein, a modified Zn foil with a zincophilic ZnSe layer deposited by a simple selenization process is proposed. An order of magnitude stronger adsorption capability toward Zn2+ ions and uniform ion diffusion tunnels of ZnSe enables lower nucleation energy barrier and faster ion-diffusion kinetics. Meanwhile, detrimental Zn corrosion in aqueous system is also effectively mitigated. As a result, ZnSe@Zn anode shows reversible Zn plating/stripping (1700 h at 1 mA cm-2 ) with ultra-low voltage hysteresis (41 mV), contributing to exceptional cycling stability over 500 cycles with negligible capacity fading for the ZnSe@Zn/MnO2 full cell.

Inorganic Colloidal Electrolyte for Highly Robust Zinc-Ion Batteries.

Zinc-ion batteries (ZIBs) is a promising electrical energy storage candidate due to its eco-friendliness, low cost, and intrinsic safety, but on the cathode the element dissolution and the formation of irreversible products, and on the anode the growth of dendrite as well as irreversible products hinder its practical application. Herein, we propose a new type of the inorganic highly concentrated colloidal electrolytes (HCCE) for ZIBs promoting simultaneous robust protection of both cathode/anode leading to an effective suppression of element dissolution, dendrite, and irreversible products growth. The new HCCE has high Zn2+ ion transference number (0.64) endowed by the limitation of SO42-, the competitive ion conductivity (1.1 × 10-2 S cm-1) and Zn2+ ion diffusion enabled by the uniform pore distribution (3.6 nm) and the limited free water. The Zn/HCCE/α-MnO2 cells exhibit high durability under both high and low current densities, which is almost 100% capacity retention at 200 mA g-1 after 400 cycles (290 mAh g-1) and 89% capacity retention under 500 mA g-1 after 1000 cycles (212 mAh g-1). Considering material sustainability and batteries' high performances, the colloidal electrolyte may provide a feasible substitute beyond the liquid and all-solid-state electrolyte of ZIBs.

Anode Materials for Aqueous Zinc Ion Batteries: Mechanisms, Properties, and Perspectives.

Aqueous Zn-ion batteries (ZIBs) are promising safe energy storage systems that have received considerable attention in recent years. Based on the electrochemical behavior of Zn2+ in the charging and discharging process, herein we review the research progress on anode materials for use in aqueous ZIBs based on two aspects: Zn deposition and Zn2+ intercalation. To date, Zn dendrite, corrosion, and passivation issues have restricted the development of aqueous ZIBs. However, many strategies have been developed, including structural design, interface protection of the Zn anode, Zn alloying, and using polymer electrolytes. The main aim is to stabilize the Zn stripping/plating layer and limit side reactions. Zn2+-intercalated anodes, with a high Zn2+ storage capacity to replace the current metal Zn anode, are also a potential option. Finally, some suggestions have been put forward for the subsequent optimization strategy, which are expected to promote further development of aqueous ZIBs.

Facilitating Phase Evolution for a High-Energy-Efficiency, Low-Cost O3-Type NaxCu0.18Fe0.3Mn0.52O2 Sodium Ion Battery Cathode.

The phase transition and lattice parameter evolution of O3 structure commonly occurs in O3-type sodium ion battery (SIB) cathodes, which might enlarge the voltage hysteresis and lower the energy efficiency. Given that the cost is one of the issues discouraging the application of SIBs in large-scale energy storage, here we focus on Co/Ni-free NaxCu0.18Fe0.3Mn0.52O2 (x = 0.8, 0.85, 0.9) and propose a convenient strategy to reduce the voltage hysteresis. It is found that when the Na content is 0.8, the highest energy efficiency of 95.4% after activation is achieved (2.5-4.0 V, 50 mA g-1, the 50th cycle), in addition to a satisfactory capacity retention (about 0.056% decay per cycle). The further characterizations reveal that Na0.8Cu0.18Fe0.3Mn0.52O2 owns a gentle O3-P3 phase transition process and does not undergo O3 phase lattice parameter evolution. The key point lies in the attainability of the O3/P3 composite of the material. This work will provide a simple strategy for the rational design of O3-type cathodes with a high energy efficiency and might offer inspiration to search for layered oxides with a higher O3/P3 critical Na content through element adjustments.

Oxygen Defects in ß-MnO2 Enabling High-Performance Rechargeable Aqueous Zinc/Manganese Dioxide Battery.

Rechargeable aqueous Zn/manganese dioxide (Zn/MnO2) batteries are attractive energy storage technology owing to their merits of low cost, high safety, and environmental friendliness. However, the ß-MnO2 cathode is still plagued by the sluggish ion insertion kinetics due to the relatively narrow tunneled pathway. Furthermore, the energy storage mechanism is under debate as well. Here, ß-MnO2 cathode with enhanced ion insertion kinetics is introduced by the efficient oxygen defect engineering strategy. Density functional theory computations show that the ß-MnO2 host structure is more likely for H+ insertion rather than Zn2+, and the introduction of oxygen defects will facilitate the insertion of H+ into ß-MnO2. This theoretical conjecture is confirmed by the capacity of 302 mA h g-1 and capacity retention of 94% after 300 cycles in the assembled aqueous Zn/ß-MnO2 cell. These results highlight the potentials of defect engineering as a strategy of improving the electrochemical performance of ß-MnO2 in aqueous rechargeable batteries.

A New Strategy to Stabilize Capacity and Insight into the Interface Behavior in Electrochemical Reaction of LiNi0.5Mn1.5O4/Graphite System for High-Voltage Lithium-Ion Batteries.

The performance of CEI and SEI configuration and formation mechanism on the cathode and anode side for LiNi0.5Mn1.5O4/natural graphite (LNMO/NG) batteries is investigated, where series permutations of the NG electrodes modified with TEOS species as the anode for the LNMO full cells. It is believed that the excellent long-term cycling performance of LNMO/NG full cells at the high voltage is a result of alleviating the devastated reaction to form the CEI and SEI on the both electrodes with electrolyte, respectively. At a voltage range from 3.4 to 4.8 V for the LNMO full cells, 95.0% capacity retention after 100 cycles is achieved when cycled with TEOS-modifying NG anode. This mechanism may be explained that eliminating the HF and absorbing water impurities in the electrolyte by introducing the TEOS group, which can transform the SiO2 species that react with the acid of HF at the organic solvent environment instead of destroying/forming the anode SEI and attacking the LNMO spinel structure to form the dense and high resistance CEI, meanwhile the SiO2 species will absorb the water molecule and precipitate into the anode surface further stabilizing the SEI configuration during the cycling.

[Development of polyaxial locking plate screw system of sacroiliac joint].

OBJECTIVE: To develop an instrument for sacroiliac joint fixation with less injury and less complications. METHODS: Firstly, 18 adult pelvic specimens (8 males and 10 females) were used to measure the anatomical data related to the locking plates and locking screws on the sacrum and ilium, and the polyaxial locking plate screw system of the sacroiliac joint was designed according to the anatomic data. This system was made of medical titanium alloy. Then 4 adult male plevic specimens were harvested and the experiment was divided into 3 groups: group A (normal pelvic), group B (the dislocated sacroiliac joint fixed with sacroiliac screws), and group C (the dislocated sacroiliac joint fixed with polyaxial locking plate screw system). The vertical displacement of sacroiliac joint under the condition of 0-700 N vertical load and the horizontal displacement on angle under the condition of 0-12 N·m torsional load were compared among the 3 groups by using the biological material test system. Finally, the simulated application test was performed on 1 adult male cadaveric specimen to observe soft tissue injury and the position of the locking plate and screw by X-ray films. RESULTS: According to the anatomic data of the sacrum and ilium, the polyaxial locking plate screw system of the sacroiliac joint was designed. The biomechanical results showed that the vertical displacement of the sacroiliac joint under the condition of 0-700 N vertical load in group A was significantly bigger than that in group B and group C (P < 0.05), but there was no significant difference between group B and group C (P > 0.05). The horizontal displacement on angle under the condition of 0-12 N·m torsional load in group A was significantly less than that in group B and group C (P < 0.05). The horizontal displacement on angle under the condition of 0-6 N·m torsional load in group B was bigger than that in group C, and the horizontal displacement on angle under the condition of 6-12 N·m torsional load in group B was less than that in group C, but there was no significant difference between group B and group C (P > 0.05). The test of simulating application showed that the specimen suffered less soft tissue injury, and this instrument could be implanted precisely and safely. CONCLUSION: The polyaxial locking plate screw system of the sacroiliac joint has the advantages of smaller volume and less injury; polyaxial fixation enables flexible adjustment screw direction. The simulated application test shows satisfactory fixing effect.